Project description:Chronic viral infections caused by HIV in humans or LCMV in mice are characterized by immunodeficiency and chronic inflammation. During chronification, T cells progressively lose effector functions, a process associated with immunoregulatory pathways and known as T-cell exhaustion. A link between ‘exhaustive’ T-cell reprogramming and chronic inflammation has not been established. Using a systems biology approach we demonstrate in HIV and LCMV infection that TNF, a prototypical mediator of chronic inflammation, functions upstream of major immunoregulatory pathways in T cells during chronic viral infection. In vivo blockade of TNFR-signaling interferes with the exhaustive T-cell program during chronic infection and reduces viral loads by several log. Continuous TNFR-signaling during disease progression towards chronic infection seems to be causative for T-cell exhaustion and an important link between immunodeficiency and chronic inflammation. TNF blockade might represent a novel therapeutic option during late stage infections caused by HIV and other virus causing chronic infections. CD4+ T cells from Infliximab or control treatment of chronic LCMV infected animals
Project description:Chronic viral infections caused by HIV in humans or LCMV in mice are characterized by immunodeficiency and chronic inflammation. During chronification, T cells progressively lose effector functions, a process associated with immunoregulatory pathways and known as T-cell exhaustion. A link between ‘exhaustive’ T-cell reprogramming and chronic inflammation has not been established. Using a systems biology approach we demonstrate in HIV and LCMV infection that TNF, a prototypical mediator of chronic inflammation, functions upstream of major immunoregulatory pathways in T cells during chronic viral infection. In vivo blockade of TNFR-signaling interferes with the exhaustive T-cell program during chronic infection and reduces viral loads by several log. Continuous TNFR-signaling during disease progression towards chronic infection seems to be causative for T-cell exhaustion and an important link between immunodeficiency and chronic inflammation. TNF blockade might represent a novel therapeutic option during late stage infections caused by HIV and other virus causing chronic infections. CD4+ T cells from Infliximab or control treatment of acute LCMV infected animals
Project description:Chronic viral infections caused by HIV in humans or LCMV in mice are characterized by immunodeficiency and chronic inflammation. During chronification, T cells progressively lose effector functions, a process associated with immunoregulatory pathways and known as T-cell exhaustion. A link between ‘exhaustive’ T-cell reprogramming and chronic inflammation has not been established. Using a systems biology approach we demonstrate in HIV and LCMV infection that TNF, a prototypical mediator of chronic inflammation, functions upstream of major immunoregulatory pathways in T cells during chronic viral infection. In vivo blockade of TNFR-signaling interferes with the exhaustive T-cell program during chronic infection and reduces viral loads by several log. Continuous TNFR-signaling during disease progression towards chronic infection seems to be causative for T-cell exhaustion and an important link between immunodeficiency and chronic inflammation. TNF blockade might represent a novel therapeutic option during late stage infections caused by HIV and other virus causing chronic infections. TNF stimulation of CD4+ T cells to generate a CD4+ T-cell specific RNA-fingerprint
Project description:The clonal expansion of HIV-1-infected CD4+ T cells is a major barrier to cure. Using single-cell ECCITE-seq, we examined the transcriptional landscape, upstream immune regulators, HIV-1 RNA expression, and T cell clonal expansion dynamics of 215,458 CD4+ T cells (267 HIV-1 RNA+ cells and 68 expanded HIV-1 RNA+ T cell clones) from six HIV-1-infected individuals (during viremia and after suppressive antiretroviral therapy) and two uninfected individuals, in unstimulated conditions and after CMV and HIV-1 antigen stimulation. We found that despite antiretroviral therapy, antigen and TNF responses persisted and shaped T cell clonal expansion. HIV-1 resided in Th1 polarized, antigen-responding T cells expressing Bcl-2 family anti-apoptotic genes. HIV-1 RNA+ T cell clones were larger in clone size, established during viremia, persistent after viral suppression, and enriched in GZMB+ cytotoxic effector memory Th1 cells. Targeting HIV-1-infected cytotoxic CD4+ T cells and drivers of clonal expansion provides a new direction for HIV-1 eradication.
Project description:The gastrointestinal tract is a major site of early HIV-1 replication and death of CD4+ T cells. As HIV-1 replicates in the gut, the protective epithelial barrier gets disrupted, leading to the entry of bacteria into the underlying tissue and the bloodstream, leading to inflammation and clinical complications even in HIV-1-infected patients taking antiviral drugs. Counteracting these pathogenic processes may require in-depth understanding of the molecular pathways that HIV-1 and microbes utilize to infect, functionally alter and/or kill CD4+ T cells. However, to date, the nature of the genes altered by relevant HIV-1 strains and bacteria in intestinal CD4+ T cells remains unclear. Here, we obtained the first gene expression profiles of transmitted/founder (TF) HIV-1 (CH40-T2A-eGFP) infected gut CD4+ T cells infected with HIV-1 in the context of microbes found in the GI tract of HIV-1 infected patients. Our findings reveal common and distinct signaling pathways altered by HIV-1 depending on the presence of microbes that may shed light on infection, inflammation and CD4+ T cell depletion in HIV-1 infected individuals. In-depth understanding of these molecular programs may inform potential ways to counteract pathogenic outcomes initiated and/or sustained by HIV-1 infection in the GI tract.