RESUMEN
Human immunodeficiency virus (HIV) cure efforts are increasingly focused on harnessing CD8+ T cell functions, which requires a deeper understanding of CD8+ T cells promoting HIV control. Here we identifiy an antigen-responsive TOXhiTCF1+CD39+CD8+ T cell population with high expression of inhibitory receptors and low expression of canonical cytolytic molecules. Transcriptional analysis of simian immunodeficiency virus (SIV)-specific CD8+ T cells and proteomic analysis of purified CD8+ T cell subsets identified TOXhiTCF1+CD39+CD8+ T cells as intermediate effectors that retained stem-like features with a lineage relationship with terminal effector T cells. TOXhiTCF1+CD39+CD8+ T cells were found at higher frequency than TCF1-CD39+CD8+ T cells in follicular microenvironments and were preferentially located in proximity of SIV-RNA+ cells. Their frequency was associated with reduced plasma viremia and lower SIV reservoir size. Highly similar TOXhiTCF1+CD39+CD8+ T cells were detected in lymph nodes from antiretroviral therapy-naive and antiretroviral therapy-suppressed people living with HIV, suggesting this population of CD8+ T cells contributes to limiting SIV and HIV persistence.
Asunto(s)
Linfocitos T CD8-positivos , Ganglios Linfáticos , Síndrome de Inmunodeficiencia Adquirida del Simio , Virus de la Inmunodeficiencia de los Simios , Virus de la Inmunodeficiencia de los Simios/inmunología , Linfocitos T CD8-positivos/inmunología , Animales , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/virología , Ganglios Linfáticos/inmunología , Humanos , Macaca mulatta , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismoRESUMEN
Understanding the complexity of the long-lived HIV reservoir during antiretroviral therapy (ART) remains a considerable impediment in research towards a cure for HIV. To address this, we developed a single-cell strategy to precisely define the unperturbed peripheral blood HIV-infected memory CD4+ T cell reservoir from ART-treated people living with HIV (ART-PLWH) via the presence of integrated accessible proviral DNA in concert with epigenetic and cell surface protein profiling. We identified profound reservoir heterogeneity within and between ART-PLWH, characterized by new and known surface markers within total and individual memory CD4+ T cell subsets. We further uncovered new epigenetic profiles and transcription factor motifs enriched in HIV-infected cells that suggest infected cells with accessible provirus, irrespective of reservoir distribution, are poised for reactivation during ART treatment. Together, our findings reveal the extensive inter- and intrapersonal cellular heterogeneity of the HIV reservoir, and establish an initial multiomic atlas to develop targeted reservoir elimination strategies.
Asunto(s)
Infecciones por VIH , VIH-1 , Humanos , VIH-1/fisiología , Linfocitos T CD4-Positivos , Latencia del Virus/genética , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/genética , Epigénesis Genética , Carga Viral , Antirretrovirales/uso terapéuticoRESUMEN
BACKGROUND: Respiratory failure in severe coronavirus disease 2019 (COVID-19) is associated with a severe inflammatory response. Acetylcholine (ACh) reduces systemic inflammation in experimental bacterial and viral infections. Pyridostigmine increases the half-life of endogenous ACh, potentially reducing systemic inflammation. We aimed to determine if pyridostigmine decreases a composite outcome of invasive mechanical ventilation (IMV) and death in adult patients with severe COVID-19. METHODS: We performed a double-blinded, placebo-controlled, phase 2/3 randomized controlled trial of oral pyridostigmine (60 mg/day) or placebo as add-on therapy in adult patients admitted due to confirmed severe COVID-19 not requiring IMV at enrollment. The primary outcome was a composite of IMV or death by day 28. Secondary outcomes included reduction of inflammatory markers and circulating cytokines, and 90-day mortality. Adverse events (AEs) related to study treatment were documented and described. RESULTS: We recruited 188 participants (94 per group); 112 (59.6%) were men; the median (IQR) age was 52 (44-64) years. The study was terminated early due to a significant reduction in the primary outcome in the treatment arm and increased difficulty with recruitment. The primary outcome occurred in 22 (23.4%) participants in the placebo group vs. 11 (11.7%) in the pyridostigmine group (hazard ratio, 0.47, 95% confidence interval 0.24-0.9; P = 0.03). This effect was driven by a reduction in mortality (19 vs. 8 deaths, respectively). CONCLUSION: Our data indicate that adding pyridostigmine to standard care reduces mortality among patients hospitalized for severe COVID-19.
Asunto(s)
Tratamiento Farmacológico de COVID-19 , Adulto , Masculino , Humanos , Persona de Mediana Edad , Femenino , Bromuro de Piridostigmina/uso terapéutico , SARS-CoV-2 , Respiración Artificial , Inflamación , Resultado del TratamientoRESUMEN
The role of lymphoid tissue as a potential source of HIV-1 rebound following interruption of antiretroviral therapy (ART) is uncertain. To address this issue, we compared the latent viruses obtained from CD4+ T cells in peripheral blood and lymph nodes to viruses emerging during treatment interruption. Latent viruses were characterized by sequencing near-full-length (NFL) proviral DNA and env from viral outgrowth assays (VOAs). Five HIV-1-infected individuals on ART were studied, four of whom participated in a clinical trial of a TLR9 agonist that included an analytical treatment interruption. We found that 98% of intact or replication-competent clonal sequences overlapped between blood and lymph node. In contrast, there was no overlap between 205 latent reservoir and 125 rebound sequences in the four individuals who underwent treatment interruption. However, rebound viruses could be accounted for by recombination. The data suggest that CD4+ T cells carrying latent viruses circulate between blood and lymphoid tissues in individuals on ART and support the idea that recombination may play a role in the emergence of rebound viremia.IMPORTANCE HIV-1 persists as a latent infection in CD4+ T cells that can be found in lymphoid tissues in infected individuals during ART. However, the importance of this tissue reservoir and its contribution to viral rebound upon ART interruption are not clear. In this study, we sought to compare latent HIV-1 from blood and lymph node CD4+ T cells from five HIV-1-infected individuals. Further, we analyzed the contribution of lymph node viruses to viral rebound. We observed that the frequencies of intact proviruses were the same in blood and lymph node. Moreover, expanded clones of T cells bearing identical proviruses were found in blood and lymph node. These latent reservoir sequences did not appear to be the direct origin of rebound virus. Instead, latent proviruses were found to contribute to the rebound compartment by recombination.
Asunto(s)
Antirretrovirales/administración & dosificación , Linfocitos T CD4-Positivos , ADN Viral/sangre , Infecciones por VIH , VIH-1/metabolismo , Ganglios Linfáticos , Provirus/metabolismo , Adulto , Linfocitos T CD4-Positivos/metabolismo , Linfocitos T CD4-Positivos/virología , Femenino , Infecciones por VIH/sangre , Infecciones por VIH/tratamiento farmacológico , Humanos , Ganglios Linfáticos/metabolismo , Ganglios Linfáticos/virología , Masculino , Persona de Mediana Edad , Receptor Toll-Like 9/agonistas , Receptor Toll-Like 9/sangreRESUMEN
CD4+ T cells subsets have a wide range of important helper and regulatory functions in the immune system. Several studies have specifically suggested that circulating effector CD4+ T cells may play a direct role in control of HIV replication through cytolytic activity or autocrine ß-chemokine production. However, it remains unclear whether effector CD4+ T cells expressing cytolytic molecules and ß-chemokines are present within lymph nodes (LNs), a major site of HIV replication. Here, we report that expression of ß-chemokines and cytolytic molecules are enriched within a CD4+ T cell population with high levels of the T-box transcription factors T-bet and eomesodermin (Eomes). This effector population is predominately found in peripheral blood and is limited in LNs regardless of HIV infection or treatment status. As a result, CD4+ T cells generally lack effector functions in LNs, including cytolytic capacity and IFNγ and ß-chemokine expression, even in HIV elite controllers and during acute/early HIV infection. While we do find the presence of degranulating CD4+ T cells in LNs, these cells do not bear functional or transcriptional effector T cell properties and are inherently poor to form stable immunological synapses compared to their peripheral blood counterparts. We demonstrate that CD4+ T cell cytolytic function, phenotype, and programming in the peripheral blood is dissociated from those characteristics found in lymphoid tissues. Together, these data challenge our current models based on blood and suggest spatially and temporally dissociated mechanisms of viral control in lymphoid tissues.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Infecciones por VIH/inmunología , VIH-1/inmunología , Vigilancia Inmunológica , Ganglios Linfáticos/inmunología , Tejido Linfoide/inmunología , Linfocitos T CD4-Positivos/virología , Estudios de Casos y Controles , Infecciones por VIH/virología , Humanos , Ganglios Linfáticos/virología , Tejido Linfoide/virología , Carga ViralRESUMEN
In contrast to pathogenic HIV/SIV infections of humans and rhesus macaques (RMs), natural SIV infection of sooty mangabeys (SMs) is typically non-pathogenic despite high viremia. Several studies suggested that low immune activation and relative resistance of CD4+ central memory T-cells from virus infection are mechanisms that protect SMs from AIDS. In 2008 it was reported that plasmacytoid dendritic cells (pDCs) of SMs exhibit attenuated interferon-alpha (IFN-α) responses to TLR7/9 ligands in vitro, and that species-specific amino acid substitutions in SM Interferon Regulatory Factor-7 (IRF7) are responsible for this observation. Based on these findings, these authors proposed that "muted" IFN-α responses are responsible for the benign nature of SIV infection in SMs. However, other studies indicated that acutely SIV-infected SMs show robust IFN-α responses and marked upregulation of Interferon Stimulated Genes (ISGs). To investigate this apparent disparity, we first examined the role of the reported IRF7 amino acid substitutions in SMs. To this end, we sequenced all IRF7 exons in 16 breeders, and exons displaying variability (exons 2,3,5,6,7,8) in the remainder of the colony (177 animals). We found that the reported Ser-Gly substitution at position 191 was a sequencing error, and that several of the remaining substitutions represent only minor alleles. In addition, functional assays using recombinant SM IRF7 showed no defect in its ability to translocate in the nucleus and drive transcription from an IFN-α promoter. Furthermore, in vitro stimulation of SM peripheral blood mononuclear cells with either the TLR7 agonist CL097 or SIV(mac239) induced an 500-800-fold induction of IFN-α and IFN-ß mRNA, and levels of IFN-α production by pDCs similar to those of RMs or humans. These data establish that IFN-α and IRF7 signaling in SMs are largely intact, with differences with RMs that are minor and unlikely to play any role in the AIDS resistance of SIV-infected SMs.
Asunto(s)
Núcleo Celular/inmunología , Factor 7 Regulador del Interferón/inmunología , Interferón-alfa/inmunología , Interferón beta/inmunología , Leucocitos Mononucleares/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/inmunología , Virus de la Inmunodeficiencia de los Simios/inmunología , Transporte Activo de Núcleo Celular/genética , Transporte Activo de Núcleo Celular/inmunología , Sustitución de Aminoácidos , Animales , Núcleo Celular/genética , Cercocebus atys , Análisis Mutacional de ADN , Células Dendríticas/inmunología , Células Dendríticas/virología , Exones/genética , Exones/inmunología , Femenino , Infecciones por VIH/genética , Infecciones por VIH/inmunología , VIH-1/genética , VIH-1/inmunología , Humanos , Imidazoles/farmacología , Factor 7 Regulador del Interferón/genética , Interferón-alfa/genética , Interferón beta/genética , Leucocitos Mononucleares/virología , Masculino , Mutación Missense , Quinolinas/farmacología , ARN Mensajero/genética , ARN Mensajero/inmunología , Transducción de Señal/genética , Transducción de Señal/inmunología , Síndrome de Inmunodeficiencia Adquirida del Simio/genética , Virus de la Inmunodeficiencia de los Simios/genética , Receptor Toll-Like 7/agonistas , Receptor Toll-Like 7/genética , Receptor Toll-Like 7/inmunologíaRESUMEN
Follicular helper CD4hi T cells (TFH) are a major cellular pool for the maintenance of the HIV reservoir. Therefore, the delineation of the follicular (F)/germinal center (GC) immune landscape will significantly advance our understanding of HIV pathogenesis. We have applied multiplex confocal imaging, in combination with the relevant computational tools, to investigate F/GC in situ immune dynamics in viremic (vir-HIV), antiretroviral-treated (cART HIV) People Living With HIV (PLWH) and compare them to reactive, non-infected controls. Lymph nodes (LNs) from viremic and cART PLWH could be further grouped based on their TFH cell densities in high-TFH and low-TFH subgroups. These subgroups were also characterized by different in situ distributions of PD1hi TFH cells. Furthermore, a significant accumulation of follicular FOXP3hiCD4hi T cells, which were characterized by a low scattering in situ distribution profile and strongly correlated with the cell density of CD8hi T cells, was found in the cART-HIV low-TFH group. An inverse correlation between plasma viral load and LN GrzBhiCD8hi T and CD16hiCD15lo cells was found. Our data reveal the complex GC immune landscaping in HIV infection and suggest that follicular FOXP3hiCD4hi T cells could be negative regulators of TFH cell prevalence in cART-HIV.
RESUMEN
The main barrier to a cure for HIV is the persistence of long-lived and proliferating latently infected CD4+ T-cells despite antiretroviral therapy (ART). Latency is well characterized in multiple CD4+ T-cell subsets, however, the contribution of regulatory T-cells (Tregs) expressing FoxP3 as well as immune checkpoints (ICs) PD-1 and CTLA-4 as targets for productive and latent HIV infection in people living with HIV on suppressive ART is less well defined. We used multiplex detection of HIV DNA and RNA with immunohistochemistry (mIHC) on formalin-fixed paraffin embedded (FFPE) cells to simultaneously detect HIV RNA and DNA and cellular markers. HIV DNA and RNA were detected by in situ hybridization (ISH) (RNA/DNAscope) and IHC was used to detect cellular markers (CD4, PD-1, FoxP3, and CTLA-4) by incorporating the tyramide system amplification (TSA) system. We evaluated latently infected cell lines, a primary cell model of HIV latency and excisional lymph node (LN) biopsies collected from people living with HIV (PLWH) on and off ART. We clearly detected infected cells that coexpressed HIV RNA and DNA (active replication) and DNA only (latently infected cells) in combination with IHC markers in the in vitro infection model as well as LN tissue from PLWH both on and off ART. Combining ISH targeting HIV RNA and DNA with IHC provides a platform to detect and quantify HIV persistence within cells identified by multiple markers in tissue samples from PLWH on ART or to study HIV latency.
Asunto(s)
ADN Viral/análisis , Infecciones por VIH/diagnóstico , VIH/genética , Inhibidores de Puntos de Control Inmunológico/análisis , Inmunohistoquímica , Hibridación in Situ , Infección Latente/diagnóstico , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/virología , ARN Viral/análisis , Infecciones por VIH/inmunología , Infecciones por VIH/virología , Humanos , Células Jurkat , Infección Latente/inmunología , Infección Latente/virología , Valor Predictivo de las Pruebas , Linfocitos T Reguladores/inmunología , Linfocitos T Reguladores/virologíaRESUMEN
Follicular-helper T cells (TFH) are an essential arm of the adaptive immune system. Although TFH were first discovered through their ability to contribute to antibody affinity maturation through co-stimulatory interactions with B cells, new light has been shed on their ability to remain a complex and functionally plastic cell type. Due to a lack sample availability, however, many studies have been limited to characterizing TFH in mice or non-canonical tissue types, such as peripheral blood. Such constraints have resulted in a limited, and sometimes contradictory, understanding of this fundamental cell type. One subset of TFH receiving attention in chronic infection are CXCR3-expressing TFH cells (CXCR3+TFH) due to their abnormal accumulation in secondary lymphoid tissues. Their function and clonal relationship with other TFH subsets in lymphoid tissues during infection, however, remains largely unclear. We thus systematically investigated this and other subsets of TFH within untreated HIV-infected human lymph nodes using Mass CyTOF and a combination of RNA and TCR repertoire sequencing. We show an inflation of the CXCR3+TFH compartment during HIV infection that correlates with a lower HIV burden. Deeper analysis into this population revealed a functional shift of CXCR3+TFH away from germinal center TFH (GC-TFH), including the altered expression of several important transcription factors and cytokines. CXCR3+TFH also upregulated cell migration transcriptional programs and were clonally related to peripheral TFH populations. In combination, these data suggest that CXCR3+TFH have a greater tendency to enter circulation than their CXCR3- counterparts, potentially functioning through distinct modalities that may lead to enhanced defense.
Asunto(s)
Infecciones por VIH , Células T Auxiliares Foliculares , Animales , Centro Germinal , Humanos , Ratones , Receptores de Antígenos de Linfocitos T/metabolismo , Receptores CXCR3/genética , Receptores CXCR3/metabolismo , Linfocitos T Colaboradores-Inductores , TranscriptomaRESUMEN
Global population immunity to SARS-CoV-2 is accumulating through heterogenous combinations of infection and vaccination. Vaccine distribution in low- and middle-income countries has been variable and reliant on diverse vaccine platforms. We studied B-cell immunity in Mexico, a middle-income country where five different vaccines have been deployed to populations with high SARS-CoV-2 incidence. Levels of antibodies that bound a stabilized prefusion spike trimer, neutralizing antibody titers and memory B-cell expansion correlated with each other across vaccine platforms. Nevertheless, the vaccines elicited variable levels of B-cell immunity, and the majority of recipients had undetectable neutralizing activity against the recently emergent omicron variant. SARS-CoV-2 infection, experienced prior to or after vaccination potentiated B-cell immune responses and enabled the generation of neutralizing activity against omicron and SARS-CoV for all vaccines in nearly all individuals. These findings suggest that broad population immunity to SARS-CoV-2 will eventually be achieved, but by heterogenous paths.
RESUMEN
Global population immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is accumulating through heterogeneous combinations of infection and vaccination. Vaccine distribution in low- and middle-income countries has been variable and reliant on diverse vaccine platforms. We studied B-cell immunity in Mexico, a middle-income country where five different vaccines have been deployed to populations with high SARS-CoV-2 incidences. Levels of antibodies that bound a stabilized prefusion spike trimer, neutralizing antibody titers, and memory B-cell expansion correlated with each other across vaccine platforms. Nevertheless, the vaccines elicited variable levels of B-cell immunity, and the majority of recipients had undetectable neutralizing activity against the recently emergent omicron variant. SARS-CoV-2 infection, experienced before or after vaccination, potentiated B-cell immune responses and enabled the generation of neutralizing activity against omicron and SARS-CoV for all vaccines in nearly all individuals. These findings suggest that broad population immunity to SARS-CoV-2 will eventually be achieved but by heterogeneous paths. IMPORTANCE The majority of studies on SARS-CoV-2 vaccine-elicited immunity and immune evasion have focused on single vaccines corresponding to those distributed in high-income countries. However, in low- and middle-income countries, vaccine deployment has been far less uniform. It is therefore important to determine the levels of immunity elicited by vaccines that have been deployed globally. Such data should help inform policy. Thus, this paper is very much a "real-world" study that focuses on a middle-income country, Mexico, in which five different vaccines based on mRNA, adenovirus, and inactivated-virus platforms have been extensively deployed, while (as documented in our study) SARS-CoV-2 variants with increasing degrees of immune evasiveness have propagated in the Mexican population, culminating in the recent emergence of B.1.1.529 (omicron).
Asunto(s)
COVID-19 , Vacunas Virales , Anticuerpos Neutralizantes , Anticuerpos Antivirales , COVID-19/prevención & control , Vacunas contra la COVID-19 , Humanos , SARS-CoV-2/genética , Glicoproteína de la Espiga del Coronavirus/genéticaRESUMEN
CD4 T cells are key mediators of adaptive immune responses during infection and vaccination. Within secondary lymphoid organs, helper CD4 T cells, particularly those residing in germinal centers known as follicular helper T cells (Tfh), provide critical help to B-cells to promote their survival, isotype switching and selection of high affinity memory B-cells. On the other hand, the important role of Tfh cells for the maintenance of HIV reservoir is well documented. Thus, interrogating and better understanding the tissue specific micro-environment and immune subsets that contribute to optimal Tfh cell differentiation and function is important for designing successful prevention and cure strategies. Here, we describe the development and optimization of eight multispectral confocal microscopy immunofluorescence panels designed for in depth characterization and immune-profiling of relevant immune cells in formalin-fixed paraffin-embedded human lymphoid tissue samples. We provide a comprehensive library of antibodies to use for the characterization of CD4+ T-cells -including Tfh and regulatory T-cells- as well as CD8 T-cells, B-cells, macrophages and dendritic cells and discuss how the resulting multispectral confocal datasets can be quantitatively dissected using the HistoCytometry pipeline to collect information about relative frequencies and immune cell spatial distributions. Cells harboring actively transcribed virus are analyzed using an in-situ hybridization assay for the characterization of HIV mRNA positive cells in combination with additional protein markers (multispectral RNAscope). The application of this methodology to lymphoid tissues offers a means to interrogate multiple relevant immune cell targets simultaneously at increased resolution in a reproducible manner to guide CD4 T-cell studies in infection and vaccination.
Asunto(s)
Reservorios de Enfermedades/virología , Infecciones por VIH/virología , Procesamiento de Imagen Asistido por Computador , Tejido Linfoide/citología , Tejido Linfoide/metabolismo , Microscopía Confocal , Imagen Molecular , Biomarcadores , Técnica del Anticuerpo Fluorescente , Centro Germinal/inmunología , Centro Germinal/metabolismo , Centro Germinal/virología , Infecciones por VIH/diagnóstico , Infecciones por VIH/inmunología , Interacciones Huésped-Patógeno , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Ganglios Linfáticos/inmunología , Ganglios Linfáticos/virología , Tejido Linfoide/virología , Microscopía Confocal/métodos , Imagen Molecular/métodosRESUMEN
The Intact Proviral DNA Assay (IPDA) was developed to address the critical need for a scalable method for intact HIV-1 reservoir quantification. This droplet digital PCR-based assay simultaneously targets two HIV-1 regions to distinguish genomically intact proviruses against a large background of defective ones, and its application has yielded insights into HIV-1 persistence. Reports of assay failures however, attributed to HIV-1 polymorphism, have recently emerged. Here, we describe a diverse North American cohort of people with HIV-1 subtype B, where the IPDA yielded a failure rate of 28% due to viral polymorphism. We further demonstrate that within-host HIV-1 diversity can lead the IPDA to underestimate intact reservoir size, and provide examples of how this phenomenon could lead to erroneous interpretation of clinical trial data. While the IPDA represents a major methodological advance, HIV-1 diversity should be addressed before its widespread adoption as a principal readout in HIV-1 remission trials.
Asunto(s)
Biodiversidad , ADN Viral/análisis , VIH-1/genética , Provirus/genética , Secuencia de Bases , Linfocitos T CD4-Positivos/virología , ADN Viral/genética , Infecciones por VIH/virología , Humanos , Filogenia , Reacción en Cadena de la Polimerasa/métodosRESUMEN
The integration of HIV DNA into the host genome contributes to lifelong infection in most individuals. Few studies have examined integration in lymphoid tissue, where HIV predominantly persists before and after antiretroviral treatment (ART). Of particular interest is whether integration site distributions differ between infection stages with paired blood and tissue comparisons. Here, we profiled HIV integration site distributions in sorted memory, tissue-resident, and/or follicular helper CD4+ T cell subsets from paired blood and lymphoid tissue samples from acute, chronic, and ART-treated individuals. We observed minor differences in the frequency of nonintronic and nondistal intergenic sites, varying with tissue and residency phenotypes during ART. Genomic and epigenetic annotations were generally similar. Clonal expansion of cells marked by identical integration sites was detected, with increased detection in chronic and ART-treated individuals. However, overlap between or within CD4+ T cell subsets or tissue compartments was only observed in 8 unique sites of the 3540 sites studied. Together, these findings suggest that shared integration sites between blood and tissue may, depending on the tissue site, be the exception rather than the rule and indicate that additional studies are necessary to fully understand the heterogeneity of tissue-sequestered HIV reservoirs.
Asunto(s)
ADN Viral/genética , Infecciones por VIH/genética , Interacciones Huésped-Patógeno/genética , Integración Viral/genética , Adulto , Antirretrovirales/administración & dosificación , Linfocitos T CD4-Positivos/virología , Genoma Humano/efectos de los fármacos , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/patología , Infecciones por VIH/virología , VIH-1/genética , VIH-1/patogenicidad , Humanos , Tejido Linfoide/virología , Masculino , Subgrupos de Linfocitos T/virología , Carga Viral/genética , Adulto JovenRESUMEN
Impaired immunity is a common symptom of aging and advanced Human Immunodeficiency Virus type 1 (HIV-1) disease. In both diseases, a decline in lymphocytic function and cellularity leads to ineffective adaptive immune responses to opportunistic infections and vaccinations. Furthermore, despite sustained myeloid cellularity there is a background of chronic immune activation and a decrease in innate immune function in aging. In HIV-1 disease, myeloid cellularity is often more skewed than in normal aging, but similar chronic activation and innate immune dysfunction typically arise. Similarities between aging and HIV-1 infection have led to several investigations into HIV-1-mediated aging of the immune system. In this article, we review various studies that report alterations of leukocyte number and function during aging, and compare those alterations with those observed during progressive HIV-1 disease. We pay particular attention to changes within lymphoid tissue microenvironments and how histoarchitectural changes seen in these two diseases affect immunity. As we review various immune compartments including peripheral blood as well as primary and secondary lymphoid organs, common themes arise that help explain the decline of immunity in the elderly and in HIV-1-infected individuals with advanced disease. In both conditions, lymphoid tissues often show signs of histoarchitectural deterioration through fat accumulation and/or fibrosis. These structural changes can be attributed to a loss of communication between leukocytes and the surrounding stromal cells that produce the extracellular matrix components and growth factors necessary for cell migration, cell proliferation, and lymphoid tissue function. Despite the common general impairment of immunity in aging and HIV-1 progression, deterioration of immunity is caused by distinct mechanisms at the cellular and tissue levels in these two diseases.
Asunto(s)
Envejecimiento/inmunología , Infecciones por VIH/inmunología , Tejido Linfoide/patología , Tejido Linfoide/virología , Anciano , Linfocitos T CD4-Positivos/inmunología , Microambiente Celular/inmunología , Progresión de la Enfermedad , Matriz Extracelular/inmunología , Fibrosis , Infecciones por VIH/complicaciones , VIH-1/inmunología , Humanos , Inmunidad Humoral , Tejido Linfoide/citologíaRESUMEN
CXCR5 is a key marker of follicular helper T (TFH) cells. Using primary lymph nodes (LNs) from HIV-infected patients, we identified a population of CXCR5- CD4+ T cells with TFH-cell-like features. This CXCR5- subset becomes expanded in severe HIV infection and is characterized by the upregulation of activation markers and high PD-1 and ICOS surface expression. Integrated analyses on the phenotypic heterogeneity, functional capacity, T cell receptor (TCR) repertoire, transcriptional profile, and epigenetic state of CXCR5-PD-1+ICOS+ T cells revealed a shared clonal relationship with TFH cells. CXCR5-PD-1+ICOS+ T cells retained a poised state for CXCR5 expression and exhibited a migratory transcriptional program. TCR sequence overlap revealed a contribution of LN-derived CXCR5-PD-1+ICOS+ T cells to circulating CXCR5- CD4+ T cells with B cell help function. These data link LN pathology to circulating T cells and expand the current understanding on the diversity of T cells that regulate B cell responses during chronic inflammation.
Asunto(s)
Linfocitos T CD4-Positivos/inmunología , Infecciones por VIH/inmunología , VIH-1/inmunología , Ganglios Linfáticos/inmunología , Receptores CXCR5/inmunología , Linfocitos B/inmunología , Linfocitos B/patología , Linfocitos T CD4-Positivos/patología , Femenino , Infecciones por VIH/patología , Humanos , Ganglios Linfáticos/patología , MasculinoRESUMEN
The functional properties of circulating CD8+ T cells have been associated with immune control of HIV. However, viral replication occurs predominantly in secondary lymphoid tissues, such as lymph nodes (LNs). We used an integrated single-cell approach to characterize effective HIV-specific CD8+ T cell responses in the LNs of elite controllers (ECs), defined as individuals who suppress viral replication in the absence of antiretroviral therapy (ART). Higher frequencies of total memory and follicle-homing HIV-specific CD8+ T cells were detected in the LNs of ECs compared with the LNs of chronic progressors (CPs) who were not receiving ART. Moreover, HIV-specific CD8+ T cells potently suppressed viral replication without demonstrable cytolytic activity in the LNs of ECs, which harbored substantially lower amounts of CD4+ T cell-associated HIV DNA and RNA compared with the LNs of CPs. Single-cell RNA sequencing analyses further revealed a distinct transcriptional signature among HIV-specific CD8+ T cells from the LNs of ECs, typified by the down-regulation of inhibitory receptors and cytolytic molecules and the up-regulation of multiple cytokines, predicted secreted factors, and components of the protein translation machinery. Collectively, these results provide a mechanistic framework to expedite the identification of novel antiviral factors, highlighting a potential role for the localized deployment of noncytolytic functions as a determinant of immune efficacy against HIV.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/metabolismo , Infecciones por VIH/inmunología , Tejido Linfoide/citología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , VIH-1/patogenicidad , Humanos , Carga ViralRESUMEN
Follicular helper CD4+ T cells (TFH) play an integral role in promoting B cell differentiation and affinity maturation. Whereas TFH cell frequencies are increased in lymph nodes (LNs) from individuals infected with HIV, humoral immunity remains impaired during chronic HIV infection. Whether HIV inhibits TFH responses in LNs remains unclear. Advances in this area have been limited by the difficulty of accessing human lymphoid tissues. Here, we combined high-dimensional mass cytometry with T cell receptor repertoire sequencing to interrogate the composition of TFH cells in primary human LNs. We found evidence for intact antigen-driven clonal expansion of TFH cells and selective utilization of specific complementarity-determining region 3 (CDR3) motifs during chronic HIV infection, but the resulting TFH cells acquired an activation-related TFH cell signature characterized by interleukin-21 (IL-21) dominance. These IL-21+ TFH cells contained an oligoclonal HIV-reactive population that preferentially accumulated in patients with severe HIV infection and was associated with aberrant B cell distribution in the same LN. These data indicate that TFH cells remain capable of responding to HIV antigens during chronic HIV infection but become functionally skewed and oligoclonally restricted under persistent antigen stimulation.
Asunto(s)
Infecciones por VIH/inmunología , Ganglios Linfáticos/inmunología , Receptores de Antígenos de Linfocitos T/inmunología , Linfocitos T Colaboradores-Inductores/inmunología , Adolescente , Adulto , Secuencia de Aminoácidos , Animales , Linfocitos B/inmunología , Femenino , Humanos , Interleucinas/inmunología , Interleucinas/metabolismo , Activación de Linfocitos/inmunología , Masculino , Persona de Mediana Edad , Receptores de Antígenos de Linfocitos T/genética , Receptores de Antígenos de Linfocitos T/metabolismo , Linfocitos T Colaboradores-Inductores/metabolismo , Adulto JovenRESUMEN
Current paradigms of CD8+ T cell-mediated protection in HIV infection center almost exclusively on studies of peripheral blood, which is thought to provide a window into immune activity at the predominant sites of viral replication in lymphoid tissues (LTs). Through extensive comparison of blood, thoracic duct lymph (TDL), and LTs in different species, we show that many LT memory CD8+ T cells bear phenotypic, transcriptional, and epigenetic signatures of resident memory T cells (TRMs). Unlike their circulating counterparts in blood or TDL, most of the total and follicular HIV-specific CD8+ T cells in LTs also resemble TRMs Moreover, high frequencies of HIV-specific CD8+ TRMs with skewed clonotypic profiles relative to matched blood samples are present in LTs of individuals who spontaneously control HIV replication in the absence of antiretroviral therapy (elite controllers). Single-cell RNA sequencing analysis confirmed that HIV-specific TRMs are enriched for effector-related immune genes and signatures compared with HIV-specific non-TRMs in elite controllers. Together, these data indicate that previous studies in blood have largely failed to capture the major component of HIV-specific CD8+ T cell responses resident within LTs.
Asunto(s)
Linfocitos T CD8-positivos/inmunología , Infecciones por VIH/inmunología , VIH-1/inmunología , Memoria Inmunológica , Tejido Linfoide/citología , Adulto , Animales , Antirreumáticos/farmacología , Antirreumáticos/uso terapéutico , Linfocitos T CD8-positivos/metabolismo , Femenino , Infecciones por VIH/sangre , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , Humanos , Tejido Linfoide/efectos de los fármacos , Tejido Linfoide/inmunología , Macaca mulatta , Masculino , Ratones , Ratones Endogámicos C57BL , Persona de Mediana Edad , Análisis de Secuencia de ARN , Análisis de la Célula Individual/métodos , Carga Viral/efectos de los fármacos , Carga Viral/inmunología , Replicación Viral/efectos de los fármacos , Replicación Viral/inmunología , Adulto JovenRESUMEN
The persistence of HIV reservoirs, including latently infected, resting CD4+ T cells, is the major obstacle to cure HIV infection. CD32a expression was recently reported to mark CD4+ T cells harboring a replication-competent HIV reservoir during antiretroviral therapy (ART) suppression. We aimed to determine whether CD32 expression marks HIV latently or transcriptionally active infected CD4+ T cells. Using peripheral blood and lymphoid tissue of ART-treated HIV+ or SIV+ subjects, we found that most of the circulating memory CD32+ CD4+ T cells expressed markers of activation, including CD69, HLA-DR, CD25, CD38, and Ki67, and bore a TH2 phenotype as defined by CXCR3, CCR4, and CCR6. CD32 expression did not selectively enrich for HIV- or SIV-infected CD4+ T cells in peripheral blood or lymphoid tissue; isolated CD32+ resting CD4+ T cells accounted for less than 3% of the total HIV DNA in CD4+ T cells. Cell-associated HIV DNA and RNA loads in CD4+ T cells positively correlated with the frequency of CD32+ CD69+ CD4+ T cells but not with CD32 expression on resting CD4+ T cells. Using RNA fluorescence in situ hybridization, CD32 coexpression with HIV RNA or p24 was detected after in vitro HIV infection (peripheral blood mononuclear cell and tissue) and in vivo within lymph node tissue from HIV-infected individuals. Together, these results indicate that CD32 is not a marker of resting CD4+ T cells or of enriched HIV DNA-positive cells after ART; rather, CD32 is predominately expressed on a subset of activated CD4+ T cells enriched for transcriptionally active HIV after long-term ART.