Publications by authors named "Carey Shive"

34 Publications

Naïve CD4+ T Cell Lymphopenia and Apoptosis in Chronic Hepatitis C Virus Infection Is Driven by the CD31+ Subset and Is Partially Normalized in Direct-Acting Antiviral Treated Persons.

Front Immunol 2021 12;12:641230. Epub 2021 Apr 12.

Department of Pathology, Case Western Reserve University, Cleveland, OH, United States.

Background: The mechanisms underlying naïve CD4+ lymphopenia during chronic Hepatitis C Virus (HCV) infection are unclear. Whether direct-acting antiviral (DAA) therapy restores peripheral naïve CD4+ T cell numbers and function is unknown.

Methods: We enumerated frequencies and counts of peripheral naïve CD4+, CD4+CD31+ and CD4+CD31- T cells by flow cytometry in a cross sectional analysis comparing chronic HCV infected (n=34), DAA-treated(n=29), and age-range matched controls (n=25), as well as in a longitudinal cohort of HCV DAA treated persons (n=16). The cross-sectional cohort was stratified by cirrhosis state. Cell apoptosis/survival (AnnexinV+7AAD+/BCL-2 labeling) and cell cycle entry (Ki67 expression) of CD31+ and CD31- naïve CD4+ T cells was analyzed directly and following 3 and 5 days of culture with media, interleukin (IL) -7 or CD3/CD28 activator.

Results: In the cross-sectional cohort, naïve CD4+ proportions were lower in chronic HCV infected persons compared to controls and DAA-treated persons, an effect in part attributed to cirrhosis. Age was associated with naïve cell counts and proportions in HCV infected and treated persons as well. Naïve CD4+ cell proportions negatively correlated with plasma levels of soluble CD14 following therapy in DAA-treated persons. Naïve CD4+ cells from HCV infected persons exhibited greater direct apoptosis and cell-cycling compared to cells from DAA-treated persons and controls, and this was localized to the CD4+CD31+ subset. On the other hand, no remarkable differences in expression of BCL-2 or IL-7 Receptor (CD127) at baseline or following media or IL7 containing culture were observed. In the longitudinal cohort, naïve CD4+CD31+/CD31- ratio tended to increase 24 weeks after DAA therapy initiation.

Conclusions: Activation and apoptosis of peripheral naïve CD4+CD31+ T cells appear to contribute to naïve CD4+ lymphopenia in chronic HCV infection, and this defect is partially reversible with HCV DAA therapy. Age and cirrhosis -associated naïve CD4+ lymphopenia is present both before and after HCV DAA therapy. These findings have implications for restoration of host immune function after DAA therapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fimmu.2021.641230DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8075159PMC
April 2021

T-cell Activation Is Correlated With Monocyte Activation in HCV/HIV Coinfection and Declines During HCV Direct-Acting Antiviral Therapy.

Open Forum Infect Dis 2021 Apr 18;8(4):ofab079. Epub 2021 Feb 18.

Department of Pathology, VA Medical Center, Case Western Reserve University, Cleveland, Ohio, USA.

Background: Immune activation markers associate with morbidity and mortality in HIV and hepatitis C virus (HCV) infection. We investigated how T-cell and monocyte activation are related over the course of HCV direct-acting antiviral (DAA) therapy during HCV/HIV coinfection.

Methods: Peripheral blood mononuclear cells from AIDS Clinical Trials Group (ACTG) A5329 participants and a single-site separate cohort treated with DAAs were analyzed for central memory (CM)/effector memory (EM) T-cell subsets, monocyte subsets, and cell activation (CD38 and HLA-DR expression) before, during, and after therapy.

Results: Before therapy, classical and inflammatory monocyte subset HLA-DR expression positively correlated with absolute counts and frequencies of CD38HLA-DR-expressing CD4 and CD8 T cells and corresponding CM and EM subsets. After therapy initiation, CD38HLA-DR co-expression on CD4 and CD8 memory T cells decreased by 12 weeks and 36 weeks, and plasma sCD14 positively correlated with CD38HLA-DR CD4 and CD4CM T-cell frequencies. Monocyte subset activation remained similar over time.

Conclusions: During HCV/HIV coinfection, memory T-cell activation is associated with monocyte subset activation, consistent with related underlying mechanisms. Following therapy initiation, memory T-cell, but not monocyte, activation decreased. Residual CD4 T-cell activation after therapy completion is associated with sCD14, potentially linking the remaining CD4 T-cell activation to residual factors driving activation in antiretroviral therapy-controlled HIV.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ofid/ofab079DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8043262PMC
April 2021

Markers of T Cell Exhaustion and Senescence and Their Relationship to Plasma TGF-β Levels in Treated HIV+ Immune Non-responders.

Front Immunol 2021 25;12:638010. Epub 2021 Mar 25.

Louis Stokes Cleveland VA Medical Center, Cleveland, OH, United States.

Immune non-responders (INR) are HIV+, ART-controlled (>2 yrs) people who fail to reconstitute their CD4 T cell numbers. Systemic inflammation and markers of T cell senescence and exhaustion are observed in INR. This study aims to investigate T cell senescence and exhaustion and their possible association with soluble immune mediators and to understand the immune profile of HIV-infected INR. Selected participants were <50 years old to control for the confounder of older age. Plasma levels of IL-6, IP10, sCD14, sCD163, and TGF-β and markers of T cell exhaustion (PD-1, TIGIT) and senescence (CD57, KLRG-1) were measured in ART-treated, HIV+ participants grouped by CD4 T cell counts ( = 63). Immune parameters were also measured in HIV-uninfected, age distribution-matched controls (HC; = 30). Associations between T cell markers of exhaustion and senescence and plasma levels of immune mediators were examined by Spearman rank order statistics. Proportions of CD4 T cell subsets expressing markers of exhaustion (PD-1, TIGIT) and senescence (CD57, KLRG-1) were elevated in HIV+ participants. When comparing proportions between INR and IR, INR had higher proportions of CD4 memory PD-1+, EM CD57+, TEM TIGIT+ and CD8 EM and TEM TIGIT+ cells. Plasma levels of IL-6, IP10, and sCD14 were elevated during HIV infection. IP10 was higher in INR. Plasma TGF-β levels and CD4 cycling proportions of T regulatory cells were lower in INR. Proportions of CD4 T cells expressing TIGIT, PD-1, and CD57 positively correlated with plasma levels of IL-6. Plasma levels of TGF-β negatively correlated with proportions of TIGIT+ and PD-1+ T cell subsets. INR have lower levels of TGF-β and decreased proportions of cycling CD4 T regulatory cells and may have difficulty controlling inflammation. IP10 is elevated in INR and is linked to higher proportions of T cell exhaustion and senescence seen in INR.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fimmu.2021.638010DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8044907PMC
March 2021

Probing the Interface of HIV and Inflammaging.

Curr HIV/AIDS Rep 2021 Jun 11;18(3):198-210. Epub 2021 Mar 11.

Department of Medicine, Division of Infectious Diseases and HIV Medicine, Case Western Reserve School of Medicine, Cleveland, OH, 44106, USA.

Purpose Of Review: Systemic inflammation increases as a consequence of aging (inflammaging) and contributes to age-related morbidities. Inflammation in people living with HIV is elevated compared with the general population even after prolonged suppression of viremia with anti-retroviral therapy. Mechanisms that contribute to inflammation during aging and in treated HIV disease are potentially interactive, leading to an exaggerated inflammatory phenotype in people with HIV.

Recent Findings: Recent studies highlight roles for anti-retroviral therapy, co-infections, immune system alterations, and microbiome perturbations as important contributors to HIV-associated inflammation. These factors likely contribute to increased risk of age-related morbidities in people living with HIV. Understanding mechanisms that exaggerate the inflammaging process in people with HIV may lead to improved intervention strategies, ultimately, extending both lifespan and healthspan.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1007/s11904-021-00547-0DOI Listing
June 2021

Hepatitis C Virus (HCV) Direct-Acting Antiviral Therapy in Persons With Human Immunodeficiency Virus-HCV Genotype 1 Coinfection Resulting in High Rate of Sustained Virologic Response and Variable in Normalization of Soluble Markers of Immune Activation.

J Infect Dis 2020 09;222(8):1334-1344

University of Colorado School of Medicine, Denver, Colorado, USA.

Background: Hepatitis C virus (HCV) direct-acting antivirals are highly effective. Less is known about changes in markers of immune activation in persons with human immunodeficiency virus (HIV) in whom a sustained virologic response (SVR) is achieved.

Methods: We conducted a nonrandomized clinical trial of 12 or 24 weeks of paritaprevir-ritonavir-ombitasvir plus dasabuvir (PrOD) with or without ribavirin in persons with HCV-1/HIV coinfection suppressed with antiretroviral therapy. Plasma HCV, soluble CD14 (sCD14), interferon-inducible protein 10, soluble CD163 (sCD163), interleukin 6 (IL-6), interleukin 18, monocyte chemoattractant protein (MCP-1), autotaxin (ATX), and Mac2-binding protein (Mac2BP) were measured over 48 weeks.

Results: Participants were treated with PrOD for 12 (n = 9) or 24 (n = 36) weeks; the SVR rate at 12 weeks was 93%. At baseline, cirrhosis was associated with higher ATX and MCP-1, female sex with higher ATX and IL-6, older age with higher Mac2BP, higher body mass index with higher ATX, and HIV-1 protease inhibitor use with higher sCD14 levels. In those with SVR, interferon-inducible protein 10, ATX, and Mac2BP levels declined by week 2, interleukin 18 levels declined by the end of treatment, sCD14 levels did not change, and sCD163, MCP-1, and IL-6 levels changed at a single time point.

Conclusions: During HIV/HCV coinfection, plasma immune activation marker heterogeneity is in part attributable to age, sex, cirrhosis, body mass index, and/or type of antiretroviral therapy. HCV treatment with paritaprevir-ritonavir-ombitasvir plus dasabuvir is highly effective and is associated with variable rate and magnitude of decline in markers of immune activation.

Clinical Trials Registration: NCT02194998.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/infdis/jiaa254DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7749191PMC
September 2020

Inflammescent CX3CR1+CD57+CD8+ T cells are generated and expanded by IL-15.

JCI Insight 2020 06 4;5(11). Epub 2020 Jun 4.

Center for AIDS Research, Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University/University Hospitals Cleveland Medical Center, Cleveland, Ohio, USA.

HIV infection is associated with an increase in the proportion of activated CD8+ memory T cells (Tmem) that express CX3CR1, but how these cells are generated and maintained in vivo is unclear. We demonstrate that increased CX3CR1 expression on CD8+ Tmem in people living with HIV (PLWH) is dependent on coinfection with human CMV, and CX3CR1+CD8+ Tmem are enriched for a putatively immunosenescent CD57+CD28- phenotype. The cytokine IL-15 promotes the phenotype, survival, and proliferation of CX3CR1+CD57+CD8+ Tmem in vitro, whereas T cell receptor stimulation leads to their death. IL-15-driven survival is dependent on STAT5 and Bcl-2 activity, and IL-15-induced proliferation requires STAT5 and mTORC1. Thus, we identify mechanistic pathways that could explain how "inflammescent" CX3CR1+CD57+ CD8+ Tmem dominate the overall memory T cell pool in CMV-seropositive PLWH and that support reevaluation of immune senescence as a nonproliferative dead end.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1172/jci.insight.132963DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7346586PMC
June 2020

Cytomegalovirus Coinfection Is Associated with Increased Vascular-Homing CD57 CD4 T Cells in HIV Infection.

J Immunol 2020 05 30;204(10):2722-2733. Epub 2020 Mar 30.

Center for AIDS Research, Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University/University Hospitals Cleveland Medical Center, Cleveland, OH 44106;

Cytotoxic CD4 T cells are linked to cardiovascular morbidities and accumulate in both HIV and CMV infections, both of which are associated with increased risk of cardiovascular disease (CVD). In this study, we identify CMV coinfection as a major driver of the cytotoxic phenotype, characterized by elevated CD57 expression and reduced CD28 expression, in circulating CD4 T cells from people living with HIV infection, and investigate potential mechanisms linking this cell population to CVD. We find that human CD57 CD4 T cells express high levels of the costimulatory receptor CD2 and that CD2/LFA-3 costimulation results in a more robust and polyfunctional effector response to TCR signals, compared with CD28-mediated costimulation. CD57 CD4 T cells also express the vascular endothelium-homing receptor CX3CR1 and migrate toward CX3CL1-expressing endothelial cells in vitro. IL-15 promotes the cytotoxic phenotype, elevates CX3CR1 expression, and enhances the trafficking of CD57 CD4 T cells to endothelium and may therefore be important in linking these cells to cardiovascular complications. Finally, we demonstrate the presence of activated CD57 CD4 T cells and expression of CX3CL1 and LFA-3 in atherosclerotic plaque tissues from HIV-uninfected donors. Our findings are consistent with a model in which cytotoxic CD4 T cells contribute to CVD in HIV/CMV coinfection and in atherosclerosis via CX3CR1-mediated trafficking and CD2/LFA-3-mediated costimulation. This study identifies several targets for therapeutic interventions and may help bridge the gap in understanding how CMV infection and immunity are linked to increased cardiovascular risk in people living with HIV infection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4049/jimmunol.1900734DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7315224PMC
May 2020

Elevated Autotaxin and LPA Levels During Chronic Viral Hepatitis and Hepatocellular Carcinoma Associate with Systemic Immune Activation.

Cancers (Basel) 2019 Nov 25;11(12). Epub 2019 Nov 25.

²The Louis Stokes VA medical Center, Cleveland, 44106, USA.

Circulating autotaxin (ATX) is elevated in persons with liver disease, particularly in the setting of chronic hepatitis C virus (HCV) and HCV/HIV infection. It is thought that plasma ATX levels are, in part, attributable to impaired liver clearance that is secondary to fibrotic liver disease. In a discovery data set, we identified plasma ATX to be associated with parameters of systemic immune activation during chronic HCV and HCV/HIV infection. We and others have observed a partial normalization of ATX levels within months of starting interferon-free direct-acting antiviral (DAA) HCV therapy, consistent with a non-fibrotic liver disease contribution to elevated ATX levels, or HCV-mediated hepatocyte activation. Relationships between ATX, lysophosphatidic acid (LPA) and parameters of systemic immune activation will be discussed in the context of HCV infection, age, immune health, liver health, and hepatocellular carcinoma (HCC).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3390/cancers11121867DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6966516PMC
November 2019

Soluble Markers of Immune Activation Differentially Normalize and Selectively Associate with Improvement in AST, ALT, Albumin, and Transient Elastography During IFN-Free HCV Therapy.

Pathog Immun 2018 Sep;3(1):149-163

The Louis Stokes VA Medical Center, Cleveland, Ohio.

Background: During chronic hepatitis C virus (HCV) infection, Aspartate Aminotransferase (AST) and Alanine Aminotransferase (ALT) levels mark active liver inflammation and tissue damage, while albumin reflects synthetic liver function and nutritional status. Transient Elastography (TE) is a clinical measure of liver stiffness that facilitates evaluation of liver damage stage. While a portion of the TE score is attributable to liver fibrosis and relatively irreversible damage, another component of the TE score is attributable to liver inflammation or edema. Markers of inflammation during chronic HCV infection include soluble markers of immune activation, which are also associated with morbid outcome (including cardiovascular disease and liver-disease progression). Whether soluble markers of immune activation or changes in their level during HCV therapy relate to normalization of AST, ALT, Albumin, or TE score, is not clear.

Methods: We evaluated soluble markers of immune activation (plasma sCD14, IL-6, sCD163, autotaxin [ATX], and Mac2BP) and TE score, and their relationship in 20 HCV-infected patients before, during, and after HCV-directed IFN-free direct-acting antiviral (DAA) therapy. We evaluated normalization of parameters and the relationship between each over a 6-month window.

Results: Before therapy, serum AST levels positively correlated with plasma levels of sCD14, sCD163, and Mac2BP, while ALT levels positively correlated with Mac2BP. Serum albumin level negatively correlated with plasma IL-6 and ATX levels. IFN-free therapy uniformly resulted in sustained virological response at 12 and 24 weeks after therapy completion. After initiation of therapy AST and ALT normalized, while levels of ATX, Mac2BP, sCD163, and TE score partially normalized over 6 months. Additionally, change in AST level and APRI score correlated with change in sCD163, IL-6, and Mac2BP levels, and change in ALT correlated with change in IL-6 and Mac2BP levels. Improvement in TE score correlated with a decrease in the level of sCD14 at week 4, and almost statistically significant with decrease in sCD14 at weeks 20-24 after initiation of IFN-free HCV therapy.

Conclusions: Soluble markers of immune activation normalize or partially normalize at different rates after initiation of curative HCV DAA therapy, and TE scores improve, with wide variability in the degree of absolute improvement in liver stiffness from patient to patient. Decline magnitude of sCD14 was associated with improvement in TE score, while magnitude of improvement in AST correlated with reduction in sCD163 levels. These data provide support for a model where monocyte/Kupffer cell activation may account for a portion of the liver inflammation and edema, which is at least partially reversible following initiation of HCV DAA therapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.20411/pai.v3i1.242DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6201254PMC
September 2018

Cycling CD4+ T cells in HIV-infected immune nonresponders have mitochondrial dysfunction.

J Clin Invest 2018 11 15;128(11):5083-5094. Epub 2018 Oct 15.

Division of Infectious Disease and.

Immune nonresponder (INR) HIV-1-infected subjects are characterized by their inability to reconstitute the CD4+ T cell pool after antiretroviral therapy. This is linked to poor clinical outcome. Mechanisms underlying immune reconstitution failure are poorly understood, although, counterintuitively, INRs often have increased frequencies of circulating CD4+ T cells in the cell cycle. While cycling CD4+ T cells from healthy controls and HIV+ patients with restored CD4+ T cell numbers complete cell division in vitro, cycling CD4+ T cells from INRs do not. Here, we show that cells with the phenotype and transcriptional profile of Tregs were enriched among cycling cells in health and in HIV infection. Yet there were diminished frequencies and numbers of Tregs among cycling CD4+ T cells in INRs, and cycling CD4+ T cells from INR subjects displayed transcriptional profiles associated with the impaired development and maintenance of functional Tregs. Flow cytometric assessment of TGF-β activity confirmed the dysfunction of Tregs in INR subjects. Transcriptional profiling and flow cytometry revealed diminished mitochondrial fitness in Tregs among INRs, and cycling Tregs from INRs had low expression of the mitochondrial biogenesis regulators peroxisome proliferator-activated receptor γ coactivator 1-α (PGC1α) and transcription factor A for mitochondria (TFAM). In vitro exposure to IL-15 allowed cells to complete division, restored the expression of PGC1α and TFAM, and regenerated mitochondrial fitness in the cycling Tregs of INRs. Our data suggest that rescuing mitochondrial function could correct the immune dysfunction characteristic of Tregs in HIV-1-infected subjects who fail to restore CD4+ T cells during antiretroviral therapy.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1172/JCI120245DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6205369PMC
November 2018

Pre-vaccine plasma levels of soluble inflammatory indices negatively predict responses to HAV, HBV, and tetanus vaccines in HCV and HIV infection.

Vaccine 2018 01 16;36(4):453-460. Epub 2017 Dec 16.

The Louis Stokes VA Medical Center, Cleveland, OH, USA; Department of Medicine, University Hospitals Medical Center, and the Center for AIDS Research, Case Western Reserve University, Cleveland, OH, USA. Electronic address:

Background: Chronic hepatitis C virus (HCV) and HIV infections are associated with impaired responses to neo-antigens contained in hepatitis A virus (HAV)/hepatitis B virus (HBV) vaccines, yet responsible mechanisms are unclear.

Methods: ACTG 5232 and CFAR0910 were clinical trials where pre-vaccine levels of plasma IP10, IL-6, sCD163 and sCD14 were measured in viremic HCV- (n = 15) or HIV-infected participants (n = 24) and uninfected controls (n = 10). Accelerated dosing HAV/HBV vaccine and tetanus booster were administered and antibody response was measured at 0, 1, 3, 8, and 24 weeks.

Results: Pre-vaccine plasma IP10, IL-6, and sCD14 levels were elevated in both HCV and HIV-infected participants, while sCD163 was also elevated in HCV-infected participants. Pre-immunization tetanus antibody levels were lower in HIV-infected than in uninfected participants, while vaccine induced antibody responses were intact in HCV and HIV-infected participants. After HAV/HBV vaccination, HCV and HIV-infected participants had lower and less durable HAV and HBV antibody responses than uninfected controls. Among HCV-infected participants, pre-vaccine plasma IP10, IL-6, sCD14, and sCD163 levels inversely correlated with HAV, HBV and tetanus antibody responses after vaccine. Low HAV/HBV vaccine responses in HIV-infected participants prohibited assessment of immune correlates.

Conclusions: During HCV and HIV infection markers of systemic inflammation reflect immune dysfunction as demonstrated by poor response to HAV/HBV neo-antigen vaccine.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.vaccine.2017.12.018DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5767517PMC
January 2018

Cytokines and T-Cell Homeostasis in HIV Infection.

J Infect Dis 2016 Oct;214 Suppl 2:S51-7

Center for AIDS Research, Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University, University Hospitals/Case Medical Center.

Untreated human immunodeficiency virus (HIV) infection is characterized by progressive CD4(+) T-cell depletion and CD8(+) T-cell expansion, and CD4(+) T-cell depletion is linked directly to the risk for opportunistic infections and infection-associated mortality. With suppression of HIV replication by antiretroviral therapy, circulating CD4(+) Tcell numbers typically improve while CD8(+) T-cell expansion persists, and both CD4(+) T-cell cytopenia and CD8(+) T-cell expansion are associated with morbidity and mortality. In this brief review, we report on the role that selected homeostatic and inflammatory cytokines may play both in the failure of CD4(+) T-cell restoration and the CD8(+) T-cell expansion that characterize HIV infection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/infdis/jiw287DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6373575PMC
October 2016

During Hepatitis C Virus (HCV) Infection and HCV-HIV Coinfection, an Elevated Plasma Level of Autotaxin Is Associated With Lysophosphatidic Acid and Markers of Immune Activation That Normalize During Interferon-Free HCV Therapy.

J Infect Dis 2016 Nov 17;214(9):1438-1448. Epub 2016 Aug 17.

Department of Medicine.

Background:  Immune activation predicts morbidity during hepatitis C virus (HCV) infection and human immunodeficiency virus (HIV) infection, although mechanisms underlying immune activation are unclear. Plasma levels of autotaxin and its enzymatic product, lysophosphatidic acid (LPA), are elevated during HCV infection, and LPA activates immunocytes, but whether this contributes to immune activation is unknown.

Methods:  We evaluated plasma levels of autotaxin, interleukin 6 (IL-6), soluble CD14 (sCD14), soluble CD163 (sCD163), and Mac2 binding protein (Mac2BP) during HCV infection, HIV infection, and HCV-HIV coinfection, as well as in uninfected controls, before and after HIV antiretroviral therapy (ART) initiation and during interferon-free HCV therapy.

Results:  We observed greater plasma autotaxin levels in HCV-infected and HCV-HIV-coinfected participants, compared with uninfected participants, primarily those with a higher ratio of aspartate aminotransferase level to platelet count. Autotaxin levels correlated with IL-6, sCD14, sCD163, Mac2BP, and LPA levels in HCV-infected participants and with Mac2BP levels in HCV-HIV-coinfected participants, while in HIV-infected individuals, sCD14 levels correlated with Mac2BP levels. Autotaxin, LPA, and sCD14 levels normalized, while sCD163 and Mac2BP levels partially normalized within 6 months of starting interferon-free HCV therapy. sCD163 and IL-6 levels normalized within 6 months of starting ART for HIV infection. In vitro, LPA activated monocytes.

Conclusions:  These data indicate that elevated levels of autotaxin and soluble markers of immune activation during HCV infection are partially reversible within 6 months of initiating interferon-free HCV treatment and that autotaxin may be causally linked to immune activation during HCV infection and HCV-HIV coinfection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/infdis/jiw372DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6281372PMC
November 2016

IL-15 promotes activation and expansion of CD8+ T cells in HIV-1 infection.

J Clin Invest 2016 07 20;126(7):2745-56. Epub 2016 Jun 20.

In HIV-1-infected patients, increased numbers of circulating CD8+ T cells are linked to increased risk of morbidity and mortality. Here, we identified a bystander mechanism that promotes CD8 T cell activation and expansion in untreated HIV-1-infected patients. Compared with healthy controls, untreated HIV-1-infected patients have an increased population of proliferating, granzyme B+, CD8+ T cells in circulation. Vβ expression and deep sequencing of CDR3 revealed that in untreated HIV-1 infection, cycling memory CD8 T cells possess a broad T cell repertoire that reflects the repertoire of the resting population. This suggests that cycling is driven by bystander activation, rather than specific antigen exposure. Treatment of peripheral blood mononuclear cells with IL-15 induced a cycling, granzyme B+ phenotype in CD8+ T cells. Moreover, elevated IL-15 expression in the lymph nodes of untreated HIV-1-infected patients correlated with circulating CD8+ T cell counts and was normalized in these patients following antiretroviral therapy. Together, these results suggest that IL-15 drives bystander activation of CD8+ T cells, which predicts disease progression in untreated HIV-1-infected patients and suggests that elevated IL-15 may also drive CD8+ T cell expansion that is linked to increased morbidity and mortality in treated patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1172/JCI85996DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4922693PMC
July 2016

Reply to Barrett, et al.

Clin Infect Dis 2016 06 21;62(11):1468-9. Epub 2016 Mar 21.

Department of Medicine, Division of Infectious Diseases and HIV Medicine, Center for AIDS Research, Case Western Reserve University/University Hospitals Case Medical Center, Cleveland, Ohio.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/cid/ciw152DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5006408PMC
June 2016

Inflammation Perturbs the IL-7 Axis, Promoting Senescence and Exhaustion that Broadly Characterize Immune Failure in Treated HIV Infection.

J Acquir Immune Defic Syndr 2016 Apr;71(5):483-92

*Department of Medicine, Division of Infectious Diseases, Center for AIDS Research, Case Western Reserve University, Cleveland, OH; †National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD; ‡School of Health and Rehabilitation Sciences, The Ohio State University, Columbus, OH; §University Hospitals Case Medical Center, Cleveland, OH; and ‖Cleveland Clinic Foundation, Cleveland, OH.

Background: HIV-infected patients who fail to normalize CD4 T cells despite suppressive antiretroviral therapy have impaired immune homeostasis: diminished naive T-cell numbers, elevated T-cell turnover, senescence, and inflammation.

Methods: Blood samples from immune failures (n = 60), immune successes (n = 20), and healthy controls (n = 20) were examined for plasma interleukin (IL)-7 levels, for cellular expression of the IL-7Rα chain (CD127), for the exhaustion and senescence markers programed death 1 (PD-1) and CD57, and for the survival factor Bcl2. Because both inflammatory and homeostatic cytokines can induce T-cell cycling, we also examined the effects of these mediators on exhaustion and senescence markers.

Results: Plasma levels of IL-7 were elevated and both CD4 and CD8 T-cell CD127 expression was decreased in immune failure. Plasma levels of IL-7 correlated directly with naive CD4 T-cell counts in immune success and inversely with T-cell cycling (Ki67) in healthy controls and immune success, but not in immune failure. CD4 T-cell density of PD-1 was increased and Bcl2+ CD4 T cells were decreased in immune failure but not in immune success, whereas the proportion of T cells expressing CD57 was increased in immune failure. PD-1 and CD57 were induced on CD4 but not CD8 T cells by stimulation in vitro with inflammatory IL-1β or homeostatic (IL-7) cytokines.

Conclusions: Perturbation of the IL-7/IL-7 receptor axis, increased T-cell turnover, and increased senescence may reflect dysregulated responses to both homeostatic and inflammatory cytokines in immune failure patients.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/QAI.0000000000000913DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4788576PMC
April 2016

CD8 T-Cell Expansion and Inflammation Linked to CMV Coinfection in ART-treated HIV Infection.

Clin Infect Dis 2016 Feb 23;62(3):392-6. Epub 2015 Sep 23.

Center for AIDS Research, Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University/University Hospitals Case Medical Center.

Background: Persistent CD8 T-cell expansion, low CD4/CD8 T-cell ratios, and heightened inflammation persist in antiretroviral therapy (ART)-treated human immunodeficiency virus (HIV) infection and are associated with increased risk of morbid outcomes. We explored the role of cytomegalovirus (CMV) infection in CD8 lymphocytosis and inflammation in ART-treated HIV infection.

Methods: Absolute CD4 and CD8 T-cell counts were abstracted from clinical records and compared among 32 HIV-infected CMV-seronegative subjects, 126 age, CD4 and gender-matched HIV-infected CMV-seropositive subjects, and among 21 HIV-uninfected controls (9 CMV-negative, 12 CMV-positive). Plasma inflammatory indices were measured in a subset by ELISA.

Results: Median CD8 counts/µL were higher in HIV-positive/CMV-positive patients (795) than in HIV-positive/CMV-negative subjects (522, P = .006) or in healthy controls (451, P = .0007), whereas CD8 T-cell counts were similar to controls' levels in HIV-positive/CMV-negative subjects. Higher plasma levels of IP-10 (P = .0011), TNF-RII (P = .0002), and D-dimer (P = .0444) were also found in coinfected patients than in HIV-positive/CMV-negative subjects.

Conclusions: CMV infection is associated with higher CD8 T-cell counts, resultant lower CD4/CD8 ratios, and increased systemic inflammation in ART-treated HIV infection. CMV infection may contribute to risk for morbid outcomes in treated HIV infection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/cid/civ840DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4706630PMC
February 2016

Soluble CD14 is a nonspecific marker of monocyte activation.

AIDS 2015 Jun;29(10):1263-5

aCenter for AIDS Research, Case Western Reserve University School of Medicine, Cleveland, Ohio bDepartment of Microbiology and Immunology, Division of Infectious Diseases, Medical University of South Carolina, Charleston, South Carolina cVeterans Administration Medical Center, Cleveland, Ohio, USA.

Soluble CD14 is associated with morbidity and mortality in HIV disease. It is a co-receptor for lipopolysaccharide (LPS) that is released from monocytes upon activation. We demonstrate here, that inflammatory cytokines can induce the release of sCD14 in peripheral blood mononuclear cell cultures from healthy donors, and that TLR ligands other than LPS can cause a decrease in the monocyte cell surface expression of CD14. Thus, sCD14 is a marker of monocyte activation, not restricted to activation by LPS.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/QAD.0000000000000735DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4452959PMC
June 2015

Gut epithelial barrier dysfunction and innate immune activation predict mortality in treated HIV infection.

J Infect Dis 2014 Oct 21;210(8):1228-38. Epub 2014 Apr 21.

Department of Medicine, Case Western Reserve University, Cleveland, Ohio.

Background: While inflammation predicts mortality in treated human immunodeficiency virus (HIV) infection, the prognostic significance of gut barrier dysfunction and phenotypic T-cell markers remains unclear.

Methods: We assessed immunologic predictors of mortality in a case-control study within the Longitudinal Study of the Ocular Complications of AIDS (LSOCA), using conditional logistic regression. Sixty-four case patients who died within 12 months of treatment-mediated viral suppression were each matched to 2 control individuals (total number of controls, 128) by duration of antiretroviral therapy-mediated viral suppression, nadir CD4(+) T-cell count, age, sex, and prior cytomegalovirus (CMV) retinitis. A similar secondary analysis was conducted in the SCOPE cohort, which had participants with less advanced immunodeficiency.

Results: Plasma gut epithelial barrier integrity markers (intestinal fatty acid binding protein and zonulin-1 levels), soluble CD14 level, kynurenine/tryptophan ratio, soluble tumor necrosis factor receptor 1 level, high-sensitivity C-reactive protein level, and D-dimer level all strongly predicted mortality, even after adjustment for proximal CD4(+) T-cell count (all P ≤ .001). A higher percentage of CD38(+)HLA-DR(+) cells in the CD8(+) T-cell population was a predictor of mortality before (P = .031) but not after (P = .10) adjustment for proximal CD4(+) T-cell count. Frequencies of senescent (defined as CD28(-)CD57(+) cells), exhausted (defined as PD1(+) cells), naive, and CMV-specific T cells did not predict mortality.

Conclusions: Gut epithelial barrier dysfunction, innate immune activation, inflammation, and coagulation-but not T-cell activation, senescence, and exhaustion-independently predict mortality in individuals with treated HIV infection with a history of AIDS and are viable targets for interventions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/infdis/jiu238DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4192038PMC
October 2014

Inflammatory cytokines drive CD4+ T-cell cycling and impaired responsiveness to interleukin 7: implications for immune failure in HIV disease.

J Infect Dis 2014 Aug 28;210(4):619-29. Epub 2014 Feb 28.

Center for AIDS Research, Case Western Reserve University.

Background: Systemic inflammation has been linked to a failure to normalize CD4(+) T-cell numbers in treated human immunodeficiency virus (HIV) infection. Although inflammatory cytokines such as interleukin 6 (IL-6) are predictors of disease progression in treated HIV infection, it is not clear how or whether inflammatory mediators contribute to immune restoration failure.

Methods: We examined the in vitro effects of IL-6 and interleukin 1β (IL-1β) on peripheral blood T-cell cycling and CD127 surface expression.

Results: The proinflammatory cytokine IL-1β induces cell cycling and turnover of memory CD4(+) T cells, and IL-6 can induce low-level cycling of naive T cells. Both IL-1β and IL-6 can decrease T-cell surface expression and RNA levels of CD127, the interleukin 7 receptor α chain (IL-7Rα). Preexposure of healthy peripheral blood mononuclear cells (PBMCs) to IL-6 or IL-1β attenuates IL-7-induced Stat5 phosphorylation and induction of the prosurvival factor Bcl-2 and the gut homing integrin α4β7. We found elevated expression of IL-1β in the lymphoid tissues of patients with HIV infection that did not normalize with antiretroviral therapy.

Conclusions: Induction of CD4(+) T-cell turnover and diminished T-cell responsiveness to IL-7 by IL-1β and IL-6 exposure may contribute to the lack of CD4(+) T-cell reconstitution in treated HIV-infected subjects.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/infdis/jiu125DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4172041PMC
August 2014

Shared monocyte subset phenotypes in HIV-1 infection and in uninfected subjects with acute coronary syndrome.

Blood 2012 Nov 11;120(23):4599-608. Epub 2012 Oct 11.

Department of Medicine, Division of Infectious Diseases, Case Western Reserve University/University Hospitals of Cleveland, Cleveland, OH 44106, USA.

The mechanisms responsible for increased cardiovascular risk associated with HIV-1 infection are incompletely defined. Using flow cytometry, in the present study, we examined activation phenotypes of monocyte subpopulations in patients with HIV-1 infection or acute coronary syndrome to find common cellular profiles. Nonclassic (CD14(+)CD16(++)) and intermediate (CD14(++)CD16(+)) monocytes are proportionally increased and express high levels of tissue factor and CD62P in HIV-1 infection. These proportions are related to viremia, T-cell activation, and plasma levels of IL-6. In vitro exposure of whole blood samples from uninfected control donors to lipopolysaccharide increased surface tissue factor expression on all monocyte subsets, but exposure to HIV-1 resulted in activation only of nonclassic monocytes. Remarkably, the profile of monocyte activation in uncontrolled HIV-1 disease mirrors that of acute coronary syndrome in uninfected persons. Therefore, drivers of immune activation and inflammation in HIV-1 disease may alter monocyte subpopulations and activation phenotype, contributing to a pro-atherothrombotic state that may drive cardiovascular risk in HIV-1 infection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1182/blood-2012-05-433946DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3512236PMC
November 2012

HIV-1 is not a major driver of increased plasma IL-6 levels in chronic HIV-1 disease.

J Acquir Immune Defic Syndr 2012 Oct;61(2):145-52

Division of Infectious Diseases, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.

Objective: Increased plasma IL-6 levels have been associated with HIV-1 disease progression risk, yet the drivers of IL-6 production in HIV-1 infection are not known. This study was designed to explore the relationship between HIV-1 replication and IL-6 induction.

Design: Correlations between plasma levels of IL-6 and HIV-1 RNA were examined in 2 clinical studies. To more directly assess the induction of IL-6 by HIV-1, several cell and tissue types that support HIV-1 replication in vivo were infected with HIV-1, and expression of IL-6 was measured.

Methods: Spearman rank correlations were used to examine the relationship between plasma levels of IL-6 and HIV-1 RNA. Macrophages and colonic and lymph node histocultures were infected with HIV-1 or stimulated with bacterial products, lipopolysaccharide (LPS) or flagellin, and IL-6 levels in supernatant were measured by enzyme-linked immunosorbent assay or multiplex bead assay.

Results: In the clinical studies, there was weak or no correlation between plasma levels of IL-6 and HIV-1 RNA, but IL-6 levels were correlated with plasma levels of the LPS coreceptor CD14. Macrophages stimulated with LPS or flagellin showed robust production of IL-6, but there was no increase in IL-6 production after HIV-1 infection. IL-6 expression was not increased in lymph node histocultures obtained from HIV-1-infected subjects nor after productive HIV-1 infection of colonic or lymph node histocultures ex vivo.

Conclusions: We find no evidence that HIV-1 replication is an important driver of IL-6 expression in vivo or in in vitro systems.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1097/QAI.0b013e31825ddbbfDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3458159PMC
October 2012

Immunologic failure despite suppressive antiretroviral therapy is related to activation and turnover of memory CD4 cells.

J Infect Dis 2011 Oct;204(8):1217-26

Division of Infectious Diseases, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA.

Background: Failure to normalize CD4(+) T-cell numbers despite effective antiretroviral therapy is an important problem in human immunodeficiency virus (HIV) infection.

Methods: To evaluate potential determinants of immune failure in this setting, we performed a comprehensive immunophenotypic characterization of patients with immune failure despite HIV suppression, persons who experienced CD4(+) T-cell restoration with therapy, and healthy controls.

Results: Profound depletion of all CD4(+) T-cell maturation subsets and depletion of naive CD8(+) T cells was found in immune failure, implying failure of T-cell production/expansion. In immune failure, both CD4(+) and CD8(+) cells were activated but only memory CD4(+) cells were cycling at increased frequency. This may be the consequence of inflammation induced by in vivo exposure to microbial products, as soluble levels of the endotoxin receptor CD14(+) and interleukin 6 were elevated in immune failure. In multivariate analyses, naive T-cell depletion, phenotypic activation (CD38(+) and HLA-DR expression), cycling of memory CD4(+) T cells, and levels of soluble CD14 (sCD14) distinguished immune failure from immune success, even when adjusted for CD4(+) T-cell nadir, age at treatment initiation, and other clinical indices.

Conclusions: Immune activation that appears related to exposure to microbial elements distinguishes immune failure from immune success in treated HIV infection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/infdis/jir507DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3218674PMC
October 2011

TLR4 and TLR5 on corneal macrophages regulate Pseudomonas aeruginosa keratitis by signaling through MyD88-dependent and -independent pathways.

J Immunol 2010 Oct 8;185(7):4272-83. Epub 2010 Sep 8.

Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, OH 44106, USA.

Pseudomonas aeruginosa is a major cause of blindness and visual impairment in the United States and worldwide. Using a murine model of keratitis in which abraded corneas are infected with P. aeruginosa parent and ΔfliC (aflagellar) strains 19660 and PAO1, we found that F4/80(+) macrophages were the predominant cell type in the cornea expressing TLR2, TLR4, and TLR5. Depletion of macrophages and dendritic cells using transgenic Mafia mice, in which Fas ligand is selectively activated in these cells, resulted in diminished cytokine production and cellular infiltration to the corneal stroma and unimpaired bacterial growth. TLR4(-/-) mice showed a similar phenotype postinfection with ΔfliC strains, whereas TLR4/5(-/-) mice were susceptible to corneal infection with parent strains. Bone marrow-derived macrophages stimulated with ΔfliC bacteria induced Toll/IL-1R intracellular domain (TIR)-containing adaptor inducing IFN-β (TRIF)-dependent phosphorylation of IFN regulatory factor 3 in addition to TIR-containing adaptor protein/MyD88-dependent phosphorylation of IκB and nuclear translocation of the p65 subunit of NFκB. Furthermore, TRIF(-/-) mice showed a similar phenotype as TLR4(-/-) mice in regulating only ΔfliC bacteria, whereas MyD88(-/-) mice were unable to clear parent or ΔfliC bacteria. Finally, IL-1R1(-/-) and IL-1α/β(-/-) mice were highly susceptible to infection. Taken together, these findings indicate that P. aeruginosa activates TLR4/5 on resident corneal macrophages, which signal through TRIF and TIR-containing adaptor protein/MyD88 pathways, leading to NF-κB translocation to the nucleus, transcription of CXCL1 and other CXC chemokines, recruitment of neutrophils to the corneal stroma, and subsequent bacterial killing and tissue damage. IL-1α and IL-1β are also produced, which activate an IL-1R1/MyD88-positive feedback loop in macrophages and IL-1R on other resident cells in the cornea.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4049/jimmunol.1000874DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3392180PMC
October 2010

Increased per cell IFN-gamma productivity indicates recent in vivo activation of T cells.

Cell Immunol 2009 8;258(2):131-7. Epub 2009 May 8.

Department of Pathology, Case Western Reserve University, Cleveland, OH 44106, USA.

Immunization with vaccinia virus causes long-term immunity. Efforts have been made to characterize the T cells responsible for this protection. Recently, T cell subsets were described that not only co-express multiple cytokines, but also show increased per cell cytokine productivity. These highly productive cells are often considered to be the most protective. We used ELISPOT assays to measure per cell IFN-gamma productivity of vaccinia-specific T cells in childhood immunized adults immediately before and at different time points after vaccinia re-vaccination. Apart from an increase in frequency, we found a marked increase of IFN-gamma productivity following vaccinia re-vaccination. However, these changes were short-lived as both parameters quickly returned to baseline values within 22days after re-vaccination. Therefore, increased per cell IFN-gamma productivity seems to be a sign of recent in vivo T cell activation rather than a stable marker of a distinct T cell subset responsible for long-term immune protection.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cellimm.2009.04.002DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2706289PMC
August 2009

Granzyme B production distinguishes recently activated CD8(+) memory cells from resting memory cells.

Cell Immunol 2007 May 7;247(1):36-48. Epub 2007 Sep 7.

Department of Pathology, Case Western Reserve University, Cleveland, OH 44106, USA.

For immune diagnostic purposes it would be critical to be able to distinguish between ongoing immune processes, such as active infections, and long-term immune memory, for example imprinted by infections that have been cleared a long time ago or by vaccinations. We tested the hypothesis that the secretion of granzyme B, as detected in ex vivo ELISPOT assays, permits this distinction. We studied EBV-, flu- and CMV-specific CD8(+) cells in healthy individuals, Vaccinia virus-reactive CD8(+) cells in the course of vaccination, and HIV-specific CD8(+) cells in HIV-infected individuals. Antigen-specific ex vivo GzB production was detected only transiently after Vaccinia immunization, and in HIV-infected individuals. Our data suggest that ex vivo ELISPOT measurements of granzyme B permit the identification of actively ongoing CD8(+) cell responses-a notion that is pertinent to the immune diagnostic of infections, transplantation, allergies, autoimmune diseases, tumors and vaccine development.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cellimm.2007.07.004DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2134935PMC
May 2007

Neonatal induction of myelin-specific Th1/Th17 immunity does not result in experimental autoimmune encephalomyelitis and can protect against the disease in adulthood.

J Neuroimmunol 2007 Jul 4;187(1-2):20-30. Epub 2007 May 4.

Institute of Pathology, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA.

The neonatal immune system is believed to be biased towards T helper type 2 (Th2) immunity, but under certain conditions neonates can also develop Th1 immune responses. Neonatal Th2 immunity to myelin antigens is not pathogenic and can prevent induction of experimental autoimmune encephalomyelitis (EAE) in adulthood, but the consequences of neonatally induced Th1 immunity to self-antigens have remained unresolved. Here, we show that neonatal injection of mice with myelin antigens emulsified in complete Freund's adjuvant (CFA) induced vigorous production of IFN-gamma and IL-17, but not IL-5, consistent with myelin-specific Th1/Th17 immunity. Importantly, the myelin-specific Th1/Th17 cells persisted in the mice until adulthood without causing symptoms of EAE. Intraperitoneal, but not subcutaneous injection of neonates with myelin antigens protected against induction of EAE as adults. Intraperitoneally injected neonates showed a substantial decrease of the number and avidity of myelin-reactive Th17 cells, suggesting a decrease in IL-17 producing precursor cells as the mechanism of protection from EAE upon re-injection with myelin antigens as adults. The results could provide a rationale for the presence of autoreactive T cells found in healthy human individuals without autoimmune disease.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.jneuroim.2007.04.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3204791PMC
July 2007

Immunogenicity of unprocessed and photooxidized bovine and human osteochondral grafts in collagen-sensitive mice.

BMC Musculoskelet Disord 2006 Mar 17;7:32. Epub 2006 Mar 17.

Ohio College of Podiatric Medicine, Cleveland, Ohio 44106, USA.

Background: Autologous and allogeneic osteochondral grafts have been used to repair damaged or diseased cartilage. There are drawbacks to both of these methods, however. Another possible source for osteochondral grafting is photooxidized xenograft scaffolds. The purpose of this study was to evaluate the adaptive immune response to unprocessed and photooxidized xenogeneic osteochondral grafts in a collagen-sensitive mouse model.

Methods: Unprocessed and photooxidized bovine and human osteochondral grafts were used. The grafts were implanted subcutaneously in collagen-sensitive DBA/1LacJ mice for four or twelve weeks. ELISPOT assays were conducted with spleen cells to evaluate the number of collagen-specific T cells that produce IL-2, IL-4, IL-5 or IFN-gamma. Serum was collected and ELISA assays were performed to determine the titers of collagen-specific and total IgG, IgG1, IgG2a, or IgM antibodies. Histology was conducted on the retrieved osteochondral grafts.

Results: Results indicated that, with respect to adaptive T cell immunity, the photooxidized bovine grafts, unprocessed human grafts and photooxidized human grafts did not induce a significant response to collagen. The unprocessed bovine grafts, however, were slightly more immunogenic, inducing a weak immune response. With respect to antibody production, the bovine grafts were less immunogenic than the human grafts. Bovine collagen-specific IgG antibodies were not induced by these grafts, but production of IgM after twelve weeks was observed with both the unprocessed and photooxidized bovine grafts. In contrast, photooxidized human osteochondral grafts induced IgG1 and IgG2a antibodies, while the unprocessed human grafts did not. Pre-existing human collagen-specific IgM antibodies were present in all mice, including sham-operated negative controls that did not receive an implant. Histological analysis revealed some degree of fibrous encapsulation and inflammatory infiltrations in both bovine and human implants, whether unprocessed or photooxidized.

Conclusion: Both bovine and human cartilage grafts showed weak, but clear immunogenicity in the DBA/1LacJ mice, indicating that immunogenic collagen was still contained in the grafts, even after cleaning and photooxidation. The process of photooxidation is still important in osteochondral grafting, since it stabilizes the surface of the cartilage by cross-linking the collagen fibers, and allows for immediate load bearing and joint resurfacing.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/1471-2474-7-32DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1459156PMC
March 2006

IL-2 absorption affects IFN-gamma and IL-5, but not IL-4 producing memory T cells in double color cytokine ELISPOT assays.

Cell Immunol 2005 Sep 27;237(1):28-36. Epub 2005 Oct 27.

Department of Pathology, Case Western Reserve University, Cleveland, OH 44106, USA, and University Hospital of Ulm, Section of Endocrinology, Germany.

Cytokine assays are gaining increasing importance for human immune monitoring because they reliably detect antigen-specific T cells in primary PBMC, even at low clonal sizes. Double color ELISPOT assays permit the simultaneous visualization of cells producing two different cytokines. Permitting the simultaneous assessment of type 1 and 2 immunity and due to the limited numbers of PBMC available from human study subjects, double color assays should be particularly attractive for clinical trials. Since the performance of double color assays has not yet been validated, we set out to compare them to single color measurements. Testing the recall antigen-induced cytokine response of PBMC, we found that double color assays regularly provided lower numbers of IFN-gamma and IL-5 spots than single color measurements when IL-2 detection was part of the double color assay. We showed that the inhibitory effect resulted from IL-2 absorption and could be overcome by either antibody free preactivation cultures or by inclusion of anti-CD28 antibody. In contrast, the simultaneous detection of IL-2 did not affect the numbers of IL-4 spots. Therefore, unlike IL-2/IL-4 and IFN-gamma/IL-5 assays, IL-2/IFN-gamma, and IL-2/IL-5 assays require compensation for the IL-2 capture to provide accurate numbers for the frequencies of cytokine producing memory T cells.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.cellimm.2005.09.002DOI Listing
September 2005

ERK1-deficient mice show normal T cell effector function and are highly susceptible to experimental autoimmune encephalomyelitis.

J Immunol 2005 Aug;175(4):2374-80

Alzheimer Research Laboratory, Department of Neurosciences, Case Western Reserve University, Cleveland, OH 44106, USA.

T cell activation engages multiple intracellular signaling cascades, including the ERK1/2 (p44/p42) pathway. It has been suggested that ERKs integrate TCR signal strength, and are important for thymocyte development and positive selection. However, the requirement of ERKs for the effector functions of peripheral mature T cells and, specifically, for T cell-mediated autoimmunity has not been established. Moreover, the specific requirements for ERK1 vs ERK2 in T cells have not been resolved. Therefore, we investigated the role of ERK1 in T cell immunity to foreign and self Ags and in the induction of experimental autoimmune encephalomyelitis. The results show that in ERK1-deficient (ERK1-/-) mice, the priming, proliferation, and cytokine secretion of T cells to the self Ag myelin oligodendrocyte glycoprotein peptide 35-55 and to the prototypic foreign Ag OVA are not impaired as compared with wild-type mice. Furthermore, ERK1-/- mice are highly susceptible to experimental autoimmune encephalomyelitis induced with myelin oligodendrocyte glycoprotein peptide 35-55. Finally, thymocyte development and mitogen-induced proliferation were not impaired in ERK1-/- mice on the inbred 129 Sv and C57BL/6 backgrounds. Collectively, the data show that ERK1 is not critical for the function of peripheral T cells in the response to self and foreign Ags and in T cell-mediated autoimmunity, and suggest that its loss can be compensated by ERK2.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.4049/jimmunol.175.4.2374DOI Listing
August 2005