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2.
J Infect Dis ; 2019 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-31776569

RESUMO

Initiation of antiretroviral therapy (ART) in early compared with chronic human immunodeficiency virus (HIV) infection is associated with a smaller HIV reservoir. This longitudinal analysis of 60 individuals who began ART during primary HIV infection (PHI) investigates which pre- and posttherapy factors best predict HIV DNA levels (a correlate of reservoir size) after treatment initiation during PHI. The best predictor of HIV DNA at 1 year was pre-ART HIV DNA, which was in turn significantly associated with CD8 memory T-cell differentiation (effector memory, naive, and T-bet-Eomes- subsets), CD8 T-cell activation (CD38 expression) and T-cell immunoglobulin and mucin-domain containing-3 (Tim-3) expression on memory T cells. No associations were found for any immunological variables after 1 year of ART. Levels of HIV DNA are determined around the time of ART initiation in individuals treated during PHI. CD8 T-cell activation and memory expansion are linked to HIV DNA levels, suggesting the importance of the initial host-viral interplay in eventual reservoir size.

3.
Front Immunol ; 10: 1844, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31440240

RESUMO

Cytolytic CD4+ T cells play a prominent role in chronic viral infection. CD4+ CTLs clones specific for HIV-1 Nef and Gag are capable of killing HIV-1 infected CD4+ T cells and macrophages. Additionally, HIV-specific cytolytic CD4+ T cell responses in acute HIV infection are predictive of disease progression. CD57 expression on CD4s identifies cytolytic cells. These cells were dramatically increased in chronic HIV infection. CD57 expression correlated with cytolytic granules, granzyme B and perforin expression. They express lower CCR5 compared to CD57- cells, have less HIV total DNA, and were a minor component of the HIV reservoir. A small percentage of CD57+ CD4+ CTLs from EC were HIV-specific, could upregulate IFNγ with Gag peptide stimulation, express cytolytic granule markers and maintain TbethighEomes+ transcription factor phenotype. This was not observed in viraemic controllers. The maintenance of HIV-specific CD4 cytolytic function in Elite controllers together with CD8 CTLs may be important for the control of HIV viraemia and of potential relevance to cure strategies.

4.
Nat Commun ; 10(1): 3017, 2019 07 09.
Artigo em Inglês | MEDLINE | ID: mdl-31289267

RESUMO

Differences among hosts, resulting from genetic variation in the immune system or heterogeneity in drug treatment, can impact within-host pathogen evolution. Genetic association studies can potentially identify such interactions. However, extensive and correlated genetic population structure in hosts and pathogens presents a substantial risk of confounding analyses. Moreover, the multiple testing burden of interaction scanning can potentially limit power. We present a Bayesian approach for detecting host influences on pathogen evolution that exploits vast existing data sets of pathogen diversity to improve power and control for stratification. The approach models key processes, including recombination and selection, and identifies regions of the pathogen genome affected by host factors. Our simulations and empirical analysis of drug-induced selection on the HIV-1 genome show that the method recovers known associations and has superior precision-recall characteristics compared to other approaches. We build a high-resolution map of HLA-induced selection in the HIV-1 genome, identifying novel epitope-allele combinations.


Assuntos
Evolução Molecular , HIV-1/genética , Antígenos HLA/imunologia , Interações Hospedeiro-Patógeno/genética , Modelos Genéticos , Fármacos Anti-HIV/farmacologia , Fármacos Anti-HIV/uso terapêutico , Teorema de Bayes , Conjuntos de Dados como Assunto , Epitopos/efeitos dos fármacos , Epitopos/genética , Epitopos/imunologia , Genoma Viral/efeitos dos fármacos , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/efeitos dos fármacos , HIV-1/imunologia , Interações Hospedeiro-Patógeno/imunologia , Humanos , Recombinação Genética/efeitos dos fármacos , Recombinação Genética/imunologia , Seleção Genética/efeitos dos fármacos , Seleção Genética/imunologia
5.
Int J Lab Hematol ; 41(5): 601-606, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31162809

RESUMO

INTRODUCTION: The Sysmex XN-10 automated hematology analyzer (Sysmex Corporation) is routinely used in hematology laboratories to perform complete blood cell count with differential (CBC w/ diff). The sensitivity of this system for blast detection is unclear, since many prior studies evaluating the blast flagging capabilities of Sysmex XN series used the white precursor cell (WPC) channel, which is not cleared for use in the United States. METHODS: We assessed the blast flagging capabilities of the Sysmex XN-10 compared with CellaVision (a cell image analyzer)-assisted visual hematology results. We evaluated the following flags: "blasts?/abnormal lymph?" and "immature granulocytes present" and compared differences in turnaround time between methods. RESULTS: We collected data on 2239 CBC w/ diff Sysmex automated analyzer differential and CellaVision-assisted visual differential from the inpatient hematology-oncology population of a tertiary care medical center. Solely analyzing the first CBC/diff from each unique patient, both flags had a combined sensitivity of 100%, specificity of 50.2%, PPV of 21.7%, and NPV of 100%. The mean turnaround time for the automated differential was 19.5 minutes (SD 35.9 minutes) compared with 66.4 minutes for the CellaVision-assisted visual differential (SD 68.5 minutes; P < 0.001; Figure 1). CONCLUSION: The Sysmex XN-10 abnormal lymphocyte/blast and immature granulocytes flags had excellent sensitivity and acceptable specificity in detecting circulating blasts with shorter turnaround time than the CellaVision-assisted visual differential. Our study suggests that automated differentials performed on Sysmex XN-10 can replace visual differentials as a first-line screening method for blast detection with improved turnaround time in hematology-oncology populations.

6.
Mucosal Immunol ; 12(5): 1212-1219, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31239514

RESUMO

Gut-associated lymphoid tissue (GALT) is a key location for the HIV reservoir. The observation that B-cell-T-cell doublets are enriched for CD32a (a low-affinity IgG receptor) in peripheral blood raises interesting questions, especially as these cells have been associated with HIV DNA in some studies. We sought to determine if similar doublets were present in GALT, the significance of these doublets, and their implications for the HIV reservoir. Given the importance of GALT as a reservoir for HIV, we looked for expression of CD32 on gut CD4 T cells and for evidence of doublets, and any relationship with HIV DNA in HIV + individuals initiated on antiretroviral therapy (ART) during primary HIV infection (PHI). Tonsil tissue was also available for one individual. As previously shown for blood, CD32high CD4 cells were mainly doublets of CD4 T cells and B cells, with T-cell expression of ICOS in tonsil and gut tissue. CD4 T cells associated with CD32 (compared with 'CD32-' CD4 cells) had higher expression of follicular markers CXCR5, PD-1, ICOS, and Bcl-6 consistent with a T follicular helper (TFH) phenotype. There was a significant correlation between rectal HIV DNA levels and CD32 expression on TFH cells. Together, these data suggest that CD32high doublets are primarily composed of TFH cells, a subset known to be preferentially infected by HIV.

7.
Int J Lab Hematol ; 41 Suppl 1: 177-183, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31069974

RESUMO

Quality management (QM), including quality assurance and quality control, was developed in clinical laboratories in North America and Western Europe, but must be implemented worldwide to ensure accurate, reproducible, and clinically useful results. India, a middle income country with a population of over 1.34 billion, has limited budget allotted to health care. As yet accreditation for clinical laboratories is not mandatory, which contributes to challenges in implementing good laboratory practice. This review provides a summary of internationally laid down QM principles and their application in a middle income country like India.


Assuntos
Acreditação , Laboratórios Hospitalares/normas , Licenciamento , Garantia da Qualidade dos Cuidados de Saúde , Controle de Qualidade , Humanos , Índia , Laboratórios Hospitalares/organização & administração
8.
AIDS ; 33(7): 1253-1256, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31045943

RESUMO

: Soluble forms of the coinhibitory receptors programmed death 1 (PD-1) and Tim-3 exist, but their relationship with T-cell surface expression remains unclear. When measured by an enzyme-linked immunosorbent assay in plasma, soluble PD-1, and soluble Tim-3 were elevated during primary HIV infection, decreased on antiretroviral therapy to levels found in controls, and correlated with cell surface expression. We conclude that soluble PD-1 and soluble Tim-3 are easy to measure biomarkers of immune exhaustion which potentially eliminate the need for flow cytometry.

9.
Expert Rev Anti Infect Ther ; 17(6): 383-386, 2019 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31071275
10.
Lancet HIV ; 6(4): e259-e268, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30885693

RESUMO

Analytical antiretroviral treatment interruption (ATI) is an important feature of HIV research, seeking to achieve sustained viral suppression in the absence of antiretroviral therapy (ART) when the goal is to measure effects of novel therapeutic interventions on time to viral load rebound or altered viral setpoint. Trials with ATIs also intend to determine host, virological, and immunological markers that are predictive of sustained viral control off ART. Although ATI is increasingly incorporated into proof-of-concept trials, no consensus has been reached on strategies to maximise its utility and minimise its risks. In addition, differences in ATI trial designs hinder the ability to compare efficacy and safety of interventions across trials. Therefore, we held a meeting of stakeholders from many interest groups, including scientists, clinicians, ethicists, social scientists, regulators, people living with HIV, and advocacy groups, to discuss the main challenges concerning ATI studies and to formulate recommendations with an emphasis on strategies for risk mitigation and monitoring, ART resumption criteria, and ethical considerations. In this Review, we present the major points of discussion and consensus views achieved with the goal of informing the conduct of ATIs to maximise the knowledge gained and minimise the risk to participants in clinical HIV research.

11.
Nature ; 568(7751): 244-248, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30836379

RESUMO

A cure for HIV-1 remains unattainable as only one case has been reported, a decade ago1,2. The individual-who is known as the 'Berlin patient'-underwent two allogeneic haematopoietic stem-cell transplantation (HSCT) procedures using a donor with a homozygous mutation in the HIV coreceptor CCR5 (CCR5Δ32/Δ32) to treat his acute myeloid leukaemia. Total body irradiation was given with each HSCT. Notably, it is unclear which treatment or patient parameters contributed to this case of long-term HIV remission. Here we show that HIV-1 remission may be possible with a less aggressive and toxic approach. An adult infected with HIV-1 underwent allogeneic HSCT for Hodgkin's lymphoma using cells from a CCR5Δ32/Δ32 donor. He experienced mild gut graft-versus-host disease. Antiretroviral therapy was interrupted 16 months after transplantation. HIV-1 remission has been maintained over a further 18 months. Plasma HIV-1 RNA has been undetectable at less than one copy per millilitre along with undetectable HIV-1 DNA in peripheral CD4 T lymphocytes. Quantitative viral outgrowth assays from peripheral CD4 T lymphocytes show no reactivatable virus using a total of 24 million resting CD4 T cells. CCR5-tropic, but not CXCR4-tropic, viruses were identified in HIV-1 DNA from CD4 T cells of the patient before the transplant. CD4 T cells isolated from peripheral blood after transplantation did not express CCR5 and were susceptible only to CXCR4-tropic virus ex vivo. HIV-1 Gag-specific CD4 and CD8 T cell responses were lost after transplantation, whereas cytomegalovirus-specific responses were detectable. Similarly, HIV-1-specific antibodies and avidities fell to levels comparable to those in the Berlin patient following transplantation. Although at 18 months after the interruption of treatment it is premature to conclude that this patient has been cured, these data suggest that a single allogeneic HSCT with homozygous CCR5Δ32 donor cells may be sufficient to achieve HIV-1 remission with reduced intensity conditioning and no irradiation, and the findings provide further support for the development of HIV-1 remission strategies based on preventing CCR5 expression.

12.
Sci Immunol ; 3(29)2018 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-30413420

RESUMO

Killer cell immunoglobulin-like receptors (KIRs) are expressed predominantly on natural killer cells, where they play a key role in the regulation of innate immune responses. Recent studies show that inhibitory KIRs can also affect adaptive T cell-mediated immunity. In mice and in human T cells in vitro, inhibitory KIR ligation enhanced CD8+ T cell survival. To investigate the clinical relevance of these observations, we conducted an extensive immunogenetic analysis of multiple independent cohorts of HIV-1-, hepatitis C virus (HCV)-, and human T cell leukemia virus type 1 (HTLV-1)-infected individuals in conjunction with in vitro assays of T cell survival, analysis of ex vivo KIR expression, and mathematical modeling of host-virus dynamics. Our data suggest that functional engagement of inhibitory KIRs enhances the CD8+ T cell response against HIV-1, HCV, and HTLV-1 and is a significant determinant of clinical outcome in all three viral infections.

13.
AIDS ; 2018 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-30325764

RESUMO

INTRODUCTION: There are few data on the frequency of virological remission in African individuals after treatment with antiretroviral therapy (ART) in primary HIV infection (PHI). METHODS: We studied participants (n = 82) from South Africa and Uganda in SPARTAC, the first trial of treatment interruption (TI) in African individuals with PHI randomized to deferred ART or 48 weeks of immediate ART. All were female and infected with non-B HIV subtypes, mainly C. We measured HIV DNA in CD4 T cells, CD4 count, plasma viral load (pVL), cell-associated HIV RNA and T cell activation and exhaustion. We explored associations with clinical progression and time to pVL rebound after TI (n = 22). Data were compared with non-African SPARTAC participants. RESULTS: Pre-therapy pVL and integrated HIV DNA were lower in Africans compared with non-Africans (median 4.16 vs 4.72 log10 copies/ml and 3.07 vs 3.61 log10 copies/million CD4 T-cells respectively; p < 0.001). Pre-ART HIV DNA in Africans was associated with clinical progression (p = 0.001, HR per log10 copies/million CD4 T cells increase (95% CI) 5.38 (1.95-14.79)) and time to pVL rebound (p = 0.034, HR per log10 copies/ml increase 4.33 (1.12-16.84)). After TI, Africans experienced longer duration of viral remission than non-Africans (p < 0.001; HR 3.90 (1.75-8.71). Five of 22 African participants (22.7%) maintained VL < 400 copies/ml over a median of 188 weeks following TI. CONCLUSION: We find evidence of greater probability of virological remission following TI among African participants, although we are unable to differentiate between sex, ethnicity and viral subtype. The finding warrants further investigation.

14.
Curr Opin HIV AIDS ; 13(5): 402-407, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29878914

RESUMO

PURPOSE OF REVIEW: The aim of the current review is to explore the evidence around virological remission in ART-treated and untreated individuals living with HIV. With increasing evidence and interest in post-treatment control within the HIV-cure field, it is now increasingly important to agree on definitions to allow different 'controller' phenotypes to be clearly distinguished and mechanisms compared. RECENT FINDINGS: This review explores recent data on potential predictors and mechanisms driving spontaneous and post-treatment control. We explore data on the role of the reservoir as a determinant of control and the challenges associated with its study, including the safety of treatment interruption. We explore options around deriving a consensus on how to define different forms of control and the longer term utility of achieving remission. SUMMARY: Post-treatment control and remission following treatment interruption are becoming increasingly common measures of intervention efficacy in cure trials. As well as a need to show treatment interruption protocols are well tolerated and acceptable, for these measures to be robust and comparable between studies, clear and consensual definitions need to be agreed.

15.
Arch Pathol Lab Med ; 142(10): 1268-1274, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29869903

RESUMO

CONTEXT.­: Immunophenotypic variations in mantle cell lymphoma (MCL) from the classic CD5+/CD10-/CD23-/FMC-7+ immunophenotype have been reported in the literature, but correlation with clinical behavior and outcome has not been fully studied. OBJECTIVE.­: To investigate clinicopathologic and prognostic differences between immunophenotypically aberrant MCL and immunophenotypically typical MCL. DESIGN.­: We evaluated differences in clinical presentation, laboratory parameters, prognostic indices, response to initial treatment, and progression-free and overall survival between patients with aberrant MCL and patients with immunophenotypically typical MCL. RESULTS.­: There were 158 patients with newly diagnosed cyclin D1 or t(11;14)(q13;q32)+ MCL identified in the original search, of which, 29 patients (18%) showed immunophenotypic aberrancies, with CD23 coexpression being the most common. When compared with 33 randomly selected patients with immunophenotypically typical MCL, statistically significant differences were seen in white blood cell counts ( P = .02), in the presence of absolute lymphocytosis ( P = .03), in the MCL International Prognostic Index score ( P = .02), and in response to initial treatment ( P = .04). The "immunophenotypic status" of the MCL was the only independent factor associated with response to treatment ( P = .05), but not with the MCL International Prognostic Index score, absolute lymphocytosis, or white blood cell count. No significant differences were seen for progression-free or overall survival. CONCLUSIONS.­: Immunophenotypic variations in MCL are associated with differences in clinical presentation and response to therapy when compared with immunophenotypically typical MCL. However, with current intensive frontline immunochemotherapy, immunophenotypic aberrations do not appear to affect progression-free or overall survival.

16.
Front Immunol ; 9: 603, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29706951

RESUMO

The greatest obstacle to a cure for HIV is the provirus that integrates into the genome of the infected cell and persists despite antiretroviral therapy. A "shock and kill" approach has been proposed as a strategy for an HIV cure whereby drugs and compounds referred to as latency-reversing agents (LRAs) are used to "shock" the silent provirus into active replication to permit "killing" by virus-induced pathology or immune recognition. The LRA most utilized to date in clinical trials has been the histone deacetylase (HDAC) inhibitor-vorinostat. Potentially, pathological off-target effects of vorinostat may result from the activation of human endogenous retroviruses (HERVs), which share common ancestry with exogenous retroviruses including HIV. To explore the effects of HDAC inhibition on HERV transcription, an unbiased pharmacogenomics approach (total RNA-Seq) was used to evaluate HERV expression following the exposure of primary CD4+ T cells to a high dose of vorinostat. Over 2,000 individual HERV elements were found to be significantly modulated by vorinostat, whereby elements belonging to the ERVL family (e.g., LTR16C and LTR33) were predominantly downregulated, in contrast to LTR12 elements of the HERV-9 family, which exhibited the greatest signal, with the upregulation of 140 distinct elements. The modulation of three different LTR12 elements by vorinostat was confirmed by droplet digital PCR along a dose-response curve. The monitoring of LTR12 expression during clinical trials with vorinostat may be indicated to assess the impact of this HERV on the human genome and host immunity.

17.
Front Immunol ; 9: 928, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29780387

RESUMO

Efforts to both characterize and eradicate the HIV reservoir have been limited by the rarity of latently infected cells and the absence of a specific denoting biomarker. CD32a (FcγRIIa) has been proposed to be a marker for an enriched CD4 T cell HIV reservoir, but this finding remains controversial. Here, we explore the expression of CD32 on CD3+CD4+ cells in participants from two primary HIV infection studies and identify at least three distinct phenotypes (CD32low, CD32+CD14+, and CD32high). Of note, CD4 negative enrichment kits remove the majority of CD4+CD32+ T cells, potentially skewing subsequent analyses if used. CD32high CD4 T cells had higher levels of HLA-DR and HIV co-receptor expression than other subsets, compatible with their being more susceptible to infection. Surprisingly, they also expressed high levels of CD20, TCRαß, IgD, and IgM (but not IgG), markers for both T cells and naïve B cells. Compared with other populations, CD32low cells had a more differentiated memory phenotype and high levels of immune checkpoint receptors, programmed death receptor-1 (PD-1), Tim-3, and TIGIT. Within all three CD3+CD4+CD32+ phenotypes, cells could be identified in infected participants, which contained HIV DNA. CD32 expression on CD4 T cells did not correlate with HIV DNA or cell-associated HIV RNA (both surrogate measures of overall reservoir size) or predict time to rebound viremia following treatment interruption, suggesting that it is not a dominant biomarker for HIV persistence. Our data suggest that while CD32+ T cells can be infected with HIV, CD32 is not a specific marker of the reservoir although it might identify a population of HIV enriched cells in certain situations.

18.
Artigo em Inglês | MEDLINE | ID: mdl-29730891

RESUMO

BACKGROUND: Multiple variants in SNCA, encoding alpha-synuclein, a main component of Lewy bodies, are implicated in Parkinson's disease. METHODS: We searched for cis-acting SNCA variants using allelic mRNA ratios in human brain tissues. In a SNCA 3'UTR (2,520 bp) luciferase reporter gene assay, translation in SH-SY5Y cells in the presence of the rs17016074 G/A alleles was measured. To assess clinical impact, we queried neurocognitive genome-wide association studies. RESULTS: Allelic ratios deviated up to twofold, measured at a marker SNP in the middle of a long 3' untranslated region (3'UTR), but not at a marker at its start, suggesting regulation of 3'UTR processing. 3'UTR SNP rs17016074 G/A, minor allele frequency (MAF) <1% in Caucasians, 13% in Africans, strongly associates with large allelic mRNA expression imbalance (AEI), resulting in reduced expression of long 3'UTR isoforms. A second 3'UTR SNP (rs356165) associates with moderate AEI and enhances SNCA mRNA expression. The rs17016074 A allele reduces overall 3'UTR expression in luciferase reporter gene assays but supports more efficient translation, resolving previous contradictory results. We failed to detect significant genome-wide associations for rs17016074, possibly a result of low MAF in Caucasians or its absence from most genotyping panels. In the "Genome Wide Association Study of Yoruba in Nigeria," rs356165 was associated with reduced memory performance. CONCLUSIONS: Here, we identify two cis-acting regulatory variants affecting SNCA mRNA expression, measured by allelic ratios in the 3'UTR. The rs17016074 minor A allele is associated with higher expression of luciferase protein activity. Resolving the genetic influence of SNCA polymorphisms requires study of the interactions between multiple regulatory variants with distinct frequencies among populations.

19.
J Infect Dis ; 217(11): 1782-1792, 2018 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-29546381

RESUMO

Background: Human immunodeficiency virus (HIV)-infected individuals have a higher risk of developing active tuberculosis (TB) than HIV-uninfected individuals, but the mechanisms underpinning this are unclear. We hypothesized that depletion of specific components of Mycobacterium tuberculosis (Mtb)-specific CD4+ and CD8+ T-cell responses contributed to this increased risk. Methods: Mtb-specific T-cell responses in 147 HIV-infected and 44 HIV-uninfected control subjects in a TB-endemic setting in Bloemfontein, South Africa, were evaluated. Using a whole-blood flow cytometry assay, we measured expression of interferon gamma, tumor necrosis factor alpha, interleukin 2, and interleukin 17 in CD4+ and CD8+ T cells in response to Mtb antigens (PPD, ESAT-6/CFP-10 [EC], and DosR regulon-encoded α-crystallin [Rv2031c]). Results: Fewer HIV-infected individuals had detectable CD4+ and CD8+ T-cell responses to PPD and Rv2031c than HIV-uninfected subjects. Mtb-specific T cells showed distinct patterns of cytokine expression comprising both Th1 (CD4 and CD8) and Th17 (CD4) cytokines, the latter at highest frequency for Rv2031c. Th17 antigen-specific responses to all antigens tested were specifically impaired in HIV-infected individuals. Conclusions: HIV-associated impairment of CD4+ and CD8+Mtb-specific T-cell responses is antigen specific, particularly impacting responses to PPD and Rv2031c. Preferential depletion of Th17 cytokine-expressing CD4+ T cells suggests this T-cell subset may be key to TB susceptibility in HIV-infected individuals.

20.
J Virol ; 92(4)2018 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-29167337

RESUMO

The well-characterized association between HLA-B*27:05 and protection against HIV disease progression has been linked to immunodominant HLA-B*27:05-restricted CD8+ T-cell responses toward the conserved Gag KK10 (residues 263 to 272) and polymerase (Pol) KY9 (residues 901 to 909) epitopes. We studied the impact of the 3 amino acid differences between HLA-B*27:05 and the closely related HLA-B*27:02 on the HIV-specific CD8+ T-cell response hierarchy and on immune control of HIV. Genetic epidemiological data indicate that both HLA-B*27:02 and HLA-B*27:05 are associated with slower disease progression and lower viral loads. The effect of HLA-B*27:02 appeared to be consistently stronger than that of HLA-B*27:05. In contrast to HLA-B*27:05, the immunodominant HIV-specific HLA-B*27:02-restricted CD8+ T-cell response is to a Nef epitope (residues 142 to 150 [VW9]), with Pol KY9 subdominant and Gag KK10 further subdominant. This selection was driven by structural differences in the F pocket, mediated by a polymorphism between these two HLA alleles at position 81. Analysis of autologous virus sequences showed that in HLA-B*27:02-positive subjects, all three of these CD8+ T-cell responses impose selection pressure on the virus, whereas in HLA-B*27:05-positive subjects, there is no Nef VW9-mediated selection pressure. These studies demonstrate that HLA-B*27:02 mediates protection against HIV disease progression that is at least as strong as or stronger than that mediated by HLA-B*27:05. In combination with the protective Gag KK10 and Pol KY9 CD8+ T-cell responses that dominate HIV-specific CD8+ T-cell activity in HLA-B*27:05-positive subjects, a Nef VW9-specific response is additionally present and immunodominant in HLA-B*27:02-positive subjects, mediated through a polymorphism at residue 81 in the F pocket, that contributes to selection pressure against HIV.IMPORTANCE CD8+ T cells play a central role in successful control of HIV infection and have the potential also to mediate the eradication of viral reservoirs of infection. The principal means by which protective HLA class I molecules, such as HLA-B*27:05 and HLA-B*57:01, slow HIV disease progression is believed to be via the particular HIV-specific CD8+ T cell responses restricted by those alleles. We focus here on HLA-B*27:05, one of the best-characterized protective HLA molecules, and the closely related HLA-B*27:02, which differs by only 3 amino acids and which has not been well studied in relation to control of HIV infection. We show that HLA-B*27:02 is also protective against HIV disease progression, but the CD8+ T-cell immunodominance hierarchy of HLA-B*27:02 differs strikingly from that of HLA-B*27:05. These findings indicate that the immunodominant HLA-B*27:02-restricted Nef response adds to protection mediated by the Gag and Pol specificities that dominate anti-HIV CD8+ T-cell activity in HLA-B*27:05-positive subjects.


Assuntos
Linfócitos T CD8-Positivos/imunologia , Infecções por HIV/imunologia , Antígeno HLA-B27/genética , Epitopos Imunodominantes/imunologia , Produtos do Gene gag do Vírus da Imunodeficiência Humana/genética , Produtos do Gene nef do Vírus da Imunodeficiência Humana/genética , Genes MHC Classe I , Infecções por HIV/virologia , HIV-1 , Humanos , Carga Viral
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