scholarly journals High Beta-Chemokine Expression Levels in Lymphoid Tissues of Simian/Human Immunodeficiency Virus 89.6-Vaccinated Rhesus Macaques Are Associated with Uncontrolled Replication of Simian Immunodeficiency Virus Challenge Inoculum

2004 ◽  
Vol 78 (12) ◽  
pp. 6399-6408 ◽  
Author(s):  
Lisa LaFranco-Scheuch ◽  
Kristina Abel ◽  
Norbert Makori ◽  
Kristina Rothaeusler ◽  
Christopher J. Miller

ABSTRACT Viral suppression by noncytolytic CD8+ T cells, in addition to that by classic antiviral CD8+ cytotoxic T lymphocytes, has been described for human immunodeficiency virus and simian immunodeficiency virus (SIV) infections. However, the role of soluble effector molecules, especially beta-chemokines, in antiviral immunity is still controversial. In an attenuated vaccine model, approximately 60% of animals immunized with simian/human immunodeficiency virus (SHIV) 89.6 and then challenged intravaginally with SIVmac239 controlled viral replication (viral RNA level in plasma, <104 copies/ml) and were considered protected (K. Abel, L. Compton, T. Rourke, D. Montefiori, D. Lu, K. Rothaeusler, L. Fritts, K. Bost, and C. J. Miller, J. Virol. 77:3099-3118, 2003). To determine the in vivo importance of beta-chemokine secretion and CD8+-T-cell proliferation in the control of viral replication in this vaccine model, we examined the relationship between viral RNA levels in the axillary and genital lymph nodes of vaccinated, protected (n = 20) and vaccinated, unprotected (n = 11) monkeys by measuring beta-chemokine mRNA levels and protein expression, the frequency of CD8+ T cells expressing beta-chemokines, and the extent of CD8+-T-cell proliferation. Tissues from uninfected (n = 3) and unvaccinated, SIVmac239-infected (n = 9) monkeys served as controls. Axillary and genital lymph nodes from unvaccinated and vaccinated, unprotected monkeys had significantly higher beta-chemokine mRNA expression levels and increased numbers of beta-chemokine-positive cells than did vaccinated, protected animals. Furthermore, the lymph nodes of vaccinated, unprotected monkeys had significantly higher numbers of beta-chemokine+ CD8+ T cells than did vaccinated, protected monkeys. Lymph nodes from vaccinated, unprotected animals also had significantly more CD8+-T-cell proliferation and marked lymph node hyperplasia than the lymph nodes of vaccinated, protected monkeys. Thus, higher levels of virus replication were associated with increased beta-chemokine secretion and there is no evidence that beta-chemokines contributed to the SHIV89.6-mediated control of viral replication after intravaginal challenge with SIVmac239.

2016 ◽  
Vol 4 (1) ◽  
Author(s):  
Josiane Warszawski ◽  
Véronique Avettand-Fenoel ◽  
Christine Rouzioux ◽  
Daniel Scott-Algara ◽  
Thomas Montange ◽  
...  

Abstract Background Gag-specific T lymphocytes play a key role in the control of human immunodeficiency virus (HIV) replication. Their restoration will be important for future reservoir targeting strategies. In this study, we aimed to identify immune correlates of Gag-specific CD8 T-cell proliferation in youths with perinatally acquired HIV-1 infection. Methods The ANRS-EP38-IMMIP study included youths of 15 to 24 years of age. Fifty-three were taking combination anti-retroviral therapy and aviremic at the time of the study and had undergone valid 5-6-carboxyfluorescein diacetate succimidyl ester-based flow cytometry T-cell proliferation assays. Plasma analytes were quantified by enzyme-linked immunosorbent assay or multiplex assays. Peripheral blood cells were phenotyped by flow cytometry. Logistic regression was used to study the association between Gag-specific T-cell proliferation and immune markers. Results Patients with Gag-specific CD8 T-cell proliferation had higher levels of plasma transforming growth factor (TGF)-β1, a lower proportion of naive cells among regulatory T cells (Tregs), and higher percentages of CD4 and CD8 T cells expressing the α4β7 integrin or CD161 molecule than those without a Gag-specific response. These associations were significant based on analyses including potential confounders. Conclusions Preserved Gag-specific CD8 T-cell proliferation was associated with higher TGF-β1 levels and increased percentages of T cells with a gut-homing phenotype at least 15 years after HIV infection during the perinatal period.


2002 ◽  
Vol 76 (19) ◽  
pp. 9981-9990 ◽  
Author(s):  
Donald L. Sodora ◽  
Jeffrey M. Milush ◽  
Felecia Ware ◽  
Aneta Wozniakowski ◽  
Lisa Montgomery ◽  
...  

ABSTRACT The thymus is responsible for de novo production of CD4+ and CD8+ T cells and therefore is essential for T-cell renewal. The goal of this study was to assess the impact of simian immunodeficiency virus (SIV) infection on the production of T cells by the thymus. Levels of recent thymic emigrants within the peripheral blood were assessed through quantification of macaque T-cell receptor excision circles (TREC). Comparison of SIV-infected macaques (n = 15) to uninfected macaques (n = 23) revealed stable or increased TREC levels at 20 to 34 weeks postinfection. Further assessment of SIV-infected macaques (n = 4) determined that TREC levels decreased between 24 and 48 weeks postinfection. Through the assessment of longitudinal time points in three additional SIVmac239-infected macaques, the SIV infection was divided into two distinct phases. During phase 1 (16 to 30 weeks), TREC levels remained stable or increased within both the CD4 and CD8 T-cell populations. During phase 2 (after 16 to 30 weeks), TREC levels declined in both T-cell populations. As has been described for human immunodeficiency virus (HIV)-infected patients, this decline in TREC levels did at times correlate with an increased level of T-cell proliferation (Ki67+ cells). However, not all TREC decreases could be attributed to increased T-cell proliferation. Further evidence for thymic dysfunction was observed directly in a SIVmac239-infected macaque that succumbed to simian AIDS at 65 weeks postinfection. The thymus of this macaque contained an increased number of memory/effector CD8+ T cells and an increased level of apoptotic cells. In summary, reduced levels of TREC can be observed beginning at 16 to 30 weeks post-SIV infection and correlate with changes indicative of dysfunction within the thymic tissue. SIV infection of macaques will be a useful model system to elucidate the mechanisms responsible for the thymic dysfunction observed in HIV-infected patients.


1998 ◽  
Vol 72 (7) ◽  
pp. 6155-6158 ◽  
Author(s):  
Linda Whetter ◽  
Francis J. Novembre ◽  
Michelle Saucier ◽  
Suryaram Gummuluru ◽  
Stephen Dewhurst

ABSTRACT The PBj14 isolate of the simian immunodeficiency virus SIVsmmPBj14 is unique among primate lentiviruses in its ability to induce lymphocyte proliferation and acutely lethal disease. The studies reported here show that viral induction of T-cell proliferation requires accessory cells, such as primary monocytes or Raji B-lymphoma cells, as well as the presence of a putative immunoreceptor tyrosine-based activation motif within the viral Nef protein. Addition of CTLA4-immunoglobulin fusion protein or anti-B7 antibodies to virally infected T cells led to substantial, but not complete, inhibition of monocyte-costimulated T-cell proliferation—suggesting that both CD28/B7-dependent and non-CD28-dependent pathways may contribute to the costimulation of virally induced lymphoproliferation. Finally, cyclosporin A, a specific inhibitor of the calcium-calmodulin-regulated phosphatase activity of calcineurin, which influences activation of the transcription factor nuclear factor of activated T cells, was shown to block virally mediated T-cell proliferation. Taken together, these findings suggest that the effect of SIVsmmPBj14 on T-cell activation may be functionally analogous, at least in part, to the effect of engagement of the T-cell receptor.


2009 ◽  
Vol 83 (22) ◽  
pp. 11876-11889 ◽  
Author(s):  
Stephen A. Migueles ◽  
Kristin A. Weeks ◽  
Eric Nou ◽  
Amy M. Berkley ◽  
Julia E. Rood ◽  
...  

ABSTRACT Identifying the functions of human immunodeficiency virus (HIV)-specific CD8+ T cells that are not merely modulated by the level of virus but clearly distinguish patients with immune control from those without such control is of paramount importance. Features of the HIV-specific CD8+ T-cell response in antiretroviral-treated patients (designated Rx <50) and untreated patients (long-term nonprogressors [LTNP]) matched for very low HIV RNA levels were comprehensively examined. The proliferative capacity of HIV-specific CD8+ T cells was not restored in Rx <50 to the level observed in LTNP, even though HIV-specific CD4+ T-cell proliferation in the two patient groups was comparable. This diminished HIV-specific CD8+ T-cell proliferation in Rx <50 was primarily due to a smaller fraction of antigen-specific cells recruited to divide and not to the numbers of divisions that proliferating cells had undergone. Exogenous interleukin-2 (IL-2) induced proliferating cells to divide further but did not rescue the majority of antigen-specific cells with defective proliferation. In addition, differences in HIV-specific CD8+ T-cell proliferation could not be attributed to differences in cellular subsets bearing a memory phenotype, IL-2 production, or PD-1 expression. Although polyfunctionality of HIV-specific CD8+ T cells in Rx <50 was not restored to the levels observed in LTNP despite prolonged suppression of HIV RNA levels, per-cell cytotoxic capacity was the functional feature that most clearly distinguished the cells of LTNP from those of Rx <50. Taken together, these data suggest that there are selective qualitative abnormalities within the HIV-specific CD8+ T-cell compartment that persist under conditions of low levels of antigen.


2005 ◽  
Vol 86 (8) ◽  
pp. 2231-2238 ◽  
Author(s):  
Lesley A. Bergmeier ◽  
Kaboutar Babaahmady ◽  
Yufei Wang ◽  
Thomas Lehner

The hypothesis was tested that mucosal stimulation with unmatched mononuclear cells would induce systemic alloimmune responses. Rectal or vaginal mucosal administration of 104–107 unmatched mononuclear cells induced significant dose-dependent T-cell proliferation stimulated by the allogeneic cells in rhesus macaques. This was associated with a significant upregulation of CD8+ T-cell-derived suppressor factor, as well as the CC chemokines CCL3, CCL4 and CCL5. In addition, there was a dose-dependent increase in antibodies to CCR5. These responses were associated with decreased in vitro simian immunodeficiency virus (SIV) infectivity of CD4+ T cells. A further investigation of SIV infectivity of CD4+ T cells separated from multiparous macaques also showed significant inhibition compared with male macaques. It is suggested that vaginal or rectal exposure to allogeneic stimulation by a partner's HLA antigens in seminal fluid, as occurs during sexual intercourse, or immunization by semi-allogeneic fetuses in multiparous females may elicit protection against SIV or human immunodeficiency virus infection.


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 ◽  
...  

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.


2008 ◽  
Vol 82 (22) ◽  
pp. 11181-11196 ◽  
Author(s):  
Meritxell Genescà ◽  
Pamela J. Skinner ◽  
Jung Joo Hong ◽  
Jun Li ◽  
Ding Lu ◽  
...  

ABSTRACT The presence, at the time of challenge, of antiviral effector T cells in the vaginal mucosa of female rhesus macaques immunized with live-attenuated simian-human immunodeficiency virus 89.6 (SHIV89.6) is associated with consistent and reproducible protection from pathogenic simian immunodeficiency virus (SIV) vaginal challenge (18). Here, we definitively demonstrate the protective role of the SIV-specific CD8+ T-cell response in SHIV-immunized monkeys by CD8+ lymphocyte depletion, an intervention that abrogated SHIV-mediated control of challenge virus replication and largely eliminated the SIV-specific T-cell responses in blood, lymph nodes, and genital mucosa. While in the T-cell-intact SHIV-immunized animals, polyfunctional and degranulating SIV-specific CD8+ T cells were present in the genital tract and lymphoid tissues from the day of challenge until day 14 postchallenge, strikingly, expansion of SIV-specific CD8+ T cells in the immunized monkeys was minimal and limited to the vagina. Thus, protection from uncontrolled SIV replication in animals immunized with attenuated SHIV89.6 is primarily mediated by CD8+ T cells that do not undergo dramatic systemic expansion after SIV challenge. These findings demonstrate that despite, and perhaps because of, minimal systemic expansion of T cells at the time of challenge, a stable population of effector-cytotoxic CD8+ T cells can provide significant protection from vaginal SIV challenge.


2003 ◽  
Vol 77 (2) ◽  
pp. 1163-1174 ◽  
Author(s):  
Ronald L. Willey ◽  
Russ Byrum ◽  
Michael Piatak ◽  
Young B. Kim ◽  
Michael W. Cho ◽  
...  

ABSTRACT An effective vaccine against the human immunodeficiency virus type 1 (HIV-1) will very likely have to elicit both cellular and humoral immune responses to control HIV-1 strains of diverse geographic and genetic origins. We have utilized a pathogenic chimeric simian-human immunodeficiency virus (SHIV) rhesus macaque animal model system to evaluate the protective efficacy of a vaccine regimen that uses recombinant vaccinia viruses expressing simian immunodeficiency virus (SIV) and HIV-1 structural proteins in combination with intact inactivated SIV and HIV-1 particles. Following virus challenge, control animals experienced a rapid and complete loss of CD4+ T cells, sustained high viral loads, and developed clinical disease by 17 to 21 weeks. Although all of the vaccinated monkeys became infected, they displayed reduced postpeak viremia, had no significant loss of CD4+ T cells, and have remained healthy for more than 15 months postinfection. CD8+ T-cell and neutralizing antibody responses in vaccinated animals following challenge were demonstrable. Despite the control of disease, virus was readily isolated from the circulating peripheral blood mononuclear cells of all vaccinees at 22 weeks postchallenge, indicating that immunologic control was incomplete. Virus recovered from the animal with the lowest postchallenge viremia generated high virus loads and an irreversible loss of CD4+ T-cell loss following its inoculation into a naïve animal. These results indicate that despite the protection from SHIV-induced disease, the vaccinated animals still harbored replication-competent and pathogenic virus.


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