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Many organizations persist in working with others that engage in known, remediable structural discrimination. We name this practice interorganizational structural discrimination (ISD) and argue it is a pivotal contributor to inequities in science and medicine. We urge organizations to leverage their relationships and demand progress from collaborators.
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Significant inequities based on sex, race, ethnicity, and age exist among participants in clinical trials dedicated to investigating medical disease states. While general demographic data regarding blood donors and blood transfusion recipients have been studied extensively, the demographics of participants involved in blood donation and blood transfusion clinical trials are unknown. We performed a cross-sectional analysis of United States (U.S.) -based interventional blood donation and blood transfusion clinical trials registered with Clinicaltrials.gov to ascertain the composition of participants' sex, race, ethnicity, and age, as well as diagnostic conditions and geographic trial locations.Eligible trials were undertaken between July 2003 and August 2020. Thirty-eight of the one hundred and fifty-two blood donation and blood transfusion clinical trials met inclusion criteria (seven blood donation and thirty-one blood transfusion trials). While the participant dataset from trial reports were incomplete, 100 % of blood donation trials reported sex and age, 71.4 % reported race, and 42.3 % reported ethnicity. 96.8 % of blood transfusion trials reported sex, 51.6 % reported race, 38.7 % reported ethnicity, and 100 % reported age. Among 2720 participants enrolled in the seven blood donation trials, females were underrepresented (28.5 %) compared to U.S. Census data. Conversely, female (50.8 %) and male participants (49.2 %) were equally represented in blood transfusion trials (9255 participants). White participants were overrepresented in blood donation trials (73.4 %), while Hispanic or Latinos were underrepresented in both blood donation (7.7 %) and blood transfusion (8.2 %) trials compared to 2019 U.S.Census data. Only 8.3 % of blood transfusion clinical trials open to adults reported including older adults (i.e., ≥ 65yo). Despite mandatory reporting requirements and an already established framework, researchers frequently failed to report complete demographics of blood donation and blood transfusion clinical trial participants. Furthermore, various demographic groups were underrepresented in blood donation and/or blood transfusion clinical trials, including females, Hispanic or Latino individuals, and older adults. These findings demonstrate the need for implementation of strategies to ensure equitable representation of individuals in blood donation and transfusion clinical trials.
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Doação de Sangue , Etnicidade , Humanos , Masculino , Feminino , Estados Unidos , Idoso , Estudos Transversais , Transfusão de Sangue , Doadores de SangueRESUMO
The RV254 cohort of HIV-infected very early acute (4thG stage 1 and 2) (stage 1/2) and late acute (4thG stage 3) (stage 3) individuals was used to study T helper- B cell responses in acute HIV infection and the impact of early antiretroviral treatment (ART) on T and B cell function. To investigate this, the function of circulating T follicular helper cells (cTfh) from this cohort was examined, and cTfh and memory B cell populations were phenotyped. Impaired cTfh cell function was observed in individuals treated in stage 3 when compared to stage 1/2. The cTfh/B cell cocultures showed lower B cell survival and IgG secretion at stage 3 compared to stage 1/2. This coincided with lower IL-10 and increased RANTES and TNF-α suggesting a role for inflammation in altering cTfh and B cell responses. Elevated plasma viral load in stage 3 was found to correlate with decreased cTfh-mediated B cell IgG production indicating a role for increased viremia in cTfh impairment and dysfunctional humoral response. Phenotypic perturbations were also evident in the mature B cell compartment, most notably a decrease in resting memory B cells in stage 3 compared to stage 1/2, coinciding with higher viremia. Our coculture assay also suggested that intrinsic memory B cell defects could contribute to the impaired response despite at a lower level. Overall, cTfh-mediated B cell responses are significantly altered in stage 3 compared to stage 1/2, coinciding with increased inflammation and a reduction in memory B cells. These data suggest that early ART for acutely HIV infected individuals could prevent immune dysregulation while preserving cTfh function and B cell memory.
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Linfócitos B/imunologia , Infecções por HIV/imunologia , Memória Imunológica/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Adulto , Fármacos Anti-HIV/uso terapêutico , Técnicas de Cocultura , Estudos de Coortes , Ensaio de Imunoadsorção Enzimática , Feminino , Citometria de Fluxo , HIV-1/imunologia , Humanos , Ativação Linfocitária/imunologia , Masculino , Carga ViralRESUMO
Acute respiratory distress syndrome (ARDS) is a devastating disorder characterized by increased alveolar permeability with no effective treatment beyond supportive care. Current mechanisms underlying ARDS focus on alveolar endothelial and epithelial injury caused by products of innate immune cells and platelets. However, the role of adaptive immune cells in ARDS remains largely unknown. In this study, we report that expansion of Ag-specific αßTh17 cells contributes to ARDS by local secretion of IL-17A, which in turn directly increases alveolar epithelial permeability. Mice with a highly restrictive defect in Ag-specific αßTh17 cells were protected from experimental ARDS induced by a single dose of endotracheal LPS. Loss of IL-17 receptor C or Ab blockade of IL-17A was similarly protective, further suggesting that IL-17A released by these cells was responsible for this effect. LPS induced a rapid and specific clonal expansion of αßTh17 cells in the lung, as determined by deep sequencing of the hypervariable CD3RßVJ region of the TCR. Our findings could be relevant to ARDS in humans, because we found significant elevation of IL-17A in bronchoalveolar lavage fluid from patients with ARDS, and rIL-17A directly increased permeability across cultured human alveolar epithelial monolayers. These results reveal a previously unexpected role for adaptive immune responses that increase alveolar permeability in ARDS and suggest that αßTh17 cells and IL-17A could be novel therapeutic targets for this currently untreatable disease.
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Interleucina-17/imunologia , Alvéolos Pulmonares/imunologia , Receptores de Antígenos de Linfócitos T alfa-beta/imunologia , Síndrome do Desconforto Respiratório/imunologia , Células Th17/imunologia , Imunidade Adaptativa , Animais , Anticorpos/farmacologia , Líquido da Lavagem Broncoalveolar/citologia , Líquido da Lavagem Broncoalveolar/imunologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/imunologia , Células Epiteliais/patologia , Humanos , Interleucina-17/antagonistas & inibidores , Interleucina-17/genética , Lipopolissacarídeos/farmacologia , Camundongos , Camundongos Transgênicos , Permeabilidade , Cultura Primária de Células , Alvéolos Pulmonares/efeitos dos fármacos , Alvéolos Pulmonares/patologia , Ratos , Ratos Sprague-Dawley , Receptores de Antígenos de Linfócitos T alfa-beta/genética , Receptores de Interleucina-17/genética , Receptores de Interleucina-17/imunologia , Síndrome do Desconforto Respiratório/genética , Síndrome do Desconforto Respiratório/patologia , Células Th17/efeitos dos fármacos , Células Th17/patologiaRESUMO
Despite the overwhelming benefits of antiretroviral therapy (ART) in curtailing viral load in HIV-infected individuals, ART does not fully restore cellular and humoral immunity. HIV-infected individuals under ART show reduced responses to vaccination and infections and are unable to mount an effective antiviral immune response upon ART cessation. Many factors contribute to these defects, including persistent inflammation, especially in lymphoid tissues, where T follicular helper (Tfh) cells instruct and help B cells launch an effective humoral immune response. In this study we investigated the phenotype and function of circulating memory Tfh cells as a surrogate of Tfh cells in lymph nodes and found significant impairment of this cell population in chronically HIV-infected individuals, leading to reduced B cell responses. We further show that these aberrant memory Tfh cells exhibit an IL-2-responsive gene signature and are more polarized toward a Th1 phenotype. Treatment of functional memory Tfh cells with IL-2 was able to recapitulate the detrimental reprogramming. Importantly, this defect was reversible, as interfering with the IL-2 signaling pathway helped reverse the abnormal differentiation and improved Ab responses. Thus, reversible reprogramming of memory Tfh cells in HIV-infected individuals could be used to enhance Ab responses. Altered microenvironmental conditions in lymphoid tissues leading to altered Tfh cell differentiation could provide one explanation for the poor responsiveness of HIV-infected individuals to new Ags. This explanation has important implications for the development of therapeutic interventions to enhance HIV- and vaccine-mediated Ab responses in patients under ART.
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Linfócitos B/imunologia , Infecções por HIV/imunologia , HIV , Interleucina-2/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Adulto , Anticorpos Antivirais/imunologia , Formação de Anticorpos , Linfócitos B/virologia , Diferenciação Celular , Células Cultivadas , Reprogramação Celular , Doença Crônica , Humanos , Memória Imunológica , Pessoa de Meia-Idade , Transdução de Sinais , Linfócitos T Auxiliares-Indutores/virologia , Adulto JovemRESUMO
RATIONALE: IL-17A is purported to help drive early pathogenesis in acute respiratory distress syndrome (ARDS) by enhancing neutrophil recruitment. Although IL-17A is the archetypal cytokine of T-helper 17 cells, it is produced by a number of lymphocytes, the source during ARDS being unknown. OBJECTIVES: To identify the cellular source and the role of IL-17A in the early phase of lung injury. METHODS: Lung injury was induced in wild-type (C57BL/6) and IL-17 knockout (KO) mice with aerosolized LPS (100 µg) or Pseudomonas aeruginosa infection. Detailed phenotyping of the cells expressing RORγt, the transcriptional regulator of IL-17 production, in the mouse lung at 24 hours was performed by flow cytometry. MEASUREMENTS AND MAIN RESULTS: A 100-fold reduction in neutrophil infiltration was observed in the lungs of the IL-17A KO compared with wild-type mice. The majority of RORγt(+) cells in the mouse lung were the recently identified group 3 innate lymphoid cells (ILC3s). Detailed characterization revealed these pulmonary ILC3s (pILC3s) to be discrete from those described in the gut. The critical role of these cells was verified by inducing injury in recombinase-activating gene 2 KO mice, which lack T cells but retain innate lymphoid cells. No amelioration of pathology was observed in the recombinase-activating gene 2 KO mice. CONCLUSIONS: IL-17 is rapidly produced during lung injury and significantly contributes to early immunopathogenesis. This is orchestrated largely by a distinct population of pILC3s. Modulation of the activity of pILC3s may potentiate early control of the inflammatory dysregulation seen in ARDS, opening up new therapeutic targets.
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Interleucina-17/biossíntese , Linfócitos/patologia , Síndrome do Desconforto Respiratório/patologia , Animais , Modelos Animais de Doenças , Feminino , Citometria de Fluxo , Pulmão/patologia , Linfócitos/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Infiltração de Neutrófilos , Síndrome do Desconforto Respiratório/metabolismoRESUMO
There is currently no prophylactic vaccine available for human immunodeficiency virus (HIV). Research efforts have resulted in improved immunogens that mimic the native envelope (Env) glycoprotein structure. Recently, a novel triple tandem trimer (TTT) platform has been used to generate a plasmid encoding Env immunogen (pBG505-TTT) that expresses only as trimers, making it more suitable for nucleic acid vaccines. We have previously demonstrated that adenosine deaminase-1 (ADA-1) is critical to the T follicular helper (TFH) function and improves vaccine immune responses in vivo. In this study, we demonstrate that co-delivery of plasmid-encoded adenosine deaminase 1 (pADA) with pBG505-TTT enhances the magnitude, durability, isotype switching and functionality of HIV-specific antibodies in a dose-sparing manner. Co-delivery of the molecular immune modulator ADA-1 also enhances HIV-specific T cell polyfunctionality, activation, and degranulation as well as memory B cell responses. These data demonstrate that pADA enhances HIV-specific cellular and humoral immunity, making ADA-1 a promising immune modulator for HIV-targeting vaccines.
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In the field of immunology, a systems biology approach is crucial to understanding the immune response to infection and vaccination considering the complex interplay between genetic, epigenetic, and environmental factors. Significant progress has been made in understanding the innate immune response, including cell players and critical signaling pathways, but many questions remain unanswered, including how the innate immune response dictates host/pathogen responses and responses to vaccines. To complicate things further, it is becoming increasingly clear that the innate immune response is not a linear pathway but is formed from complex networks and interactions. To further our understanding of the crosstalk and complexities, systems-level analyses and expanded experimental technologies are now needed. In this review, we discuss the most recent immunoprofiling techniques and discuss systems approaches to studying the global innate immune landscape which will inform on the development of personalized medicine and innovative vaccine strategies.
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Vacinas , Imunidade Inata , Vacinação , Biologia de SistemasRESUMO
The impact of endemic infections on protective immunity is critical to inform vaccination strategies. In this study, we assessed the influence of Schistosoma mansoni infection on host responses in a Ugandan fishing cohort given a Hepatitis B (HepB) vaccine. Concentrations of schistosome-specific circulating anodic antigen (CAA) pre-vaccination showed a significant bimodal distribution associated with HepB titers, which were lower in individuals with high CAA. We established that participants with high CAA had significantly lower frequencies of circulating T follicular helper (cTfh) subpopulations pre- and post-vaccination and higher regulatory T cells (Tregs) post-vaccination. Polarization towards higher frequencies of Tregs: cTfh cells can be mediated by changes in the cytokine environment favoring Treg differentiation. In fact, we observed higher levels of CCL17 and soluble IL-2R pre-vaccination (important for Treg recruitment and development), in individuals with high CAA that negatively associated with HepB titers. Additionally, alterations in pre-vaccination monocyte function correlated with HepB titers, and changes in innate-related cytokines/chemokine production were associated with increasing CAA concentration. We report, that by influencing the immune landscape, schistosomiasis has the potential to modulate immune responses to HepB vaccination. These findings highlight multiple Schistosoma -related immune associations that could explain abrogated vaccine responses in communities with endemic infections. Author Summary: Schistosomiasis drives host immune responses for optimal pathogen survival, potentially altering host responses to vaccine-related antigen. Chronic schistosomiasis and co-infection with hepatotropic viruses are common in countries where schistosomiasis is endemic. We explored the impact of Schistosoma mansoni ( S. mansoni ) infection on Hepatitis B (HepB) vaccination of individuals from a fishing community in Uganda. We demonstrate that high schistosome-specific antigen (circulating anodic antigen, CAA) concentration pre-vaccination, is associated with lower HepB antibody titers post-vaccination. We show higher pre-vaccination levels of cellular and soluble factors in instances of high CAA that are negatively associated with HepB antibody titers post-vaccination, which coincided with lower frequencies of circulating T follicular helper cell populations (cTfh), proliferating antibody secreting cells (ASCs), and higher frequencies of regulatory T cells (Tregs). We also show that monocyte function is important in HepB vaccine responses, and that high CAA is associated with alterations in the early innate cytokine/chemokine microenvironment. Our findings suggest that in individuals with high CAA and likely high worm burden, schistosomiasis creates and sustains an environment that is polarized against optimal host immune responses to the vaccine, which puts many endemic communities at risk for infection against HepB and other diseases that are preventable by vaccines.
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Schistosomiasis is a disease caused by parasitic flatworms of the Schistosoma spp., and is increasingly recognized to alter the immune system, and the potential to respond to vaccines. The impact of endemic infections on protective immunity is critical to inform vaccination strategies globally. We assessed the influence of Schistosoma mansoni worm burden on multiple host vaccine-related immune parameters in a Ugandan fishing cohort (n = 75) given three doses of a Hepatitis B (HepB) vaccine at baseline and multiple timepoints post-vaccination. We observed distinct differences in immune responses in instances of higher worm burden, compared to low worm burden or non-infected. Concentrations of pre-vaccination serum schistosome-specific circulating anodic antigen (CAA), linked to worm burden, showed a significant bimodal distribution associated with HepB titers, which was lower in individuals with higher CAA values at month 7 post-vaccination (M7). Comparative chemokine/cytokine responses revealed significant upregulation of CCL19, CXCL9 and CCL17 known to be involved in T cell activation and recruitment, in higher CAA individuals, and CCL17 correlated negatively with HepB titers at month 12 post-vaccination. We show that HepB-specific CD4+ T cell memory responses correlated positively with HepB titers at M7. We further established that those participants with high CAA had significantly lower frequencies of circulating T follicular helper (cTfh) subpopulations pre- and post-vaccination, but higher regulatory T cells (Tregs) post-vaccination, suggesting changes in the immune microenvironment in high CAA could favor Treg recruitment and activation. Additionally, we found that changes in the levels of innate-related cytokines/chemokines CXCL10, IL-1ß, and CCL26, involved in driving T helper responses, were associated with increasing CAA concentration. This study provides further insight on pre-vaccination host responses to Schistosoma worm burden which will support our understanding of vaccine responses altered by pathogenic host immune mechanisms and memory function and explain abrogated vaccine responses in communities with endemic infections.
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Esquistossomose mansoni , Animais , Esquistossomose mansoni/epidemiologia , Antígenos de Helmintos , Schistosoma mansoni , Citocinas , Vacinação , ImunidadeRESUMO
Streptococcus pyogenes is the causative agent of numerous diseases ranging from benign infections (pharyngitis and impetigo) to severe infections associated with high mortality (necrotizing fasciitis and bacterial sepsis). As with other bacterial infections, there is considerable interest in characterizing the contribution of interleukin-17A (IL-17A) responses to protective immunity. We here show significant il17a up-regulation by quantitative real-time PCR in secondary lymphoid organs, correlating with increased protein levels in the serum within a short time of S. pyogenes infection. However, our data offer an important caveat to studies of IL-17A responsiveness following antigen inoculation, because enhanced levels of IL-17A were also detected in the serum of sham-infected mice, indicating that inoculation trauma alone can stimulate the production of this cytokine. This highlights the potency and speed of innate IL-17A immune responses after inoculation and the importance of proper and appropriate controls in comparative analysis of immune responses observed during microbial infection.
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Interleucina-17/sangue , Interleucina-17/genética , Streptococcus pyogenes/imunologia , Streptococcus pyogenes/patogenicidade , Imunidade Adaptativa/genética , Animais , Antígenos de Bactérias/administração & dosagem , Sequência de Bases , Primers do DNA/genética , Feminino , Antígenos HLA-DQ/genética , Humanos , Imunidade Inata/genética , Camundongos , Camundongos Transgênicos , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Sepse/genética , Sepse/imunologia , Infecções Estreptocócicas/genética , Infecções Estreptocócicas/imunologia , Células Th17/imunologia , Fatores de Tempo , Regulação para CimaRESUMO
Early initiation of antiretroviral therapy (ART) in acute HIV infection (AHI) is effective at limiting seeding of the HIV viral reservoir, but little is known about how the resultant decreased antigen load affects long-term Ab development after ART. We report here that Env-specific plasma antibody (Ab) levels and Ab-dependent cellular cytotoxicity (ADCC) increased during the first 24 weeks of ART and correlated with Ab levels persisting after 48 weeks of ART. Participants treated in AHI stage 1 had lower Env-specific Ab levels and ADCC activity on ART than did those treated later. Importantly, participants who initiated ART after peak viremia in AHI developed elevated cross-clade ADCC responses that were detectable 1 year after ART initiation, even though clinically undetectable viremia was reached by 24 weeks. These data suggest that there is more germinal center (GC) activity in the later stages of AHI and that Ab development continues in the absence of detectable viremia during the first year of suppressive ART. The development of therapeutic interventions that can enhance earlier development of GCs in AHI and Abs after ART initiation could provide important protection against the viral reservoir that is seeded in individuals treated early in the disease.
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Antirretrovirais/administração & dosagem , Anticorpos Anti-HIV/sangue , Infecções por HIV/sangue , Infecções por HIV/tratamento farmacológico , HIV-1/metabolismo , Doença Aguda , Adulto , Linhagem Celular , Feminino , Humanos , Masculino , Viremia/sangue , Viremia/tratamento farmacológicoRESUMO
IL-9 is a cytokine of great current interest associated with allergic/Th2 responses. High levels of IL-9 are present in bronchial secretions from infants with respiratory syncytial virus (RSV) bronchiolitis. To test its effects in RSV disease with a Th2 profile, BALB/c mice were vaccinated with recombinant vaccinia virus expressing the RSV G protein. On RSV challenge, immunized mice developed augmented disease characterized by enhanced pulmonary Th2 and local IL-9 production peaking on days 7-10 of RSV infection. Depletion with anti-IL-9 Ab at vaccination or RSV challenge enhanced viral clearance. Depletion only at challenge had no effect on disease severity, whereas depletion at immunization and challenge enhanced Th1 responses, inhibited virus-specific IgG1 production, and enhanced disease severity. By contrast, depletion of IL-9 at immunization boosted IgG2a and inhibited the Th2 response and disease during subsequent infection without a concomitant increase in type 1 cytokines. Adoptive transfer of secondary memory CD4 T cells from the spleens of IL-9-depleted mice into naive recipients replicated many of the effects of depletion, indicating that IL-9 acts via CD4 T cells. Therefore, IL-9 is a previously unknown but key modulator of antiviral immunity, regulating T and B cell responses and having potent and specific effects on viral lung disease.
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Memória Imunológica , Interleucina-9/imunologia , Infecções por Vírus Respiratório Sincicial/patologia , Células Th1/imunologia , Células Th2/imunologia , Animais , Ensaio de Imunoadsorção Enzimática , Feminino , Citometria de Fluxo , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Infecções por Vírus Respiratório Sincicial/imunologia , Vírus Sinciciais Respiratórios/imunologia , Células Th1/virologia , Células Th2/virologiaRESUMO
Innate Lymphoid Cells (ILCs) are immune cells typically found on mucosal surfaces and in secondary lymphoid organs where they regulate the immune response to pathogens. Despite their key role in the immune response, there are still fundamental gaps in our understanding of ILCs. Here we report a human ILC population present in the follicles of tonsils and lymph nodes termed follicular regulatory ILCs (ILCFR) that to our knowledge has not been previously identified. ILCFR have a distinct phenotype and transcriptional program when compared to other defined ILCs. Surprisingly, ILCFR inhibit the ability of follicular helper T (Tfh) cells to provide B cell help. The localization of ILCFR to the germinal centers suggests these cells may interfere with germinal center B cell (GC-B) and germinal center Tfh cell (GC-Tfh) interactions through the production of transforming growth factor beta (TGF-ß. Intriguingly, under conditions of impaired GC-Tfh-GC-B cell interactions, such as human immunodeficiency virus (HIV) infection, the frequency of these cells is increased. Overall, we predict a role for ILCFR in regulating GC-Tfh-GC-B cell interactions and propose they expand in chronic inflammatory conditions.
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Centro Germinativo/imunologia , Centro Germinativo/fisiologia , Linfócitos/imunologia , Adolescente , Adulto , Linfócitos B/imunologia , Criança , Pré-Escolar , Feminino , Humanos , Imunidade Inata/imunologia , Linfonodos/imunologia , Linfonodos/metabolismo , Ativação Linfocitária/imunologia , Linfócitos/metabolismo , Masculino , Tonsila Palatina/imunologia , Tonsila Palatina/metabolismo , Células T Auxiliares Foliculares/imunologiaRESUMO
An effective vaccine to prevent HIV transmission has not yet been achieved. Modulation of the microbiome via probiotic therapy has been suggested to result in enhanced mucosal immunity. Here, we evaluated whether probiotic therapy could improve the immunogenicity and protective efficacy of SIV/HIV vaccination. Rhesus macaques were co-immunized with an SIV/HIV DNA vaccine via particle-mediated epidermal delivery and an HIV protein vaccine administered intramuscularly with Adjuplex™ adjuvant, while receiving daily oral Visbiome® probiotics. Probiotic therapy alone led to reduced frequencies of colonic CCR5+ and CCR6+ CD4+ T cells. Probiotics with SIV/HIV vaccination led to similar reductions in colonic CCR5+ CD4+ T cell frequencies. SIV/HIV-specific T cell and antibody responses were readily detected in the periphery of vaccinated animals but were not enhanced with probiotic treatment. Combination probiotics and vaccination did not impact rectal SIV/HIV target populations or reduce the rate of heterologous SHIV acquisition during the intrarectal challenge. Finally, post-infection viral kinetics were similar between all groups. Thus, although probiotics were well-tolerated when administered with SIV/HIV vaccination, vaccine-specific responses were not significantly enhanced. Additional work will be necessary to develop more effective strategies of microbiome modulation in order to enhance mucosal vaccine immunogenicity and improve protective immune responses.
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Plasmacytoid dendritic cells (pDCs) are robust producers of IFNα and one of the first immune cells to respond to SIV infection. To elucidate responses to early HIV-1 replication, we studied blood pDCs in 29 HIV-infected participants who initiated antiretroviral therapy during acute infection and underwent analytic treatment interruption (ATI). We observed an increased frequency of partially activated pDCs in the blood before detection of HIV RNA. Concurrent with peak pDC frequency, we detected a transient decline in the ability of pDCs to produce IFNα in vitro, which correlated with decreased phosphorylation of IFN regulatory factory 7 (IRF7) and NF-κB. The levels of phosphorylated IRF7 and NF-κB inversely correlated with plasma IFNα2 levels, implying that pDCs were refractory to in vitro stimulation after IFNα production in vivo. After ATI, decreased expression of IFN genes in pDCs inversely correlated with the time to viral detection, suggesting that pDC IFN loss is part of an effective early immune response. These data from a limited cohort provide a critical first step in understanding the earliest immune response to HIV-1 and suggest that changes in blood pDC frequency and function can be used as an indicator of viral replication before detectable plasma viremia.
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Células Dendríticas/imunologia , Infecções por HIV/imunologia , HIV-1/fisiologia , Viremia/imunologia , Replicação Viral/imunologia , Adulto , Células Dendríticas/patologia , Feminino , Infecções por HIV/patologia , Infecções por HIV/terapia , Humanos , Fator Regulador 7 de Interferon/imunologia , Interferon-alfa/imunologia , Masculino , NF-kappa B/imunologia , Viremia/patologia , Viremia/terapiaRESUMO
Follicular helper T cells (Tfh) play critical roles instructing, and initiating T-cell dependent antibody responses. The underlying mechanisms that enhance their function is therefore critical for vaccine development. Here we apply gene array analysis identifying adenosine deaminase (ADA) as a key molecule that delineates a human Tfh helper program in proliferating circulating Tfh (cTfh) cells and Germinal Centers Tfh (GC-Tfh). ADA-1 expression and enzymatic activity are increased in efficient cTfh2-17/GC-Tfh cells. Exogenous ADA-1 enhances less efficient cTfh1 and pro-follicular Tfh PD-1+ CXCR5+ cells to provide B cell help, while pharmacological inhibition of ADA-1 activity impedes cTfh2-17/GC-Tfh function and diminished antibody response. Mechanistically, ADA-1 controls the Tfh program by influencing IL6/IL-2 production, controlling CD26 extracellular expression and could balance signals through adenosine receptors. Interestingly, dysfunctional Tfh from HIV infected-individual fail to regulate the ADA pathway. Thus, ADA-1 regulates human Tfh and represents a potential target for development of vaccine strategy.