scholarly journals Inactivated Simian Immunodeficiency Virus-Pulsed Autologous Fresh Blood Cells as an Immunotherapy Strategy

2008 ◽  
Vol 83 (3) ◽  
pp. 1501-1510 ◽  
Author(s):  
Rosemarie D. Mason ◽  
Sheilajen Alcantara ◽  
Viv Peut ◽  
Liyen Loh ◽  
Jeffrey D. Lifson ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Simian Immunodeficiency Virus ◽  
Blood Cells ◽  
Mononuclear Cells ◽  
T Cell Responses ◽  
T Cell Epitopes ◽  
Peripheral Blood Mononuclear ◽  
Cell Responses ◽  
Immunodeficiency Virus

ABSTRACT Practical immunotherapies for human immunodeficiency virus infection are needed. We evaluated inactivated simian immunodeficiency virus (SIV) pulsed onto fresh peripheral blood mononuclear cells in 12 pigtail macaques with chronic SIVmac251 infection for T-cell immunogenicity in a randomized cross-over design study. The immunotherapy was safe and convincingly induced high levels of SIV-specific CD4+ T-cell responses (mean, 5.9% ± 1.3% of all CD4+ T cells) and to a lesser extent SIV-specific CD8+ T-cell responses (mean, 0.7% ± 0.4%). Responses were primarily directed toward Gag and less frequently toward Env but not Pol or regulatory/accessory SIV proteins. T-cell responses against Gag were generally broad and polyfunctional, with a mean of 2.7 CD4+ T-cell epitopes mapped per animal and more than half of the SIV Gag-specific CD4+ T cells expressing three or more effector molecules. The immunogenicity was comparable to that found in previous studies of peptide-pulsed blood cells. Despite the high-level immunogenicity, no reduction in viral load was observed in the chronically viremic macaques. This contrasts with our studies of immunization with peptide-pulsed blood cells during early SIV infection in macaques. Future studies of inactivated virus-pulsed blood cell immunotherapy during early infection of patients receiving antiretroviral therapy are warranted.

scholarly journals Increased Loss of CCR5+ CD45RA− CD4+ T Cells in CD8+ Lymphocyte-Depleted Simian Immunodeficiency Virus-Infected Rhesus Monkeys

2008 ◽  
Vol 82 (11) ◽  
pp. 5618-5630 ◽  
Author(s):  
Ronald S. Veazey ◽  
Paula M. Acierno ◽  
Kimberly J. McEvers ◽  
Susanne H. C. Baumeister ◽  
Gabriel J. Foster ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Lymph Nodes ◽  
Simian Immunodeficiency Virus ◽  
Peripheral Blood ◽  
T Cell Responses ◽  
Lymphocyte Depletion ◽  
Cell Responses ◽  
Immunodeficiency Virus ◽  
Siv Infection

ABSTRACT Previously we have shown that CD8+ T cells are critical for containment of simian immunodeficiency virus (SIV) viremia and that rapid and profound depletion of CD4+ T cells occurs in the intestinal tract of acutely infected macaques. To determine the impact of SIV-specific CD8+ T-cell responses on the magnitude of the CD4+ T-cell depletion, we investigated the effect of CD8+ lymphocyte depletion during primary SIV infection on CD4+ T-cell subsets and function in peripheral blood, lymph nodes, and intestinal tissues. In peripheral blood, CD8+ lymphocyte-depletion changed the dynamics of CD4+ T-cell loss, resulting in a more pronounced loss 2 weeks after infection, followed by a temporal rebound approximately 2 months after infection, when absolute numbers of CD4+ T cells were restored to baseline levels. These CD4+ T cells showed a markedly skewed phenotype, however, as there were decreased levels of memory cells in CD8+ lymphocyte-depleted macaques compared to controls. In intestinal tissues and lymph nodes, we observed a significantly higher loss of CCR5+ CD45RA− CD4+ T cells in CD8+ lymphocyte-depleted macaques than in controls, suggesting that these SIV-targeted CD4+ T cells were eliminated more efficiently in CD8+ lymphocyte-depleted animals. Also, CD8+ lymphocyte depletion significantly affected the ability to generate SIV Gag-specific CD4+ T-cell responses and neutralizing antibodies. These results reemphasize that SIV-specific CD8+ T-cell responses are absolutely critical to initiate at least partial control of SIV infection.

scholarly journals Reduced Protection from Simian Immunodeficiency Virus SIVmac251 Infection Afforded by Memory CD8+ T Cells Induced by Vaccination during CD4+ T-Cell Deficiency

2008 ◽  
Vol 82 (19) ◽  
pp. 9629-9638 ◽  
Author(s):  
Monica Vaccari ◽  
Joseph Mattapallil ◽  
Kaimei Song ◽  
Wen-Po Tsai ◽  
Anna Hryniewicz ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Simian Immunodeficiency Virus ◽  
Rhesus Macaques ◽  
Interleukin 2 ◽  
T Cell Responses ◽  
Memory Cd8 T Cells ◽  
Cell Responses ◽  
Modified Vaccinia Virus Ankara ◽  
Immunodeficiency Virus

ABSTRACT Adaptive CD4+ and CD8+ T-cell responses have been associated with control of human immunodeficiency virus/simian immunodeficiency virus (HIV/SIV) replication. Here, we have designed a study with Indian rhesus macaques to more directly assess the role of CD8 SIV-specific responses in control of viral replication. Macaques were immunized with a DNA prime-modified vaccinia virus Ankara (MVA)-SIV boost regimen under normal conditions or under conditions of antibody-induced CD4+ T-cell deficiency. Depletion of CD4+ cells was performed in the immunized macaques at the peak of SIV-specific CD4+ T-cell responses following the DNA prime dose. A group of naïve macaques was also treated with the anti-CD4 depleting antibody as a control, and an additional group of macaques immunized under normal conditions was depleted of CD8+ T cells prior to challenge exposure to SIVmac251. Analysis of the quality and quantity of vaccine-induced CD8+ T cells demonstrated that SIV-specific CD8+ T cells generated under conditions of CD4+ T-cell deficiency expressed low levels of Bcl-2 and interleukin-2 (IL-2), and plasma virus levels increased over time. Depletion of CD8+ T cells prior to challenge exposure abrogated vaccine-induced protection as previously shown. These data support the notion that adaptive CD4+ T cells are critical for the generation of effective CD8+ T-cell responses to SIV that, in turn, contribute to protection from AIDS. Importantly, they also suggest that long-term protection from disease will be afforded only by T-cell vaccines for HIV that provide a balanced induction of CD4+ and CD8+ T-cell responses and protect against early depletion of CD4+ T cells postinfection.

scholarly journals Gag p27-Specific B- and T-Cell Responses in Simian Immunodeficiency Virus SIVagm-Infected African Green Monkeys

2008 ◽  
Vol 83 (6) ◽  
pp. 2770-2777 ◽  
Author(s):  
José-Manuel Lozano Reina ◽  
David Favre ◽  
Zeljka Kasakow ◽  
Véronique Mayau ◽  
Marie-Thérèse Nugeyre ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Antibody Response ◽  
Simian Immunodeficiency Virus ◽  
Cell Response ◽  
T Cell Responses ◽  
T Cell Response ◽  
Cell Responses ◽  
Immunodeficiency Virus ◽  
Green Monkeys

ABSTRACT Nonpathogenic simian immunodeficiency virus SIVagm infection of African green monkeys (AGMs) is characterized by the absence of a robust antibody response against Gag p27. To determine if this is accompanied by a selective loss of T-cell responses to Gag p27, we studied CD4+ and CD8+ T-cell responses against Gag p27 and other SIVagm antigens in the peripheral blood and lymph nodes of acutely and chronically infected AGMs. Our data show that AGMs can mount a T-cell response against Gag p27, indicating that the absence of anti-p27 antibodies is not due to the absence of Gag p27-specific T cells.

scholarly journals Inhibition of Adaptive Vγ2Vδ2+ T-Cell Responses during Active Mycobacterial Coinfection of Simian Immunodeficiency Virus SIVmac-Infected Monkeys

2003 ◽  
Vol 77 (5) ◽  
pp. 2998-3006 ◽  
Author(s):  
Dejiang Zhou ◽  
Xiaomin Lai ◽  
Yun Shen ◽  
Prabhat Sehgal ◽  
Ling Shen ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Simian Immunodeficiency Virus ◽  
Γδ T Cells ◽  
Subsequent Development ◽  
T Cell Responses ◽  
Cell Responses ◽  
Immunodeficiency Virus

ABSTRACT Adaptive immune responses of γδ T cells during active mycobacterial coinfection of human immunodeficiency virus-infected humans have not been studied. Macaques infected with the simian immunodeficiency virus (SIV) SIVmac were employed to determine the extent to which a coincident AIDS virus infection might compromise immune responses of mycobacterium-specific Vγ2Vδ2+ T cells during active mycobacterial infection. Control SIVmac-negative macaques developed primary and recall expansions of phosphoantigen-specific Vγ2Vδ2+ T cells after Mycobacterium bovis BCG infection and BCG reinfection, respectively. In contrast, SIVmac-infected macaques did not exhibit sound primary and recall expansions of Vγ2Vδ2+ T cells in the blood and pulmonary alveoli following BCG infection and reinfection. The absence of adaptive Vγ2Vδ2+ T-cell responses was associated with profound CD4+ T-cell deficiency and subsequent development of SIVmac-related tuberculosis-like disease in the coinfected monkeys. Consistently, Vγ2Vδ2+ T cells from coinfected monkeys displayed a reduced capacity to expand in vitro following stimulation with phosphoantigen. The reduced ability of Vγ2Vδ2+ peripheral blood lymphocytes (PBL) to expand could be restored to some extent by coculture of these cells with CD4+ T cells purified from PBL of SIV-negative monkeys. Furthermore, naïve monkeys inoculated simultaneously with SIVmac and BCG were unable to sustain expansion of Vγ2Vδ2+ T cells at the time that the coinfected monkeys developed lymphoid depletion and a fatal tuberculosis-like disease. Nevertheless, no deletion in Vδ2 T-cell receptor repertoire was identified in SIVmac-BCG-coinfected macaques, implicating an SIVmac-induced down-regulation rather than a clonal exhaustion of these cells. Thus, an SIVmac-induced compromise of the adaptive Vγ2Vδ2+ T-cell responses may contribute to the immunopathogenesis of the SIV-related tuberculosis-like disease in macaques.

scholarly journals Naive T cells are dispensable for memory CD4+ T cell homeostasis in progressive simian immunodeficiency virus infection

2012 ◽  
Vol 209 (4) ◽  
pp. 641-651 ◽  
Author(s):  
Afam A. Okoye ◽  
Mukta Rohankhedkar ◽  
Chike Abana ◽  
Audrie Pattenn ◽  
Matthew Reyes ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Disease Progression ◽  
Simian Immunodeficiency Virus ◽  
T Cell Responses ◽  
Cd4 T Cell ◽  
Naïve T Cells ◽  
Cell Responses ◽  
Immunodeficiency Virus ◽  
Siv Infection

The development of AIDS in chronic HIV/simian immunodeficiency virus (SIV) infection has been closely linked to progressive failure of CD4+ memory T cell (TM) homeostasis. CD4+ naive T cells (TN) also decline in these infections, but their contribution to disease progression is less clear. We assessed the role of CD4+ TN in SIV pathogenesis using rhesus macaques (RMs) selectively and permanently depleted of CD4+ TN before SIV infection. CD4+ TN-depleted and CD4+ TN-repleted RMs were created by subjecting juvenile RMs to thymectomy versus sham surgery, respectively, followed by total CD4+ T cell depletion and recovery from this depletion. Although thymectomized and sham-treated RMs manifested comparable CD4+ TM recovery, only sham-treated RMs reconstituted CD4+ TN. CD4+ TN-depleted RMs responded to SIVmac239 infection with markedly attenuated SIV-specific CD4+ T cell responses, delayed SIVenv-specific Ab responses, and reduced SIV-specific CD8+ T cell responses. However, CD4+ TN-depleted and -repleted groups showed similar levels of SIV replication. Moreover, CD4+ TN deficiency had no significant effect on CD4+ TM homeostasis (either on or off anti-retroviral therapy) or disease progression. These data demonstrate that the CD4+ TN compartment is dispensable for CD4+ TM homeostasis in progressive SIV infection, and they confirm that CD4+ TM comprise a homeostatically independent compartment that is intrinsically capable of self-renewal.

scholarly journals Comparison of Human Immunodeficiency Virus (HIV)-Specific T-Cell Responses in HIV-1- and HIV-2-Infected Individuals in Senegal

2004 ◽  
Vol 78 (24) ◽  
pp. 13934-13942 ◽  
Author(s):  
N. N. Zheng ◽  
N. B. Kiviat ◽  
P. S. Sow ◽  
S. E. Hawes ◽  
A. Wilson ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cells ◽  
T Cell ◽  
Mononuclear Cells ◽  
T Cell Responses ◽  
T Helper ◽  
Cell Responses ◽  
Cell Immunity ◽  
Immunodeficiency Virus ◽  
Hiv 1

ABSTRACT Human immunodeficiency virus type 2 (HIV-2) infection is typically less virulent than HIV-1 infection, which may permit the host to mount more effective, sustained T-cell immunity. We investigated antiviral gamma interferon-secreting T-cell responses by an ex vivo Elispot assay in 68 HIV-1- and 55 HIV-2-infected Senegalese patients to determine if differences relate to more efficient HIV-2 control. Homologous HIV-specific T cells were detected in similar frequencies (79% versus 76%, P = 0.7) and magnitude (3.12 versus 3.08 log10 spot-forming cells/106 peripheral blood mononuclear cells) in HIV-1 and HIV-2 infection, respectively. Gag-specific responses predominated in both groups (≥64%), and significantly higher Nef-specific responses occurred in HIV-1-infected (54%) than HIV-2-infected patients (22%) (P < 0.001). Heterologous responses were more frequent in HIV-1 than in HIV-2 infection (46% versus 27%, P = 0.04), but the mean magnitude was similar. Total frequencies of HIV-specific responses in both groups did not correlate with plasma viral load and CD4+ T-cell count in multivariate regression analyses. However, the magnitude of HIV-2 Gag-specific responses was significantly associated with lower plasma viremia in HIV-1-infected patients (P = 0.04). CD4+ T-helper responses, primarily recognizing HIV-2 Gag, were detected in 48% of HIV-2-infected compared to only 8% of HIV-1-infected patients. These findings indicate that improved control of HIV-2 infection may relate to the contribution of T-helper cell responses. By contrast, the superior control of HIV-1 replication associated with HIV-2 Gag responses suggests that these may represent cross-reactive, higher-avidity T cells targeting epitopes within Gag regions of functional importance in HIV replication.

scholarly journals JC Virus-Specific Immune Responses in Human Immunodeficiency Virus Type 1 Patients with Progressive Multifocal Leukoencephalopathy

2009 ◽  
Vol 83 (9) ◽  
pp. 4404-4411 ◽  
Author(s):  
Nina Khanna ◽  
Marcel Wolbers ◽  
Nicolas J. Mueller ◽  
Christian Garzoni ◽  
Renaud A. Du Pasquier ◽  
...  
Keyword(s):  
Human Immunodeficiency Virus ◽  
T Cell ◽  
Progressive Multifocal Leukoencephalopathy ◽  
Mononuclear Cells ◽  
Jc Virus ◽  
T Cell Responses ◽  
Peripheral Blood Mononuclear ◽  
Cell Responses ◽  
Cell Counts ◽  
Immunodeficiency Virus

ABSTRACT Progressive multifocal leukoencephalopathy (PML) is a frequently fatal disease caused by uncontrolled polyomavirus JC (JCV) in severely immunodeficient patients. We investigated the JCV-specific cellular and humoral immunity in the Swiss HIV Cohort Study. We identified PML cases (n = 29), as well as three matched controls per case (n = 87), with prospectively cryopreserved peripheral blood mononuclear cells and plasma at diagnosis. Nested controls were matched according to age, gender, CD4+ T-cell count, and decline. Survivors (n = 18) were defined as being alive for >1 year after diagnosis. Using gamma interferon enzyme-linked immunospot assays, we found that JCV-specific T-cell responses were lower in nonsurvivors than in their matched controls (P = 0.08), which was highly significant for laboratory- and histologically confirmed PML cases (P = 0.004). No difference was found between PML survivors and controls or for cytomegalovirus-specific T-cell responses. PML survivors showed significant increases in JCV-specific T cells (P = 0.04) and immunoglobulin G (IgG) responses (P = 0.005). IgG responses in survivors were positively correlated with CD4+ T-cell counts (P = 0.049) and negatively with human immunodeficiency virus RNA loads (P = 0.03). We conclude that PML nonsurvivors had selectively impaired JCV-specific T-cell responses compared to CD4+ T-cell-matched controls and failed to mount JCV-specific antibody responses. JCV-specific T-cell and IgG responses may serve as prognostic markers for patients at risk.

scholarly journals Evaluation of Antigen-Specific T-Cell Responses with a Miniaturized and Automated Method

2008 ◽  
Vol 15 (12) ◽  
pp. 1811-1818 ◽  
Author(s):  
Giuseppina Li Pira ◽  
Federico Ivaldi ◽  
Chiara Dentone ◽  
Elda Righi ◽  
Valerio Del Bono ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Mononuclear Cells ◽  
T Cell Responses ◽  
T Cell Immunity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Peripheral Blood Mononuclear ◽  
Cell Responses ◽  
Automated Method ◽  
Cell Immunity

ABSTRACT The evaluation of antigen-specific T-cell responses is helpful for both research and clinical settings. Several techniques can enumerate antigen-responsive T cells or measure their products, but they require remarkable amounts of peripheral blood mononuclear cells (PBMCs). Since screening numerous antigens or testing samples from pediatric or lymphopenic patients is hampered in clinical practice, we refined a miniaturized, high-throughput assay for T-cell immunity. Antigens and cells in 10-μl volumes were dispensed into 1,536-well culture plates precoated with anti-gamma interferon (anti-IFN-γ) antibodies. After being cultured, the wells were developed by enzyme-linked immunosorbent assay for bound cytokine. Miniaturization and automation allowed quantitation of antigen-specific responses on 104 PBMCs. This method was applied for epitope mapping of mycobacterial antigens and was used in the clinic to evaluate T-cell immunity to relevant opportunistic pathogens by using small blood samples. A comparison with conventional methods showed similar sensitivity. Therefore, current flow cytometric methods that provide information on frequency and phenotype of specific T cells can be complemented by this assay that provides extensive information on cytokine concentrations and profiles and requires 20- to 50-fold fewer PBMCs than other analytical methods.

scholarly journals Antiviral Therapy during Primary Simian Immunodeficiency Virus Infection Fails To Prevent Acute Loss of CD4+ T Cells in Gut Mucosa but Enhances Their Rapid Restoration through Central Memory T Cells

2008 ◽  
Vol 82 (8) ◽  
pp. 4016-4027 ◽  
Author(s):  
David Verhoeven ◽  
Sumathi Sankaran ◽  
Melanie Silvey ◽  
Satya Dandekar
Keyword(s):  
T Cells ◽  
T Cell ◽  
Simian Immunodeficiency Virus ◽  
Peripheral Blood ◽  
Viral Suppression ◽  
T Cell Responses ◽  
Cell Loss ◽  
Central Memory ◽  
Cell Responses ◽  
Immunodeficiency Virus

ABSTRACT Gut-associated lymphoid tissue (GALT) is an early target of human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) and a site for severe CD4+ T-cell depletion. Although antiretroviral therapy (ART) is effective in suppressing HIV replication and restoring CD4+ T cells in peripheral blood, restoration in GALT is delayed. The role of restored CD4+ T-cell help in GALT during ART and its impact on antiviral CD8+ T-cell responses have not been investigated. Using the SIV model, we investigated gut CD4+ T-cell restoration in infected macaques, initiating ART during either the primary stage (1 week postinfection), prior to acute CD4+ cell loss (PSI), or during the chronic stage at 10 weeks postinfection (CSI). ART led to viral suppression in GALT and peripheral blood mononuclear cells of PSI and CSI animals at comparable levels. CSI animals had incomplete CD4+ T-cell restoration in GALT. In PSI animals, ART did not prevent acute CD4+ T-cell loss by 2 weeks postinfection in GALT but supported rapid and complete CD4+ T-cell restoration thereafter. This correlated with an accumulation of central memory CD4+ T cells and better suppression of inflammation. Restoration of CD4+ T cells in GALT correlated with qualitative changes in SIV gag-specific CD8+ T-cell responses, with a dominance of interleukin-2-producing responses in PSI animals, while both CSI macaques and untreated SIV-infected controls were dominated by gamma interferon responses. Thus, central memory CD4+ T-cell levels and qualitative antiviral CD8+ T-cell responses, independent of viral suppression, were the immune correlates of gut mucosal immune restoration during ART.

scholarly journals Selection and T-cell antigenicity of synthetic long peptides derived from SARS-CoV-2

2022 ◽  
Vol 103 (1) ◽  
Author(s):  
Katarzyna Piadel ◽  
Amin Haybatollahi ◽  
Angus George Dalgleish ◽  
Peter Lawrence Smith
Keyword(s):  
T Cells ◽  
T Cell ◽  
T Cell Activation ◽  
Cell Activation ◽  
Mononuclear Cells ◽  
T Cell Responses ◽  
Hla Class I ◽  
Peripheral Blood Mononuclear ◽  
Cell Responses

The pandemic caused by SARS-CoV-2 has led to the successful development of effective vaccines however the prospect of variants of SARS-CoV-2 and future coronavirus outbreaks necessitates the investigation of other vaccine strategies capable of broadening vaccine mediated T-cell responses and potentially providing cross-immunity. In this study the SARS-CoV-2 proteome was assessed for clusters of immunogenic epitopes restricted to diverse human leucocyte antigen. These regions were then assessed for their conservation amongst other coronaviruses representative of different alpha and beta coronavirus genera. Sixteen highly conserved peptides containing numerous HLA class I and II restricted epitopes were synthesized from these regions and assessed in vitro for their antigenicity against T-cells from individuals with previous SARS-CoV-2 infection. Monocyte derived dendritic cells were generated from these peripheral blood mononuclear cells (PBMC), loaded with SARS-CoV-2 peptides, and used to induce autologous CD4+ and CD8+ T cell activation. The SARS-CoV-2 peptides demonstrated antigenicity against the T-cells from individuals with previous SARS-CoV-2 infection indicating that this approach holds promise as a method to activate anti-SAR-CoV-2 T-cell responses from conserved regions of the virus which are not included in vaccines utilising the Spike protein.

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