Publications by authors named "Honglin Jia"

51 Publications

Expression of immunoproteasome subunits in the brains of Toxoplasma gondii-infected mice.

Exp Mol Pathol 2021 Sep 18:104684. Epub 2021 Sep 18.

State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute of Chinese Academy of Agricultural Sciences, Harbin, China. Electronic address:

The immunoproteasomes are specific proteasomes that clear oxidant-damaged proteins under inflammatory conditions in various diseases. Toxoplasma gondii (T. gondii) infects the central nervous system, causing encephalitis. However, the relationship between the immunoproteasomes and brain inflammation during T. gondii infection is not well characterized. In this study, we established an in vivo mouse model of T. gondii PLK strain infection via intraperitoneal injection and evaluated the expression of immunoproteasome subunits in the brains of infected mice. The results demonstrated that first, pathological changes in the brains of infected mice increase in severity over time. Second, following T. gondii infection, activated microglia and astrocytes undergo a series of functional alterations and morphological transformations, including proliferation and migration. Third, T. gondii infection induces expression of inflammatory cytokines, including IFN-γ, IL-1β, TNF-α, and IL-6. Fourth, the immunoproteasome subunits low-molecular-weight polypeptide 2 (LMP2), LMP7, and LMP10 mRNA and protein levels are significantly upregulated in T. gondii-infected mouse brains, as shown by the RT-qPCR and western blot analysis, compared with that in vehicle-treated brains, and their expression is localized to the microglia, astrocytes, and neurons of T. gondii-infected brains, as determined via immunofluorescence staining. Furthermore, the western blot mean gray value for the immunoproteasome subunits and the positive microglia and astrocyte immunohistochemical signals in the brains of T. gondii-infected mice were positively correlated, indicating that the observed relationships were highly significant. Therefore, it was concluded that the induction of the immunoproteasomes is a pathogenic mechanism underlying T. gondii infection-induced inflammation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.yexmp.2021.104684DOI Listing
September 2021

Multifaceted roles of a bioengineered nanoreactor in repressing radiation-induced lung injury.

Biomaterials 2021 Aug 27;277:121103. Epub 2021 Aug 27.

Department of Pharmacology, College of Pharmacy and Laboratory Medicine, Army Medical University (Third Military Medical University), Chongqing, 400038, PR China. Electronic address:

Radiation-induced lung injury (RILI) is a potentially fatal and dose-limiting complication of thoracic cancer radiotherapy. However, effective therapeutic agents for this condition are limited. Here, we describe a novel strategy to exert additive effects of a non-erythropoietic EPO derivative (ARA290), along with a free radical scavenger, superoxide dismutase (SOD), using a bioengineered nanoreactor ([email protected]). ARA290-chimeric nanoreactor makes SOD present in a confined reaction space by encapsulation into its interior to heighten stability against denaturing stimuli. In a RILI mouse model, intratracheal administration of [email protected] was shown to significantly ameliorate acute radiation pneumonitis and pulmonary fibrosis. Our investigations revealed that [email protected] performs its radioprotective effects by protecting against radiation induced alveolar epithelial cell apoptosis and ferroptosis, suppressing oxidative stress, inhibiting inflammation and by modulating the infiltrated macrophage phenotype, or through a combination of these mechanisms. In conclusion, [email protected] is a potential therapeutic agent for RILI, and given its multifaceted roles, it may be further developed as a translational nanomedicine for other related disorders.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.biomaterials.2021.121103DOI Listing
August 2021

The Dissection of SNAREs Reveals Key Factors for Vesicular Trafficking to the Endosome-like Compartment and Apicoplast via the Secretory System in Toxoplasma gondii.

mBio 2021 Aug 3;12(4):e0138021. Epub 2021 Aug 3.

State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China.

Vesicular trafficking is a fundamental cellular process involved in material transport in eukaryotes, but the diversity of the intracellular compartments has prevented researchers from obtaining a clear understanding of the specific functions of vesicular trafficking factors, including SNAREs, tethers, and Rab GTPases, in . In this study, we analyzed the localization of SNAREs and investigated their roles in vesicular trafficking in Toxoplasma gondii. Our results revealed the specific localizations of SNAREs in the endoplasmic reticulum (ER) (T. gondii Stx18 [TgStx18] and TgStx19), Golgi stacks (TgGS27), and endosome-like compartment (TgStx10 and TgStx12). The conditional ablation of ER- and Golgi-residing SNAREs caused severe defects in the secretory system. Most importantly, we found an R-SNARE (TgVAMP4-2) that is targeted to the apicoplast; to our knowledge, this work provides the first information showing a SNARE protein on endosymbiotic organelles and functioning in vesicular trafficking in eukaryotes. Conditional knockout of TgVAMP4-2 blocked the entrance of TgCPN60, TgACP, TgATrx2, and TgATrx1 into the apicoplast and interfered with the targeting of TgAPT1 and TgFtsH1 to the outermost membrane of the apicoplast. Together, our findings revealed the functions of SNAREs in the secretory system and the transport of nucleus-encoded proteins to an endosymbiotic organelle in a model organism of . SNAREs are essential for the fusion of the transport vesicles and target membranes and, thus, provide perfect targets for obtaining a global view of the vesicle transport system. In this study, we report that a novel Qc-SNARE (TgStx19) instead of Use1 is located at the ER and acts as a partner of TgStx18 in T. gondii. TgGS27 and the tethering complex TRAPP III are conserved and critical for the biogenesis of the Golgi complex in T. gondii. A novel R-SNARE, TgVAMP4-2, is found on the outermost membrane of the apicoplast. The transport of NEAT proteins into the secondary endosymbiotic organelle depends on its function. To our knowledge, this work provides the first mention of a SNARE located on endosymbiotic organelles that functions in vesicular trafficking in eukaryotes.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/mBio.01380-21DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8406237PMC
August 2021

In Situ biomimetic Nanoformulation for metastatic cancer immunotherapy.

Acta Biomater 2021 Jul 27. Epub 2021 Jul 27.

Department of Pharmacology, College of Pharmacy and Laboratory Medicine, Army Medical University (Third Military Medical University), Chongqing, 400038, P.R. China. Electronic address:

Metastasis is the leading cause of death in cancer patients. Eliciting anti-tumor immune responses against lung metastasis is hindered by the immunosuppressive microenvironment. This study explored a biomimetic nanoformulation, comprising a nanovaccine (OP) that delivers tumor antigens and adjuvants spatially and temporally in a virus-like manner, and a pulmonary surfactant-biomimetic liposome with an immunomodulator, JQ1 (PS-JQ1). The findings of this study showed that intratracheal administration of OP+PS-JQ1 activated lung immune cells without concomitant excess inflammation, enhanced tumor antigen cross-presentation, generated a significantly high antigen-specific CD8 T cell response, and reshaped the immunocellular composition in B16 melanoma tumor-bearing lung. OP+PS-JQ1 nanoformulation exhibited a striking immunotherapeutic efficacy, induced local and systemic tumor suppression, improved survival of mice, initiated immune memory that prevents recurrence of secondary tumors. This stable and nontoxic nanoformulation provides a simple, flexible, and robust strategy for augmenting anti-tumor immunity for metastatic cancer. STATEMENT OF SIGNIFICANCE: Egg glue proteins are produced by female insects, which can make the eggs firmly attached to the oviposition sites, not affected by wind and rain. However, genes encoding insect egg glue proteins have not yet been reported, and the molecular mechanism underpinning their adhesion is still unknown. Our study makes a significant contribution to the literature as it identifies the sequence, structure, adhesive property, and mechanism of silkworm egg glue protein. Furthermore, it outlines key insights into the structure-function relationships associated with egg glue proteins. We believe that this paper will be of interest to the readership of your journal as it identifies the first complete sequence of insect egg glue proteins, thereby highlighting their potentials future applications in both the biomedical and technical fields.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.actbio.2021.07.055DOI Listing
July 2021

Biogenesis and maintenance of the apicoplast in model apicomplexan parasites.

Parasitol Int 2021 Apr 13;81:102270. Epub 2020 Dec 13.

State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Haping Street 678, Nangang District, Harbin 150069, PR China. Electronic address:

The apicoplast is a non-photosynthetic relict plastid of Apicomplexa that evolved from a secondary symbiotic system. During its evolution, most of the genes derived from its alga ancestor were lost. Only genes involved in several valuable metabolic pathways, such as the synthesis of isoprenoid precursors, heme, and fatty acids, have been transferred to the host genome and retained to help these parasites adapt to a complex life cycle and various living environments. The biological function of an apicoplast is essential for most apicomplexan parasites. Considering their potential as drug targets, the metabolic functions of this symbiotic organelle have been intensively investigated through computational and biological means. Moreover, we know that not only organellar metabolic functions are linked with other organelles, but also their biogenesis processes have developed and evolved to tailor their biological functions and proper inheritance. Several distinct features have been found in the biogenesis process of apicoplasts. For example, the apicoplast borrows a dynamin-related protein (DrpA) from its host to implement organelle division. The autophagy system has also been repurposed for linking the apicoplast and centrosome during replication and the division process. However, many vital questions remain to be answered about how these parasites maintain and properly inherit this symbiotic organelle. Here we review our current knowledge about its biogenesis process and discuss several critical questions remaining to be answered in this field.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.parint.2020.102270DOI Listing
April 2021

TgMAP1c is involved in apicoplast biogenesis in Toxoplasma gondii.

Int J Parasitol 2020 06 5;50(6-7):487-499. Epub 2020 May 5.

Division of Fundamental Immunology, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), 678 Haping Street, Harbin 150069, People's Republic of China. Electronic address:

Methionine aminopeptidases (MAPs), which remove the N-terminal methionine from newly synthesised proteins, are present in all life forms. Three type I MAPs and one type II MAP are encoded in the genome of Toxoplasma gondii. In this study, we found that the inducible knockdown of each type I TgMAP (TgMAP1a-c) reduced the growth and proliferation of the parasite significantly. Among them, TgMAP1c was found to be localised to the apicoplast of the parasite. Inducible knockdown of TgMAP1c led to a defect in the abundance of apicoplast-encoded transcripts, and a later reduction in the apicoplast genome copy number and loss of the apicoplast structure. This finding indicates that transcription of the apicoplast genome was impaired upon knockdown of TgMAP1c. We also found that the function of TgMAP1c in apicoplast biogenesis depends on its enzymatic domain. Expression of a recombinant protein in which the active domain of TgMAP1c was replaced with that of TgMAP1a or TgMAP1b could not restore the defective growth and replication phenotype caused by knockdown of TgMAP1c, indicating that these three enzymes have distinct substrate preferences. An in vitro analysis also revealed that TgMAP1c is an active enzyme that acts specifically on the substrate H-Met-p-NA. In addition, inducible knockdown of TgMAP1c reduced the virulence of T. gondii in mice. Taken together, these results demonstrate that TgMAP1c plays a key role in the biogenesis and maintenance of the T. gondii apicoplast.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ijpara.2020.03.004DOI Listing
June 2020

GABARAPL2 Is Critical for Growth Restriction of Toxoplasma gondii in HeLa Cells Treated with Gamma Interferon.

Infect Immun 2020 04 20;88(5). Epub 2020 Apr 20.

Division of Fundamental Immunology, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences (CAAS), Harbin, People's Republic of China

Gamma interferon (IFN-γ)-induced innate immune responses play important roles in the inhibition of infection. It has been reported that IFN-γ stimulates non-acidification-dependent growth restriction of in HeLa cells, but the mechanism remains unclear. Here, we found that γ-aminobutyric acid (GABA) receptor-associated protein-like 2 (GABARAPL2) plays a critical role in parasite restriction in IFN-γ-treated HeLa cells. GABARAPL2 is recruited to membrane structures surrounding parasitophorous vacuoles (PV). Autophagy adaptors are required for the proper localization and function of GABARAPL2 in the IFN-γ -induced immune response. These findings provide further understanding of a noncanonical autophagy pathway responsible for IFN-γ-dependent inhibition of growth in human HeLa cells and demonstrate the critical role of GABARAPL2 in this response.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/IAI.00054-20DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7171250PMC
April 2020

Hydroxylamine and Carboxymethoxylamine Can Inhibit Growth through an Aspartate Aminotransferase-Independent Pathway.

Antimicrob Agents Chemother 2020 02 21;64(3). Epub 2020 Feb 21.

National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido, Japan

is an obligate intracellular protozoan parasite and a successful parasitic pathogen in diverse organisms and host cell types. Hydroxylamine (HYD) and carboxymethoxylamine (CAR) have been reported as inhibitors of aspartate aminotransferases (AATs) and interfere with the proliferation in Therefore, AATs are suggested as drug targets against The genome encodes only one predicted AAT in both type I strain RH and type II strain PLK. However, the effects of HYD and CAR, as well as their relationship with AAT, on remain unclear. In this study, we found that HYD and CAR impaired the lytic cycle of , including the inhibition of invasion or reinvasion, intracellular replication, and egress. Importantly, HYD and CAR could control acute toxoplasmosis Further studies showed that HYD and CAR could inhibit the transamination activity of rAAT However, our results confirmed that deficiency of AAT in both RH and PLK did not reduce the virulence in mice, although the growth ability of the parasites was affected HYD and CAR could still inhibit the growth of AAT-deficient parasites. These findings indicated that HYD and CAR inhibition of growth and control of toxoplasmosis can occur in an AAT-independent pathway. Overall, further studies focusing on the elucidation of the mechanism of inhibition are warranted. Our study hints at new substrates of HYD and CAR as potential drug targets to inhibit growth.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1128/AAC.01889-19DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7038254PMC
February 2020

Localization and enzyme kinetics of aminopeptidase N3 from Toxoplasma gondii.

Parasitol Res 2020 Jan 13;119(1):357-364. Epub 2019 Dec 13.

State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, 150001, China.

Aminopeptidase N is an important metalloenzyme from the M1 zinc metallopeptidase family, which is present in numerous apicomplexan parasites, including Plasmodium, Eimeria, and Cryptosporidium. Aminopeptidase N is a potential drug target, and hence, its properties have been widely investigated. In the current study, the cellular localization and enzyme characteristics of Toxoplasma gondii aminopeptidase N3 (TgAPN3) were evaluated in vitro. Cellular localization analysis revealed that TgAPN3 and GRA protein were co-located in the organelle and parasitophorous vacuole of T. gondii. The secretion assay showed that TgAPN3 could be co-secreted from the tachyzoites with GRA protein. A functional recombinant Toxoplasma aminopeptidase N3 (rTgAPN3) was produced in Escherichia coli. The enzyme activity was first determined using a fluorogenic H-Ala-MCA substrate. Some activity of rTgAPN3 was observed between pH 3.0 and 8.0, with a peak at pH 7.0. The activity was significantly enhanced in the presence of Co ions. Substrate specificity of rTgAPN3 was then evaluated. The enzyme showed a preference for substrates containing N-terminal Ala residues, followed by Tyr and Cys. The rTgAPN3 activity was significantly inhibited by bestatin and phebestatin. In general, TgAPN3 was a structurally conserved member of the M1 family, although it also displayed unique biochemical characteristics. These results lay the foundation for a functional study of TgAPN3 and constitute its putative identification as a drug target.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00436-019-06512-6DOI Listing
January 2020

The Sec1/Munc18-like proteins TgSec1 and TgVps45 play pivotal roles in assembly of the pellicle and sub-pellicle network in Toxoplasma gondii.

Mol Microbiol 2020 01 19;113(1):208-221. Epub 2019 Nov 19.

State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, People's Republic of China.

Post-Golgi vesicle trafficking is indispensable for precise movement of proteins to the pellicle, the sub-pellicle network and apical secretory organelles in Apicomplexa. However, only a small number of molecular complexes involved in trafficking, tethering and fusion of vesicles have been identified in Toxoplasma gondii. Consequently, it is unclear how complicated vesicle trafficking is accomplished in this parasite. Sec1/Munc18-like (SM) proteins are essential components of protein complexes involved in vesicle fusion. Here, we found that depletion of the SM protein TgSec1 using an auxin-inducible degron-based conditional knockout strategy led to mislocalization of plasma membrane proteins. By contrast, conditional depletion of the SM protein TgVps45 led to morphological changes, asymmetrical loss of the inner membrane complex and defects in nucleation of sub-pellicular microtubules, polarization and symmetrical assembly of daughter parasites during repeated endodyogeny. TgVps45 interacts with the SNARE protein TgStx16 and TgVAMP4-1. Conditional ablation of TgStx16 causes the similar growth defect like TgVps45 deficiency suggested they work together for the vesicle fusion at TGN. These findings indicate that these two SM proteins are crucial for assembly of pellicle and sub-pellicle network in T. gondii respectively.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/mmi.14411DOI Listing
January 2020

Establishment of BV2 microglia polarization model and its effect on Toxoplasma gondii proliferation.

Res Vet Sci 2019 Aug 5;125:382-389. Epub 2019 Aug 5.

National Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, China. Electronic address:

Toxoplasma gondii is an intracellular opportunistic, parasitic protozoan. Microglia have been classified into two main types: M1 (classically activated macrophages) and M2 (alternatively activated macrophages). BV2 cells were used in this study, together with lipopolysaccharide (LPS) and interferon (IFN)-γ or interleukin (IL)-4, which were used to induce resting microglia. Expression levels of M1/M2 markers were determined at both mRNA and protein levels, using PCR, western blot, and flow cytometry. Furthermore, cells were infected with T. gondii PLK strain, and the dynamic changes in M1/M2 marker expression levels were determined. An in vitro polarization model was successfully established. Expression of Nos2 and M1-associated markers was significantly upregulated at 12 h post-infection in BV2 cells. Further, the JAK/STAT1 and NF-κB signaling pathways were also activated following T. gondii infection. This demonstrated that T. gondii infection induces M1-type microglial polarization in vitro. The present study demonstrated that T. gondii infection affects microglial activation in vitro and elucidated the effects of activated microglia on T. gondii proliferation. This data may serve as a useful reference for more detailed elucidation of interactions between T. gondii and the innate immune system.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.rvsc.2019.08.002DOI Listing
August 2019

Evolution from covalent conjugation to non-covalent interaction in the ubiquitin-like ATG12 system.

Nat Struct Mol Biol 2019 04 25;26(4):289-296. Epub 2019 Mar 25.

Department of Biochemistry and Molecular Biology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.

Ubiquitin or ubiquitin-like proteins can be covalently conjugated to multiple proteins that do not necessarily have binding interfaces. Here, we show that an evolutionary transition from covalent conjugation to non-covalent interaction has occurred in the ubiquitin-like autophagy-related 12 (ATG12) conjugation system. ATG12 is covalently conjugated to its sole substrate, ATG5, by a ubiquitylation-like mechanism. However, the apicomplexan parasites Plasmodium and Toxoplasma and some yeast species such as Komagataella phaffii (previously Pichia pastoris) lack the E2-like enzyme ATG10 and the most carboxy (C)-terminal glycine of ATG12, both of which are required for covalent linkage. Instead, ATG12 in these organisms forms a non-covalent complex with ATG5. This non-covalent ATG12-ATG5 complex retains the ability to facilitate ATG8-phosphatidylethanolamine conjugation. These results suggest that ubiquitin-like covalent conjugation can evolve to a simpler non-covalent interaction, most probably when the system has a limited number of targets.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1038/s41594-019-0204-3DOI Listing
April 2019

Characterization of strain-specific phenotypes associated with knockout of dense granule protein 9 in Toxoplasma gondii.

Mol Biochem Parasitol 2019 04 5;229:53-61. Epub 2019 Mar 5.

National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan. Electronic address:

Toxoplasma gondii is an obligate intracellular parasite that can invade any nucleated cell of mammals and cause toxoplasmosis. Dense granule proteins play major structural functions within the parasitophorous vacuole (PV) and the cyst wall of T. gondii. Moreover, their particular location within the PV allows them to be involved in various interactions between parasites and the host cells. Dense granule protein 9 (GRA9) gene has been identified in T. gondii, although its role in the lytic cycle remains unclear. In the current study, the function of GRA9 in type I and type II Toxoplasma parasites was characterized. T. gondii GRA9 sequence and its expression were analyzed and derivatives of T. gondii RH and PLK strains with a null mutation in GRA9 were generated using CRISPR/Cas9 system. The phenotypes of GRA9 in wild types, knockout and complemented strains were analyzed in vitro and in vivo using Vero cells and BALB/c mice, respectively. Alignment of the amino acid sequence indicated that RH strain GRA9 contained one amino acid substitution when compared with PLK strain. Western blot analysis revealed that PLK strain had a higher expression level of GRA9 than RH strain. The phenotype analysis revealed that knockout of GRA9 in PLK parasites inhibited the plaque formation and egress from PV. Both the plaque formation and egress ability of PLKΔGRA9 strain were restored by complementation with a synonymous allele of PLK strain GRA9. Mouse experiments demonstrated that loss of GRA9 in PLK strain significantly reduced the pathogenicity of T. gondii. However, there was no phenotypic diferences between RH and RHΔGRA9 strains except the defect in host cell invasion. Overall, T. gondii GRA9 knockout only influenced the growth and virulence of PLK strain. These results indicate that GRA9 may be involved in parasite egress and virulence in mice in a strain-specific manner.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.molbiopara.2019.01.003DOI Listing
April 2019

The Nrf2 pathway is required for intracellular replication of Toxoplasma gondii in activated macrophages.

Parasite Immunol 2019 05 4;41(5):e12621. Epub 2019 Apr 4.

State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China.

Reactive oxygen species (ROS) produced by oxidases and nonenzymatic sources are important for host defence against intracellular pathogens. In this study, we knocked out the Nrf2 gene in RAW264.7 cells using the CRISPR/Cas9 system and investigated the antioxidant effects of the Nrf2 pathway in the cells stimulated by IFN-γ and TNF-α. The results indicated that the Nrf2 signalling pathway is necessary for maintaining redox homeostasis in activated RAW264.7 cells. Inactivation of Nrf2 impaired parasite growth. We also found that p62 contributes to Nrf2-mediated pathways involved in T gondii infection. These findings suggest that the Nrf2/Keap1 pathway may be targeted to prevent and treat toxoplasmosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/pim.12621DOI Listing
May 2019

Clp family protein: ClpB1 plays a crucial role in thermotolerance.

Oncotarget 2017 Oct 18;8(49):86117-86129. Epub 2017 Sep 18.

State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China.

Caseinolytic peptidase B (ClpB) plays a pivotal role in suppressing and reversing protein aggregation. is an intracellular parasitic protozoan that infects a wide variety of mammals and birds and therefore is exposed to a broad range of living condition. We screened ToxoDB (http://ToxoDB.org) and identified 10 putative genes encoding members of the Clp superfamily of caseinolytic proteases and chaperones. Of these, we focused on characterizing the Class I ATP-dependent molecular chaperones ClpB1, ClpB2, and ClpB3. We found that ClpB1, the most divergent of the five Class I Clp ATPases, is cytoplasmic, ClpB2 is found in the mitochondria of the parasites, and ClpB3 is a ClpB with novel apicoplast localization. Knockout strains of ClpB1 and ClpB2 were established by CRISPR/Cas9 mutagenesis, and their complementing strains were constructed with FLAG-tag. Although knockout of ClpB1 or ClpB2 did not affect growth under normal circumstances, ClpB1 was required for thermotolerance. The growth, replication, and invasion capabilities of ClpB1-deficient mutants were significantly inhibited after extracellular parasites were pretreated at 45°C. Moreover, ClpB1 were observed at the poles of the ΔClpB1 FLAG-tagged strain treated at 42°C.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.18632/oncotarget.20989DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5689671PMC
October 2017

Translationally controlled tumor protein is required for the fast growth of Toxoplasma gondii and maintenance of its intracellular development.

FASEB J 2018 02 4;32(2):906-919. Epub 2018 Jan 4.

State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin, China.

Translationally controlled tumor protein (TCTP) is a highly conserved, multifunctional protein that has been implicated in a range of cell physiologic processes, especially cell growth and development. A TCTP-like gene has been identified in the Toxoplasma genome [ Toxoplasma gondii TCTP ( TgTCTP)], although its function remains unknown. The sequence analysis of TgTCTP indicated that it is a highly conserved protein in eukaryotes. We found that the expression level of TgTCTP in the virulent RH strain was significantly higher than that in the avirulent PLK strain. Indirect immunofluorescence showed that TgTCTP was expressed in the parasite cytoplasm. The localization of TgTCTP was unchanged during the replication of the parasite. We expressed a functional recombinant TgTCTP (r TgTCTP) protein in Escherichia coli and found that the recombinant protein could form a multimer. We then evaluated the function of TgTCTP using the clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 knockout (KO) system. Phenotypic analysis of the KO strain (Δ TgTCTP) revealed that TgTCTP is required for the robust growth of the parasites. TgTCTP deficiency also led to early egress of the parasites and subsequent impairment in their invasion and attachment abilities. We subsequently found that the multimer form of TgTCTP might not be necessary for the growth and replication of the parasite. Then the expression profiling of genes in the Δ TgTCTP and complement strains were analyzed. The results revealed that 988 genes were regulated in Δ TgTCTP compared with the complement strain. Overall, although not essential, TgTCTP is required for the fast growth of Tg and maintenance of its intracellular development.-Zheng, J., Chen, Y., Li, Z., Cao, S., Zhang, Z., Jia, H. Translationally controlled tumor protein is required for the fast growth of Toxoplasma gondii and maintenance of its intracellular development.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1096/fj.201700994RDOI Listing
February 2018

Biochemical characterization of aminopeptidase N2 from Toxoplasma gondii.

J Vet Med Sci 2017 Aug 13;79(8):1404-1411. Epub 2017 Jul 13.

Department of Gastrointestinal Medical Oncology, The Affiliated Tumor Hospital of Harbin Medical University, Harbin 150001, China.

Aminopeptidase N (APN) is a member of the highly conserved M1 family of metalloproteases, and is considered to be a valuable target for the treatment of a variety of diseases, e.g., cancer, malaria, and coccidiosis. In this study, we identified an APN gene (TgAPN2) in the Toxoplasma gondii genome, and performed a biochemical characterization of the recombinant TgAPN2 (rTgAPN2) protein. Active rTgAPN2 was first produced and purified in Escherichia coli. The catalytic activity of the enzyme was verified using a specific fluorescent substrate, H-Ala-MCA; the rTgAPN2 was relatively active in the absence of added metal ions. The addition of some metal ions, especially Zn, inhibited the activity of the recombinant enzyme. The activity of rTgAPN2 was reduced in the presence of the EDTA chelator in the absence of added metal ions. The optimum pH for enzyme activity was 8.0; the enzyme was active in the 3-10 pH range. The substrate preference of rTgAPN2 was evaluated. The enzyme showed a preference for substrates containing N-terminal Ala and Arg residues. Finally, bestatin and amastatin were shown to inhibit the activity of the enzyme. In conclusion, rTgAPN2 shared general characteristics with the M1 family of aminopeptidases but also had some unique characteristics. This provides a basis for the function of aminopeptidases and the study of drug targets.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1292/jvms.17-0119DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5573830PMC
August 2017

The moving junction protein RON4, although not critical, facilitates host cell invasion and stabilizes MJ members.

Parasitology 2017 Sep 30;144(11):1490-1497. Epub 2017 Jun 30.

College of Veterinary Medicine, Northeast Agricultural University,Harbin, Heilongjiang,China.

Toxoplasma gondii is an obligate intracellular parasite of phylum Apicomplexa. To facilitate high-efficiency invasion of host cells, T. gondii secretes various proteins related to the moving junction (MJ) complex from rhoptries and micronemes into the interface between the parasite and host. AMA1/RON2/4/5/8 is an important MJ complex, but its mechanism of assembly remains unclear. In this study, we used the CRISPR-Cas9 system to generate a derivative of T. gondii strain RH with a null mutation in TgRON4, thought to be an essential MJ component. Deficiency of TgRON4 moderately decreased invasion ability relative to that of the wild-type parasite. In addition, expression of the endogenous N-terminal fragment of RON5 decreased in the mutant. Together, the results improve our understanding of the assembly mechanism of the MJ complex of T. gondii and raise the possibility of developing new therapeutic drugs that target this complex.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1017/S0031182017000968DOI Listing
September 2017

Characterization of aspartyl aminopeptidase from Toxoplasma gondii.

Sci Rep 2016 Sep 28;6:34448. Epub 2016 Sep 28.

Harbin Veterinary Research Institute, CAAS-Michigan State University Joint Laboratory of Innate Immunity, State Key Laboratory of Veterinary Biotechnology, Chinese Academy of Agricultural Sciences, Maduan Street 427, Nangang District, Harbin 150001, P. R. China.

Aminopeptidases have emerged as new promising drug targets for the development of novel anti-parasitic drugs. An aspartyl aminopeptidase-like gene has been identified in the Toxoplasma gondii genome (TgAAP), although its function remains unknown. In this study, we characterized TgAAP and performed functional analysis of the gene product. Firstly, we expressed a functional recombinant TgAAP (rTgAAP) protein in Escherichia coli, and found that it required metal ions for activity and showed a substrate preference for N-terminal acidic amino acids Glu and Asp. Then, we evaluated the function and drug target potential of TgAAP using the CRISPR/Cas9 knockout system. Western blotting demonstrated the deletion of TgAAP in the knockout strain. Indirect immunofluorescence analysis showed that TgAAP was localized in the cytoplasm of the wild-type parasite, but was not expressed in the knockout strain. Phenotype analysis revealed that TgAAP knockout inhibited the attachment/invasion, replication, and substrate-specific activity in T. gondii. Finally, the activity of drug CID 23724194, previously described as targeting Plasmodium and malarial parasite AAP, was tested against rTgAAP and the parasite. Overall, TgAAP knockout affected the growth of T. gondii but did not completely abolish parasite replication and growth. Therefore, TgAAP may comprise a useful adjunct drug target of T. gondii.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5039622PMC
http://dx.doi.org/10.1038/srep34448DOI Listing
September 2016

Functional characterization of X-prolyl aminopeptidase from Toxoplasma gondii.

Parasitology 2016 09 25;143(11):1443-9. Epub 2016 May 25.

College of Veterinary Medicine, Northeast Agricultural University,Harbin,Heilongjiang,China.

In the present study, a recombinant aminopeptidase P (rTgAPP) from Toxoplasma gondii was expressed in Escherichia coli to evaluate its enzyme parameters. The rTgAPP showed strong activity against a synthetic substrate for aminopeptidase P at pH 8·0 with a K m value of 0·255 µ m and a k cat value of 35·6 s-1. The overall catalytic efficiency (k cat/K m) of the rTgAPP was 139·6 × 105 M-1 s-1. The activity of rTgAPP was enhanced by the addition of divalent cations and inhibited by bestatin. Deletion of TgAPP gene in the parasite through a CRISPR/Cas9 system resulted in inhibition of growth indicating the importance of TgAPP. Thus our findings reveal that TgAPP is an active enzyme in T. gondii and provide an insight into the function of TgAPP.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1017/S0031182016000986DOI Listing
September 2016

High-level expression and characterization of two serine protease inhibitors from Trichinella spiralis.

Vet Parasitol 2016 Mar 3;219:34-9. Epub 2016 Feb 3.

Key Laboratory of Animal Common Disease Prevention, College of Veterinary Medicine, Northeast Agricultural University, 59 Mucai Street, Harbin 150030, PR China. Electronic address:

Serine protease inhibitors (SPIs) play important roles in tissue homeostasis, cell survival, development, and host defense. So far, SPIs have been identified from various organisms, such as animals, plants, bacteria, poxviruses, and parasites. In this study, two SPIs (Tsp03044 and TspAd5) were identified from the genome of Trichinella spiralis and expressed in Escherichia coli. Sequence analysis revealed that these two SPIs contained essential structural motifs, which were well conserved within the tumor-infiltrating lymphocytes (TIL) and serpin superfamily. Based on protease inhibition assays, the recombinant Tsp03044 showed inhibitory effects on trypsin, α-chymotrypsin, and pepsin, while the recombinant TspAd5 could effectively inhibit the activities of α-chymotrypsin and pepsin. Both these inhibitors showed activity between 28 and 48 °C. The expression levels of the two SPIs were also determined at different developmental stages of the parasite with real-time PCR. Our results indicate that Tsp03044 and TspAd5 are functional serine protease inhibitors.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vetpar.2016.02.003DOI Listing
March 2016

Knockout of leucine aminopeptidase in Toxoplasma gondii using CRISPR/Cas9.

Int J Parasitol 2015 Feb 13;45(2-3):141-8. Epub 2014 Nov 13.

Harbin Veterinary Research Institute, CAAS-Michigan State University Joint Laboratory of Innate Immunity, State Key Laboratory of Veterinary Biotechnology, Chinese Academy of Agricultural Sciences, Maduan Street 427, Nangang District, Harbin 150001, PR China.

Leucine aminopeptidases of the M17 peptidase family represent ideal drug targets for therapies directed against the pathogens Plasmodium, Babesia and Trypanosoma. Previously, we characterised Toxoplasma gondii leucine aminopeptidase and demonstrated its role in regulating the levels of free amino acids. In this study, we evaluated the potential of T. gondii leucine aminopeptidase as a drug target in T. gondii by a knockout method. Existing knockout methods for T. gondii have many drawbacks; therefore, we developed a new technique that takes advantage of the CRISPR/Cas9 system. We first chose a Cas9 target site in the gene encoding T. gondii leucine aminopeptidase and then constructed a knockout vector containing Cas9 and the single guide RNA. After transfection, single tachyzoites were cloned in 96-well plates by limiting dilution. Two transfected strains derived from a single clone were cultured in Vero cells, and then subjected to expression analysis by western blotting. The phenotypic analysis revealed that knockout of T. gondii leucine aminopeptidase resulted in inhibition of attachment/invasion and replication; both the growth and attachment/invasion capacity of knockout parasites were restored by complementation with a synonymously substituted allele of T. gondii leucine aminopeptidase. Mouse experiments demonstrated that T. gondii leucine aminopeptidase knockout somewhat reduced the pathogenicity of T. gondii. An enzymatic activity assay showed that T. gondii leucine aminopeptidase knockout reduced the processing of a leucine aminopeptidase-specific substrate in T. gondii. The absence of leucine aminopeptidase activity could be slightly compensated for in T. gondii. Overall, T. gondii leucine aminopeptidase knockout influenced the growth of T. gondii, but did not completely block parasite development, virulence or enzymatic activity. Therefore, we conclude that leucine aminopeptidase would be useful only as an adjunctive drug target in T. gondii.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ijpara.2014.09.003DOI Listing
February 2015

First characterization in China of Encephalitozoon cuniculi in the blue fox (Alopex lagopus).

J Eukaryot Microbiol 2014 Nov-Dec;61(6):580-5. Epub 2014 Aug 14.

College of Wildlife Resources Northeast Forestry University, Hexing Road 26, Xiangfang District, Harbin, 150040, China; Harbin Veterinary Research Institute, CAAS-Michigan State University Joint Laboratory of Innate Immunity, State Key Laboratory of Veterinary Biotechnology, Chinese Academy of Agricultural Sciences, Maduan Street 427, Nangang District, Harbin, 150001, China.

Encephalitozoon cuniculi is a microsporidian parasite that infects a wide range of vertebrates, including primates. It has recently emerged as an opportunistic parasite of patients infected with the human immunodeficiency virus. The blue fox (Alopex lagopus; also known as the arctic fox) is one of the most susceptible species for encephalitozoonosis. Here, we report an outbreak of encephalitozoonosis at a fox farm in China. The isolated parasites displayed the typical morphology of E. cuniculi as assessed by Masson's trichrome staining. Analysis of the internal transcribed spacer sequence indicated that the isolated parasite is a genotype III strain of E. cuniculi. Furthermore, phylogenetic analysis of the PTP1 gene verifies classification of this new strain (termed LN-1) with other genotype III E. cuniculi strains, though the PTP3 and SWP1 sequences diverge from the reference strain. This is the first report of encephalitozoonosis in farmed blue foxes in China.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/jeu.12135DOI Listing
June 2015

Genotypes of Enterocytozoon bieneusi in livestock in China: high prevalence and zoonotic potential.

PLoS One 2014 20;9(5):e97623. Epub 2014 May 20.

Division of Foodborne, Waterborne and Environmental Diseases, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.

Despite many recent advances in genotype characterization of Enterocytozoon bieneusi worldwide and the exploration of the extent of cross-species transmission of microsporidiosis between humans and animals, the epidemiology of this neglected disease in China is poorly understood. In this study, a very high prevalence (60.3%; 94/156) of E. bieneusi infections in farmed pigs in Jilin province was detected by PCR of the ribosomal internal transcribed spacer (ITS). DNA sequence analysis of 88 E. bieneusi-positive specimens identified 12 distinct genotypes (11 known: CHN7, CS-1, CS-4, CS-6, EbpA, EbpB, EbpC, EbpD, EBITS3, G, and Henan-I; one novel: CS-9). Frequent appearance of mixed genotype infections was seen in the study animals. Weaned (74.6%; 53/71) or pre-weaned (68.8%; 22/32) pigs have infection rates significantly higher than growing pigs (35.8%; 19/53) (p<0.01). Likewise, E. bieneusi was detected in 2 of 45 sheep fecal specimens (4.4%) in Heilongjiang province, belonging to the known genotype BEB6. Genotypes EbpA, EbpC, EbpD, and Henan-I examined herein have been documented in the cases of human infections and BEB6, EbpA, EbpC, and EbpD in wastewater in central China. Infections of EbpA and EbpC in humans were also reported in other areas of the world. The other known genotypes (CHN7, CS-1, CS-4, CS-6, EBITS3, EbpB, and G) and the new genotype CS-9 were genetically clustered into a group of existing E. bieneusi genotypes with zoonotic potential. Thus, pigs could be a potential source of human E. bieneusi infections in China.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0097623PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4028308PMC
February 2015

Evaluation of spore wall protein 1 as an alternative antigen for the diagnosis of Encephalitozoon cuniculi infection of farmed foxes using an enzyme-linked immunosorbent assay.

Vet Parasitol 2014 Jul 20;203(3-4):331-4. Epub 2014 Mar 20.

Harbin Veterinary Research Institute, CAAS-Michigan State University Joint Laboratory of Innate Immunity, State Key Laboratory of Veterinary Biotechnology, Chinese Academy of Agricultural Sciences, Maduan Street 427, Nangang District, Harbin 150001, PR China. Electronic address:

The sequence encoding SWP1 was cloned from the genome of Encephalitozoon cuniculi. Recombinant SWP1 (rSWP1) was expressed in Escherichia coli and used to detect E. cuniculi infections in farmed foxes and dogs with an indirect enzyme-linked immunosorbent assay (ELISA) in the present study. The sera of foxes infected with E. cuniculi could be distinguished from the sera of foxes infected with Toxoplasma gondii, Neospora caninum, and Cryptosporidium parvum using the ELISA. In total, 198 fox samples collected in Liaoning were used to determine the prevalence of antibodies against this disease. The results showed that 16.7% of the fox serum samples were positive according to the ELISA using rSWP1, which agreed with the ELISA results based on recombinant PTP2 (rPTP2). The sensitivity and specificity of the ELISA based on rSWP1 suggest that this could be an alternative method for the diagnosis of E. cuniculi infections in foxes. In addition, 298 dog samples collected in Beijing, Shanghai, and Hunan were also detected in this study, of which six dog samples (2%) were positive according to the ELISA using rSWP1. To the best of our knowledge, this is the first study to demonstrate the serological prevalence of E. cuniculi infections in dogs and foxes in China.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vetpar.2014.03.011DOI Listing
July 2014

Eimeria tenella rhomboid 3 has a potential role in microneme protein cleavage.

Vet Parasitol 2014 Mar 28;201(1-2):146-9. Epub 2014 Jan 28.

Key Laboratory of Zoonosis, Ministry of Education, College of Veterinary Medicine, Jilin University, Changchun, China. Electronic address:

Invasion in several apicomplexan parasites, including Eimeria tenella, is accompanied by shedding of surface adhesins by intramembrane proteolysis mediated by rhomboid protease. We have previously identified E. tenella rhomboid 3 (EtROM3), but its precise role has not been elucidated. In this study, the interactions between EtROM3 and microneme (MIC) proteins were analyzed using the yeast two hybrid technique. The results showed that c-Myc-ROM3 fusion protein interacted with EtMIC4 protein in co-transformed AH109 yeasts, which was further confirmed by immunoprecipitation assay. Smaller EtMIC4 band from co-transformed cells suggested that EtROM3 was an active protease and involved in the cleavage of EtMIC4.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vetpar.2014.01.010DOI Listing
March 2014

Epidemiological investigation of equine piroplasmosis in China by enzyme-linked immunosorbent assays.

J Vet Med Sci 2014 Apr 29;76(4):549-52. Epub 2013 Nov 29.

Harbin Veterinary Research Institute-Michigan State University Joint Laboratory of Innate Immunity & State Key Laboratory of Veterinary Biotechnology, Chinese Academy of Agricultural Sciences, Maduan Street 427, Nangang District, Harbin 150001, P. R. China.

The objective of this study is to investigate the seroprevalence of equine piroplasmosis in China. A total of 1990 sera were collected from clinically healthy horses in various districts located in ten different provinces of China and examined by using indirect enzyme-linked immunosorbent assays (ELISAs) with recombinant Theileria equi (T. equi) merozoite antigen 2 (rEMA-2) and Babesia caballi (B. caballi) 48-kDa rhoptry protein (rBc48), respectively. The results showed that 1,018 (51.16%) and 229 (11.51%) samples were positive for B. caballi and T. equi infection, respectively. The number of samples with mixed infection was 152 (7.64%). These results indicated that equine piroplasmosis was widespread in China.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4064140PMC
http://dx.doi.org/10.1292/jvms.13-0477DOI Listing
April 2014

Four promising antigens, BgP32, BgP45, BgP47, and BgP50, for serodiagnosis of Babesia gibsoni infection were classified as B. gibsoni merozoite surface protein family.

Parasitol Int 2012 Jun 8;61(2):364-8. Epub 2011 Dec 8.

National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Hokkaido 080-8555, Japan.

We determined the molecular characteristics of four proteins, BgP32, BgP45, BgP47, and BgP50, of Babesia gibsoni. Localization by subcellular fractionations followed by Western blotting revealed that the corresponding native proteins belong to merozoite surface protein family of B. gibsoni (BgMSP). Moreover, antisera against either rBgP45 or rBgP47 cross-reacted with all the proteins of the BgMSP family on ELISA and IFAT analyses. Of the four candidate antigens, ELISA with rBgP45 yielded high sensitivity, and ELISA with rBgP32 resulted in high specificity and in concordance with IFAT results.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.parint.2011.11.007DOI Listing
June 2012

A double antibody sandwich enzyme-linked immunosorbent assay for detection of secreted antigen 1 of Babesia microti using hamster model.

Exp Parasitol 2012 Feb 9;130(2):178-82. Epub 2011 Nov 9.

National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Inada-cho, Obihiro, Hokkaido 080-8555, Japan.

A double antibody sandwich enzyme-linked immunosorbent assay (DAS-ELISA) targeting secreted antigen 1 of Babesia microti (BmSA1) was developed for detection of B. microti infection. The optimized DAS-ELISA was sensitive enough to detect circulating BmSA1 by day 2 post-infection, in sequential sera of a hamster infected with B. microti. This detection was 4 days earlier than antibody detection by indirect ELISA. The kinetics of circulating BmSA1 coincided with the profile of parasitemia. The specificity of this assay was evaluated using sera from animals experimentally infected with different species of Babesia. The DAS-ELISA had a higher sensitivity than the microscopic examination of Giemsa-stained blood smears for detection of the infection in hamsters. Taken together, these results indicated that BmSA1 could be a potential marker for surveillance of human babesiosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.exppara.2011.10.012DOI Listing
February 2012

Immunogenicity of orally administrated recombinant Lactobacillus casei Zhang expressing Cryptosporidium parvum surface adhesion protein P23 in mice.

Curr Microbiol 2011 May 20;62(5):1573-80. Epub 2011 Feb 20.

Key Laboratory of Dairy Biotechnology and Engineering, Ministry of Education, Inner Mongolia Agricultural University, 306 Zhaowuda Road, Hohhot, Inner Mongolia 010018, China.

Cryptosporidium parvum, an intestinal apicomplexan parasite, is a significant cause of diarrheal diseases in both humans and animals. What is more, there is no promising strategy for controlling cryptosporidiosis. In this study, the P23 immunodominant surface protein of C. parvum sporozoites was stably expressed in the Lactobacillus casei Zhang strain and its immunogenicity was evaluated in a mouse model. The molecular weight (23 kDa) and immunogenicity of p23 gene expressed by L. casei Zhang were similar to that of the native P23 protein. Oral immunization with control L. casei Zhang and recombinant L. casei Zhang-p23 activated the mucosal immune system to elicit serum immunoglobulin G (IgG) and mucosal IgA in mice. Furthermore, the expression of cytokines such as IL-4, IL-6, and IFN-γ in splenocytes of mice was detected by real-time PCR after oral immunization. P23-specific immunocyte activation was also verified. These findings indicate that the live L. casei Zhang vector may be a new tool for the production of mucosal vaccines against cryptosporidiosis in animals.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s00284-011-9894-4DOI Listing
May 2011
-->