RESUMO
FREM1 (Fras-related extracellular matrix 1) and its splice variant TILRR (Toll-like interleukin-1 receptor regulator) have been identified as integral components of innate immune systems. The potential involvement of FREM1 in HIV-1 (human immunodeficiency virus 1) acquisition was suggested by a genome-wide SNP (single nucleotide polymorphism) analysis of HIV-1 resistant and susceptible sex workers enrolled in the Pumwani sex worker cohort (PSWC) in Nairobi, Kenya. The studies showed that the minor allele of a FREM1 SNP rs1552896 is highly enriched in the HIV-1 resistant female sex workers. Subsequent studies showed that FREM1 mRNA is highly expressed in tissues relevant to mucosal HIV-1 infection, including cervical epithelial tissues, and TILRR is a major modulator of many genes in the NF-κB signal transduction pathway. In this article, we review the role of FREM1 and TILRR in modulating inflammatory responses and inflammation, and how their influence on inflammatory responses of cervicovaginal tissue could enhance the risk of vaginal HIV-1 acquisition.
Assuntos
Infecções por HIV/virologia , HIV-1/patogenicidade , Inflamação/complicações , Polimorfismo de Nucleotídeo Único , Receptores de Interleucina/metabolismo , Profissionais do Sexo/estatística & dados numéricos , Vagina/virologia , Feminino , Infecções por HIV/epidemiologia , Humanos , Isoformas de Proteínas , Receptores de Interleucina/genéticaRESUMO
BACKGROUND: Understanding natural HIV control may lead to new preventative or therapeutic strategies. Several protective major histocompatibility complex (MHC) genotypes were found in humans and rhesus macaques. Here, we report a simian immunodeficiency virus (SIV) controller MHC genotype in Mauritian cynomolgus macaques (MCMs). METHODS: Twelve MHC-genotyped MCMs were infected with SIVmac251 and monitored for viral loads and CD4+ T-cell counts. RESULTS: Two macaques with M3M4 genotype exhibited the lowest peak viral loads (log plasma SIV RNA copies/mL), nearly 3 logs lower than those in most macaques with other MHC haplotype combinations, and set point viral loads below the level of detection limit by RT-qPCR (<2 log RNA copies/mL). They maintained healthy CD4+ T-cell counts of >500 cells/µL blood, while CD4 counts in the vast majority of other macaques were below this level. CONCLUSIONS: The M3M4 MHC genotype may confer enhanced control of SIV replication in MCMs.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Haplótipos , Macaca fascicularis/genética , Síndrome de Imunodeficiência Adquirida dos Símios/virologia , Carga Viral , Animais , Feminino , Macaca fascicularis/imunologia , Maurício , Síndrome de Imunodeficiência Adquirida dos Símios/genética , Vírus da Imunodeficiência Símia/fisiologiaRESUMO
HIV preferentially infects activated CD4+ T cells and mutates rapidly. The classical vaccine approach aimed to generate broad immune responses to full HIV proteins largely failed to address the potential adverse impact of increased number of activated CD4+ T cells as viral targets. Learning from natural immunity observed in a group of HIV resistant Kenyan female sex workers, we are testing a novel vaccine approach. It focuses immune response to the highly conserved sequences surrounding the HIV protease cleavage sites (PCS) to disrupt viral maturation, while limiting excessive immune activation. Our pilot studies using nonhuman primate SIV infection models suggest that this approach is feasible and promising.
Assuntos
Vacinas contra a AIDS , Infecções por HIV/prevenção & controle , Protease de HIV/imunologia , Protease de HIV/metabolismo , HIV-1/imunologia , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/virologia , Sequência Conservada/genética , Sequência Conservada/imunologia , Feminino , Infecções por HIV/epidemiologia , Infecções por HIV/imunologia , Infecções por HIV/virologia , Protease de HIV/genética , HIV-1/enzimologia , HIV-1/genética , Humanos , Imunidade Inata , Quênia/epidemiologia , Macaca mulatta , Projetos Piloto , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Vírus da Imunodeficiência Símia/imunologiaRESUMO
The major histocompatibility complex (MHC) containing the classical human leukocyte antigen (HLA) Class I and Class II genes is among the most polymorphic and diverse regions in the human genome. Despite the clinical importance of identifying the HLA types, very few databases jointly characterize densely genotyped single nucleotide polymorphisms (SNPs) and HLA alleles in the same samples. To date, the HapMap presents the only public resource that provides a SNP reference panel for predicting HLA alleles, constructed with four collections of individuals of north-western European, northern Han Chinese, cosmopolitan Japanese and Yoruba Nigerian ancestry. Owing to complex patterns of linkage disequilibrium in this region, it is unclear whether the HapMap reference panels can be appropriately utilized for other populations. Here, we describe a public resource for the Singapore Genome Variation Project with: (i) dense genotyping across â¼ 9000 SNPs in the MHC; (ii) four-digit HLA typing for eight Class I and Class II loci, in 96 southern Han Chinese, 89 Southeast Asian Malays and 83 Tamil Indians. This resource provides population estimates of the frequencies of HLA alleles at these eight loci in the three population groups, particularly for HLA-DPA1 and HLA-DPB1 that were not assayed in HapMap. Comparing between population-specific reference panels and a cosmopolitan panel created from all four HapMap populations, we demonstrate that more accurate imputation is obtained with population-specific panels than with the cosmopolitan panel, especially for the Malays and Indians but even when imputing between northern and southern Han Chinese. As with SNP imputation, common HLA alleles were imputed with greater accuracy than low-frequency variants.
Assuntos
Alelos , Antígenos HLA/genética , Cadeias alfa de HLA-DP/genética , Cadeias beta de HLA-DP/genética , Polimorfismo de Nucleotídeo Único , Povo Asiático/genética , Povo Asiático/estatística & dados numéricos , Loci Gênicos , Humanos , Complexo Principal de Histocompatibilidade/genéticaRESUMO
The female genital tract is a portal of entry for sexual HIV transmission and a possible viral reservoir. In this study, the ectocervical CD8+ T cell distribution was explored in situ and was related to expression of CD3 and HLA-DR and presence of HIV RNA. For this purpose, ectocervical tissue samples and genital secretions were collected from HIV-seropositive (HIV+) Kenyan female sex workers (FSWs) (n = 20), HIV-seronegative (HIV-) FSWs (n = 17), and HIV(-) lower-risk women (n = 21). Cell markers were assessed by in situ staining and by quantitative PCR. HIV RNA expression in tissue was analyzed by in situ hybridization, and viral shedding was assessed by quantitative PCR. The HIV+ FSW group had a higher amount of total cells and CD8+, CD3+, and HLA-DR+ cells compared with the HIV(-)FSW group and HIV- lower-risk women. The majority of CD8+ cells were CD3+ T cells, and the numbers of CD8+ cells correlated significantly with plasma and cervical viral load. HIV RNA expression in situ was found in 4 of the 20 HIV+FSW women but did not correlate with cervical or plasma viral load. Thus, the HIV+ women displayed high numbers of CD8+, CD3+, and HLA-DR+ cells, as well as a limited number of HIV RNA+ cells, in their ectocervical mucosa; hence, this localization cannot be neglected as a potential viral reservoir. The elevated levels of CD8+ T cells may play a role in the immunopathogenesis of HIV in the female genital tract.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Colo do Útero , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/imunologia , Mucosa/imunologia , Eliminação de Partículas Virais/imunologia , Adulto , Complexo CD3/genética , Complexo CD3/metabolismo , Antígenos CD8/genética , Antígenos CD8/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Feminino , Regulação da Expressão Gênica , Regulação Viral da Expressão Gênica , HIV-1/genética , Antígenos HLA-DR/genética , Antígenos HLA-DR/imunologia , Antígenos HLA-DR/metabolismo , Humanos , Pessoa de Meia-Idade , Mucosa/virologia , Fenótipo , RNA Viral , Fatores de Risco , Profissionais do Sexo , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Carga Viral , Adulto JovemRESUMO
BACKGROUND: LAG-3 is a potent negative regulator of the immune response but its impact in HIV infection in poorly understood. Unlike exhaustion markers such as PD-1, Tim-3, 2B4 and CD160, LAG-3 is poorly expressed on bulk and antigen-specific T cells during chronic HIV infection and its expression on innate lymphocyte subsets is not well understood. The aim of this study was to assess LAG-3 expression and association with cellular dysfunction on T cells, NK cells and iNKT cells among a cohort of healthy and HIV-infected female sex workers in Nairobi, Kenya. RESULTS: Ex vivo LAG-3 expression was measured by multiparametric flow cytometry, and plasma cytokine/chemokine concentrations measured by bead array. Although LAG-3 expression on bulk T cells was significantly increased among HIV-infected women, the proportion of cells expressing the marker was extremely low. In contrast, LAG-3 was more highly expressed on NK and iNKT cells and was not reduced among women treated with ART. To assess the functional impact of LAG-3 on iNKT cells, iNKT cytokine production was measured in response to lipid (αGalCer) and PMA/Io stimulation by both flow cytometry and cytokine bead array. iNKT cytokine production is profoundly altered by both HIV infection and treatment, and LAG-3, but not PD-1, expression is associated with a reduction in iNKT IFNγ production. CONCLUSIONS: LAG-3 does not appear to mediate T cell exhaustion in this African population, but is instead expressed on innate lymphocyte subsets including iNKT cells. HIV infection alters iNKT cytokine production patterns and LAG-3 expression is uniquely associated with iNKT dysfunction. The continued expression of LAG-3 during treatment suggests it may contribute to the lack of innate immune reconstitution commonly observed during ART.
Assuntos
Antígenos CD/metabolismo , Citocinas/metabolismo , Infecções por HIV/imunologia , HIV-1/imunologia , Interações Hospedeiro-Patógeno , Células T Matadoras Naturais/imunologia , Receptor de Morte Celular Programada 1/metabolismo , Adulto , Estudos de Coortes , Feminino , Expressão Gênica , Voluntários Saudáveis , Humanos , Quênia , Pessoa de Meia-Idade , Profissionais do Sexo , Regulação para Cima , Proteína do Gene 3 de Ativação de LinfócitosRESUMO
Multiple genome-wide association studies (GWAS) have been performed in HIV-1 infected individuals, identifying common genetic influences on viral control and disease course. Similarly, common genetic correlates of acquisition of HIV-1 after exposure have been interrogated using GWAS, although in generally small samples. Under the auspices of the International Collaboration for the Genomics of HIV, we have combined the genome-wide single nucleotide polymorphism (SNP) data collected by 25 cohorts, studies, or institutions on HIV-1 infected individuals and compared them to carefully matched population-level data sets (a list of all collaborators appears in Note S1 in Text S1). After imputation using the 1,000 Genomes Project reference panel, we tested approximately 8 million common DNA variants (SNPs and indels) for association with HIV-1 acquisition in 6,334 infected patients and 7,247 population samples of European ancestry. Initial association testing identified the SNP rs4418214, the C allele of which is known to tag the HLA-B*57:01 and B*27:05 alleles, as genome-wide significant (p = 3.6 × 10⻹¹). However, restricting analysis to individuals with a known date of seroconversion suggested that this association was due to the frailty bias in studies of lethal diseases. Further analyses including testing recessive genetic models, testing for bulk effects of non-genome-wide significant variants, stratifying by sexual or parenteral transmission risk and testing previously reported associations showed no evidence for genetic influence on HIV-1 acquisition (with the exception of CCR5Δ32 homozygosity). Thus, these data suggest that genetic influences on HIV acquisition are either rare or have smaller effects than can be detected by this sample size.
Assuntos
Infecções por HIV/genética , HIV-1/fisiologia , Interações Hospedeiro-Patógeno , Polimorfismo de Nucleotídeo Único , Estudos de Casos e Controles , Estudos de Coortes , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Infecções por HIV/virologia , Humanos , População BrancaRESUMO
Studies using genital tissue samples from HIV-infected women might provide important information about HIV susceptibility and transmission. In this study, ectocervical biopsies were obtained from 20 HIV-seropositive (HIV(+)) Kenyan female sex workers (FSW) and 20 HIV-seronegative lower risk (HIV(-) LR) women. To control for the impact of sex work, 20 HIV(-) FSW were also recruited. Immune molecules were assessed in situ by immunohistochemistry and for mRNA expression by quantitative PCR. The HIV(+) women were reportedly infected for a median of 3 y (1-21 y), with a median viral load of 11,735 copies/ml (20-648,000 copies/ml). These women had significantly lower CD4 blood cell counts than the HIV(-) LR women but comparable levels of CD4 expression in ectocervix. Whereas cellular markers were similar between the HIV(+) group and the HIV(-) LR women, the HIV-binding molecules CCR5, dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin, and mannose receptor as well as the inflammatory markers CD69, IFN-γ, IL-6, and IL-22 were significantly upregulated in the HIV(+) group. As compared with the HIV(-) FSW women, the HIV(+) women had significantly upregulated levels of CD4, CD3, CCR5, Langerin, dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin, and mannose receptor as well as inflammatory cytokines. The CD4 cell depletion previously seen in the gut mucosa of HIV-infected individuals was thus not observed in the ectocervical mucosa. Stable CD4 cell expression and local immune activation in the lower female genital tract may promote viral replication and genital shedding and increase the risk of sexual HIV transmission.
Assuntos
Antígenos CD4/metabolismo , Colo do Útero/imunologia , Colo do Útero/metabolismo , Infecções por HIV/imunologia , HIV-1/imunologia , Mucosa/imunologia , Mucosa/metabolismo , Adulto , Biomarcadores/metabolismo , Antígenos CD4/genética , Contagem de Linfócito CD4 , Colo do Útero/virologia , Citocinas/biossíntese , Feminino , Expressão Gênica , Infecções por HIV/genética , Infecções por HIV/metabolismo , Humanos , Pessoa de Meia-Idade , Mucosa/virologia , Profissionais do Sexo , Adulto JovemRESUMO
BACKGROUND: Unprotected intercourse and seminal discharge are powerful activators of the mucosal immune system and are important risk factors for transmission of human immunodeficiency virus (HIV). This study was designed to determine if female sex work is associated with changes in the mucosal immunity. METHODS: Cervicovaginal lavage and plasma from 122 HIV-uninfected female sex workers (FSW) and 44 HIV-uninfected low-risk non-FSW from the same socioeconomic district of Nairobi were analyzed for evidence of immune activation (IA). The cervico-mononuclear cells (CMC) were analyzed for cellular activation by flow cytometry. RESULTS: Lower IA was observed in FSW compared to the low-risk women as demonstrated by the lower level of MIP-3α (P < .001), ITAC (P < .001), MIG (p.0001), IL-1α (P < .001), IL-1ß (P < .001), IL-1Rα (P = .0002), IL-6 (P < .001), IL-8 (P < .001), IL-10 (P = .01), IP-10 (P = .0001), MDC (P < .001), MIP-1α, (P < .001), MIP-1ß (P = .005), MCP-1 (P = .03), and TNF-α (P = .006). Significant differences were noted as early as 1 year following initiation of sex work and increased with duration of sex work. CONCLUSION: This study showed that sex work is associated with important changes in the mucosal immune system. By analyzing chemokine/cytokine levels and CMC activation, we observed a lower mucosal IA in HIV-uninfected FSW compared to low-risk women.
Assuntos
Citocinas/metabolismo , Imunidade nas Mucosas , Leucócitos Mononucleares/imunologia , Profissionais do Sexo , Adulto , Idoso , Feminino , Humanos , Ativação Linfocitária , Pessoa de Meia-Idade , Plasma/química , Plasma/imunologia , Vagina/química , Vagina/imunologia , Adulto JovemRESUMO
MS/MS is the technology of choice for analyzing complex protein mixtures. However, due to the intrinsic complexity and dynamic range present in higher eukaryotic proteomes, prefractionation is an important step to maximize the number of proteins identified. Off-gel IEF (OG-IEF) and high pH RP (Hp-RP) column chromatography have both been successfully utilized as a first-dimension peptide separation technique in shotgun proteomic experiments. Here, a direct comparison of the two methodologies was performed on ex vivo peripheral blood mononuclear cell lysate. In 12-fraction replicate analysis, Hp-RP resulted in more peptides and proteins identified than OG-IEF fractionation. Distributions of peptide pIs and hydropathy did not reveal any appreciable bias in either technique. Resolution, defined here as the ability to limit a specific peptide to one particular fraction, was significantly better for Hp-RP. This leads to a more uniform distribution of total and unique peptides for Hp-RP across all fractions collected. These results suggest that fractionation by Hp-RP over OG-IEF is the better choice for typical complex proteome analysis.
Assuntos
Fracionamento Químico/métodos , Cromatografia de Fase Reversa/métodos , Focalização Isoelétrica/métodos , Proteoma/metabolismo , Proteômica/métodos , Fenômenos Biofísicos , Bases de Dados de Proteínas , Humanos , Concentração de Íons de Hidrogênio , Leucócitos Mononucleares/metabolismo , Nanotecnologia , Peptídeos/isolamento & purificação , Proteínas/isolamento & purificação , Reprodutibilidade dos Testes , Tripsina/metabolismoRESUMO
A subset of women in the Pumwani Sex Worker Cohort, established in 1985 in Nairobi, Kenya, remains uninfected despite repeated high-risk exposure (HIV-exposed, seronegative [HESN]) through active sex work. This HESN phenotype is associated with several alleles of human leukocyte antigens (HLAs) and specific CD8(+) and CD4(+) T cell responses to HIV-1. The associations of HLA alleles with differential HIV-1 infection are most likely due to their different abilities to present antigen and the different immune responses they induce. The characteristics of epitopes of HLA alleles associated with different outcomes of HIV-1 infection might therefore point to a vital clue for developing an effective vaccine. In this study, we systematically analyzed HIV-1 clade A and D Gag CD8(+) T cell epitopes of two HLA class I alleles associated with different outcomes of HIV-1 infection. Binding affinity and off-rates of the identified epitopes were determined. Gamma interferon (IFN-γ) enzyme-linked immunospot (ELISpot) assays with patient peripheral blood mononuclear cells (PBMCs) validated the epitopes. Epitope-specific CD8(+) T cells were further phenotyped for memory markers with tetramer staining. Our study showed that the protective allele A*01:01 recognizes only three Gag epitopes. By contrast, B*07:02, the allele associated with susceptibility, binds 30 epitope variants. These two alleles differ most importantly in the spectrum of Gag epitopes they can present and not in affinity, off-rates, the location of the epitopes, or epitope-specific Tem/Tcm frequencies. The binding of more epitopes and strong IFN-gamma ELISpot responses are associated with susceptibility to HIV-1 infection, while more focused antigen recognition of multiple subtypes is protective. Rational vaccine design should take these observations into account.
Assuntos
Epitopos de Linfócito T/imunologia , Infecções por HIV/genética , Infecções por HIV/prevenção & controle , HIV-1/imunologia , Antígenos HLA/genética , Produtos do Gene gag do Vírus da Imunodeficiência Humana/imunologia , Adulto , Alelos , Sequência de Aminoácidos , Estudos de Coortes , Epitopos de Linfócito T/química , Epitopos de Linfócito T/genética , Feminino , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/química , HIV-1/genética , HIV-1/fisiologia , Antígenos HLA/imunologia , Humanos , Quênia , Dados de Sequência Molecular , Alinhamento de Sequência , Profissionais do Sexo , Produtos do Gene gag do Vírus da Imunodeficiência Humana/química , Produtos do Gene gag do Vírus da Imunodeficiência Humana/genéticaRESUMO
Cervicovaginal lavage fluid (CVL) is a natural source of anti-HIV-1 factors; however, molecular characterization of the anti-HIV-1 activity of CVL remains elusive. In this study, we confirmed that CVLs from HIV-1-resistant (HIV-R) compared to HIV-1-susceptible (HIV-S) commercial sex workers (CSWs) contain significantly larger amounts of serine antiprotease trappin-2 (Tr) and its processed form, elafin (E). We assessed anti-HIV-1 activity of CVLs of CSWs and recombinant E and Tr on genital epithelial cells (ECs) that possess (TZM-bl) or lack (HEC-1A) canonical HIV-1 receptors. Our results showed that immunodepletion of 30% of Tr/E from CVL accounted for up to 60% of total anti-HIV-1 activity of CVL. Knockdown of endogenous Tr/E in HEC-1A cells resulted in significantly increased shedding of infectious R5 and X4 HIV-1. Pretreatment of R5, but not X4 HIV-1, with either Tr or E led to inhibition of HIV-1 infection of TZM-bl cells. Interestingly, when either HIV-1 or cells lacking canonical HIV-1 receptors were pretreated with Tr or E, HIV-1 attachment and transcytosis were significantly reduced, and decreased attachment was not associated with altered expression of syndecan-1 or CXCR4. Determination of 50% inhibitory concentrations (IC(50)) of Tr and E anti-HIV-1 activity indicated that E is â¼130 times more potent than its precursor, Tr, despite their equipotent antiprotease activities. This study provides the first experimental evidence that (i) Tr and E are among the principal anti-HIV-1 molecules of CVL; (ii) Tr and E affect cell attachment and transcytosis of HIV-1; (iii) E is more efficient than Tr regarding anti-HIV-1 activity; and (iv) the anti-HIV-1 effect of Tr and E is contextual.
Assuntos
Fármacos Anti-HIV/farmacologia , Elafina/farmacologia , Genitália Feminina/virologia , HIV-1/efeitos dos fármacos , Fármacos Anti-HIV/metabolismo , Antígenos CD4/metabolismo , Linhagem Celular , Elafina/genética , Elafina/metabolismo , Células Epiteliais/imunologia , Feminino , Inativação Gênica , Genitália Feminina/imunologia , Genitália Feminina/metabolismo , HIV-1/imunologia , Humanos , Imunidade nas Mucosas , Elastase de Leucócito/antagonistas & inibidores , RNA Interferente Pequeno/metabolismo , Receptores CXCR5/metabolismo , Transcitose/efeitos dos fármacos , Ligação Viral/efeitos dos fármacosRESUMO
A subgroup of women enrolled in the Pumwani sex worker cohort remain seronegative and PCR negative for human immunodeficiency virus type 1 despite repeated exposure through high-risk sex work. Studies have shown that polymorphisms of genes involved in antigen presentation and viral restriction factors are associated with resistance to HIV infection. To discover other possible genetic factors underlying this HIV-resistant phenotype, we conducted an exploratory nonbiased, low-resolution, genome-wide single-nucleotide polymorphism (SNP) analysis comparing 60 HIV-resistant women to 48 HIV-infected controls. The SNP minor allele rs1552896, in an intron of FREM1, was significantly associated with the resistant phenotype (P = 1.68 × 10(-5); adjusted P = 2.37 × 10(-4); odds ratio [OR], 9.51; 95% confidence interval [CI], 2.82 to 32.05). We expanded the sample size by genotyping rs1552896 in the Pumwani cohort and comparing 114 HIV-resistant women to 609 HIV-infected controls and confirmed the association (P = 1.7 × 10(-4); OR, 2.67; 95% CI, 1.47 to 4.84). To validate the association in a second cohort, we genotyped 783 women enrolled in a mother-child health study and observed the minor allele of rs1552896 enriched in HIV-uninfected women (n = 488) compared to HIV-infected enrollees (n = 295) (P = 0.036; OR, 1.69; 95% CI, 0.98 to 2.93). Quantitative reverse transcription-PCR showed that FREM1 mRNA was highly expressed in tissues relevant for HIV-1 infection, and immunohistochemical analysis revealed that FREM1 protein is expressed in the ectocervical mucosa of HIV-resistant women. The significant association of rs1552896 with an HIV-resistant phenotype, together with the expression profile of FREM1 in tissues relevant to HIV infection, suggests that FREM1 is a potentially novel candidate gene for resistance to HIV infection.
Assuntos
Resistência à Doença , Infecções por HIV/imunologia , HIV-1/patogenicidade , Receptores de Interleucina/genética , Adulto , Colo do Útero/imunologia , Estudos de Coortes , Feminino , Perfilação da Expressão Gênica , Estudos de Associação Genética , Humanos , Imunidade nas Mucosas , Imuno-Histoquímica , Quênia , Polimorfismo de Nucleotídeo Único , Profissionais do SexoRESUMO
Not all individuals exposed to HIV become infected. Understanding why these HIV-exposed seronegative individuals remain uninfected will help inform the development of preventative measures against HIV infection. Interferon regulatory factor-1 (IRF1) plays a critical role both in host antiviral immunity and in HIV-1 replication. This study examined IRF1 expression regulation in the ex vivo peripheral blood mononuclear cells of HIV-exposed seronegative commercial sex workers who can be epidemiologically defined as relatively resistant to HIV infection (HIV-R), versus HIV-uninfected, susceptible controls (HIV-S). Whereas HIV-susceptible individuals demonstrated a biphasic, prolonged increase in IRF1 expression after interferon-γ stimulation, HIV-R individuals demonstrated a robust, but transient response. We also found that the IRF1 promoter in HIV-R was primed by increased basal histone deacetylase-2 binding, independently of transcription regulators, STAT1 and nuclear factor-κB/p65, implicating an epigenetic silencing mechanism. Interestingly, the transitory IRF1 response in HIV-R was sufficient in comparable regulation of interleukin-12 and interleukin-4 expression compared with the HIV-susceptible controls. This is the first study characterizing IRF1 responsiveness in individuals who demonstrate altered susceptibility to HIV infection. These data suggest that transitory IRF1 responsiveness in HIV-R may be one of the key contributors to the altered susceptibility to HIV infection during the early stages of primary HIV infection.
Assuntos
Suscetibilidade a Doenças , Epigênese Genética , Infecções por HIV/genética , Soronegatividade para HIV/genética , Fator Regulador 1 de Interferon/genética , Acetilação/efeitos dos fármacos , Estudos de Casos e Controles , Regulação para Baixo/efeitos dos fármacos , Epigênese Genética/efeitos dos fármacos , Inativação Gênica/efeitos dos fármacos , Loci Gênicos , Infecções por HIV/imunologia , Histona Desacetilase 2/metabolismo , Histonas/metabolismo , Humanos , Fator Regulador 1 de Interferon/metabolismo , Interferon gama/farmacologia , Cinética , NF-kappa B/metabolismo , Regiões Promotoras Genéticas/genética , Ligação Proteica/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Fator de Transcrição STAT1/metabolismo , Fator de Transcrição RelA/metabolismoRESUMO
BACKGROUND: Aging of the immune system, known as immunosenescence, is associated with profound changes in both innate and adaptive immune responses, resulting in increased susceptibility to infection and a decreased ability to respond to vaccination. The purpose of this study was to investigate the effect of age and menopause on the expression of 22 different cytokines/chemokines in both plasma and cervical lavage samples from female sex-worker cohort from Nairobi, Kenya (age range 20-65). RESULTS: Cytokine/chemokine levels were measured using a Miliplex multiplex assay (Millipore). We found that age positively correlated with MCP-1 (p = 0.0002) and IP-10 (p = 0.03) systemic cytokine expression, and that women over 50 expressed the highest levels of these cytokines, but also had elevated expression of MIG (ANOVA p = 0.0096) and MIP-3ß(ANOVA p = 0.0434). We also found that IL-8 (p = 0.047) and sCD40L (p = 0.01) systemic expression negatively correlated with age. Further, MIG (p = 0.0081) and MCP-1 (p = 0.0157) were present at higher levels in post-menopausal women suggesting a potential estrogen dependant systemic regulation of these cytokines. In cervical lavage samples, age did not directly correlate with the expression of any of the tested cytokines/chemokines, however sIL-2Rα (ANOVA p = 0.0170) and IL-15 (ANOVA p = 0.0251)were significantly higher in women over 50. Menopause was shown to have a more profound effect on cytokine expression in the cervical mucosa with MIG (p = 0.0256), MIP-3α (p = 0.0245), IL-1ß (p = 0.0261), IL-6 (p = 0.0462), IL-8 (p = 0.007), IP-10 (p = 0.0357) and MCP-1 (p = 0.0427) all significantly under-expressed in post-menopausal women. CONCLUSIONS: This study demonstrates that aging and menopause-associated hormonal changes are associated with significant changes in systemic and mucosal cytokine/chemokine expression, which may have implications for the age-related decline in the ability to fight against infections.
RESUMO
Some people remain healthier throughout life than others but the underlying reasons are poorly understood. Here we hypothesize this advantage is attributable in part to optimal immune resilience (IR), defined as the capacity to preserve and/or rapidly restore immune functions that promote disease resistance (immunocompetence) and control inflammation in infectious diseases as well as other causes of inflammatory stress. We gauge IR levels with two distinct peripheral blood metrics that quantify the balance between (i) CD8+ and CD4+ T-cell levels and (ii) gene expression signatures tracking longevity-associated immunocompetence and mortality-associated inflammation. Profiles of IR metrics in ~48,500 individuals collectively indicate that some persons resist degradation of IR both during aging and when challenged with varied inflammatory stressors. With this resistance, preservation of optimal IR tracked (i) a lower risk of HIV acquisition, AIDS development, symptomatic influenza infection, and recurrent skin cancer; (ii) survival during COVID-19 and sepsis; and (iii) longevity. IR degradation is potentially reversible by decreasing inflammatory stress. Overall, we show that optimal IR is a trait observed across the age spectrum, more common in females, and aligned with a specific immunocompetence-inflammation balance linked to favorable immunity-dependent health outcomes. IR metrics and mechanisms have utility both as biomarkers for measuring immune health and for improving health outcomes.
Assuntos
COVID-19 , Longevidade , Feminino , Humanos , Envelhecimento , Inflamação , Avaliação de Resultados em Cuidados de SaúdeRESUMO
BACKGROUND: The GNB3 C825T polymorphism is associated with increased G protein-mediated signal transduction, SDF-1α-mediated lymphocyte chemotaxis, accelerated HIV-1 progression, and altered responses to antiretroviral therapy among Caucasian subjects. The GNB3 825T allele is highly prevalent in African populations, and as such any impact on HIV-1 acquisition or progression rates could have a dramatic impact. This study examines the association of the 825T polymorphism with HIV-1 acquisition, disease progression and immune activation in two African cohorts. GNB3 825 genotyping was performed for enrolees in both a commercial sex worker cohort and a perinatal HIV transmission (PHT) cohort in Nairobi, Kenya. Ex vivo immune activation was quantified by flow cytometry, and plasma chemokine levels were assessed by cytokine bead array. RESULTS: GNB3 genotype was not associated with sexual or vertical HIV-1 acquisition within these cohorts. Within the Pumwani cohort, GNB3 genotype did not affect HIV-1 disease progression among seroconverters or among HIV-1-positive individuals after adjustment for baseline CD4 count. Maternal CD4 decline and viral load increase in the PHT cohort did not differ between genotypes. Multi-parametric flow cytometry assessment of T cell activation (CD69, HLA-DR, CD38) and Treg frequency (CD25(+)FOXP3(+)) found no differences between genotype groups. Plasma SDF-1α, MIP-1ß and TRAIL levels quantified by cytokine bead array were also similar between groups. CONCLUSIONS: In contrast to previous reports, we were unable to provide evidence to suggest that the GNB3 C825T polymorphism affects HIV-1 acquisition or disease progression within African populations. Ex vivo immune activation and plasma chemokine levels were similarly unaffected by GNB3 genotype in both HIV-1-negative and HIV-1-positive individuals. The paucity of studies investigating the impact of GNB3 polymorphism among African populations and the lack of mechanistic studies make it difficult to assess the true biological significance of this polymorphism in HIV-1 infection.
Assuntos
Predisposição Genética para Doença , Infecções por HIV/genética , HIV-1/imunologia , HIV-1/patogenicidade , Proteínas Heterotriméricas de Ligação ao GTP/genética , Polimorfismo Genético , Estudos de Coortes , Citocinas/metabolismo , Progressão da Doença , Feminino , Humanos , Lactente , Recém-Nascido , Quênia , GravidezRESUMO
Human immunodeficiency virus (HIV)-specific CD8(+) T-cell proliferation is consistently correlated with enhanced host HIV immune control, but whether proliferative responses are a cause or consequence of immune protection is unclear. We measured Env-specific CD8(+) T-cell proliferation and interferon (IFN)-γ secretion in HIV-infected participants with CD4 counts >200, who then completed 121 person-years of prospective follow-up to monitor HIV disease progression. In all, 13 of 31 participants (42%) reached end point during longitudinal follow-up. Strong Env-specific CD8(+) T-cell proliferation (>10% of CD8(+) T cells) was observed in 14/31 participants at baseline, and this was associated with a longer time to HIV disease progression end point, stratified baseline CD4 count (P=0.016). No associations were observed for IFN-γ ELISPOT responses and progression (P>0.2). Strong proliferation remained significant in multivariate Cox regression analyses (P=0.044) as an independent predictor of delayed HIV disease progression, along with baseline CD4 count (P=0.04). Duration of HIV infection was associated with more rapid progression in univariate, but not multivariate, analysis (P=0.112). Age and baseline viral load were not predictive of progression. HIV-specific CD8(+) T-cell proliferation was a correlate of protective immunity in this prospective study; such responses may be important for HIV vaccine protection.
Assuntos
Linfócitos T CD8-Positivos/metabolismo , Infecções por HIV/imunologia , HIV/imunologia , Adulto , Contagem de Linfócito CD4 , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/patologia , Proliferação de Células , Células Cultivadas , Progressão da Doença , Intervalo Livre de Doença , ELISPOT , Feminino , Seguimentos , Infecções por HIV/diagnóstico , Infecções por HIV/fisiopatologia , Humanos , Interferon gama/metabolismo , Ativação Linfocitária , Masculino , Estudos Prospectivos , Produtos do Gene env do Vírus da Imunodeficiência Humana/imunologia , Produtos do Gene env do Vírus da Imunodeficiência Humana/metabolismoRESUMO
The limited success of HIV vaccine candidates to date highlights our need to better characterize protective cell-mediated immunity (CMI). While HIV-specific CD8(+) T cell responses have been defined largely by measuring gamma interferon (IFN-γ), these responses are not always protective, and it is unclear whether the same epitopes would predominate if other functional parameters were examined. Here, we assessed the epitope specificity of HIV-specific CD8(+) T cell responses by multiparametric flow cytometry, measuring five CD8(+) T cell functions (IFN-γ, macrophage inflammatory protein 1ß [MIP-1ß], tumor necrosis factor alpha [TNF-α], interleukin-2 [IL-2], and proliferative capacity) in 24 chronically HIV-infected individuals. Sixty-nine epitope-specific responses to 50 epitopes within p24 were measured. Surprisingly, most epitope-specific responses were IFN-γ negative (50/69 responses). Many responses had polyfunctional (33%) and proliferative (19%) components. An inverse association between IL-2 and proliferation responses was also observed, contrary to what was described previously. We confirm that long-term nonprogressors (LTNP) have more polyfunctional responses and also have higher-magnitude and broader p24-specific proliferation and higher levels of IL-2 and TNF-α production than do progressing controls. Together, these data suggest that the specificity of CD8(+) T cell responses differs depending on the immunological readout, with a 3.5-fold increase in breadth detected by including multiple parameters. Furthermore, the identification of epitopes that elicit polyfunctional responses reinforces the need for the comprehensive evaluation of HIV vaccine candidates, and these epitopes may represent novel targets for CMI-based vaccines.