RESUMO
CD8 T cells are emerging as important mediators in atherosclerosis and cardiovascular disease (CVD). Immune activation may play a particular role in people with HIV (PWH) who are at an increased risk of CVD, even after controlling for known CVD risk factors. Latent CMV infection is associated with increased CVD risk for both PWH and people without HIV, and human CMV-specific CD4 and CD8 T cells are enriched for an immunosenescent phenotype. We previously showed that CMV coinfection in PWH promotes vascular homing and activation of inflammatory CD4 T cells through the CD2-LFA-3 axis. However, the role of CD2/LFA3 costimulation of CD8 T cells in PWH with CMV has yet to be described. In the present study, we demonstrate that CD2 expression on CX3CR1+CD57+CD28- inflammescent CD8 T cells is increased on cells from CMV-seropositive PWH. In vitro CD2/LFA-3 costimulation enhances TCR-mediated activation of these inflammatory CD8 memory T cells. Finally, we show that LFA-3 is highly expressed in aortas of SIV-infected rhesus macaques and in atherosclerotic plaques of people without HIV. Our findings are consistent with a model in which CMV infection enhances CD2 expression on highly proinflammatory CD8 T cells that can then be stimulated by LFA-3 expressed in the vasculature, even in the absence of CD28 costimulation. This model, in which CMV infection exacerbates toxic cytokine and granzyme production by CD8 T cells within the vasculature, highlights a potential therapeutic target in atherosclerosis development and progression, especially for PWH.
Assuntos
Aterosclerose , Doenças Cardiovasculares , Infecções por Citomegalovirus , Infecções por HIV , Animais , Humanos , Antígenos CD28/metabolismo , Infecções por HIV/tratamento farmacológico , Citomegalovirus , Antígenos CD58/metabolismo , Macaca mulatta , Linfócitos T CD8-Positivos , Linfócitos T CD4-Positivos , Aterosclerose/metabolismoRESUMO
Therapeutic monoclonal antibodies (mAbs) have been studied in humans, but the impact on immune memory of mAb treatment during an ongoing infection has remained unclear. We evaluated the effect of infusion of the anti-SARS-CoV-2 spike receptor binding domain (RBD) mAb bamlanivimab on memory B cells (MBCs) in SARS-CoV-2-infected individuals. Bamlanivimab treatment skewed the repertoire of memory B cells targeting Spike towards non-RBD epitopes. Furthermore, the relative affinity of RBD memory B cells was weaker in mAb-treated individuals compared to placebo-treated individuals over time. Subsequently, after mRNA COVID-19 vaccination, memory B cell differences persisted and mapped to a specific reduction in recognition of the class II RBD site, the same RBD epitope recognized by bamlanivimab. These findings indicate a substantial role of antibody feedback in regulating memory B cell responses to infection, and single mAb administration can continue to impact memory B cell responses to additional antigen exposures months later.
RESUMO
BACKGROUND: People with human immunodeficiency virus (PWH) are at increased risk for comorbidities, and plasma interleukin 6 (IL-6) levels are among the most robust predictors of these outcomes. Tocilizumab (TCZ) blocks the receptor for IL-6, inhibiting functions of this cytokine. METHODS: This was a 40-week, placebo-controlled, crossover trial (NCT02049437) where PWH on stable antiretroviral therapy (ART) were randomized to receive 3 monthly doses of TCZ or matching placebo intravenously. Following a 10-week treatment period and a 12-week washout, participants were switched to the opposite treatment. The primary endpoints were safety and posttreatment levels of C-reactive protein (CRP) and CD4+ T-cell cycling. Secondary endpoints included changes in inflammatory indices and lipid levels. RESULTS: There were 9 treatment-related toxicities of grade 2 or greater during TCZ administration (mostly neutropenia) and 2 during placebo administration. Thirty-one of 34 participants completed the study and were included in a modified intent-to-treat analysis. TCZ reduced levels of CRP (median decrease, 1819.9 ng/mL, P < .0001; effect size, 0.87) and reduced inflammatory markers in PWH, including D-dimer, soluble CD14, and tumor necrosis factor receptors. T-cell cycling tended to decrease in all maturation subsets after TCZ administration, but was only significant among naive CD4 T cells. Lipid levels, including lipid classes that have been related to cardiovascular disease risk, increased during TCZ treatment. CONCLUSIONS: TCZ is safe and decreases inflammation in PWH; IL-6 is a key driver of the inflammatory environment that predicts morbidity and mortality in ART-treated PWH. The clinical significance of lipid elevations during TCZ treatment requires further study. Clinical Trials Registration. NCT02049437.
Assuntos
Infecções por HIV , Interleucina-6 , Humanos , Infecções por HIV/tratamento farmacológico , Inflamação/tratamento farmacológico , Interleucina-6/metabolismo , Lipídeos , Estudos Cross-OverRESUMO
BACKGROUND: Biological sex and the estrogen receptor alpha (ESR1) modulate human immunodeficiency virus (HIV) activity. Few women have enrolled in clinical trials of latency reversal agents (LRAs); their effectiveness in women is unknown. We hypothesized that ESR1 antagonism would augment induction of HIV expression by the LRA vorinostat. METHODS: AIDS Clinical Trials Group A5366 enrolled 31 virologically suppressed, postmenopausal women on antiretroviral therapy. Participants were randomized 2:1 to receive tamoxifen (arm A, TAMOX/VOR) or observation (arm B, VOR) for 5 weeks followed by 2 doses of vorinostat. Primary end points were safety and the difference between arms in HIV RNA induction after vorinostat. Secondary analyses included histone 4 acetylation, HIV DNA, and plasma viremia by single copy assay (SCA). RESULTS: No significant adverse events were attributed to study treatments. Tamoxifen did not enhance vorinostat-induced HIV transcription (between-arm ratio, 0.8; 95% confidence interval [CI], .2-2.4). Vorinostat-induced HIV transcription was higher in participants with increases in H4Ac (fold increase, 2.78; 95% CI, 1.34-5.79) vs those 9 who did not (fold increase, 1.04; 95% CI, .25-4.29). HIV DNA and SCA plasma viremia did not substantially change. CONCLUSIONS: Tamoxifen did not augment vorinostat-induced HIV RNA expression in postmenopausal women. The modest latency reversal activity of vorinostat, postmenopausal status, and low level of HIV RNA expression near the limits of quantification limited assessment of the impact of tamoxifen. This study is the first HIV cure trial done exclusively in women and establishes both the feasibility and necessity of investigating novel HIV cure strategies in women living with HIV. CLINICAL TRIALS REGISTRATION: NCT03382834.
Assuntos
Síndrome da Imunodeficiência Adquirida , Infecções por HIV , HIV-1 , Síndrome da Imunodeficiência Adquirida/tratamento farmacológico , Linfócitos T CD4-Positivos , DNA/uso terapêutico , Receptor alfa de Estrogênio/metabolismo , Feminino , HIV-1/genética , Inibidores de Histona Desacetilases/metabolismo , Inibidores de Histona Desacetilases/farmacologia , Inibidores de Histona Desacetilases/uso terapêutico , Histonas/metabolismo , Histonas/uso terapêutico , Humanos , RNA/metabolismo , RNA/uso terapêutico , Tamoxifeno/efeitos adversos , Tamoxifeno/metabolismo , Viremia/tratamento farmacológico , Latência Viral , Vorinostat/metabolismo , Vorinostat/farmacologia , Vorinostat/uso terapêuticoRESUMO
Atherosclerotic cardiovascular disease (ASCVD) remains an important cause of morbidity in the general population and risk for ASCVD is increased approximately 2-fold in persons living with HIV infection (PLWH). This risk is linked to elevated CD8 T cell counts that are abundant in atherosclerotic plaques and have been implicated in disease pathogenesis yet the mechanisms driving T cell recruitment to and activation within plaques are poorly defined. Here we investigated the role of CD8 T cells in atherosclerosis in a non-human primate model of HIV infection and in the HIV-uninfected elderly; we sought to identify factors that promote the activation, function, and recruitment to endothelium of CX3CR1+ CD8 T cells. We measured elevated expression of CX3CL1 and IL-15, and increased CD8 T cell numbers in the aortas of rhesus macaques infected with SIV or SHIV, and demonstrated similar findings in atherosclerotic vessels of HIV-uninfected humans. We found that recombinant TNF enhanced the production and release of CX3CL1 and bioactive IL-15 from aortic endothelial cells, but not from aortic smooth muscle cells. IL-15 in turn promoted CX3CR1 surface expression on and TNF synthesis by CD8 T cells, and IL-15-treated CD8 T cells exhibited enhanced CX3CL1-dependent chemoattraction toward endothelial cells in vitro. Finally, we show that CD8 T cells in human atherosclerotic plaques have an activated, resident phenotype consistent with in vivo IL-15 and CX3CL1 exposure. In this report, we define a novel model of CD8 T cell involvement in atherosclerosis whereby CX3CL1 and IL-15 operate in tandem within the vascular endothelium to promote infiltration by activated CX3CR1+ memory CD8 T cells that drive further endothelial activation via TNF. We propose that these interactions are prevalent in aging and in PLWH, populations where circulating activated CX3CR1+ CD8 T cell numbers are often expanded.
Assuntos
Aterosclerose/metabolismo , Linfócitos T CD8-Positivos/metabolismo , Quimiocina CX3CL1/metabolismo , Infecções por HIV/metabolismo , Interleucina-15/metabolismo , Idoso , Animais , Células Endoteliais/metabolismo , Humanos , Macaca mulatta/metabolismo , Receptores de Quimiocinas/metabolismoRESUMO
People with HIV (PWH) are at increased risk for atherosclerotic cardiovascular disease (ASCVD). Proportions of vascular homing monocytes are enriched in PWH; however, little is known regarding monocyte-derived macrophages (MDMs) that may drive atherosclerosis in this population. We isolated PBMCs from people with and without HIV, and cultured these cells for 5 days in medium containing autologous serum to generate MDMs. Differential gene expression (DGE) analysis of MDMs from PWH identified broad alterations in innate immune signaling (IL-1ß, TLR expression, PPAR ßδ) and lipid processing (LXR/RXR, ACPP, SREBP1). Transcriptional changes aligned with the functional capabilities of these cells. Expression of activation markers and innate immune receptors (CD163, TLR4, and CD300e) was altered on MDMs from PWH, and these cells produced more TNFα, reactive oxygen species (ROS), and matrix metalloproteinases (MMPs) than did cells from people without HIV. MDMs from PWH also had greater lipid accumulation and uptake of oxidized LDL. PWH had increased serum levels of free fatty acids (FFAs) and ceramides, with enrichment of saturated FAs and a reduction in polyunsaturated FAs. Levels of lipid classes and species that are associated with CVD correlated with unique DGE signatures and altered metabolic pathway activation in MDMs from PWH. Here, we show that MDMs from PWH display a pro-atherogenic phenotype; they readily form foam cells, have altered transcriptional profiles, and produce mediators that likely contribute to accelerated ASCVD.
Assuntos
Aterosclerose/etiologia , Infecções por HIV/virologia , HIV/imunologia , Lipídeos/sangue , Macrófagos/patologia , Modelos Cardiovasculares , Monócitos/virologia , Aterosclerose/patologia , Estudos de Casos e Controles , HIV/genética , Infecções por HIV/imunologia , Infecções por HIV/patologia , Humanos , Macrófagos/imunologia , Macrófagos/metabolismo , Macrófagos/virologia , Monócitos/metabolismo , TranscriptomaRESUMO
Cytotoxic CD4 T cells are linked to cardiovascular morbidities and accumulate in both HIV and CMV infections, both of which are associated with increased risk of cardiovascular disease (CVD). In this study, we identify CMV coinfection as a major driver of the cytotoxic phenotype, characterized by elevated CD57 expression and reduced CD28 expression, in circulating CD4 T cells from people living with HIV infection, and investigate potential mechanisms linking this cell population to CVD. We find that human CD57+ CD4 T cells express high levels of the costimulatory receptor CD2 and that CD2/LFA-3 costimulation results in a more robust and polyfunctional effector response to TCR signals, compared with CD28-mediated costimulation. CD57+ CD4 T cells also express the vascular endothelium-homing receptor CX3CR1 and migrate toward CX3CL1-expressing endothelial cells in vitro. IL-15 promotes the cytotoxic phenotype, elevates CX3CR1 expression, and enhances the trafficking of CD57+ CD4 T cells to endothelium and may therefore be important in linking these cells to cardiovascular complications. Finally, we demonstrate the presence of activated CD57+ CD4 T cells and expression of CX3CL1 and LFA-3 in atherosclerotic plaque tissues from HIV-uninfected donors. Our findings are consistent with a model in which cytotoxic CD4 T cells contribute to CVD in HIV/CMV coinfection and in atherosclerosis via CX3CR1-mediated trafficking and CD2/LFA-3-mediated costimulation. This study identifies several targets for therapeutic interventions and may help bridge the gap in understanding how CMV infection and immunity are linked to increased cardiovascular risk in people living with HIV infection.
Assuntos
Vasos Sanguíneos/fisiologia , Linfócitos T CD4-Positivos/imunologia , Infecções por Citomegalovirus/imunologia , Citomegalovirus/fisiologia , Infecções por HIV/imunologia , HIV-1/fisiologia , Placa Aterosclerótica/imunologia , Antígenos CD28/metabolismo , Antígenos CD57/metabolismo , Antígenos CD58/metabolismo , Receptor 1 de Quimiocina CX3C/metabolismo , Movimento Celular , Quimiocina CX3CL1/metabolismo , Coinfecção , Citotoxicidade Imunológica , Humanos , Receptores CXCR3/metabolismo , RiscoRESUMO
Recent studies have implicated a role for adenosine-dependent immunosuppression in head and neck tumor microenvironments. We describe expression of CD73, an enzyme critical to the generation of adenosine from extracellular AMP, in T cells and other cell types within human head and neck tumors. Flow cytometric analyses of tumor-infiltrating cells indicate that CD3+ cells are the predominant source of CD73 among immune infiltrating cells and that CD73 expression, especially among CD8+ T cells, is inversely related to indices of T cell infiltration and T cell activation in the microenvironment of head and neck tumors. We provide evidence that CD73 expression on peripheral T cells and levels of soluble CD73 in circulation are correlated with CD73 expression on CD8+ T cells in tumors. Moreover, fluorescent microscopy studies reveal that CD8+ CD73+ cells are observed in close proximity to tumor cells as well as in surrounding tissue. In vitro studies with peripheral blood T cells indicate that anti-CD3-stimulation causes loss of CD73 expression, especially among cells that undergo proliferation and that exogenous AMP can impair T cell proliferation, while sustaining CD73 expression. These data suggest that CD8+ CD73+ T cells may be especially important mediators of immunosuppression in human head and neck cancer.
Assuntos
5'-Nucleotidase/imunologia , Linfócitos T CD8-Positivos/imunologia , Neoplasias de Cabeça e Pescoço/imunologia , Linfócitos do Interstício Tumoral/imunologia , Microambiente Tumoral/imunologia , Idoso , Idoso de 80 Anos ou mais , Proliferação de Células/fisiologia , Feminino , Proteínas Ligadas por GPI/imunologia , Humanos , Tolerância Imunológica/imunologia , Ativação Linfocitária/imunologia , Masculino , Pessoa de Meia-IdadeRESUMO
PURPOSE OF REVIEW: Systemic inflammation increases as a consequence of aging (inflammaging) and contributes to age-related morbidities. Inflammation in people living with HIV is elevated compared with the general population even after prolonged suppression of viremia with anti-retroviral therapy. Mechanisms that contribute to inflammation during aging and in treated HIV disease are potentially interactive, leading to an exaggerated inflammatory phenotype in people with HIV. RECENT FINDINGS: Recent studies highlight roles for anti-retroviral therapy, co-infections, immune system alterations, and microbiome perturbations as important contributors to HIV-associated inflammation. These factors likely contribute to increased risk of age-related morbidities in people living with HIV. Understanding mechanisms that exaggerate the inflammaging process in people with HIV may lead to improved intervention strategies, ultimately, extending both lifespan and healthspan.
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Infecções por HIV , Envelhecimento , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Humanos , Inflamação , FenótipoRESUMO
The plant virus, cowpea mosaic virus (CPMV), has demonstrated a remarkable capacity to induce anti-tumour immune responses following direct administration into solid tumours. The molecular pathways that account for these effects and the capacity of CPMV to activate human cells are not well defined. Here, we examine the ability of CPMV particles to activate human monocytes, dendritic cells (DCs) and macrophages. Monocytes in peripheral blood mononuclear cell cultures and purified CD14+ monocytes were readily activated by CPMV in vitro, leading to induction of HLA-DR, CD86, PD-L1, IL-15R and CXCL10 expression. Monocytes released chemokines, CXCL10, MIP-1α and MIP-1ß into cell culture supernatants after incubation with CPMV. DC subsets (pDC and mDC) and monocyte-derived macrophages also demonstrated evidence of activation after incubation with CPMV. Inhibitors of spleen tyrosine kinase (SYK), endocytosis or endocytic acidification impaired the capacity of CPMV to activate monocytes. Furthermore, CPMV activation of monocytes was partially blocked by a TLR7/8 antagonist. These data demonstrate that CPMV activates human monocytes in a manner dependent on SYK signalling, endosomal acidification and with an important contribution from TLR7/8 recognition.
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Comovirus/patogenicidade , Endossomos/virologia , Monócitos/virologia , Receptor 7 Toll-Like/metabolismo , Receptor 8 Toll-Like/metabolismo , Células Cultivadas , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Células Dendríticas/virologia , Endossomos/imunologia , Endossomos/metabolismo , Interações Hospedeiro-Patógeno , Humanos , Concentração de Íons de Hidrogênio , Ativação de Macrófagos , Macrófagos/imunologia , Macrófagos/metabolismo , Macrófagos/virologia , Monócitos/imunologia , Monócitos/metabolismo , Transdução de Sinais , Quinase Syk/metabolismo , Receptor 7 Toll-Like/imunologia , Receptor 8 Toll-Like/imunologiaRESUMO
Oxidized low-density lipoprotein (LDL) contributes to cardiovascular disease in part by mediating activation and maturation of monocytes and macrophages. Furthermore, co-localization studies using histochemical approaches have implicated a potential role for oxidized LDL as a mediator of interleukin-15 (IL-15) expression in myeloid cells of atherosclerotic plaque. The latter activity could be an important pro-inflammatory mechanism that mediates myeloid cell/T-cell crosstalk. Here, we examined the responses of primary human monocytes to highly oxidized LDL molecules. Oxidized LDL readily induced secretion of chemokines MCP-1 (CCL2) and GRO-α (CXCL1) but unlike lipopolysaccharide (LPS), has limited capacity to induce a variety of other cytokines including tumor necrosis factor-α, IL-6, IL-1ß and interferon-γ-induced protein-10 and also displayed a poor capacity to induce p-Akt or P-S6 signaling. Failure of oxidized LDL to induce IL-1ß secretion was associated with limited induction of caspase-1 activation. Furthermore, despite finding evidence that oxidized LDL could enhance the expression of IL-15 and IL-15 receptor expression in monocytes, we found no evidence that it could confer IL-15 transpresentation capability to these cells. This observation contrasted with induction of IL-15 transpresentation in lipopolysaccharide-stimulated monocytes. Overall, our data suggest that highly oxidized LDL is a selective inducer of monocyte activation. Sterile inflammatory mediators, particularly those implicated in Toll-like receptor 4 signaling, may play a role in vascular pathology but the activities of these agents are not uniform.
Assuntos
Interleucina-15/metabolismo , Interleucina-1beta/metabolismo , Lipoproteínas LDL/farmacologia , Monócitos/efeitos dos fármacos , Caspase 1/metabolismo , Células Cultivadas , Citocinas/imunologia , Citocinas/metabolismo , Humanos , Inflamassomos/imunologia , Inflamassomos/metabolismo , Interleucina-15/imunologia , Interleucina-1beta/imunologia , Lipopolissacarídeos/farmacologia , Monócitos/imunologia , Monócitos/metabolismo , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptores de Interleucina-15/imunologia , Receptores de Interleucina-15/metabolismo , Proteínas Quinases S6 Ribossômicas/metabolismo , Via Secretória , Transdução de Sinais , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T/metabolismoRESUMO
Circulating CD8+ T cells and monocytes are activated during human immunodeficiency virus (HIV) infection and colocalize in the aortas of simian immunodeficiency virus-infected nonhuman primates. We hypothesized that CD8+ T cells could exert a proatherosclerotic effect via paracrine actions on monocytes. We found that T-cell receptor-stimulated CD8+ T cells induce monocytes to express tissue factor, a potent activator of coagulation. Tumor necrosis factor was both necessary and sufficient for this effect.
Assuntos
Linfócitos T CD8-Positivos/imunologia , Monócitos/imunologia , Tromboplastina/imunologia , Fator de Necrose Tumoral alfa/imunologia , Coagulação Sanguínea/imunologia , Células Cultivadas , Células Endoteliais/imunologia , Infecções por HIV/imunologia , Humanos , Receptores de Antígenos de Linfócitos T/imunologiaRESUMO
IL-7 is a key homeostatic cytokine that provides signals for T cell survival and proliferation in vivo. In this article, we provide evidence that IL-7 utilization is enhanced by a novel mechanism of cytokine "recycling" during which T cells treated with rIL-7 are rapidly induced to express p-STAT5 and are subsequently able to recycle biologically active cytokine for release to neighboring cells in soluble form. Our observations indicate that the ability of cells to recycle IL-7 is dependent on IL-7R α-chain (CD127) and endocytosis, consistent with a model whereby IL-7 is internalized via receptor interactions before recycling. These observations provide evidence of a novel mechanism that enables cells to optimally use IL-7.
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Interleucina-7/imunologia , Interleucina-7/metabolismo , Transdução de Sinais/imunologia , Linfócitos T/imunologia , Linfócitos T/metabolismo , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Humanos , Imuno-Histoquímica , Ativação Linfocitária/imunologiaRESUMO
Human ß defensin-3 (hBD-3), an epithelial cell-derived antimicrobial peptide, mediates chemotaxis and activation of myeloid cells. In this study, we provide evidence that hBD-3 induces the costimulatory molecule CD86 on primary human monocytes by a mechanism involving autocrine activation of ionotropic P2X7 receptors (P2X7R) by ATP. Incubation of monocytes with hBD-3 resulted in increased expression of both the CD80 and CD86 costimulatory molecules. Treatment of monocytes with a selective P2X7R antagonist inhibited the ability of hBD-3 to induce expression of CD86 but not CD80. The hBD-3-dependent upregulation of CD86 was also attenuated in monocytes incubated with apyrase, a potent scavenger of extracellular ATP. Finally, direct activation of monocyte P2X7R by exogenous ATP mimicked the ability of hBD-3 to induce CD86 expression. These data suggest that hBD-3 induces monocyte activation by both P2X7-dependent (CD86 upregulation) and P2X7-independent (CD80 upregulation) signaling mechanisms and raise the possibility that activation of P2X7R could play an important role in shaping the inflammatory microenvironment in conditions where hBD-3 is highly expressed, such as psoriasis or oral carcinoma.
Assuntos
Trifosfato de Adenosina/farmacologia , Antígeno B7-2/metabolismo , Monócitos/efeitos dos fármacos , Receptores Purinérgicos P2X7/metabolismo , beta-Defensinas/farmacologia , Apirase/metabolismo , Apirase/farmacologia , Antígeno B7-1/genética , Antígeno B7-1/metabolismo , Antígeno B7-2/genética , Cálcio/metabolismo , Células Cultivadas , Citometria de Fluxo , Expressão Gênica/efeitos dos fármacos , Humanos , Monócitos/metabolismo , Antagonistas do Receptor Purinérgico P2X/farmacologia , Receptores Purinérgicos P2X7/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genéticaRESUMO
BACKGROUND: Human immunodeficiency virus (HIV) infection is associated with increased risk of thromboembolic and cardiovascular comorbid conditions. Although systemic inflammation is linked to cardiovascular risk, direct evidence of vascular inflammation and endothelial dysfunction is lacking. METHODS: We examined by immunofluorescence microscopy thoracic aortas from 16 simian immunodeficiency virus (SIV)- or simian-human immunodeficiency virus (SHIV)-infected and 16 uninfected rhesus macaques. RESULTS: Focal endothelial proliferation and subendothelial inflammatory cells were found in sections of all infected animals, compared with minimal changes in sections from the 16 uninfected controls. In the infected animals, we detected increased endothelial levels of bacterial 16s ribosomal DNA as well as increased subendothelial accumulation of CD68(+) monocytes/macrophages (P< .001) and CD8(+) T lymphocytes (P< .001). Endothelial dysfunction was manifested by decreased levels of endothelial nitric oxide synthase (P< .005) and Krüppel-like factor 2 (KLF2) (P< .005). KLF2 expression was decreased in primary human aortic endothelial cells exposed to bacterial lipopolysaccharide or to oxidized low-density lipoprotein in vitro, and this could be prevented by simvastatin. CONCLUSIONS: SIV and SHIV infection lead to endothelial inflammation, dysfunction, and decreased KLF2 expression reflecting early atherosclerotic changes. Translocated bacterial components and lipid oxidation products may induce endothelial dysfunction in HIV infection that could be prevented by statin treatment.
Assuntos
Endotélio Vascular/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Fatores de Transcrição Kruppel-Like/imunologia , Síndrome de Imunodeficiência Adquirida dos Símios/imunologia , Vírus da Imunodeficiência Símia/imunologia , Vasculite/imunologia , Animais , Aorta Torácica/citologia , Aorta Torácica/imunologia , Aorta Torácica/microbiologia , Células Cultivadas , DNA Bacteriano/análise , Endotélio Vascular/microbiologia , Infecções por HIV/fisiopatologia , Humanos , Macaca mulatta , Síndrome de Imunodeficiência Adquirida dos Símios/fisiopatologiaRESUMO
Increases in inflammation, coagulation, and CD8+ T-cell numbers are associated with an elevated cardiovascular disease (CVD) risk in human immunodeficiency virus (HIV)-infected antiretroviral therapy (ART) recipients. Circulating memory CD8+ T cells that express the vascular endothelium-homing receptor CX3CR1 (fractalkine receptor) are enriched in HIV-infected ART recipients. Thrombin-activated receptor (PAR-1) expression is increased in HIV-infected ART recipients and is particularly elevated on CX3CR1+ CD8+ T cells, suggesting that these cells could interact with coagulation elements. Indeed, thrombin directly enhanced T-cell receptor-mediated interferon γ production by purified CD8+ T cells but was attenuated by thrombin-induced release of transforming growth factor ß by platelets. We have therefore identified a population of circulating memory CD8+ T cells in HIV infection that may home to endothelium, can be activated by clot-forming elements, and are susceptible to platelet-mediated regulation. Complex interactions between inflammatory elements and coagulation at endothelial surfaces may play an important role in CVD risk in HIV-infected ART recipients.
Assuntos
Plaquetas/metabolismo , Linfócitos T CD8-Positivos/imunologia , Infecções por HIV/patologia , Receptores de Quimiocinas/análise , Subpopulações de Linfócitos T/imunologia , Linfócitos T CD8-Positivos/química , Linfócitos T CD8-Positivos/efeitos dos fármacos , Receptor 1 de Quimiocina CX3C , Infecções por HIV/imunologia , Humanos , Subpopulações de Linfócitos T/química , Subpopulações de Linfócitos T/efeitos dos fármacos , Fator de Crescimento Transformador beta/metabolismoRESUMO
BACKGROUND: Persistent CD8 T-cell expansion, low CD4/CD8 T-cell ratios, and heightened inflammation persist in antiretroviral therapy (ART)-treated human immunodeficiency virus (HIV) infection and are associated with increased risk of morbid outcomes. We explored the role of cytomegalovirus (CMV) infection in CD8 lymphocytosis and inflammation in ART-treated HIV infection. METHODS: Absolute CD4 and CD8 T-cell counts were abstracted from clinical records and compared among 32 HIV-infected CMV-seronegative subjects, 126 age, CD4 and gender-matched HIV-infected CMV-seropositive subjects, and among 21 HIV-uninfected controls (9 CMV-negative, 12 CMV-positive). Plasma inflammatory indices were measured in a subset by ELISA. RESULTS: Median CD8 counts/µL were higher in HIV-positive/CMV-positive patients (795) than in HIV-positive/CMV-negative subjects (522, P = .006) or in healthy controls (451, P = .0007), whereas CD8 T-cell counts were similar to controls' levels in HIV-positive/CMV-negative subjects. Higher plasma levels of IP-10 (P = .0011), TNF-RII (P = .0002), and D-dimer (P = .0444) were also found in coinfected patients than in HIV-positive/CMV-negative subjects. CONCLUSIONS: CMV infection is associated with higher CD8 T-cell counts, resultant lower CD4/CD8 ratios, and increased systemic inflammation in ART-treated HIV infection. CMV infection may contribute to risk for morbid outcomes in treated HIV infection.
Assuntos
Antirretrovirais/uso terapêutico , Linfócitos T CD8-Positivos/imunologia , Coinfecção/patologia , Infecções por Citomegalovirus/patologia , Infecções por HIV/complicações , Infecções por HIV/tratamento farmacológico , Adulto , Relação CD4-CD8 , Linfócitos T CD4-Positivos/imunologia , Estudos de Coortes , Citocinas/sangue , Ensaio de Imunoadsorção Enzimática , Feminino , Infecções por HIV/patologia , Humanos , Contagem de Linfócitos , Linfocitose/patologia , Masculino , Pessoa de Meia-Idade , Plasma/químicaRESUMO
UNLABELLED: The mechanisms of increased memory CD4+ T cell cycling in HIV disease are incompletely understood but have been linked to antigen stimulation, homeostatic signals, or exposure to microbial products and the inflammatory cytokines that they induce. We examined the phenotype and Vß family distribution in cycling memory CD4+ T cells among 52 healthy and 59 HIV-positive (HIV+) donors. Cycling memory CD4+ T cells were proportionally more frequent in subjects with HIV infection than in controls, more often expressed CD38 and PD-1, and less frequently expressed OX40 and intracellular CD40L. OX40 expression on memory CD4+ T cells was induced in vitro by anti-CD3, interleukin-2 (IL-2), IL-7, or IL-15 but not by Toll-like receptor ligands. In HIV+ donors, memory CD4+ T cell cycling was directly related to plasma lipopolysaccharide (LPS) levels, to plasma HIV RNA levels, and to memory CD8+ T cell cycling and was inversely related to peripheral blood CD4+ T cell counts but not to the levels of IL-2, IL-7, or IL-15, while in HIV-negative donors, memory CD4+ T cell cycling was related to IL-7 levels and negatively related to the plasma levels of LPS. In both controls and HIV+ donors, cycling memory CD4+ T cells had a broad distribution of Vß families comparable to that of noncycling cells. Increased memory CD4+ T cell cycling in HIV disease is reflective of generalized immune activation and not driven primarily by cognate peptide stimulation or exposure to common gamma-chain cytokines. This cycling may be a consequence of exposure to microbial products, to plasma viremia, or, otherwise, to proinflammatory cytokines. IMPORTANCE: This work provides evidence that the increased memory CD4+ T cell cycling in HIV infection is not a result of cognate peptide recognition but, rather, is more likely related to the inflammatory environment of HIV infection.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Infecções por HIV/imunologia , Memória Imunológica , Ativação Linfocitária , Receptores de Antígenos de Linfócitos T/análise , Subpopulações de Linfócitos T/imunologia , Adulto , Linfócitos T CD4-Positivos/química , Feminino , Humanos , Imunofenotipagem , Masculino , Pessoa de Meia-Idade , Subpopulações de Linfócitos T/químicaRESUMO
UNLABELLED: The effects of heightened microbial translocation on B cells during HIV infection are unknown. We examined the in vitro effects of HIV and lipopolysaccharide (LPS) on apoptosis of CD27+ IgD- memory B (mB) cells from healthy controls. In vivo analysis was conducted on a cohort of 82 HIV+ donors and 60 healthy controls. In vitro exposure of peripheral blood mononuclear cells (PBMCs) to LPS and HIV led to mB cell death via the Fas/Fas ligand (FasL) pathway. Plasmacytoid dendritic cells (pDCs) produced FasL in response to HIV via binding to CD4 and chemokine coreceptors. HIV and LPS increased Fas expression on mB cells in PBMCs, which was dependent on the presence of pDCs and monocytes. Furthermore, mB cells purified from PBMCs and pretreated with both HIV and LPS were more sensitive to apoptosis when cocultured with HIV-treated pDCs. Blocking the interferon receptor (IFNR) prevented HIV-stimulated FasL production in pDCs, HIV-plus-LPS-induced Fas expression, and apoptosis of mB cells. In vivo or ex vivo, HIV+ donors have higher levels of plasma LPS, Fas expression on mB cells, and mB cell apoptosis than controls. Correspondingly, in HIV+ donors, but not in controls, a positive correlation was found between plasma FasL and HIV RNA levels and between Fas expression on mB cells and plasma LPS levels. This work reveals a novel mechanism of mB cell apoptosis mediated by LPS and HIV through the Fas/FasL pathway, with key involvement of pDCs and type I IFN, suggesting a role for microbial translocation in HIV pathogenesis. IMPORTANCE: This study demonstrates that lipopolysaccharide (LPS) and type I interferon (IFN) play an important role in memory B cell apoptosis in HIV infection. It reveals a previously unrecognized role of microbial translocation in HIV pathogenesis.
Assuntos
Apoptose/imunologia , Linfócitos B/imunologia , Infecções por HIV/imunologia , HIV-1/imunologia , Lipopolissacarídeos/imunologia , Linfócitos B/efeitos dos fármacos , Linfócitos B/patologia , Bactérias/química , Bactérias/imunologia , Translocação Bacteriana , Separação Celular , Células Cultivadas , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/imunologia , Células Dendríticas/patologia , Proteína Ligante Fas/genética , Proteína Ligante Fas/imunologia , Regulação da Expressão Gênica , Infecções por HIV/genética , Infecções por HIV/microbiologia , Infecções por HIV/patologia , Interações Hospedeiro-Patógeno , Humanos , Imunoglobulina D/genética , Memória Imunológica , Interferon Tipo I/genética , Interferon Tipo I/imunologia , Lipopolissacarídeos/farmacologia , Monócitos/efeitos dos fármacos , Monócitos/imunologia , Monócitos/patologia , Transdução de Sinais , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/genética , Membro 7 da Superfamília de Receptores de Fatores de Necrose Tumoral/imunologia , Receptor fas/genética , Receptor fas/imunologiaRESUMO
The determinants of HIV-1-associated lymphadenopathy are poorly understood. We hypothesized that lymphocytes could be sequestered in the HIV-1+ lymph node (LN) through impairments in sphingosine-1-phosphate (S1P) responsiveness. To test this hypothesis, we developed novel assays for S1P-induced Akt phosphorylation and actin polymerization. In the HIV-1+ LN, naïve CD4 T cells and central memory CD4 and CD8 T cells had impaired Akt phosphorylation in response to S1P, whereas actin polymerization responses to S1P were impaired dramatically in all LN maturation subsets. These defects were improved with antiretroviral therapy. LN T cells expressing CD69 were unable to respond to S1P in either assay, yet impaired S1P responses were also seen in HIV-1+ LN T cells lacking CD69 expression. Microbial elements, HIV-1, and interferon α - putative drivers of HIV-1 associated immune activation all tended to increase CD69 expression and reduce T-cell responses to S1P in vitro. Impairment in T-cell egress from lymph nodes through decreased S1P responsiveness may contribute to HIV-1-associated LN enlargement and to immune dysregulation in a key organ of immune homeostasis.