Publications by authors named "Mahmood Bozorgmehr"

29 Publications

  • Page 1 of 1

Morphological and molecular characteristics of spheroid formation in HT-29 and Caco-2 colorectal cancer cell lines.

Cancer Cell Int 2021 Apr 13;21(1):204. Epub 2021 Apr 13.

Oncopathology Research Center, Iran University of Medical Sciences, Tehran, Iran.

Background: Relapse and metastasis in colorectal cancer (CRC) are often attributed to cancer stem-like cells (CSCs), as small sub-population of tumor cells with ability of drug resistance. Accordingly, development of appropriate models to investigate CSCs biology and establishment of effective therapeutic strategies is warranted. Hence, we aimed to assess the capability of two widely used and important colorectal cancer cell lines, HT-29 and Caco-2, in generating spheroids and their detailed morphological and molecular characteristics.

Methods: CRC spheroids were developed using hanging drop and forced floating in serum-free and non-attachment conditions and their morphological features were evaluated by scanning electron microscopy (SEM). Then, the potential of CSCs enrichment in spheroids was compared to their adherent counterparts by analysis of serial sphere formation capacity, real-time PCR of key stemness genes (KLF4, OCT4, SOX2, NANOG, C-MYC) and the expression of potential CRC-CSCs surface markers (CD166, CD44, and CD133) by flow cytometry. Finally, the expression level of some EMT-related (Vimentin, SNAIL1, TWIST1, N-cadherin, E-cadherin, ZEB1) and multi-drug resistant (ABCB1, ABCC1, ABCG2) genes was evaluated.

Results: Although with different morphological features, both cell lines were formed CSCs-enriched spheroids, indicated by ability to serial sphere formation, significant up-regulation of stemness genes, SOX2, C-MYC, NANOG and OCT4 in HT-29 and SOX2, C-MYC and KLF4 in Caco-2 spheroids (p-value < 0.05) and increased expression of CRC-CSC markers compared to parental cells (p-value < 0.05). Additionally, HT-29 spheroids exhibited a significant higher expression of both ABCB1 and ABCG2 (p-value = 0.02). The significant up-regulation of promoting EMT genes, ZEB1, TWIST1, E-cadherin and SNAIL1 in HT-29 spheroids (p-value = 0.03), SNAIL1 and Vimentin in Caco-2 spheroids (p-value < 0.05) and N-cadherin down-regulation in both spheroids were observed.

Conclusion: Enrichment of CSC-related features in HT-29 and Caco-2 (for the first time without applying special scaffold/biochemical) spheroids, suggests spheroid culture as robust, reproducible, simple and cost-effective model to imitate the complexity of in vivo tumors including self-renewal, drug resistance and invasion for in vitro research of CRC-CSCs.
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http://dx.doi.org/10.1186/s12935-021-01898-9DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8042991PMC
April 2021

Dendritic cells loaded with exosomes derived from cancer stem cell-enriched spheroids as a potential immunotherapeutic option.

J Cell Mol Med 2021 Apr 25;25(7):3312-3326. Epub 2021 Feb 25.

Oncopathology Research Center, Iran University of Medical Sciences (IUMS), Tehran, Iran.

Cancer stem cells (CSCs) are responsible for therapeutic resistance and recurrence in colorectal cancer. Despite advances in immunotherapy, the inability to specifically eradicate CSCs has led to treatment failure. Hence, identification of appropriate antigen sources is a major challenge in designing dendritic cell (DC)-based therapeutic strategies against CSCs. Here, in an in vitro model using the HT-29 colon cancer cell line, we explored the efficacy of DCs loaded with exosomes derived from CSC-enriched colonospheres (CSC -EXOs) as an antigen source in activating CSC-specific T-cell responses. HT-29 lysate, HT-29-EXOs and CSC lysate were independently assessed as separate antigen sources. Having confirmed CSCs enrichment in spheroids, CSC -EXOs were purified and characterized, and their impact on DC maturation was investigated. Finally, the impact of the antigen-pulsed DCs on the proliferation rate and also spheroid destructive capacity of autologous T cells was assessed. CSC -EXOs similar to other antigen groups had no suppressive/negative impacts on phenotypic maturation of DCs as judged by the expression level of costimulatory molecules. Notably, similar to CSC lysate, CSC -EXOs significantly increased the IL-12/IL-10 ratio in supernatants of mature DCs. CSC -EXO-loaded DCs effectively promoted T-cell proliferation. Importantly, T cells stimulated with CSC -EXOs disrupted spheroids' structure. Thus, CSC -EXOs present a novel and promising antigen source that in combination with conventional tumour bulk-derived antigens should be further explored in pre-clinical immunotherapeutic settings for the efficacy in hampering recurrence and metastatic spread.
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http://dx.doi.org/10.1111/jcmm.16401DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8034455PMC
April 2021

Culture density of menstrual blood-derived stromal/stem cells determines the quality of T cell responses: An experimental study.

Int J Reprod Biomed 2021 Jan 25;19(1):75-86. Epub 2021 Jan 25.

Reproductive Immunology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.

Background: Menstrual blood-derived stromal/stem cells (MenSCs) are a new population of refreshing and highly proliferative stem cells. Immunomodulatory effects of MenSCs profoundly depend on their relative density.

Objective: To find whether MenSCs cultured at varying numbers would differentially affect the allogenic peripheral blood mononuclear cells (PBMCs) key features.

Materials And Methods: PBMCs were co-cultured with various MenSCs numbers. PBMCs proliferation was investigated via H-thymidine incorporation. Flow cytometry was used to assess human leukocyte antigen (HLA)-DR, HLA-ABC, HLA-G, and co-stimulatory markers on MenSCs and the percentage of regulatory T cells (Tregs) among PBMCs. The concentration of cytokines was determined in supernatant of co-cultures.

Results: The support of PBMCs proliferation at low MenSCs densities correlated with higher levels of pro-inflammatory interferon gamma (IFN-γ) in MenSCs/PBMCs co-culture and increased expression of HLA-DR by MenSCs. On the other hand, the suppressive property of MenSCs at higher densities was independent of Treg frequency, but correlated with a high concentration of Interleukin (IL)-6 and IL-10 in the co-cultures.

Conclusion: Totally, at different seeding densities, MenSCs could differentially interact with PBMCs leading to significant changes in the level of anti- and/or pro-inflammatory factors. These preliminary in vitro results are suggested to be taken into consideration in experimental models of MenSC-based immunomodulation. Nonetheless, for efficient utilization of MenSCs anti-inflammatory features in pre-clinical disease models, we still need to broaden our knowledge on MenSC-immune system cross-talk; this could play a part in designing more optimized MenSCs injection modalities in the case of future pre-clinical and subsequently clinical settings.
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http://dx.doi.org/10.18502/ijrm.v19i1.8182DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7851477PMC
January 2021

MneSCs exert a supportive role in establishing a pregnancy-friendly microenvironment by inhibiting TH17 polarization.

J Reprod Immunol 2021 04 26;144:103252. Epub 2020 Nov 26.

Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran; Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran. Electronic address:

Objectives: Uncontrolled TH17 differentiation has been suggested to play a role in the pathogenesis of pregnancy loss. We recently showed that menstrual blood stromal/stem cells (MenSCs) alter functional features of natural killer cells. Here, we hypothesized that MenSCs could modulate differentiation of TH17 cells.

Method: MenSCs were collected from 18 apparently healthy women and characterized. Bone marrow mesenchymal stem cells (BMSCs) served as a control. TH17 polarization and proliferation of purified T CD4+ cells were assessed by flow cytometry in a well-defined co-culture system containing T CD4+ cells and MenSCs or BMSCs. Indoleamine 2,3-Dioxygenase (IDO) activity was evaluated in MenSC and BMSC culture supernatants by a colorimetric assay. The impact of MenSCs on expression of transcription factors, RORC, T-bet, Gata3, NRP-1 and Helios were studied by qPCR.

Results: MenSCs significantly inhibited TH17 differentiation (p = 0.0383) and percentage of the cells co-expressing IL-17 and IFN-γ (p = 0.0023). PGE2 blockade significantly reduced percentage and proliferation of T CD4+IL-17+ (p = 0.003, p = 0.0018), T CD4+ IFN-γ+ (p = 0.002, p = 0.0022) and T CD4+IL-17+ IFN-γ+ (p = 0.004, p = 0.02) cells. MenSCs produced a considerable activity of IDO (p = 0.0002), induced a significant rise in the Treg frequency (p = 0.0091) and a sharp increase in TH17/Tregs ratio (p = 0.0022). MenSCs increased expression of NRP1 (p = 0.001), while downregulated expression of RORC in T cells (p = 0.001).

Conclusion: Our results suggest a supportive role for MenSCs in establishing a pregnancy-friendly microenvironment in the uterus and put forth the idea that inherent abnormalities of MenSCs may be a basis for dysregulated endometrial immune network leading to pregnancy loss.
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http://dx.doi.org/10.1016/j.jri.2020.103252DOI Listing
April 2021

Tumor-derived exosomes: the next generation of promising cell-free vaccines in cancer immunotherapy.

Oncoimmunology 2020 06 16;9(1):1779991. Epub 2020 Jun 16.

Department of Molecular Medicine, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran.

Identification of immunogenic tumor antigens that are efficiently processed and delivered by dendritic cells to prime the immune system and to induce an appropriate immune response is a research hotspot in the field of cancer vaccine development. High biosafety is an additional demand. Tumor-derived exosomes (TEXs) are nanosized lipid bilayer encapsulated vesicles that shuttle bioactive information to the tumor microenvironment facilitating tumor progression. However, accumulating evidence points toward the capacity of TEXs to efficiently stimulate immune responses against tumors provided they are appropriately administered. After briefly describing the function of exosomes in cancer biology and their communication with immune cells, we summarize in this review and preclinical studies eliciting the potency of TEXs in inducing effective anti-tumor responses and recently modified strategies further improving TEX-vaccination efficacy. We interpret the available data as TEXs becoming a lead in cancer vaccination based on tumor antigen-selective high immunogenicity.
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http://dx.doi.org/10.1080/2162402X.2020.1779991DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7466856PMC
June 2020

The effect of human amniotic epithelial cell on dendritic cell differentiation of peripheral blood monocytes: An experimental study.

Int J Reprod Biomed 2020 Jun 30;18(6):449-464. Epub 2020 Jun 30.

Department of Immunology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.

Background: The amniotic membrane plays an important role in maintaining a healthy pregnancy. The main population cells from amniotic membrane include human amnion epithelial cells (hAECs) which have been shown to possess immunomodulatory properties.

Objective: The proximity of hAECs with monocyte leads to the generation of tollerogenic dendritic cells.

Materials And Methods: hAECs were obtained from normal pregnancy. Peripheral blood monocytes were isolated by anti-CD14 MACS method. Co-cultures of monocytes and hAECs were established in Transwell chambers supplemented with granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4) in the absence and presence of lipopolysaccharide (LPS) to produce immature and mature DCs, respectively. Immunophenotyping of the obtained DCs was done through flow cytometry and the production of cytokines was measured by ELISA. Mixed leukocyte Reaction (MLR) was also performed for the functional assessment of DCs.

Results: Immunophenotyping of [hAECs - Immature DC (iDC)] and [hAECs - iDC] + LPS cells revealed that the expression of CD1a, CD80, CD86, CD40, HLA-DR, and CD83 markers showed no significant difference as compared with the control group (iDCs and mDCs alone). In the [hAECs-iDCs] + LPS cells, the percentage of CD14 cells at the ratio of 1:2.5 showed significant differences compared to the control group. The production of IL-10 and IL-12 showed no significant difference in any of the cultures as compared to the control groups. Also, co-cultured DCs did not inhibit proliferation of lymphocyte.

Conclusion: Our findings show that factors secreted from cultured hAECs are unable to generate of tollerogenic dendritic cells. To achieve a better understanding of other mechanisms more investigations are needed.
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http://dx.doi.org/10.18502/ijrm.v13i6.7286DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7340990PMC
June 2020

Endometrial and Menstrual Blood Mesenchymal Stem/Stromal Cells: Biological Properties and Clinical Application.

Front Cell Dev Biol 2020 9;8:497. Epub 2020 Jul 9.

The Ritchie Centre, Hudson Institute of Medical Research, Melbourne, VIC, Australia.

A highly proliferative mesenchymal stem/stromal cell (MSC) population was recently discovered in the dynamic, cyclically regenerating human endometrium as clonogenic stromal cells that fulfilled the International Society for Cellular Therapy (ISCT) criteria. Specific surface markers enriching for clonogenic endometrial MSC (eMSC), CD140b and CD146 co-expression, and the single marker SUSD2, showed their perivascular identity in the endometrium, including the layer which sheds during menstruation. Indeed, cells with MSC properties have been identified in menstrual fluid and commonly termed menstrual blood stem/stromal cells (MenSC). MenSC are generally retrieved from menstrual fluid as plastic adherent cells, similar to bone marrow MSC (bmMSC). While eMSC and MenSC share several biological features with bmMSC, they also show some differences in immunophenotype, proliferation and differentiation capacities. Here we review the phenotype and functions of eMSC and MenSC, with a focus on recent studies. Similar to other MSC, eMSC and MenSC exert immunomodulatory and anti-inflammatory impacts on key cells of the innate and adaptive immune system. These include macrophages, T cells and NK cells, both and in small and large animal models. These properties suggest eMSC and MenSC as additional sources of MSC for cell therapies in regenerative medicine as well as immune-mediated disorders and inflammatory diseases. Their easy acquisition via an office-based biopsy or collected from menstrual effluent makes eMSC and MenSC attractive sources of MSC for clinical applications. In preparation for clinical translation, a serum-free culture protocol was established for eMSC which includes a small molecule TGFβ receptor inhibitor that prevents spontaneous differentiation, apoptosis, senescence, maintains the clonogenic SUSD2 population and enhances their potency, suggesting potential for cell-therapies and regenerative medicine. However, standardization of MenSC isolation protocols and culture conditions are major issues requiring further research to maximize their potential for clinical application. Future research will also address crucial safety aspects of eMSC and MenSC to ensure these protocols produce cell products free from tumorigenicity and toxicity. Although a wealth of data on the biological properties of eMSC and MenSC has recently been published, it will be important to address their mechanism of action in preclinical models of human disease.
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http://dx.doi.org/10.3389/fcell.2020.00497DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7364758PMC
July 2020

Assessment of a poly-epitope candidate vaccine against Hepatitis B, C, and poliovirus in interaction with monocyte-derived dendritic cells: An ex-vivo study.

Hum Immunol 2020 May 26;81(5):218-227. Epub 2020 Feb 26.

Michener Institute of Education at University Health Network, Toronto, Canada.

Design and application of epitope-based polyvalent vaccines have recently garnered attention as an efficient alternative for conventional vaccines. We previously have reported the in silico design of HHP antigen which encompasses the immune-dominant epitopes of Hepatitis B surface antigen (HBsAg), Hepatitis C core protein (HCVcp) and Poliovirus viral proteins (VPs). It has been shown that the HHP has desirable conformation to expose the epitopes, high antigenicity and other desired physicochemical and immunological properties. To confirm the accuracy of these predictions, the ex-vivo immunogenicity of the HHP was assessed. The HHP gene was chemically synthesized in pET28a and expressed in E. coli (BL21). The expressed protein was purified and its immunological potency was evaluated on dendritic cells (DCs) as antigen presenting cells (APCs). Functional analysis was assessed in co-cultivation of autologous T-cells with matured DCs (mDCs). T-cell activation, proliferation and cytokines secretion were evaluated using flowcytometry and ELISA methods. Our results indicated that the HHP could induce the DC maturation. The mDCs were able to trigger T-cell activation and proliferation. In silico design and ex-vivo confirmation of immunological potential could pave the way to introduce efficient immunogens for further analysis. The ability of HHP in DC maturation and T-cell activation makes it an amenable vaccine candidate for further in-vivo studies.
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http://dx.doi.org/10.1016/j.humimm.2020.02.010DOI Listing
May 2020

Primary colonospheres maintain stem cell-like key features after cryopreservation.

J Cell Physiol 2020 03 2;235(3):2452-2463. Epub 2019 Oct 2.

Oncopathology Research Center, Iran University of Medical Sciences, Tehran, Iran.

The development of efficient and repeatable protocols for biobanking and prolonged storage of cancer stem cells (CSCs), with minimum alterations in biological function, is valuable and desired, particularly for retrospective analysis and clinical applications. In particular, data regarding the effect of cryopreservation on CSCs's functional features is scarce. In this regard, few studies have been shown that 3D spheroid structures, which enriched for CSCs, can keep their biological phenotype and genetic profiles. Here, for the first time, we present data on cryopreservation of CT-26 colonospheres, with the focus on essential stem cell-like properties after thawing. Tumor biopsy-derived colonospheres were frozen in standard freezing media (90% fetal bovine serum + 10% dimethyl sulfoxide) and stored in liquid nitrogen for 10 months. Then, cryopreservation effect on preservation of CSCs-related features was verified using real-time polymerase chain reaction for evaluation of stemness genes and flow cytometry for the putative colorectal CSC surface biomarkers. The self-renewal capacity of thawed spheres was also compared with their fresh counterparts using serial formation assay. Finally, tumorigenic capacity of both groups was evaluated in immunocompetence mouse model. Our data indicated that postthawed colonospheres had high viability without drastic alteration in biological and structural features and maintained self-renewal potential after sequential passages. Real-time analysis showed that both fresh and frozen colonospheres displayed similar expression pattern for key stemness genes: SOX2 and OCT4. Cryopreserved spheroids expressed CD133, CD166, and DCLK1 CSCs surface biomarkers at elevated levels when compared with parental as non-cryopreserved counterparts. Our electron scanning microscopy micrographs clearly demonstrated that postthawed colonospheres retain their integrity and cell surface morphology and characteristics. We also found that both fresh and frozen spheroids were equally tumorigenic. This study represented an effective strategy for reliable storage of intact CT-26 colonospheres; this can provide researchers with a functionally reliable repository of murine colorectal CSCs for their future CSCs projects.
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http://dx.doi.org/10.1002/jcp.29150DOI Listing
March 2020

Human menstrual blood-derived stromal/stem cells modulate functional features of natural killer cells.

Sci Rep 2019 07 10;9(1):10007. Epub 2019 Jul 10.

Department of Immunology, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran.

Although natural killer (NK) cells play a crucial role in the maintenance of a successful pregnancy, their cytotoxic activity should be tightly controlled. We hypothesized that endometrial mesenchymal stromal/stem cells (eMSCs) could potentially attenuate the functional features of NK cells. Herein, we assessed immunomodulatory effects of menstrual blood-derived stromal/stem cells (MenSCs), as a surrogate for eMSCs, on NK cells function. Our results showed that MenSCs induced proliferation of NK cells. However, IFN-γ/IL-1β pretreated MenSCs significantly inhibited NK cell proliferation. Of 41 growth factors tested, MenSCs produced lower levels of insulin-like growth factor binding proteins (IGFBPs) 1-4, VEGF-A, β-NGF, and M-CSF compared to bone marrow-derived mesenchymal stem cells (BMSCs). MenSCs displayed high activity of IDO upon IFN-γ treatment. The antiproliferative potential of IFN-γ/IL-1β-pretreated MenSCs was mediated through IL-6 and TGF-β. MenSCs impaired the cytotoxic activity of NK cells on K562 cells, consistent with the lower expression of perforin, granzymes A, and B. We also observed that in vitro decidualization of MenSCs in the presence of IFN-γ reduced the inhibitory effect of MenSCs on NK cell cytotoxicity against K562 target cells. Additionally, MenSCs were found to be prone to NK cell-mediated lysis in an MHC-independent manner. Our findings imply that dysregulation of NK cells in such pregnancy-related disorders as miscarriage may stem from dysfunctioning of eMSCs.
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http://dx.doi.org/10.1038/s41598-019-46316-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6620360PMC
July 2019

Evaluating the Potential of Three Sperm Surface Antigens as Egg-adhesion Biomarkers for Human Sperm Selection.

J Reprod Infertil 2018 Oct-Dec;19(4):203-210

Monoclonal Antibody Research Center, Avicenna Research Institute, ACERCR, Tehran, Iran.

Background: The selection of sperm with good genomic integrity and surface antigens is suggested for improving assisted reproductive technology (ART) outcome. The aim of this study was evaluating the heat shock protein (HSPA2), Dj-1 and serum amyloid P compound (SAP) three sperm surface proteomes as biomarkers for this purpose.

Methods: In this study, semen samples were obtained from 114 men who presented at Avicenna Fertility Clinic for their treatment. The semen characteristics, DNA fragmentation Index (DFI), chromatin maturation index (CMI), biomarker levels, and their embryo quality were considered. The paired-samples t-test and independent-samples t-test were used for analyzing the data and p-values<0.05 were considered significant.

Results: Outcomes exhibited the major reduction in HSPA2, DJ-1 and SAP following reduction in sperm quality and DNA integrity (p<0.001) with cut-off value of 14% (HSPA2), 12% (DJ-1) and 10% (SAP). The specificity of these three biomarkers was 95.2, 73.8 and 88.1%, respectively. Also, DFI (p<0.001), CMI (p<0.05), cleavage (p<0.05), and embryos quality (p<0.001) decreased significantly in abnormal spermiogram (ANS) group in compared with normal spermiogram (NS) group. It was shown that DFI was 97.1% in HSPA2, 76.5% in DJ-1 and 94.1% in SAP, and CMI was 95.0%, 75.50% and 87.5%, respectively. The significant correlation was found between of the three biomarkers and CMI (p<0.001), DFI (p<0.001) and embryos quality (p<0.001).

Conclusion: By comparing the efficiency of these three biomarkers for selecting sperm with the lowest level of chromatin damages, it seems that selection based on HSPA2 has significance over others.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6328979PMC
February 2019

Different frequencies of memory B-cells induced by tetanus, botulinum, and heat-labile toxin binding domains.

Microb Pathog 2019 Feb 4;127:225-232. Epub 2018 Dec 4.

Chemical Injuries Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran. Electronic address:

Along with robust immunogenicity, an ideal vaccine candidate should be able to produce a long lasting protection. In this regard, the frequency of memory B-cells is possibly an important factor in memory B-cell persistency and duration of immunological memory. On this basis, binding domains of tetanus toxin (HcT), botulinum type A1 toxin (HcA), and heat-labile toxin (LTB) were selected as antigen models that induced long-term, midterm and short-term immune memory, respectively. In the present study, the frequency of total memory B-cells after immunization with HcT, HcA and LTB antigens after 90 and 180 days, and also after one booster, in 190 days, was evaluated. The results showed a significant correlation between frequency of total memory B-cells and duration of humoral immunity. Compared to other antigens, the HcT antibody titers and HcT total memory B-cell populations were greater and persistent even after 6 months. At 6 months after the final immunization, all HcT- and HcA-immunized mice survived against tetanus and botulinum toxins, and also LT toxin binding to GM1 ganglioside was blocked in LTB-immunized mice. We conclude the frequency of memory B-cells and their duration are likely a key factor for vaccine memory duration.
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http://dx.doi.org/10.1016/j.micpath.2018.12.003DOI Listing
February 2019

Menstrual Blood-Derived Stromal Stem Cells Augment CD4+ T Cells Proliferation.

Avicenna J Med Biotechnol 2018 Jul-Sep;10(3):183-191

Department of Immunology, Faculty of Public Health, Tehran University of Medical Sciences, Tehran, Iran.

Background: It is more than sixty years that the concept of the fetal allograft and immunological paradox of pregnancy was proposed and in this context, several regulatory networks and mechanisms have been introduced so far. It is now generally recognized that mesenchymal stem cells exert potent immunoregulatory activity. In this study, for the first time, the potential impact of Menstrual blood Stem Cells (MenSCs), as surrogate for endometrial stem cells, on proliferative capacity of CD4+ T cells was tested.

Methods: MenSCs and Bone marrow Mesenchymal Stem Cells (BMSCs) were isolated and assessed for their immunophenotypic features and multi-lineage differentiation capability. BMSCs and MenSCs with or without IFNγ pre-stimulation were co-cultured with purified anti-CD3/CD28-activated CD4+ T cells and the extent of T cell proliferation at different MenSCs: T cell ratios were investigated by CSFE flow cytometry. IDO activity of both cell types was measured after stimulation with IFNγ by a colorimetric assay.

Results: MenSCs exhibited dual mesenchymal and embryonic markers and multi-lineage differentiation capacity. MenSCs significantly increased proliferation of CD4+ cells at ratios 1:2, 1:4 and 1:8. IFNγ pre-treated BMSCs but not MenSCs significantly suppressed CD4+ T cells proliferation. Such proliferation promoting capacity of MenSCs was not correlated with IDO activity as these cells showed the high IDO activity following IFNγ treatment.

Conclusion: Although augmentation of T cell proliferation by MenSCs can be a basis for maintenance of endometrial homeostasis to cope with ascending infections, this may not fulfill the requirement for immunological tolerance to a semi-allogeneic fetus. However, more investigation is needed to examine whether or not the immunomodulatory properties of these cells are affected by endometrial microenvironment during pregnancy.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6063997PMC
August 2018

A Novel Platinum-based Compound with Preferential Cytotoxic Activity against a Panel of Cancer Cell Lines.

Anticancer Agents Med Chem 2016 ;16(3):393-403

Nanobiotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.

Purpose: Cisplatin as a platinum (Pt)-based chemotherapeutic compound is commonly applied for the treatment of several types of cancer. Nonetheless, drug resistance and severe adverse effects have been observed upon using cisplatin. Here, we have explored the cytotoxicity of novel Pt-based compounds on several cancer cell lines.

Methods: Five synthetic Pt compounds as well as cisplatin were investigated by XTT assay to determine their cytotoxicity against cell lines originated from prostate, ovary, and breast cancers at different time periods at various concentrations. Additionally, the apoptosis rate in cell lines was determined using flow cytometry. Binding to DNA was investigated through spectrophotometric and viscometric studies.

Results: With the exception of one compound, all of the Pt-complexes effectively killed the prostate cancer cell lines (i.e. PC-3 and DU 145). One compound, [Pt(2,2'- dipyridylamine)Cl4].DMF, was chosen as the most potent compound due to its high selective cytotoxic activity and its cytotoxicity was further tested and compared with that of cisplatin on SKOV-3, Caov-4, MDA-MB-231, and MCF7 cell lines. [Pt(2,2'-dipyridylamine)Cl4].DMF had a higher selective cytotoxic capacity in comparison with cisplatin at higher concentrations and longer culture periods. Furthermore, as related to apoptosis induction, treatment with [Pt(2,2'-dipyridylamine)Cl4 ].DMF was significantly more effective than that of cisplatin in five out of six examined cell lines. [Pt(2,2'-dipyridylamine)Cl4].DMF was shown to intercalate into DNA.

Conclusions: The current study introduced a novel Pt-based complex with highly selective and potent in vitro anti-tumor impacts superior to those of cisplatin, a conventional chemotherapeutic agent. [Pt (2,2'-dipyridylamine)Cl4].DMF could be regarded as a promising antitumor agent in future investigations.
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November 2016

Assessment of Treg/Th17 axis role in immunopathogenesis of chronic injuries of mustard lung disease.

J Recept Signal Transduct Res 2016 Oct 19;36(5):531-41. Epub 2016 Feb 19.

a Chemical Injuries Research Center, Baqiyatallah University of Medical Sciences , Tehran , Iran and.

Purpose: Sulfur mustard (SM) lung is a heterogeneous disease associated with abnormal inflammatory immune responses. The Th17/Treg axis imbalance is associated with the pathogenesis of chronic inflammatory pulmonary disease. We aimed to determine the distribution of different Th17 and Treg cells in patients with SM lung and chronic obstructive pulmonary disease (COPD) and evaluate the clinical implications in this homeostasis.

Methods: In this analytical cross-sectional study, CD4 (+) Foxp3(+ )Treg and CD4(+) IL-17(+ )Th17 cells were measured in peripheral blood mononuclear cells (PBMCs) and transbronchial biopsy (TBB) samples of 15 SM-exposed patients, 12 COPD and 13 healthy controls (HCs). The potential correlation between the ratio of Th17/Tregs and lung function was evaluated with multivariate logistic regression (MLR) analysis.

Results: The frequency of CD4 (+) FoxP3(+) Tregs and CD4 (+) IL-17(+) Th17 was increased ∼1.7-fold (8.71/4.95) and ∼2.7-fold (1.028/0.371) respectively, in the PBMC of SM patients compared with the health controls (p < 0.001). The results indicated that there were increases in the frequency of Th17 and Tregs cells in the patients with COPD versus the HC, that is, ∼2.6-fold (0.987/0.371) and ∼1.4-fold (7.12/4.95), respectively; but they did not reach to SM level (p ≥ 0.05). Moreover, in the TBB samples, the CD4 (+) IL-17(+ )Th17 and CD4(+) FoxP3(+ )Tregs numbers were significantly higher in SM and COPD patients than HC (p < 0.05). The Th17 and Treg cells were inversely correlated with forced expiratory volume in 1s (FEV1%) (r = -0.351, p   = 0.001; r = -0.344, p = 0.021) and FEV1/FVC (r = -0.44, p = 0.001; r = -0.302, p = 0.011), respectively. Instead, positive correlations were found between Treg/Th17 ratios and forced FEV1%pred (r = 0.156, p = 0.007), as well as FEV1/FVC ratio (r = 0.334, p = 0.006).

Conclusions: The imbalance of Th17/Treg has a key role in immunopathogenesis of chronic phase of mustard lung disease.
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http://dx.doi.org/10.3109/10799893.2016.1141953DOI Listing
October 2016

A Novel Platinum-based Compound with Preferential Cytotoxic Activity against a Panel of Cancer Cell Lines

Anticancer Agents Med Chem 2016 02;16(3):393 - 403

Nanobiotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.

Purpose: Cisplatin as a platinum (Pt)-based chemotherapeutic compound is commonly applied for the treatment of several types of cancer. Nonetheless, drug resistance and severe adverse effects have been observed upon using cisplatin. Here, we have explored the cytotoxicity of novel Pt-based compounds on several cancer cell lines.

Methods: Five synthetic Pt compounds as well as cisplatin were investigated by XTT assay to determine their cytotoxicity against cell lines originated from prostate, ovary, and breast cancers at different time periods at various concentrations. Additionally, the apoptosis rate in cell lines was determined using flow cytometry. Binding to DNA was investigated through spectrophotometric and viscometric studies.

Results: With the exception of one compound, all of the Pt-complexes effectively killed the prostate cancer cell lines (i.e. PC-3 and DU 145). One compound, [Pt(2,2'- dipyridylamine)Cl4].DMF, was chosen as the most potent compound due to its high selective cytotoxic activity and its cytotoxicity was further tested and compared with that of cisplatin on SKOV-3, Caov-4, MDA-MB-231, and MCF7 cell lines. [Pt(2,2'-dipyridylamine)Cl4].DMF had a higher selective cytotoxic capacity in comparison with cisplatin at higher concentrations and longer culture periods. Furthermore, as related to apoptosis induction, treatment with [Pt(2,2'-dipyridylamine)Cl4 ].DMF was significantly more effective than that of cisplatin in five out of six examined cell lines. [Pt(2,2'-dipyridylamine)Cl4].DMF was shown to intercalate into DNA.

Conclusions: The current study introduced a novel Pt-based complex with highly selective and potent in vitro anti-tumor impacts superior to those of cisplatin, a conventional chemotherapeutic agent. [Pt (2,2'-dipyridylamine)Cl4].DMF could be regarded as a promising anti-tumor agent in future investigations.
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February 2016

Improved Efficacy of a Dendritic Cell-Based Vaccine against a Murine Model of Colon Cancer: The Helper Protein Effect.

Cancer Res Treat 2015 Jul 27;47(3):518-26. Epub 2014 Nov 27.

Department of Immunology, Iran University of Medical Sciences, Tehran, Iran.

Purpose: Targeted immunotherapy using dendritic cells (DCs) has been employed in numerous investigations aiming at combating neoplasms. We previously showed that copulsing of an antigen with a helper protein could considerably enhance antigen presenting capacity of ex vivo-generated DCs. In this study, we attempted to administer an effective treatment in a murine model of colon cancer with DCs pulsed with the mixture of a tumor-specific gp70-derived peptide (AH1) and a helper protein, ovalbumin (OVA).

Materials And Methods: First, the presence of gp70 in CT26 tumor cells and tumor tissues was verified using immunofluorescence and Western blot analyses. Next, DCs were purified from normal mice, loaded ex vivowith AH1 and OVA (DC-Pep-OVA), and injected into tumor-bearing mice. Tumor volume, in vitro antigen (Ag)-specific proliferation of splenic cells, and survival rate were measured to determine the efficacy of DC-Pep-OVA. As the control groups, tumor-bearing mice were vaccinated with DC-Pep, unpulsed DC, and DCs loaded with a mixture of OVA and an irrelevant peptide (P15), or were not vaccinated at all.

Results: DC-Pep-OVA showed superior efficacy over other groups, as indicated by smaller tumor volume, higher Ag-specific proliferation rate of splenic cells, and prolonged survival.

Conclusion: Overall, in the present study we showed for the first time that DCs copulsed with AH1 (tumor Ag) and OVA (helper molecule) could be considered as potentially robust weapons for use in future antitumor immunotherapies.
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http://dx.doi.org/10.4143/crt.2013.241DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4506100PMC
July 2015

Menstrual blood-derived stromal stem cells inhibit optimal generation and maturation of human monocyte-derived dendritic cells.

Immunol Lett 2014 Dec 18;162(2 Pt B):239-46. Epub 2014 Oct 18.

Nanobiotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran; Immunology Research Center, Iran University of Medical Sciences, Tehran, Iran.

Introduction: Menstrual blood stromal stem Cells (MenSCs) have shown promising potential for future clinical settings. Nonetheless, data regarding their interaction with immune cells is still scarce. Here, we investigated whether MenSCs could affect the generation and/or maturation of human blood monocyte-derived dendritic cells (DCs).

Materials And Methods: MenSCs were isolated from menstrual blood of normal women through culture of adherent mononuclear cells. Magnetically-isolated peripheral blood monocytes were differentiated toward immature DCs (iDC) and mature DCs (mDCs) in the presence or absence of MenSCs. Monocyte-derived cells were assessed for the percentage of monocyte-, iDC-, and mDC-specific markers as well as the expression of costimulatory molecules. IL-6 and IL-10 levels were also determined in supernatants of MenSC-monocytes cocultures.

Results: Optimal phenotypic differentiation of monocytes into iDCs was inhibited upon coculture with MenSCs. Moreover, higher levels of IL-6 and IL-10 were detected in these settings. Even though addition of MenSCs to iDC cultures could not prevent iDC maturation, coculture of MenSCs with monocytes from the beginning of differentiation process could effectively hinder generation of fully mature DCs.

Conclusion: This is the first study to address the inhibitory impact of MenSCs on generation and maturation of DCs. IL-6 and IL-10 could be partly held responsible for this effect. Given the central roles of DCs in regulation of immune responses, these results highlight the importance of further research on the potential modulatory impacts of MenSCs, as rather easily accessible and expandable stem cells, on the immune system-related cells.
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http://dx.doi.org/10.1016/j.imlet.2014.10.005DOI Listing
December 2014

Menstrual blood-derived stromal stem cells from women with and without endometriosis reveal different phenotypic and functional characteristics.

Mol Hum Reprod 2014 Sep 16;20(9):905-18. Epub 2014 Jun 16.

Reproductive Immunology Research Center, Avicenna Research Institute, ACECR, PO Box 19615-1177, Tehran, Iran Nanobiotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran Immunology Research Center, Iran University of Medical Sciences, Tehran, Iran

Retrograde flow of menstrual blood cells during menstruation is considered as the dominant theory for the development of endometriosis. Moreover, current evidence suggests that endometrial-derived stem cells are key players in the pathogenesis of endometriosis. In particular, endometrial stromal stem cells have been suggested to be involved in the pathogenesis of this disease. Here, we aimed to use menstrual blood, as a novel source of endometrial stem cells, to investigate whether stromal stem cells from endometriosis (E-MenSCs) and non-endometriosis (NE-MenSCs) women differed regarding their morphology, CD marker expression pattern, proliferation, invasion and adhesion capacities and their ability to express certain immunomodulatory molecules. E-MenSCs were morphologically different from NE-MenSCs and showed higher expression of CD9, CD10 and CD29. Furthermore, E-MenSCs had higher proliferation and invasion potentials compared with NE-MenSCs. The amount of indoleamine 2,3-dioxygenase-1 (IDO1) and cyclooxygenase-2 (COX-2) in E-MenSCs co-cultured with allogenic peripheral blood mononuclear cells (PBMCs) was shown to be higher both at the gene and protein levels, and higher IDO1 activity was detected in the endometriosis group. However, NE-MenSCs revealed increased concentrations of forkhead transcription factor-3 (FOXP3) when compared with E-MenSCs. Nonetheless, interferon (IFN)-γ, Interleukin (IL)-10 and monocyte chemoattractant protein-1 (MCP-1) levels were higher in the supernatant of E-MenSCs-PBMC co-cultures. Here, we showed that there are inherent differences between E-MenSCs and NE-MenSCs. These findings propose the key role MenSCs could play in the pathogenesis of endometriosis and further support the retrograde and stem cell theories of endometriosis. Hence, considering its renewable and easily available nature, menstrual blood could be viewed as a reliable and inexpensive material for studies addressing the cellular and molecular aspects of endometriosis.
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http://dx.doi.org/10.1093/molehr/gau044DOI Listing
September 2014

Isolation and partial characterization of human amniotic epithelial cells: the effect of trypsin.

Avicenna J Med Biotechnol 2014 Jan;6(1):10-20

Nanobiotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran ; Immunology Research Center, Iran University of Medical Sciences, Tehran, Iran.

Background: Despite the extensive information available in the literature, cell surface marker signature of human Amniotic Epithelial Cells (hAECs) remains controversial. The aim of the present study was to characterize immunophenotypic features, proliferative capacity and immunogenicity of hAECs. We also tested whether expression of some cell surface markers is influenced by the type of trypsin used for tissue digestion.

Methods: Single cell suspensions of amniotic membranes from four human placentas were isolated by enzymatic digestion and expression of CD9, CD10, CD29, CD34, CD38, CD44, CD45, CD73, CD105, CD133, HLA-I, HLA-DR, HLA-G, SSEA-4, STRO-1 and OCT-4 was then evaluated by flow cytometry. The differential impact of four trypsin types on the yield and expression of CD105 and HLA-I was also determined. The proliferative capacity of cultured hAECs was assessed and compared in the presence and absence of Epidermal Growth Factor (EGF). To test their immunogenicity, hAECs were injected into Balb/c mice and the reactivity of hyperimmunized sera was examined by immunofluorescence staining.

Results: Nearly all purified cells expressed mesenchymal markers, CD9, CD10, CD29, and CD73 and the embryonic marker, SSEA-4. A large proportion of the cells also expressed STRO-1 and OCT-4. The purified cells also expressed HLA-G and HLA-I. A very small proportion of hAECs expressed CD34, CD38, CD44, CD133 and HLA-DR. The type of trypsin used for enzymatic digestion affected both the percentage and expression of HLA-I and CD105. hAECs revealed substantial proliferative capacity only when cultured in the medium supplemented with EGF. These cells were shown to be capable of inducing high amounts of anti-donor antibodies.

Conclusion: Here we provided evidence that hAECs are immunogenic cells with high level of HLA-I expression. Furthermore, this work highlighted the impact of isolation procedure on the immunophenotype of hAEC.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3895574PMC
January 2014

Evaluation of the Effect of the 47 kDa Protein Isolated from Aged Garlic Extract on Dendritic Cells.

Iran J Basic Med Sci 2012 Mar;15(2):745-51

Department of Immunology, School of Medicine, Tarbiat Modares University, Tehran, Iran.

Objectives: Garlic (Allium sativum) is known as a potent spice and a medicine with broad therapeutic properties ranging from antibacterial to anticancer, and anticoagulant. One of the major purified garlic protein components is the 47 kDa protein. In this study, the effect of 47 kDa protein extracted from aged garlic (AGE) was evalua.

Materials And Methods: Forty seven kDa protein was purified from AGE by ammonium sulfate precipitation and gel filtration. SDS-PAGE was used to determine the molecular weight and purity of the isolated protein. DCs were purified from spleen of BALB/c mice by Nycodenz centrifugation and their adhesiveness to the plastic dish. The 47 kDa protein isolated from AGE was added to DCs medium during the overnight culture and the expression of DC surface markers was assessed via flowcytometry.

Results: The 47 kDa protein-treated DCs lowered the expression of DC maturation markers including: CD40, CD86 and MHC-II in comparison with non-treated DCs; (median of 41% versus 47%, 84% versus 91% and 83% versus 90%, respectively) but we observed no statistical difference between the two groups.

Conclusion: Upon treatment with DCs with 47 kDa protein, DCs down regulated the expression of costimulatory and MHC-II surface molecules, which is similar to tolerogenic DC phenotype. According to the results of the present study, we found that 47 kDa protein purified from AGE can be considered as a potential candidate to generate tolerogenic DCs in vitro.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3586875PMC
March 2012

Effect of menstrual blood-derived stromal stem cells on proliferative capacity of peripheral blood mononuclear cells in allogeneic mixed lymphocyte reaction.

J Obstet Gynaecol Res 2012 May 22;38(5):804-9. Epub 2012 Mar 22.

Department of Immunology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.

Aim: Menstrual blood stromal stem cells (MBSCs) have been demonstrated to exhibit stem cell properties such as the capability for self-renewal and multipotency, allowing for multilineage differentiation. In addition, this cell type has various immunomodulatory effects. In this study, we examined the potential effect of MBSCs on proliferation of peripheral blood mononuclear cells (PBMCs) in allogeneic mixed lymphocyte reaction (MLR).

Materials And Methods: Menstrual blood was collected from healthy donors after menstrual blood flow initiated and its mononuclear cell fraction was separated. Cells were subsequently cultured and adherent cells were allowed to propagate and used as stem cells. Flowcytometric immunophenotyping was performed using a panel of monoclonal antibodies including CD44, CD45, CD34, CD9, CD29, CD10, CD38, CD105, CD73, CD133, STRO-1 and Oct-4A. For functional analysis, PBMCs were co-cultured with MBSCs, collected after 4 days and added to allogeneic PBMCs. 2,3-Bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide (XTT) assay was carried out to evaluate cell proliferation.

Results: MBSCs showed surface and intracellular markers of mesenchymal stem cells with the exception of the high expression of Oct-4A. MBSCs affected the proliferative response of PBMC in a dose-dependent manner. At ratio of 1:1 to 1:2, MBSCs inhibited, while at lower ratios (1:32 to 1:64) stimulated the proliferative capacity of allogeneic PBMCs.

Conclusion: According to the present study, MBSCs exert their immunoregulatory effects on allogeneic PBMCs in a dose-dependent manner. This finding can be considered as a valuable point in future cell therapy strategies, when this cell population is used.
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http://dx.doi.org/10.1111/j.1447-0756.2011.01800.xDOI Listing
May 2012

Suppressive effect of pregnant serum on murine dendritic cell function.

J Obstet Gynaecol Res 2012 May 22;38(5):797-803. Epub 2012 Mar 22.

Department of Immunology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.

Aim: Tolerance to the semi-allogenic fetal graft by the maternal immune system is a medical enigma. Many aspects of immunoregulation at the feto-maternal interface have been clarified, but systemic effects of pregnancy on the immune system are still elusive. The present study was undertaken to determine whether mid-pregnancy mouse serum has an inhibitory effect on dendritic cells (DC) function.

Material And Methods: Mid-gestational sera were obtained from allogenic pregnant Balb/c mice (Balb/c × C57BL/6) on days 9-11 of gestation. Splenic DC were purified from Balb/c mice, and treated with mid-pregnancy mouse serum. Antigen pulsed DC were injected into mice palms. After 5 days, draining lymph nodes were removed, cultured in the presence of cognate antigen, and proliferation of responding cells was measured by (3)H-thymidin incorporation. Interleukin (IL)-10 and interferon-gamma (IFN-γ) production by stimulated lymph node antigen-specific cells was also measured in culture supernatants using sandwich ELISA.

Results: Treatment of DC with pregnant mouse serum markedly blocked their ability to induce antigen-specific lymphocyte proliferation and IFN-γ and IL-10 production by primed lymph node cells in comparison with non-pregnant serum-treated DC.

Conclusion: Pregnant mouse serum has an inhibitory effect on DC capacity to induce antigen-specific proliferation and cytokine secretion by lymph node cells. The suppressive effects of pregnant serum on DC could be considered as one of the mechanisms responsible for the systemic immunomodulation observed during pregnancy.
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http://dx.doi.org/10.1111/j.1447-0756.2011.01803.xDOI Listing
May 2012

Evaluation of the immunomodulatory effect of the 14 kDa protein isolated from aged garlic extract on dendritic cells.

Cell Immunol 2011 23;269(2):90-5. Epub 2011 Feb 23.

Department of Immunology, School of Medicine, Tarbiat Modares University, Tehran, Iran.

Garlic is used all over the world for treatment of different diseases. A wide range of biological activities of garlic has been verified in vitro and in vivo. One of major proteins of garlic which has been isolated and purified is the 14 kDa protein. This protein has been shown to have immunomodulatory effects. In this study, the effect of the 14 kDa protein isolated from aged garlic extract (AGE) was investigated on maturation and immunomodulatory activity of dendritic cells (DC). Proteins were purified from AGE by biochemical method; the semi-purified 14 kDa protein was run on gel filtration Sephadex G50 and its purity was checked by SDS-PAGE. DC were isolated from spleen of BALB/c mice by Nycodenz centrifugation and their adhesiveness to plastic dish. 14 kDa protein from AGE was added to overnight culture of DC medium and the expression percentage of CD40, CD86, and MHC-II was evaluated by flowcytometric analysis. Also, proliferation of T-cells was measured by allogenic mixed lymphocyte reaction (MLR) test. The purified 14 kDa protein isolated from AGE increased the expression of CD40 molecule on DC, but it did not influence CD86 and MHCII molecules. Furthermore, no significant differences were noticed in the pulsed-DC with 14 kDa protein and non-pulsed DC on the MLR.
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http://dx.doi.org/10.1016/j.cellimm.2011.02.005DOI Listing
August 2011

Potentiation strategies of dendritic cell-based antitumor vaccines: combinational therapy takes the front seat.

Drug Discov Today 2011 Aug 1;16(15-16):733-40. Epub 2011 May 1.

Department of Immunology, Faculty of Medicine, Tehran University of Medical Sciences, Tehran, Iran.

Despite recent attempts to take advantage of dendritic cell (DC)-based vaccines for cancer immunotherapy, the results of clinical studies have been disappointing. This is mainly as a result of the diverse immune escape mechanisms used by the tumor together with the insufficient ability of DCs to mount an effective immune response against these mechanisms. In this regard, several approaches have been devised to improve the efficacy of DC-based vaccines. However, the application of each individual approach per se might not be sufficient to overwhelm the diverse immune escape mechanisms. In this review, we focus on current strategies for the ex vivo potentiation of DC-based vaccines, with an emphasis on combinational therapy methods as a promising alternative for tumor immunotherapy.
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http://dx.doi.org/10.1016/j.drudis.2011.04.010DOI Listing
August 2011

The effects of Candida albicans cell wall protein fraction on dendritic cell maturation.

Iran J Immunol 2009 Jun;6(2):67-74

Department of Mycology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.

Background: Candida albicans is a member of the normal human microflora. C. albicans cell wall is composed of several protein and carbohydrate components which have been shown to play a crucial role in C. albicans interaction with the host immune system. Major components of C. albican cell wall are carbohydrates such as mannans, beta glucans and chitins, and proteins that partially modulate the host immune responses. Dendritic cells (DC), as the most important antigen-presenting cells of the immune system, play a critical role in inducing immune responses against different pathogens.

Objective: We investigated the effect of the cell wall protein fraction (CPF) of C. albicans on DC maturation.

Methods: The CPF of C. albicans cells was extracted by a lysis buffer containing sodium dodecyl sulphate, 2-mercaptoethanol and phosphate-buffered saline. The extract was dialyzed and its protein pattern was evaluated by electrophoresis. Dendritic cells were purified from Balb/c mice spleens through a three-step method including mononuclear cell separation, as well as 2-h and overnight cultures. The purified CPF was added at different concentrations to DC. The purity and maturation status of DC were determined by flow cytometry using monoclonal antibodies against CD11c, MHC-II, CD40 and CD86.

Results: Treatment of DC with 10 microg/ml of CPF increased the expression of maturation markers including MHC-II, CD86 and CD40 on DC compared to the control group.

Conclusion: In this study we used C. albicans CPF with the molecular weight of 40-45 kDa for pulsing and maturation of dendritic cells. Since according to our results CPF significantly increased the expression of maturation markers on DC, we suggest that CPF may act as an efficient immunomodulator, or may be used as a potential adjuvant to boost the host immune system against infections.
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http://dx.doi.org/IJIv6i2A2DOI Listing
June 2009

Mutual helper effect in copulsing of dendritic cells with 2 antigens: a novel approach for improvement of dendritic-based vaccine efficacy against tumors and infectious diseases simultaneously.

J Immunother 2009 May;32(4):325-32

Department of Reproductive Immunology, Reproductive Biotechnology Research Center, Avicenna Research Institute, Shahid Beheshti University, Evin, Tehran, Iran.

To develop an efficient dendritic cell (DC)-based immunotherapy protocol, we examined whether simultaneous pulsing of DCs with a given antigen and a third-party antigen could enhance their antigen presentation capacity. Purified splenic DCs of Balb/c mice were pulsed separately with immunoglobulin G, ovalbumin, conalbumin, P15 peptide of Mycobacterium tuberculosis, and prostate-specific antigen or double combinations of the aforementioned antigens. In some settings, DCs pulsed with 1 antigen were mixed equally with those pulsed with another antigen. Antigen-pulsed DCs were injected into the footpad of syngeneic mice and proliferation of whole, CD4 and CD8 depleted lymph node cells was measured after restimulation with cognate antigen. Antigen-specific production of interferon-gamma (IFNgamma) was tested in culture supernatants. Frequency of responding lymph node cells was determined by IFNgamma enzyme-linked immunosorbent spot assay. Our results showed that copulsing of DCs with 2 unrelated antigens increased the capacity of DCs to induce antigen-specific T-cell proliferation against both antigens up to 16-fold. Injection of 2 populations of DCs each pulsed with a different antigen, increased proliferation of primed T cells significantly as well. Both CD4 and CD8 depleted populations showed vigorous proliferative response in copulsing system. In addition, copulsing of DCs with 2 antigens resulted in higher frequency of antigen-specific responding cells and significantly more IFNgamma production. Our results clearly showed that unrelated peptides and proteins could be used to enhance efficacy of DC-based vaccines and in this system, each antigen served to help the other one, a condition that we termed as "mutual helper effect."
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http://dx.doi.org/10.1097/CJI.0b013e31819aa31eDOI Listing
May 2009

The 14kDa protein molecule isolated from garlic suppresses indoleamine 2, 3-dioxygenase metabolites in mononuclear cells in vitro.

Iran J Allergy Asthma Immunol 2008 Dec;7(4):203-8

Department of Immunology, School of Medicine, Tarbiat Modarres University of Medical Sciences, Tehran, Iran.

A wide range of biological activities of garlic in vitro and in vivo have been verified including its antioxidant, antitumor and anti-inflammatory effects. Indoleamine 2,3-dioxygenase (IDO) is an enzyme widely distributed in mammals and is inducible preferentially by IFN-gamma. IDO degrades the essential amino acid tryptophan to form N-formyl kynurenine. In the present in vitro study, the modulatory effect of 14kDa molecule isolated from garlic on IDO induction was tested. Cultures of mononuclear cells were exposed to 14kDa garlic fraction. Then, their proliferation responses and IDO metabolites were measured. A significant down-regulatory effect of garlic on IDO activity was found and also the proliferation responses of mononuclear cells increased. If these results are verified in vivo, an explanation will be provided on how garlic may interfere in IDO induction, which paves the way for elucidating its specific therapeutic effect in preventing tumor progress.
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http://dx.doi.org/07.04ijaai.203208DOI Listing
December 2008

Immunosuppressive effect of pregnant mouse serum on allostimulatory activity of dendritic cells.

J Reprod Immunol 2007 Aug 16;75(1):23-31. Epub 2007 Apr 16.

Department of Immunology, Faculty of Medical Sciences, Tarbiat Modarres University, Tehran, Iran.

In normal pregnancy, the maternal immune system is directed towards tolerance or suppression in order to prevent rejection of the semi-allogenic fetus. Antigen-presenting cells, especially dendritic cells (DCs), are key cells in initiation and regulation of immune responses. The presence of potent immunostimulatory DCs in the decidual tissue of pregnancy has been demonstrated. The aim of this study was to determine how allostimulatory activity of DCs could be affected during pregnancy. DCs were isolated from spleen of pregnant or non-pregnant Balb/c mice and co-cultured with allogenic T lymphocytes prepared from brachial lymph nodes of C57BL/6 mice. Some cultures of non-pregnant female DCs were treated by 2.5% serum obtained from pregnant mice at early, middle or late gestational periods, and were used in the same mixed lymphocyte reaction (MLR) settings. Cell proliferation was measured by 3H-thymidine incorporation, and cytokine production measured in supernatants of MLR cultures using ELISA. The effect of pregnant mouse serum on expression of DC surface markers was evaluated by flow cytometry. No significant difference was found between stimulatory potential of splenic DCs from pregnant and non-pregnant mice in induction of allogenic T cell proliferative response. Moreover, serum of early or late pregnancy did not have any effect on DC function in comparison with non-pregnant mouse serum, while mid-pregnancy serum significantly inhibited allostimulatory activity of DCs. IFNgamma production in co-culture of DCs treated with pregnant mouse serum was significantly lower than that of the control group; however, no significant difference in IL-10 production was observed. Treatment of DCs with pregnant mouse serum did not influence the percentage of cells expressing MHC-II, CD86, CD8alpha or CD11b. However, a marked reduction of the mean fluorescence intensity of MHC-II was observed. Collectively, our results concerning the diminished capacity of DCs to induce production of Th1 cytokines and allogenic T cell proliferation after treatment with pregnant mouse serum reveal a new way of immunologic tolerance against the semi-allogenic fetus.
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http://dx.doi.org/10.1016/j.jri.2007.02.006DOI Listing
August 2007