Project description:In chronic inflammatory diseases of the central nervous system (CNS), immune cells persisting behind the blood-brain barrier are supposed to promulgate local tissue destruction. The drivers of such compartmentalized inflammation remain unclear, but tissue-resident memory T cells (TRM) represent a potentially important cellular player in this process
Project description:In chronic inflammatory diseases of the central nervous system (CNS), immune cells persisting behind the blood-brain barrier are supposed to promulgate local tissue destruction. The drivers of such compartmentalized inflammation remain unclear, but tissue-resident memory T cells (TRM) represent a potentially important cellular player in this process
Project description:Evaluation of HIV cure strategies requires antiretroviral therapy (ART) interruption, but ethical and clinical considerations make this difficult in children. Uncovering predictors of time to viral rebound (TTR) and post-treatment control (PTC) of rebound viremia in a pediatric preclinical model may inform the design of studies testing novel cure interventions in these populations. We thus assessed 141 variables in SHIV-infected infant rhesus macaques (RMs) where ART initiation was staggered then followed by analytical treatment interruption (ATI). Viral rebound occurred in 25/30 RMs within 7-98 d of ATI, with TTR significantly delayed in the Early ART group compared to the Intermediate and Late ART groups (median TTR 84, 18, and 17 d, respectively; p<0.001). Peak plasma viral load pre-ART best described TTR, with increased predictive strength through the successive inclusion of six additional variables. Increased peak viral load pre-ART decreased the odds of no rebound and elevated Ki67+ effector memory CD8+ T cells in lymph nodes pre-ATI increased the odds of PTC. RNA sequencing of CD4+ T cells pre-ATI showed heme metabolism and IFNg response pathways were most upregulated in RMs with sustained suppression of viremia during ATI. Analysis of only the Early ART group also implicated TGFb pathway genes in lack of viral rebound off ART. This comprehensive investigation reveals major determinants of viral rebound dynamics following ART interruption that should be validated and explored as biomarkers to screen children with HIV being considered for ATI.
Project description:The combination of replication-competent HIV-1 proviral persistence and virus-specific immune dysfunction prevents virus clearance during antiretroviral therapy (ART), resulting in rebound viremia after treatment interruption. Functional impairment of HIV-specific CD8+ T cells during chronic infection is typically not reversed by ART but has recently been shown to improve in some individuals after prolonged treatment. To evaluate the impact of cellular immune function on viral persistence, we mapped and functionally characterized HIV-1 epitope-specific CD8+ T cell responses and virus reservoirs in sixty people with HIV-1 (PWH) who initiated prolonged ART during chronic progressive infection. In 17% of participants, recall cytotoxicity of proliferative CD8+ T cells targeting one or more autologous proviral epitopes was comparable to responses in spontaneous HIV-1 controllers. These responses were associated with smaller and less transcriptionally active HIV-1 reservoirs during prolonged ART. Treatment interruption in one participant with moderately high HIV-specific CD8+ T cell proliferative and cytolytic capacity resulted in a rapid reduction of rebound viremia coincident with in vivo HIV-specific CD8+ T cell expansion and secondary cytotoxic effector cell differentiation. Collectively, these results highlight a potential role for recall cytotoxicity in limiting HIV-1 persistence during ART and attenuating rebound viremia after treatment interruption, which may inform strategies to elicit durable post-ART immune control.
Project description:B cells have emerged as a critical player in autoimmune disorders of the central nervous system (CNS), such as multiple sclerosis (MS). While locally educated B cells with a CNS non-self-reactive immune repertoire are observed at the brain borders, the specific function of these CNS-compartmentalized B cells in the neuroinflammation pathogenesis remains unclear. Here we demonstrated that autoreactive B cells promoted neuroinflammation through local cognate interaction with pathogenic T cells in the meninges. By selectively perturbing B cell compositions in the CNS through intra-cisterna magna injection, we found that CNS-compartmentalized autoreactive T-B interactions drove the influx of pro-inflammatory phagocytes and initiated vascular inflammation responses, which were dependent on the expression of class II major histocompatibility complex molecules. Selective targeting of B cells in the CNS effectively alleviated relapses of neurological inflammation. These findings elucidate the pathogenic functions of CNS-compartmentalized B cells, highlighting their potential as therapeutic targets for relapsing MS.
Project description:The development of biomarkers that can predict viral rebound following discontinuation of antiretroviral therapy (ART) in HIV-1-infected humans would be an important advance in HIV-1 cure research. In a prior study, we initiated ART in 20 rhesus macaques on days 0, 1, 2, and 3 following SIVmac251 infection prior to plasma viremia1. Following 6 months of suppressive ART, we discontinued ART and observed viral rebound in 9 of 20 animals. Here we show that transcriptomic and proteomic signatures of inflammation and immune activation in peripheral blood during ART suppression predicted viral rebound following ART discontinuation. Higher levels of proinflammatory and cellular immune activation pathways, including TNF, IL-1, IL-6, monocyte, and T cell activation signaling pathways, correlated with viral rebound following ART discontinuation. Immune modulatory IL-10 and TGF-b signaling also correlated with viral rebound. We then validated these candidate biomarkers of viral rebound in a second cohort of SIV-infected, ART-suppressed macaques. Taken together, these data suggest that persistent upregulation of inflammatory and immune activation pathways despite suppressive ART may represent a peripheral blood biomarker signature of the rebound-competent viral reservoir. The development of interventions that target the viral reservoir and modulate this signature may open new avenues in HIV-1 cure research.
Project description:The earliest events of viral rebound following discontinuation of ART in persons living with HIV-1 (PLWH) remain largely unknown. Here we show that viral rebound in SIV-infected rhesus macaques following ART discontinuation involves serial clonal reactivation in gastrointestinal (GI) and lymph node (LN) tissues followed by rapid local and systemic spread. We investigated viral rebound dynamics in 18 SIV-infected rhesus macaques treated with antiretroviral therapy (ART) for 70 weeks and necropsied on day 12 after ART discontinuation. Using molecularly barcoded SIVmac239M, we tracked viral clonotypes following ATI in both peripheral blood and necropsy tissues. Viral rebound originated by reactivation of a single or a few clonotypes from a limited number of GI tissues and deep LNs, followed by replication of each clonotype and then serial reactivation of additional clonotypes from different anatomic sites, resulting in oligoclonal plasma viremia. Daily transcriptomic and proteomics profiling in peripheral blood identified early upregulation of pathways related to T cell signaling, cytokine responses, and cellular metabolism prior to detectable plasma viremia, presumably reflecting initial viral replication in tissues. Taken together, these data demonstrate the early clonal dynamics of viral rebound in SIV-infected macaques following ART discontinuation, which provides critical information for the development of next generation HIV-1 cure strategies.
Project description:We compared transcriptional profiles of CD4+ and CD8+ T lymphocytes from HIV infected individuals before and 1 year after interruption of antiretroviral therapy (ART).
2018-01-01 | GSE98902 | GEO
Project description:HIV Rebound in the Male Genital Tract after Interruption of Antiretroviral Therapy