CD8+ lymphocytes control viral replication in SIVmac239-infected rhesus macaques without decreasing the lifespan of productively infected cells.
Ontology highlight
ABSTRACT:
SUBMITTER: Klatt NR
PROVIDER: S-EPMC2813271 | biostudies-literature | 2010 Jan
REPOSITORIES: biostudies-literature
Publications
CD8+ lymphocytes control viral replication in SIVmac239-infected rhesus macaques without decreasing the lifespan of productively infected cells.
Klatt Nichole R NR Shudo Emi E Ortiz Alex M AM Engram Jessica C JC Paiardini Mirko M Lawson Benton B Miller Michael D MD Else James J Pandrea Ivona I Estes Jacob D JD Apetrei Cristian C Schmitz Joern E JE Ribeiro Ruy M RM Perelson Alan S AS Silvestri Guido G
PLoS pathogens 20100129 1
While CD8+ T cells are clearly important in controlling virus replication during HIV and SIV infections, the mechanisms underlying this antiviral effect remain poorly understood. In this study, we assessed the in vivo effect of CD8+ lymphocyte depletion on the lifespan of productively infected cells during chronic SIVmac239 infection of rhesus macaques. We treated two groups of animals that were either CD8+ lymphocyte-depleted or controls with antiretroviral therapy, and used mathematical modeli ...[more]
Similar Datasets
Project description:CD8(+) T cells inhibit virus replication in SIV-infected rhesus macaques. However, it is unclear to what extent the viral suppression mediated by CD8(+) T cells reflects direct killing of infected cells as opposed to indirect, noncytolytic mechanisms. In this study, we used functional genomics to investigate noncytolytic mechanisms of in vivo viral suppression mediated by CD8(+) lymphocytes. Eight chronically SIVmac239-infected rhesus macaques underwent CD8(+) lymphocyte depletion, and RNA from whole blood was obtained prior to depletion, during the nadir of CD8(+) cell depletion, and after CD8(+) lymphocyte numbers had rebounded. We observed significant downregulation of the expression of genes encoding factors that can suppress SIV replication, including the CCR5-binding chemokine CCL5/RANTES and CCL4 and several members of the tripartite motif-containing (TRIM) family. Surprisingly, we also noted a strong, widespread downregulation of ?- and ?-defensins with anti-HIV activity, which are not expressed by CD8(+) T cells. After cessation of depleting antibody treatment, we observed induction of a transcriptional signature indicative of B lymphocyte activation. Validation experiments demonstrated that animals during this period had elevated levels of B cells coupled with higher expression of the proliferative marker Ki67, indicating that CD8(+) depletion triggered a potent expansion of B cell numbers. Collectively, these data identify antiviral pathways perturbed by in vivo CD8(+) T cell depletion that may contribute to noncytolytic control of SIV replication.
| S-EPMC3536408 | biostudies-literature
Project description:CD8+ T-cells inhibit virus replication in SIV-infected rhesus macaques (RM). However, it is unclear to what extent the viral suppression mediated by CD8+ T-cells reflects direct killing of infected cells as opposed to indirect, non-cytolytic mechanisms. In this study, we used functional genomics to investigate potential mechanisms of in vivo viral suppression mediated by CD8+ lymphocytes. Eight chronically SIVmac239-infected RMs underwent CD8+ lymphocyte depletion, and RNA from whole blood was obtained prior to depletion, at the nadir of CD8+ lymphocytes (5 days post-depletion), and during the repopulation phase (11 days post-depletion). Principal components analysis demonstrated that overall gene expression during the nadir of CD8+ T-cells was highly divergent from other intervals. Conversely, the genomic signature of samples from the CD8+ cell rebound phase was similar to that of pre-depletion samples. During CD8+ lymphocyte depletion we detected a strongly significant decrease in the expression of the genes encoding CD8α and CD8β chains, consistent with the near complete CD8+ T-cell depletion measured by flow cytometry. Of note, we observed significant down-regulation of the expression of genes encoding for factors that can suppress SIV replication, including the CCR5-binding chemokine CCL5/Rantes, several retroviral restriction factors (TRIM10, TRIM15, APOBEC3G/H) and defensins. Reduced expression of various genes related to T cell activation and proliferation was also observed. Collectively, these data indicate that depletion of CD8+ lymphocytes in SIV-infected RMs is associated with the establishment of a pattern of gene expression that may result in increased intrinsic permissivity to virus replication. A total of 60 RNA samples were hybridized on to Rhesus Affymetrix 3' Expression arrays. The study was composed of 8 replicate rhesus macaques subjected to SIVmac239 infection and followed over infection, during subsequent treatment with monocloncal antibody OKT8F to deplete CD8+ T lymphocytes, antiretroviral therapy to suppress virus. Samples were taken at various time points during acute and chronic infection, after CD8+ cell depletion, after CD8+ cell reconstition, and during ART suppression of virus.
2013-02-08 | E-GEOD-37834 | biostudies-arrayexpress
Project description:CD8+ T-cells inhibit virus replication in SIV-infected rhesus macaques (RM). However, it is unclear to what extent the viral suppression mediated by CD8+ T-cells reflects direct killing of infected cells as opposed to indirect, non-cytolytic mechanisms. In this study, we used functional genomics to investigate potential mechanisms of in vivo viral suppression mediated by CD8+ lymphocytes. Eight chronically SIVmac239-infected RMs underwent CD8+ lymphocyte depletion, and RNA from whole blood was obtained prior to depletion, at the nadir of CD8+ lymphocytes (5 days post-depletion), and during the repopulation phase (11 days post-depletion). Principal components analysis demonstrated that overall gene expression during the nadir of CD8+ T-cells was highly divergent from other intervals. Conversely, the genomic signature of samples from the CD8+ cell rebound phase was similar to that of pre-depletion samples. During CD8+ lymphocyte depletion we detected a strongly significant decrease in the expression of the genes encoding CD8α and CD8β chains, consistent with the near complete CD8+ T-cell depletion measured by flow cytometry. Of note, we observed significant down-regulation of the expression of genes encoding for factors that can suppress SIV replication, including the CCR5-binding chemokine CCL5/Rantes, several retroviral restriction factors (TRIM10, TRIM15, APOBEC3G/H) and defensins. Reduced expression of various genes related to T cell activation and proliferation was also observed. Collectively, these data indicate that depletion of CD8+ lymphocytes in SIV-infected RMs is associated with the establishment of a pattern of gene expression that may result in increased intrinsic permissivity to virus replication.
2013-02-08 | GSE37834 | GEO
Project description:Certain major histocompatibility complex class I (MHC-I) alleles are associated with spontaneous control of viral replication in human immunodeficiency virus (HIV)-infected people and simian immunodeficiency virus (SIV)-infected rhesus macaques (RMs). These cases of "elite" control of HIV/SIV replication are often immune-mediated, thereby providing a framework for studying anti-lentiviral immunity. In this study, we examined how vaccination impacts SIV replication in RMs expressing the MHC-I allele Mamu-B*17 Approximately 21% of Mamu-B*17+ and 50% of Mamu-B*08+ RMs control chronic-phase viremia after SIVmac239 infection. Because CD8+ T cells targeting Mamu-B*08-restricted SIV epitopes have been implicated in virologic suppression in Mamu-B*08+ RMs, we investigated whether this might also be true for Mamu-B*17+ RMs. Two groups of Mamu-B*17+ RMs were vaccinated with genes encoding Mamu-B*17-restricted epitopes in Vif and Nef. These genes were delivered by themselves (group 1) or together with env (group 2). Group 3 included MHC-I-matched RMs and served as the control group. Surprisingly, the group 1 vaccine regimen had little effect on viral replication compared to group 3, suggesting that unlike Mamu-B*08+ RMs, preexisting SIV-specific CD8+ T cells alone do not facilitate long-term virologic suppression in Mamu-B*17+ RMs. Remarkably, however, 5/8 group 2 vaccinees controlled viremia to <15 viral RNA copies/ml soon after infection. No serological neutralizing activity against SIVmac239 was detected in group 2, although vaccine-elicited gp140-binding antibodies correlated inversely with nadir viral loads. Collectively, these data shed new light on the unique mechanism of elite control in Mamu-B*17+ RMs and implicate vaccine-induced, nonneutralizing anti-Env antibodies in the containment of immunodeficiency virus infection.IMPORTANCE A better understanding of the immune correlates of protection against HIV might facilitate the development of a prophylactic vaccine. Therefore, we investigated simian immunodeficiency virus (SIV) infection outcomes in rhesus macaques expressing the major histocompatibility complex class I allele Mamu-B*17 Approximately 21% of Mamu-B*17+ macaques spontaneously controlled chronic phase viremia after SIV infection, an effect that may involve CD8+ T cells targeting Mamu-B*17-restricted SIV epitopes. We vaccinated Mamu-B*17+ macaques with genes encoding immunodominant epitopes in Vif and Nef alone (group 1) or together with env (group 2). Although neither vaccine regimen prevented SIV infection, 5/8 group 2 vaccinees controlled viremia to below detection limits shortly after infection. This outcome, which was not observed in group 1, was associated with vaccine-induced, nonneutralizing Env-binding antibodies. Together, these findings suggest a limited contribution of Vif- and Nef-specific CD8+ T cells for virologic control in Mamu-B*17+ macaques and implicate anti-Env antibodies in containment of SIV infection.
| S-EPMC6069176 | biostudies-literature
Project description:A prophylactic vaccine against human immunodeficiency virus (HIV) remains a top priority in biomedical research. Given the failure of conventional immunization protocols to confer robust protection against HIV, new and unconventional approaches may be needed to generate protective anti-HIV immunity. Here we vaccinated rhesus macaques (RMs) with a recombinant (r)DNA prime (without any exogenous adjuvant), followed by a booster with rhesus monkey rhadinovirus (RRV)-a herpesvirus that establishes persistent infection in RMs (Group 1). Both the rDNA and rRRV vectors encoded a near-full-length simian immunodeficiency virus (SIVnfl) genome that assembles noninfectious SIV particles and expresses all nine SIV gene products. This rDNA/rRRV-SIVnfl vaccine regimen induced persistent anti-Env antibodies and CD8+ T-cell responses against the entire SIV proteome. Vaccine efficacy was assessed by repeated, marginal-dose, intrarectal challenges with SIVmac239. Encouragingly, vaccinees in Group 1 acquired SIVmac239 infection at a significantly delayed rate compared to unvaccinated controls (Group 3). In an attempt to improve upon this outcome, a separate group of rDNA/rRRV-SIVnfl-vaccinated RMs (Group 2) was treated with a cytotoxic T-lymphocyte antigen-4 (CTLA-4)-blocking monoclonal antibody during the vaccine phase and then challenged in parallel with Groups 1 and 3. Surprisingly, Group 2 was not significantly protected against SIVmac239 infection. In sum, SIVnfl vaccination can protect RMs against rigorous mucosal challenges with SIVmac239, a feat that until now had only been accomplished by live-attenuated strains of SIV. Further work is needed to identify the minimal requirements for this protection and whether SIVnfl vaccine efficacy can be improved by means other than anti-CTLA-4 adjuvant therapy.
| S-EPMC6791558 | biostudies-literature
Project description:CD8+ cytotoxic T lymphocytes (CTLs) exert potent antiviral activity after HIV/SIV infection. However, efforts to harness the antiviral efficacy of CTLs for HIV/SIV prophylaxis and therapy have been severely hindered by two major problems: viral escape and exhaustion. By contrast, CTLs directed against human cytomegalovirus (HCMV), a ubiquitous chronic herpesvirus, seldom select for escape mutations and remain functional and refractory to exhaustion during chronic HCMV and HIV infection. Recently, attempts have been made to retarget HCMV-specific CTLs for cancer immunotherapy. We speculate that such a strategy may also be beneficial in the context of HIV/SIV infection, facilitating CTL-mediated control of HIV/SIV replication. As a preliminary assessment of the validity of this approach, we investigated the phenotypes and functionality of rhesus CMV (RhCMV)-specific CTLs in SIVmac239-infected Indian rhesus macaques (RMs), a crucial HIV animal model system. We recently identified two immunodominant, Mamu-A∗02-restricted CTL epitopes derived from RhCMV proteins and sought to evaluate the phenotypic and functional characteristics of these CTL populations in chronic SIVmac239 infection. We analyzed and directly compared RhCMV- and SIVmac239-specific CTLs during SIVmac239 infection in a cohort of Mamu-A∗01 + and Mamu-A∗02 + RMs. CTL populations specific for at least one of the RhCMV-derived CTL epitopes were detected in ten of eleven Mamu-A∗02 + animals tested, and both populations were detected in five of these animals. Neither RhCMV-specific CTL population exhibited significant changes in frequency, memory phenotype, granzyme B expression, exhaustion marker (PD-1 and CTLA-4) expression, or polyfunctionality between pre- and chronic SIVmac239 infection timepoints. In chronic SIVmac239 infection, RhCMV-specific CTLs exhibited higher levels of granzyme B expression and polyfunctionality, and lower levels of exhaustion marker expression, than SIVmac239-specific CTLs. Additionally, compared to SIVmac239-specific CTLs, greater proportions of RhCMV-specific CTLs were of the terminally differentiated effector memory phenotype (CD28- CCR7-) during chronic SIVmac239 infection. These results suggest that, in contrast to SIVmac239-specific CTLs, RhCMV-specific CTLs maintain their phenotypes and cytolytic effector functions during chronic SIVmac239 infection, and that retargeting RhCMV-specific CTLs might be a promising SIV immunotherapeutic strategy.
| S-EPMC7457070 | biostudies-literature
Project description:A number of simian and simian human immunodeficiency viruses (SIV and SHIV, respectively) have been used to assess the efficacy of HIV-1 vaccine strategies. Among these, SIVmac239 is considered among the most stringent because, unlike SHIV models, its full genome has coevolved in its macaque host and its tier 3 envelope glycoprotein (Env) is exceptionally hard to neutralize. Here, we investigated the ability of eCD4-Ig, an antibody-like entry inhibitor that emulates the HIV-1 and SIV receptor and coreceptor, to prevent SIVmac239 infection. We show that rh-eCD4-IgI39N expressed by recombinant adeno-associated virus (AAV) vectors afforded four rhesus macaques complete protection from high-dose SIVmac239 challenges that infected all eight control macaques. However, rh-eCD4-IgI39N-expressing macaques eventually succumbed to serial escalating challenge doses that were 2, 8, 16, and 32 times the challenge doses that infected the control animals. Despite receiving greater challenge doses, these macaques had significantly lower peak and postpeak viral loads than the control group. Virus isolated from three of four macaques showed evidence of strong immune pressure from rh-eCD4-IgI39N, with mutations located in the CD4-binding site, which, in one case, exploited a point-mutation difference between rh-eCD4-IgI39N and rhesus CD4. Other escape pathways associated with clear fitness costs to the virus. Our data report effective protection of rhesus macaques from SIVmac239.
| S-EPMC6716512 | biostudies-literature
Project description:The elderly population infected with HIV-1 is often characterized by the rapid AIDS progression and poor treatment outcome, possibly because of immunosenescence resulting from both HIV infection and aging. However, this hypothesis remains to be fully tested. Here, we studied 6 young and 12 old Chinese rhesus macaques (ChRM) over the course of three months after simian immunodeficiency virus (SIV) SIVmac239 infection. Old ChRM showed a higher risk of accelerated AIDS development than did young macaques, owing to rapidly elevated plasma viral loads and decreased levels of CD4+ T cells. The low frequency of naïve CD4+ T cells before infection was strongly predictive of an increased disease progression, whereas the severe depletion of CD4+ T cells and the rapid proliferation of naïve lymphocytes accelerated the exhaustion of naïve lymphocytes in old ChRM. Moreover, in old ChRM, a robust innate host response with defective regulation was associated with a compensation for naïve T cell depletion and a high level of immune activation. Therefore, we suggest that immunosenescence plays an important role in the accelerated AIDS progression in elderly individuals and that SIV-infected old ChRM may be a favorable model for studying AIDS pathogenesis and researching therapies for elderly AIDS patients.
| S-EPMC5428349 | biostudies-literature
Project description:Activated CD8+ T-cells correlate with viral load and may foretell antiretroviral therapy (ART) failure. HIV infection has been suggested to accelerate immunosenescence through chronic persistent inflammation. Alcohol-use disorders (AUD) are prevalent in persons living with HIV/AIDS (PLWHA). We tested the hypothesis that hazardous alcohol consumption accelerates immune activation and immunosenescence. Immune activation and immunosenescence were examined in CD8+ T lymphocytes (CD3+CD4-CD8+) isolated from intestinal biopsies, axillary lymph nodes, and peripheral blood mononuclear cells (PBMCs) of chronic binge alcohol (CBA)-consuming simian immunodeficiency virus (SIV)-infected male rhesus macaques with and without antiretroviral therapy (ART; CBA/ART+, CBA/ART-) and in PBMCs isolated from a cohort of PLWHA. Polychromatic flow cytometry was used to phenotype cells isolated from intestinal biopsies, lymph nodes, and peripheral blood from rhesus macaques and PLWHA. The Alcohol Use Disorders Identification Test (AUDIT) identified hazardous alcohol drinking in PLWHA. Viral load was determined by RT-qPCR and telomere length was measured using qPCR. PBMC CD8+ T-cell activation (CD38+HLA-DR+) and immunosenescence (CD28-) were increased over baseline levels (857% ± 334, p < 0.05; 398% ± 80, p < 0.05, respectively) only in CBA animals not receiving ART. Viral load correlated with CD8+ T-cell immunosenescence in macaque PBMCs (r(s) = 0.49, p = 0.02). Activated immunosenescent T-cell (CD8+CD38+CD28-) frequencies in PBMCs from PLWHA significantly correlated with AUDIT scores (r(s) = 0.75, p = 0.001), while no correlation was observed with CD4+ T-cell and AUDIT scores (r(s) = -0.24, p = 0.38). Activated immunosenescent T-cells had shorter telomeres than CD8+ T-cells (CD8+CD28+) from PLWHA. Our results suggest that CBA and AUD augment immune activation and immunosenescence in SIV-infected macaques and PLWHA.
| S-EPMC4691397 | biostudies-literature
Project description:The immunologic and virologic outcome of therapeutic DNA-vaccines administered during antiretroviral therapy (ART) using electroporation with or without (interleukin) IL-2 treatment was evaluated in the SIVmac239/macaque model. Rhesus macaques inoculated with pathogenic SIVmac239 were treated with ART [(R(-9-(2-phosphonomethoxypropyl) adenine) (PMPA), FTC, Zerit] from weeks 13 to 41 postinfection (wpi). Group 1 (n = 7) received ART only, groups 2 and 3 (each n = 6) additionally received SIVmac239-derived gp140Env, GagPol, and TatRevNef plasmids by in vivo electroporation at 22, 26, 30, and 34 wpi, and group 3 also IL-2 for 14 days after each vaccination. Endpoints evaluated were viral load, Gag(181189)-specific CD8+ T-cell responses in MamuA01+ animals, lymphoproliferative responses, and CD4 T-cell counts. Viremia in all animals dropped below 200 RNA copies/ml during ART. Frequencies of Gag(181189)-specific CD8+ T cells prior to ART were detectable in all three groups (1.27-3.01%) and increased significantly (p < 0.01) postvaccination with maximum responses after the fourth immunization (0.2% versus 3.49-7.15%). Gag(181189)-specific CD8+ T-cell frequencies increased post-ART cessation in all groups and remained at significantly higher levels (p < 0.001) until the end of the study (75 wpi) in both groups of vaccinated animals. Lymphoproliferative responses were detected against Gag in a limited number of animals after vaccination and post-ART. However, plasma RNA viral loads rebounded after ART termination to similar levels in all three groups, but remained below 10(5) copies/ml until the end of the study, which could be a late effect of the triple drug therapy.
| S-EPMC3139522 | biostudies-literature