RESUMO
INTRODUCTION: Mucosal immune activation, in the context of sexual transmission of HIV-1 infection, is crucial, as the increased presence of activated T cells enhance susceptibility to infection. In this regard, it has been proposed that immunomodulatory compounds capable of modulating immune activation, such as Vitamin D (VitD) may reduce HIV-1 transmission and might be used as a safe and cost-effective strategy for prevention. Considering this, we examined the in vitro effect of the treatment of peripheral blood mononuclear cells (PBMCs) with the active form of VitD, calcitriol, on cellular activation, function and susceptibility of CD4+ T cells to HIV-1 infection. METHODS: We treated PBMCs from healthy HIV unexposed individuals (Co-HC) and frequently exposed, HIV-1 seronegative individuals (HESNs) from Colombia and from healthy non-exposed individuals from Canada (Ca-HC) with calcitriol and performed in vitro HIV-1 infection assays using X4- and R5-tropic HIV-1 strains respectively. In addition, we evaluated the activation and function of T cells and the expression of viral co-receptors, and select antiviral genes following calcitriol treatment. RESULTS: Calcitriol reduced the frequency of infected CD4+ T cells and the number of viral particles per cell, for both, X4- and R5-tropic viruses tested in the Co-HC and the Ca-HC, respectively, but not in HESNs. Furthermore, in the Co-HC, calcitriol reduced the frequency of polyclonally activated T cells expressing the activation markers HLA-DR and CD38, and those HLA-DR+CD38-, whereas increased the subpopulation HLA-DR-CD38+. Calcitriol treatment also decreased production of granzyme, IL-2 and MIP-1ß by T cells and increased the transcriptional expression of the inhibitor of NF-kB and the antiviral genes cathelicidin (CAMP) and APOBEC3G in PBMCs from Co-HC. CONCLUSION: Our in vitro findings suggest that VitD treatment could reduce HIV-1 transmission through a specific modulation of the activation levels and function of T cells, and the production of antiviral factors. In conclusion, VitD remains as an interesting potential strategy to prevent HIV-1 transmission that should be further explored.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Calcitriol/administração & dosagem , Infecções por HIV/prevenção & controle , Ativação Linfocitária/efeitos dos fármacos , Vitaminas/administração & dosagem , Desaminase APOBEC-3G/imunologia , Desaminase APOBEC-3G/metabolismo , Peptídeos Catiônicos Antimicrobianos/imunologia , Peptídeos Catiônicos Antimicrobianos/metabolismo , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/metabolismo , Células Cultivadas , Feminino , Infecções por HIV/sangue , Infecções por HIV/transmissão , Infecções por HIV/virologia , HIV-1/imunologia , HIV-1/patogenicidade , Antígenos HLA-DR/imunologia , Antígenos HLA-DR/metabolismo , Humanos , Imunidade nas Mucosas/efeitos dos fármacos , Masculino , Cultura Primária de Células , CatelicidinasRESUMO
Systems biological analysis has recently revealed how innate immune variants as well as gut microbiota impact the individual response to immunization. HIV-infected (HIV+) patients have a worse response rate after standard vaccinations, possibly due to the immune exhaustion, increased gut permeability and microbial translocation. In the last decade, dendritic cells (DC)-based immunotherapy has been proposed as an alternative approach to control HIV plasma viral load, however clinical trials showed a heterogeneity of immunization response. Hypothesizing that host genetics may importantly affects the outcome of immunotherapy in HIV+ patients, genetic polymorphisms' distribution and gene expression modulation were analyzed in a phase I/II clinical trial of DC-based immunotherapy according to immunization response, and quality of vaccine product (DC). Polymorphisms in genes previously associated with progression of HIV infection to AIDS (i.e.: PARD3B, CCL5) contribute to a better response to immunotherapy in HIV+ individuals, possibly through a systemic effect on host immune system, but also directly on vaccine product. Genes expression profile after immunization correlates with different degrees of immune chronic activation/exhaustion of HIV+ patients (i.e. PD1, IL7RA, EOMES), but also with anti-viral response and DC quality (i.e.: APOBEC3G, IL8, PPIA), suggested that an immunocompetent individual would have a better vaccine response. These findings showed once more that host genetics can affect the response to DC-based immunotherapy in HIV+ individuals, contributing to the heterogeneity of response observed in concluded trials; and it can be used as predictor of immunization success.
Assuntos
Vacinas contra a AIDS/imunologia , Células Dendríticas/imunologia , Infecções por HIV/terapia , Interações entre Hospedeiro e Microrganismos/genética , Imunoterapia/métodos , Vacinas contra a AIDS/administração & dosagem , Desaminase APOBEC-3G/genética , Desaminase APOBEC-3G/metabolismo , Adulto , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Estudos de Coortes , Feminino , Perfilação da Expressão Gênica , Infecções por HIV/genética , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/patogenicidade , HIV-1/fisiologia , Interações entre Hospedeiro e Microrganismos/imunologia , Humanos , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Pessoa de Meia-Idade , Polimorfismo Genético/imunologia , Resultado do Tratamento , Carga Viral , Adulto JovemRESUMO
Introducción: La infección por el virus del Zika (ZIKV) es, en la mayoría de los casos, asinto-mática o se presenta como una enfermedad leve y auto-limitada, principalmente con erupción cutánea, fiebre, artralgias y conjuntivitis. Sin embargo, en algunos pacientes puede producir efectos graves en el sistema nervioso, entre los cuales se destaca el síndrome de Guillain-Ba-rré (SGB), una polirradiculoneuropatía aguda, con características autoinmunes y, por lo ge-neral, desmielinizante. Objetivo: Realizar el primer estudio de asociación del genoma com-pleto en pacientes con infección por ZIKV y en aquellos que desarrollaron SGB post-viral.
Assuntos
Síndrome de Guillain-Barré , Desaminase APOBEC-3G , Zika virusRESUMO
BACKGROUND: Host restriction factors are cellular proteins able to diminish or block viral replication in a cell-specific way. OBJECTIVE AND METHOD: We evaluated the distribution of single nucleotide polymorphisms (SNPs) in APOBEC3G (rs3736685, rs2294367) and CUL5 (rs7117111, rs7103534, rs11212495) genes, among 264 HIV-1 infected (HIV-1+) and 259 unexposed- uninfected individuals from Northeast Brazil, looking for a possible association with susceptibility to HIV-1 infection, viral load during treatment, CD4+ T cell count and therapeutic success of the antiretroviral treatment. RESULTS: The rs11212495 CUL5 G allele and the CUL5 rs7103534-rs7117111 CG haplotype were more frequent among unexposed-uninfected than in HIV-1+ individuals, suggesting an association with a lower HIV-1 infection susceptibility. The APOBEC3G rs2294367 G/C genotype correlated with delayed viral load suppression. Our results showed a great heterogeneity in relation to the literature findings, possibly due to ethnic differences among the studied populations, sample size used in the studies and, also, to the type of controls, i.e. in our study used unexposed-uninfected rather than exposed-uninfected individuals (rare and considered gold standard for susceptibility studies). CONCLUSION: Our findings report genetic variants possibly associated with susceptibility to HIV-1 infection (CUL5 rs11212495, rs7103534, rs7117111) and partial viral load control (APOBEC3G rs2294367). Replica studies performed on higher number of subjects are envisaged to confirm our results.
Assuntos
Desaminase APOBEC-3G/genética , Antirretrovirais/uso terapêutico , Proteínas Culina/genética , Predisposição Genética para Doença , Infecções por HIV/tratamento farmacológico , Infecções por HIV/genética , Adulto , Brasil , Contagem de Linfócito CD4 , Feminino , Infecções por HIV/patologia , Infecções por HIV/virologia , Humanos , Masculino , Pessoa de Meia-Idade , Polimorfismo de Nucleotídeo Único , Estudos Retrospectivos , Resultado do Tratamento , Carga Viral , Adulto JovemRESUMO
Lichen planus (LP) is a common inflammatory skin disease of unknown etiology. Reports of a common transactivation of quiescent human endogenous retroviruses (HERVs) support the connection of viruses to the disease. HERVs are ancient retroviral sequences in the human genome and their transcription is often deregulated in cancer and autoimmune diseases. We explored the transcriptional activity of HERV sequences as well as the antiviral restriction factor and interferon-inducible genes in the skin from LP patients and healthy control (HC) donors. The study included 13 skin biopsies from patients with LP and 12 controls. Real-time PCR assay identified significant decrease in the HERV-K gag and env mRNA expression levels in LP subjects, when compared to control group. The expressions of HERV-K18 and HERV-W env were also inhibited in the skin of LP patients. We observed a strong correlation between HERV-K gag with other HERV sequences, regardless the down-modulation of transcripts levels in LP group. In contrast, a significant up-regulation of the cytidine deaminase APOBEC 3G (apolipoprotein B mRNA-editing), and the GTPase MxA (Myxovirus resistance A) mRNA expression level was identified in the LP skin specimens. Other transcript expressions, such as the master regulator of type I interferon-dependent immune responses, STING (stimulator of interferon genes) and IRF-7 (interferon regulatory factor 7), IFN-ß and the inflammassome NALP3, had increased levels in LP, when compared to HC group. Our study suggests that interferon-inducible factors, in addition to their role in innate immunity against exogenous pathogens, contribute to the immune control of HERVs. Evaluation of the balance between HERV and interferon-inducible factor expression could possibly contribute to surveillance of inflammatory/malignant status of skin diseases.
Assuntos
Retrovirus Endógenos/metabolismo , Produtos do Gene env/metabolismo , Produtos do Gene gag/metabolismo , Interferon beta/metabolismo , Líquen Plano/imunologia , Proteínas de Membrana/metabolismo , Proteínas da Gravidez/metabolismo , Pele/metabolismo , Superantígenos/metabolismo , Desaminase APOBEC-3G , Adulto , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Citidina Desaminase/genética , Citidina Desaminase/metabolismo , Retrovirus Endógenos/genética , Feminino , Regulação Viral da Expressão Gênica , Produtos do Gene env/genética , Produtos do Gene gag/genética , Humanos , Vigilância Imunológica , Fator Regulador 7 de Interferon/genética , Fator Regulador 7 de Interferon/metabolismo , Interferon beta/genética , Líquen Plano/genética , Líquen Plano/virologia , Masculino , Proteínas de Membrana/genética , Pessoa de Meia-Idade , Proteínas de Resistência a Myxovirus/genética , Proteínas de Resistência a Myxovirus/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR , Proteínas da Gravidez/genética , Pele/virologia , Superantígenos/genética , Ativação Transcricional , Regulação para Cima , Adulto JovemRESUMO
Human immunodeficiency virus requires receptors and cellular factors in target cells in order to complete a successful replication. Conversely, host cells express different proteins like TRIM5a, Tetherin BST-2, as well as cytidine deaminase proteins (APOBEC3) to suppress viral replication. These proteins, known as cellular restriction factors, provide an initial defense against infection as components of the innate immune response. The best characterized restriction factor is the cytidine deaminase APOBEC3G that has been shown to have an important role in HIV pathogenesis. Here, we review the current knowledge of host restriction factors, focusing on APOBEC3G, and possible therapeutic strategies against HIV infection.
Assuntos
Fármacos Anti-HIV/farmacologia , Citidina Desaminase/metabolismo , Infecções por HIV/virologia , Desaminase APOBEC-3G , Infecções por HIV/tratamento farmacológico , Infecções por HIV/imunologia , Humanos , Imunidade Inata/imunologia , Replicação Viral/efeitos dos fármacos , Replicação Viral/imunologiaRESUMO
Programs for the prevention of mother-to-child transmission of HIV have reduced the transmission rate of perinatal HIV infection and have thereby increased the number of HIV-exposed uninfected (HEU) infants. Natural immunity to HIV-1 infection in both mothers and newborns needs to be further explored. In this study, we compared the expression of antiviral restricting factors in HIV-infected pregnant mothers treated with antiretroviral therapy (ART) in pregnancy (n=23) and in cord blood (CB) (n=16), placental tissues (n=10-13) and colostrum (n=5-6) samples and compared them to expression in samples from uninfected (UN) pregnant mothers (n=21). Mononuclear cells (MNCs) were prepared from maternal and CB samples following deliveries by cesarean section. Maternal (decidua) and fetal (chorionic villus) placental tissues were obtained, and colostrum was collected 24 h after delivery. The mRNA and protein expression levels of antiviral factors were then evaluated. We observed a significant increase in the mRNA expression levels of antiviral factors in MNCs from HIV-infected mothers and CB, including the apolipoprotein B mRNA-editing enzyme 3G (A3G), A3F, tripartite motif family-5α (TRIM-5α), TRIM-22, myxovirus resistance protein A (MxA), stimulator of interferon (IFN) genes (STING) and IFN-ß, compared with the levels detected in uninfected (UN) mother-CB pairs. Moreover, A3G transcript and protein levels and α-defensin transcript levels were decreased in the decidua of HIV-infected mothers. Decreased TRIM-5α protein levels in the villi and increased STING mRNA expression in both placental tissues were also observed in HIV-infected mothers compared with uninfected (UN) mothers. Additionally, colostrum cells from infected mothers showed increased tetherin and IFN-ß mRNA levels and CXCL9 protein levels. The data presented here indicate that antiviral restricting factor expression can be induced in utero in HIV-infected mothers. Future studies are warranted to determine whether this upregulation of antiviral factors during the perinatal period has a protective effect against HIV-1 infection.
Assuntos
Sangue Fetal/metabolismo , Regulação da Expressão Gênica/imunologia , Infecções por HIV/sangue , Infecções por HIV/imunologia , Imunidade Inata/imunologia , Viremia/prevenção & controle , Desaminase APOBEC-3G , Fatores de Restrição Antivirais , Western Blotting , Brasil , Proteínas de Transporte/metabolismo , Vilosidades Coriônicas/metabolismo , Colostro/metabolismo , Citidina Desaminase/metabolismo , Primers do DNA/genética , Decídua/metabolismo , Feminino , Perfilação da Expressão Gênica , Humanos , Interferon beta/economia , Interferon beta/metabolismo , Leucócitos Mononucleares/metabolismo , Proteínas de Membrana/metabolismo , Antígenos de Histocompatibilidade Menor , Mães , Proteínas de Resistência a Myxovirus/metabolismo , Gravidez , Reação em Cadeia da Polimerase em Tempo Real , Proteínas Repressoras/metabolismo , Estatísticas não Paramétricas , Proteínas com Motivo Tripartido , Ubiquitina-Proteína Ligases , Viremia/metabolismoRESUMO
BACKGROUND: The human APOBEC3G (A3G) protein activity is associated with innate immunity against HIV-1 by inducing high rates of guanosines to adenosines (G-to-A) mutations (viz., hypermutation) in the viral DNA. If hypermutation is not enough to disrupt the reading frames of viral genes, it may likely increase the HIV-1 diversity. To counteract host innate immunity HIV-1 encodes the Vif protein that binds A3G protein and form complexes to be degraded by cellular proteolysis. METHODS: Here we studied the pattern of substitutions in the vif gene and its association with clinical status of HIV-1 infected individuals. To perform the study, unique vif gene sequences were generated from 400 antiretroviral-naïve individuals. RESULTS: The codon pairs: 78-154, 85-154, 101-157, 105-157, and 105-176 of vif gene were associated with CD4+ T cell count lower than 500 cells per mm(3). Some of these codons were located in the (81)LGQGVSIEW(89) region and within the BC-Box. We also identified codons under positive selection clustered in the N-terminal region of Vif protein, between (21)WKSLVK(26) and (40)YRHHY(44) regions (i.e., 31, 33, 37, 39), within the BC-Box (i.e., 155, 159) and the Cullin5-Box (i.e., 168) of vif gene. All these regions are involved in the Vif-induced degradation of A3G/F complexes and the N-terminal of Vif protein binds to viral and cellular RNA. CONCLUSIONS: Adaptive evolution of vif gene was mostly to optimize viral RNA binding and A3G/F recognition. Additionally, since there is not a fully resolved structure of the Vif protein, codon pairs associated with CD4+ T cell count may elucidate key regions that interact with host cell factors. Here we identified and discriminated codons under positive selection and codons under functional constraint in the vif gene of HIV-1.
Assuntos
Substituição de Aminoácidos , Linfócitos T CD4-Positivos/virologia , Infecções por HIV/imunologia , Infecções por HIV/virologia , HIV-1/genética , Produtos do Gene vif do Vírus da Imunodeficiência Humana/genética , Desaminase APOBEC-3G , Sequência de Aminoácidos , Contagem de Linfócito CD4 , Citidina Desaminase/metabolismo , Citosina Desaminase/metabolismo , Feminino , Humanos , Masculino , Modelos Moleculares , Dados de Sequência Molecular , Ligação Proteica , Conformação Proteica , RNA Viral/metabolismoRESUMO
The HIV-1 vif gene encodes for an accessory protein that is central for virus replication due mainly to its capacity to counteract the antiviral action of host APOBEC3 restriction factors. In order to evaluate whether HIV-1 vif alterations account for a delayed progression to AIDS in children infected perinatally, the vif genes from a group of 11 patients who exhibited an extremely slow disease progression (slow progressors) were studied by direct sequencing. In addition, the vif genes from a group of 93 children with typical disease progression (typical progressors) were analyzed for comparison. Phylogenetic analysis indicated that sequences from slow progressors did not have a common origin, discarding a shared ancestor of reduced virulence. There were no differences in the diversity between the vif genes from slow and typical progressors. No gross defects showing a clear distinction among sequences from both groups of children were found. However, in the deduced Vif proteins, changes V13I, V55T, and L81M were observed only in sequences from slow progressors. By analyzing sequences stored in databases, these mutations were determined as unusual substitutions occurring at highly conserved Vif sites across different HIV-1 clades, but were observed with an increased frequency in sequences from elite controllers. These mutations were in the Vif regions reported as relevant for protein activity. These findings suggest that the Vif sequences from slow progressors carry unusual substitutions, which may alter the protein function and may contribute to viral attenuation.
Assuntos
Síndrome da Imunodeficiência Adquirida/virologia , Substituição de Aminoácidos , HIV-1/genética , Transmissão Vertical de Doenças Infecciosas , Produtos do Gene vif do Vírus da Imunodeficiência Humana/genética , Desaminase APOBEC-3G , Síndrome da Imunodeficiência Adquirida/transmissão , Sequência de Aminoácidos , Criança , Pré-Escolar , Citidina Desaminase/genética , Bases de Dados Genéticas , Progressão da Doença , Feminino , Genes Virais , Variação Genética , Técnicas de Genotipagem , HIV-1/patogenicidade , HIV-1/fisiologia , Humanos , Lactente , Masculino , Dados de Sequência Molecular , Mutação , Filogenia , Estrutura Terciária de Proteína , Fatores de Tempo , Carga Viral , Replicação ViralRESUMO
The APOBEC3 proteins are cytidine deaminases that can introduce GâA mutations in the HIV-1 plus DNA strand. This editing process may inhibit virus replication through lethal mutagenesis (hypermutation), but could also contribute to viral diversification leading to the emergence of escape forms. The HIV-1 Vif protein has the capacity to counteract APOBEC3 factors by recruiting a CUL5-based ubiquitin ligase complex that determines their proteasomal degradation. In this work, we analyzed the APOBEC3-mediated editing in proviral HIV-1 from perinatally infected children (n=93) in order to explore its association with polymorphisms of APOBEC3G and CUL5 genes (APOBEC3G H186R, APOBEC3G C40693T, and CUL5 SNP6), the Vif protein variability, and also the time to AIDS development. To calculate the level of editing, we have developed an index exploiting the properties of a region within the HIV-1 pol gene that includes the central polypurine tract (cPPT). We detected a reduced editing associated with the CUL5 SNP6 minor allele and also with certain Vif variants (mutations at sites 46, 122, and 160), although we found no evidence supporting an impact of APOBEC3 activity on disease progression. Thus, our findings suggest that APOBEC3-mediated editing of HIV-1 could be modulated by host and virus genetic characteristics in the context of pediatric infection.