RESUMEN
Cell activation is a vital step for T-cell memory/effector differentiation as well as for productive HIV infection. To identify novel regulators of this process, we used next-generation sequencing to profile changes in microRNA expression occurring in purified human naive CD4 T cells in response to TCR stimulation and/or HIV infection. Our results demonstrate, for the first time, the transcriptional up-regulation of miR-34c-5p in response to TCR stimulation in naive CD4 T cells. The induction of this miR was further consistently found to be reduced by both HIV-1 and HIV-2 infections. Overexpression of miR-34c-5p led to changes in the expression of several genes involved in TCR signaling and cell activation, confirming its role as a novel regulator of naive CD4 T-cell activation. We additionally show that miR-34c-5p promotes HIV-1 replication, suggesting that its down-regulation during HIV infection may be part of an anti-viral host response.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , VIH/fisiología , Interacciones Huésped-Patógeno , Activación de Linfocitos , MicroARNs/análisis , Receptores de Antígenos de Linfocitos T/metabolismo , Replicación Viral , Linfocitos T CD4-Positivos/virología , Perfilación de la Expresión Génica , VIH/inmunología , Humanos , Evasión InmuneRESUMEN
Until recently, hematopoietic stem cell transplantation was the only curative option for Wiskott-Aldrich syndrome (WAS). The first attempts at gene therapy for WAS using a Ï-retroviral vector improved immunological parameters substantially but were complicated by acute leukemia as a result of insertional mutagenesis in a high proportion of patients. More recently, treatment of children with a state-of-the-art self-inactivating lentiviral vector (LV-w1.6 WASp) has resulted in significant clinical benefit without inducing selection of clones harboring integrations near oncogenes. Here, we describe a case of a presplenectomized 30-year-old patient with severe WAS manifesting as cutaneous vasculitis, inflammatory arthropathy, intermittent polyclonal lymphoproliferation, and significant chronic kidney disease and requiring long-term immunosuppressive treatment. Following reduced-intensity conditioning, there was rapid engraftment and expansion of a polyclonal pool of transgene-positive functional T cells and sustained gene marking in myeloid and B-cell lineages up to 20 months of observation. The patient was able to discontinue immunosuppression and exogenous immunoglobulin support, with improvement in vasculitic disease and proinflammatory markers. Autologous gene therapy using a lentiviral vector is a viable strategy for adult WAS patients with severe chronic disease complications and for whom an allogeneic procedure could present an unacceptable risk. This trial was registered at www.clinicaltrials.gov as #NCT01347242.
Asunto(s)
Terapia Genética , Síndrome de Wiskott-Aldrich/genética , Síndrome de Wiskott-Aldrich/terapia , Adulto , Proliferación Celular , Preescolar , Ensayos Clínicos como Asunto , Células Clonales , Citocinas/sangre , Humanos , Subgrupos Linfocitarios/inmunología , Linfocitos T/inmunología , Vacunación , Síndrome de Wiskott-Aldrich/sangreRESUMEN
UNLABELLED: A unique HIV-host equilibrium exists in untreated HIV-2-infected individuals. This equilibrium is characterized by low to undetectable levels of viremia throughout the disease course, despite the establishment of disseminated HIV-2 reservoirs at levels comparable to those observed in untreated HIV-1 infection. Although the clinical spectrum is similar in the two infections, HIV-2 infection is associated with a much lower rate of CD4 T-cell decline and has a limited impact on the mortality of infected adults. Here we investigated HIV-2 infection of the human thymus, the primary organ for T-cell production. Human thymic tissue and suspensions of total or purified CD4 single-positive thymocytes were infected with HIV-2 or HIV-1 primary isolates using either CCR5 or CXCR4 coreceptors. We found that HIV-2 infected both thymic organ cultures and thymocyte suspensions, as attested to by the total HIV DNA and cell-associated viral mRNA levels. Nevertheless, thymocytes featured reduced levels of intracellular Gag viral protein, irrespective of HIV-2 coreceptor tropism and cell differentiation stage, in agreement with the low viral load in culture supernatants. Our data show that HIV-2 is able to infect the human thymus, but the HIV-2 replication cycle in thymocytes is impaired, providing a new model to identify therapeutic targets for viral replication control. IMPORTANCE: HIV-1 infects the thymus, leading to a decrease in CD4 T-cell production that contributes to the characteristic CD4 T-cell loss. HIV-2 infection is associated with a very low rate of progression to AIDS and is therefore considered a unique naturally occurring model of attenuated HIV disease. HIV-2-infected individuals feature low to undetectable plasma viral loads, in spite of the numbers of circulating infected T cells being similar to those found in patients infected with HIV-1. We assessed, for the first time, the direct impact of HIV-2 infection on the human thymus. We show that HIV-2 is able to infect the thymus but that the HIV-2 replication cycle in thymocytes is impaired. We propose that this system will be important to devise immunotherapies that target viral production, aiding the design of future therapeutic strategies for HIV control.
Asunto(s)
VIH-2/fisiología , Interacciones Huésped-Patógeno , Timocitos/virología , Timo/virología , Replicación Viral , Adulto , Células Cultivadas , Preescolar , VIH-1/fisiología , Humanos , Lactante , Recién Nacido , Técnicas de Cultivo de Órganos , Timo/patologíaRESUMEN
Monocytes and myeloid dendritic cells (mDCs) are important orchestrators of innate and human immunodeficiency virus (HIV)-specific immune responses and of the generalized inflammation that characterizes AIDS progression. To our knowledge, we are the first to investigate monocyte and mDC imbalances in HIV type 2 (HIV-2)-positive patients, who typically feature reduced viremia and slow disease progression despite the recognized ability of HIV-2 to establish viral reservoirs and overcome host restriction factors in myeloid cells. We found a heightened state of monocyte and mDC activation throughout HIV-2 infection (characterized by CD14(bright)CD16(+) expansion, as well as increased levels of soluble CD14, HLA-DR, and CD86), together with progressive mDC depletion. Importantly, HIV-2-positive patients also featured overexpression of the inhibitory molecule PD-L1 on monocytes and mDCs, which may act by limiting the production of proinflammatory molecules. These data, from patients with a naturally occurring form of attenuated HIV disease, challenge current paradigms regarding the role of monocytes in HIV/AIDS and open new perspectives regarding potential strategies to modulate inflammatory states.
Asunto(s)
Células Dendríticas/inmunología , Infecciones por VIH/inmunología , Infecciones por VIH/virología , VIH-2/inmunología , VIH-2/patogenicidad , Monocitos/inmunología , Adulto , Anciano , Antígenos CD/análisis , Antígeno B7-H1/análisis , Células Dendríticas/química , Femenino , Antígenos HLA-DR/análisis , Humanos , Inmunofenotipificación , Masculino , Persona de Mediana Edad , Monocitos/química , Adulto JovenRESUMEN
Haploidentical hematopoietic stem cell transplantation (HSCT) constitutes an important alternative for patients lacking a human leukocyte antigen (HLA)-matched donor. Although the use of haploidentical donors is increasingly common, the long-term impact of generating a donor-derived immune system in the context of an HLA-mismatched thymic environment remains poorly characterized. We performed an in-depth assessment of immune reconstitution in a group of haploidentical HSCT recipients 4 to 6 years posttransplantation, in parallel with the respective parental donors and age-matched healthy control subjects. Our data show that the proportion of naive and memory subsets in the recipients, both within CD8(+) and CD4(+) T cells, more closely resembled that observed in age-matched control subjects than in the donors. HSCT recipients displayed relatively high signal-joint T cell-receptor excision circle levels and a high frequency of the recent thymic emigrant-enriched CD31(+) subset within naive CD4(+) and naive regulatory T cells. Moreover, CD8(+), CD4(+), and regulatory T cells from HSCT recipients displayed a diverse T cell repertoire. These results support a key role for thymic output in T cell reconstitution. Nevertheless, HSCT recipients had significantly shorter telomeres within a naive-enriched CD4(+) T cell population than age-matched control subjects, despite the similar telomere length observed within the most differentiated CD8(+) and CD4(+) T cell subsets. Overall, our data suggest that long-term immune reconstitution was successfully achieved after haploidentical HSCT, a process that appears to have largely relied on de novo T cell production.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Antígenos HLA/inmunología , Trasplante de Células Madre Hematopoyéticas/métodos , Subgrupos de Linfocitos T/inmunología , Adulto , Anemia Aplásica/inmunología , Anemia Aplásica/cirugía , Estudios Transversales , Femenino , Haploidia , Humanos , Memoria Inmunológica , Leucemia/inmunología , Leucemia/cirugía , Masculino , Persona de Mediana Edad , Donantes de Tejidos , Inmunología del Trasplante , Trasplante Homólogo , Adulto JovenRESUMEN
Viremia is significantly lower in HIV-2 than in HIV-1 infection, irrespective of disease stage. Nevertheless, the comparable proviral DNA burdens observed for these two infections indicate similar numbers of infected cells. Here we investigated this apparent paradox by assessing cell-associated viral replication. We found that untreated HIV-1-positive (HIV-1(+)) and HIV-2(+) individuals, matched for CD4 T cell depletion, exhibited similar gag mRNA levels, indicating that significant viral transcription is occurring in untreated HIV-2(+) patients, despite the reduced viremia (undetectable to 2.6 × 10(4) RNA copies/ml). However, tat mRNA transcripts were observed at significantly lower levels in HIV-2(+) patients, suggesting that the rate of de novo infection is decreased in these patients. Our data also reveal a direct relationship of gag and tat transcripts with CD4 and CD8 T cell activation, respectively. Antiretroviral therapy (ART)-treated HIV-2(+) patients showed persistent viral replication, irrespective of plasma viremia, possibly contributing to the emergence of drug resistance mutations, persistent hyperimmune activation, and poor CD4 T cell recovery that we observed with these individuals. In conclusion, we provide here evidence of significant ongoing viral replication in HIV-2(+) patients, further emphasizing the dichotomy between amount of plasma virus and cell-associated viral burden and stressing the need for antiretroviral trials and the definition of therapeutic guidelines for HIV-2 infection.
Asunto(s)
Linfocitos T CD4-Positivos/virología , Linfocitos T CD8-positivos/virología , Infecciones por VIH/virología , VIH-2/fisiología , Carga Viral , Viremia/virología , Replicación Viral , Adulto , Anciano , Fármacos Anti-VIH/uso terapéutico , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Estudios de Cohortes , Femenino , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/inmunología , VIH-2/genética , Humanos , Masculino , Persona de Mediana Edad , Viremia/tratamiento farmacológico , Viremia/inmunología , Adulto JovenRESUMEN
Plasmacytoid dendritic cells (pDC) provide an important link between innate and acquired immunity, mediating their action mainly through IFN-alpha production. pDC suppress HIV-1 replication, but there is increasing evidence suggesting they may also contribute to the increased levels of cell apoptosis and pan-immune activation associated with disease progression. Although having the same clinical spectrum, HIV-2 infection is characterized by a strikingly lower viremia and a much slower rate of CD4 decline and AIDS progression than HIV-1, irrespective of disease stage. We report here a similar marked reduction in circulating pDC levels in untreated HIV-1 and HIV-2 infections in association with CD4 depletion and T cell activation, in spite of the undetectable viremia found in the majority of HIV-2 patients. Moreover, the same overexpression of CD86 and PD-L1 on circulating pDC was found in both infections irrespective of disease stage or viremia status. Our observation that pDC depletion occurs in HIV-2 infected patients with undetectable viremia indicates that mechanisms other than direct viral infection determine the pDC depletion during persistent infections. However, viremia was associated with an impairment of IFN-alpha production on a per pDC basis upon TLR9 stimulation. These data support the possibility that diminished function in vitro may relate to prior activation by HIV virions in vivo, in agreement with our finding of higher expression levels of the IFN-alpha inducible gene, MxA, in HIV-1 than in HIV-2 individuals. Importantly, serum IFN-alpha levels were not elevated in HIV-2 infected individuals. In conclusion, our data in this unique natural model of "attenuated" HIV immunodeficiency contribute to the understanding of pDC biology in HIV/AIDS pathogenesis, showing that in the absence of detectable viremia a major depletion of circulating pDC in association with a relatively preserved IFN-alpha production does occur.
Asunto(s)
Apoptosis/fisiología , Células Dendríticas/patología , Infecciones por VIH/sangre , Infecciones por VIH/patología , VIH-1/patogenicidad , VIH-2/patogenicidad , Adulto , Anciano , Estudios de Casos y Controles , Células Cultivadas , Estudios de Cohortes , Estudios Transversales , Células Dendríticas/metabolismo , Femenino , Proteínas de Unión al GTP/metabolismo , Infecciones por VIH/fisiopatología , VIH-1/fisiología , VIH-2/fisiología , Humanos , Interferón-alfa/metabolismo , Masculino , Persona de Mediana Edad , Proteínas de Resistencia a Mixovirus , Receptor Toll-Like 9/metabolismo , Carga Viral/fisiología , Viremia/sangre , Viremia/virología , Replicación Viral/fisiologíaRESUMEN
The CD31(+) subset of human naive CD4(+) T cells is thought to contain the population of cells that have recently emigrated from the thymus, while their CD31(-) counterparts have been proposed to originate from CD31(+) cells after homeostatic cell division. Naive T-cell maintenance is known to involve homeostatic cytokines such as interleukin-7 (IL-7). It remains to be investigated what role this cytokine has in the homeostasis of naive CD4(+) T-cell subsets defined by CD31 expression. We provide evidence that IL-7 exerts a preferential proliferative effect on CD31(+) naive CD4(+) T cells from adult peripheral blood compared with the CD31(-) subset. IL-7-driven proliferation did not result in loss of CD31 expression, suggesting that CD31(+) naive CD4(+) T cells can undergo cytokine-driven homeostatic proliferation while preserving CD31. Furthermore, IL-7 sustained or increased CD31 expression even in nonproliferating cells. Both proliferation and CD31 maintenance were dependent on the activation of phosphoinositide 3-kinase (PI3K) signaling. Taken together, our data suggest that during adulthood CD31(+) naive CD4(+) T cells are maintained by IL-7 and that IL-7-based therapies may exert a preferential effect on this population.
Asunto(s)
Linfocitos T CD4-Positivos/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Interleucina-7/farmacología , Fosfatidilinositol 3-Quinasas/fisiología , Molécula-1 de Adhesión Celular Endotelial de Plaqueta/metabolismo , Adulto , Envejecimiento/inmunología , Envejecimiento/metabolismo , Linfocitos T CD4-Positivos/metabolismo , Células Cultivadas , Sangre Fetal/citología , Sangre Fetal/inmunología , Humanos , Recién Nacido , Interleucina-7/fisiología , Especificidad de Órganos/efectos de los fármacos , Fosfatidilinositol 3-Quinasas/metabolismo , Transducción de Señal/inmunología , Transducción de Señal/fisiología , Subgrupos de Linfocitos T/efectos de los fármacos , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismoRESUMEN
: Potent HIV-neutralizing antibodies are critical for vaccination and viral reservoir control. High levels of neutralizing antibodies characterize HIV-2 infection, a naturally occurring model of attenuated HIV disease with low-to-undectable viremia. We found that HIV-2-specific antibody potency increased in direct association with the loss of both switched and unswitched memory B cells in untreated HIV-2 infection. Thus, HIV antibody affinity maturation is linked to memory B-cell exhaustion even in reduced viremia settings.
Asunto(s)
Anticuerpos Neutralizantes/sangre , Linfocitos B/inmunología , Anticuerpos Anti-VIH/sangre , Infecciones por VIH/inmunología , VIH-2/inmunología , Memoria Inmunológica , Adulto , Infecciones por VIH/virología , HumanosRESUMEN
Chronic granulomatous disease (CGD) results from primary defects in phagocytic reactive oxygen species (ROS) production. T-cell evaluation is usually neglected during patients' follow-up, although T-cell depletion has been reported in CGD through unknown mechanisms. We describe here a 36-year-old patient with X-linked CGD with severe CD4 T-cell depletion <200 CD4 T-cells/µl, providing insights into the mechanisms that underlie T-cell loss in the context of oxidative burst defects. In addition to the typical infections, the patient featured a progressive T-cell loss associated with persistent lymphocyte activation, expansion of interleukin (IL)-17-producing CD4 T-cells, and impaired thymic activity, leading to a reduced replenishment of the T-cell pool. A relative CD4 depletion was also found at the gut mucosal level, although no bias to IL-17-production was documented. This immunological pattern of exhaustion of immune resources favors prompt, potentially curative, therapeutic interventions in CGD patients, namely, stem-cell transplantation or gene therapy. Moreover, this clinical case raises new research questions on the interplay of ROS production and T-cell homeostasis and immune senescence.
RESUMEN
HIV-2 infection features a much slower course than HIV-1 infection, often asymptomatic for over 20 years, without antiretroviral therapy (ART). Nevertheless, CD4 T cells progressively decline, in direct correlation with immune activation and cell cycling. We report, for the first time, preserved telomere length within naive and memory CD4 subsets in prolonged HIV-2 infection despite the increased CD4 turnover.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Infecciones por VIH/inmunología , VIH-1/inmunología , VIH-2/inmunología , Telómero/inmunología , Adulto , Recuento de Linfocito CD4 , Estudios de Cohortes , Femenino , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Factores de TiempoRESUMEN
OBJECTIVE: Memory B-cell loss has long been recognized as an important contributor to HIV immunodeficiency. HIV-2 infection, which is characterized by a slow rate of progression to AIDS and reduced to undetectable viremia, provides a unique model to investigate B-cell disturbances. DESIGN AND METHODS: B-cell subsets were evaluated in 38 HIV-2-infected individuals, along with markers of T-cell activation and serum levels of immunoglobulins and a major B-cell homeostatic cytokine, B-cell activating factor (BAFF). Untreated HIV-1-infected and seronegative control individuals were studied in parallel. Statistical analysis was performed using Mann-Whitney tests and Spearman's correlations. RESULTS: We found that HIV-2 was associated with significant depletion of both unswitched (CD27(+)IgD(+)) and switched (CD27(+)IgD(neg)) memory B-cells that directly correlated with T-cell activation, even in individuals with undetectable plasma viral load. Nevertheless, the presence of detectable viremia, even at low levels, was associated with significant memory B-cell loss and higher BAFF levels. Moreover, these alterations were not recovered by antiretroviral-therapy, as treated HIV-2-infected patients showed more pronounced B-cell disturbances, possibly related to their extended length of infection. CONCLUSION: These first data regarding B-cell imbalances during HIV-2 infection show that, irrespective of viremia, prolonged HIV infection leads to irreversible damage of memory B-cell homeostasis.
Asunto(s)
Síndrome de Inmunodeficiencia Adquirida/inmunología , Linfocitos B/inmunología , Progresión de la Enfermedad , Seropositividad para VIH/inmunología , VIH-2/efectos de los fármacos , Síndrome de Inmunodeficiencia Adquirida/tratamiento farmacológico , Síndrome de Inmunodeficiencia Adquirida/genética , Adulto , Fármacos Anti-VIH/farmacología , Factor Activador de Células B/inmunología , Subgrupos de Linfocitos B/inmunología , Linfocitos B/virología , Femenino , Citometría de Flujo , Seronegatividad para VIH/inmunología , Seropositividad para VIH/tratamiento farmacológico , VIH-1/inmunología , VIH-2/inmunología , Humanos , Memoria Inmunológica , Inmunofenotipificación , Activación de Linfocitos/inmunología , Masculino , Persona de Mediana Edad , ARN Viral/sangre , Carga Viral , Viremia/diagnóstico , Viremia/virologíaRESUMEN
OBJECTIVE: Hyper-immune activation is a main determinant of HIV disease progression, potentially counter-acted by T-cell inhibitory pathways. Here we investigated, for the first time, inhibitory molecules in HIV-2 infection, a naturally occurring attenuated form of HIV disease, associated with reduced viremia and very slow rates of CD4 T-cell decline. DESIGN: Programmed death (PD)-1/PD-L1, an important pathway in limiting immunopathology, and its possible relationship with T-cell immunoglobulin and mucin-domain containing molecule-3 (TIM-3), a recently identified inhibitory molecule, were studied in untreated HIV-2 and HIV-1 cohorts, matched for degree of CD4 T-cell depletion, and noninfected individuals. METHODS: Flow cytometric analysis of T-cell expression of PD-1, PD-L1 and TIM-3, combined with markers of cell differentiation, activation, cycling and survival. Statistical analysis was performed using ANOVA, Mann-Whitney/Wilcoxon tests, Spearman's correlations, multiple linear regressions and canonical correlation analysis. RESULTS: T-cell expression of PD-1 and PD-L1 was tightly associated and directly correlated with CD4 T-cell depletion and immune activation in HIV-2 infection. No such correlation was found for PD-L1 expression in HIV-1-positive patients. Central memory and intermediate memory cells, rather than terminally differentiated T-cells, expressed the highest levels of both PD-1 and PD-L1 molecules. Conversely, TIM-3 expression was independent of T-cell differentiation and dissociated from cell cycling, suggesting distinct induction mechanisms. Importantly, in contrast with HIV-1, no significant increases in TIM-3 expression were found in the HIV-2 cohort. CONCLUSIONS: Our data suggest that PD-1/PD-L1 molecules, rather than markers of T-cell exhaustion, may act as modulators of T-cell immune activation, contributing to the slower course of HIV-2 infection. These data have implications for the design of antiretroviral therapy-complementary immune-based strategies.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD8-positivos/inmunología , Infecciones por VIH/inmunología , VIH-1/inmunología , VIH-2/inmunología , Biomarcadores de Tumor/metabolismo , Estudios de Casos y Controles , Infecciones por VIH/metabolismo , Receptor 2 Celular del Virus de la Hepatitis A , Humanos , Proteínas de la Membrana/metabolismo , Proteína 2 Ligando de Muerte Celular Programada 1/metabolismo , Receptor de Muerte Celular Programada 1/metabolismo , Regulación hacia ArribaRESUMEN
OBJECTIVE: The dynamics of CD4(+) regulatory T cells (Treg) during HIV-1 infection remains unclear. To further investigate Treg in this context, we characterized, for the first time, this population in HIV-2-positive individuals. Although both HIV infections are associated with hyperimmune activation and CD4(+) T-cell lymphopenia, most HIV-2-positive individuals display slower disease progression and low-to-undetectable viremia. DESIGN/METHODS: Samples were obtained from cohorts of untreated HIV-2-positive and HIV-1-positive, treated HIV-1-positive and seronegative individuals. The proportion of CD4(+) T cells bearing a Treg phenotype, defined in terms of high-level CD25 or Foxp3 expression, was assessed by flow cytometry and correlated with markers of disease progression. The proportions of naive and memory-like subsets as well as cycling cells were determined. RESULTS: We observed an increased proportion of Treg, associated with disease progression, as well as increased proportions of cycling (Ki67(+)) memory Treg, in untreated HIV-2-positive and HIV-1-positive individuals. We also noted an expansion of Treg that persisted over time in treated, immunologically discordant HIV-1-positive individuals, who, similarly to HIV-2-positive patients, present undetectable viremia and low CD4 T-cell count. CONCLUSION: Overall, we demonstrated that Treg frequency was increased in all lymphopenic HIV-2-positive and HIV-1-positive individuals irrespective of the presence or absence of viremia or antiretroviral treatment. This, in turn, suggests that the observed alterations in Treg frequency in HIV/AIDS are more directly related to the degree of CD4 depletion than to viremia.
Asunto(s)
Infecciones por VIH/inmunología , VIH-1/inmunología , VIH-2/inmunología , Inmunofenotipificación , Linfocitos T Reguladores/inmunología , Adulto , Anciano , Estudios Transversales , Progresión de la Enfermedad , Femenino , Citometría de Flujo , Infecciones por VIH/genética , Humanos , Masculino , Persona de Mediana Edad , Fenotipo , Viremia/inmunología , Viremia/virologíaRESUMEN
HIV-1 mother-to-child transmission (MTCT) was evaluated in terms of the molecular characterization of the env and nef genomic regions and quantification of maternal RNA viral loads. Assignment of viral subtype was achieved by direct sequencing of PCR 1172 products amplified from proviral DNA in 45 HIV-1-nontransmitting mothers (NTM), along with 13 pairs of HIV-1-transmitting mothers (TM) and their infected children (C). Analysis of the env C2V3C3 and nef sequences revealed that subtypes G and B, and their genetic combinations (AG, BG), accounted for over 84.5% of all viruses identified. The genetic structure form envA-nefG was the most commonly observed, with a lower frequency in the NTM (13.3%) compared to the TM (23.1%) group. A greater number of genetic forms was observed among NTM, namely the presence of sequences assigned to subtypes D and F, as well as the intergenetic A/J, and C/U, recombinant forms, along with a mosaic provirus with a complex putative envA-nefEGE genetic structure. No significant differences were found when RNA viral loads were evaluated as a function of the viral subtypes. Nevertheless, a relatively high quantification of HIV-1 RNA was obtained in the NTM group, emphasizing the importance of the compliance and effectiveness of therapeutic schemes to control viral replication and reduce the risk of HIV vertical transmission. V3 sequences displaying features associated with the R5 phenotype dominated in both groups. Both C2V3C3 and Nef's functional domains were conserved during HIV-1 vertical transmission.