Biology subjects

Sandner, L.

Publications and source records attributed to Sandner, L..

3 recordsLinked to original sources

bioRxiv2024

HDAC1 controls the generation and maintenance of effector-like CD8+ T cells during chronic viral infection

CD8+ T cell exhaustion is a complex process that involves the differentiation of persistently activated CD8+ T cells into functionally distinct cell subsets. Here, we investigated the role of the key epigenetic regulator histone deacetylase 1 (HDAC1) in the differentiation of exhausted T (Tex) cells during chronic viral infection. We uncovered that HDAC1 controls the generation and maintenance of effector-like CX3CR1+ Tex cells in a CD8+ T cell-intrinsic manner. Deletion of HDAC1 led to expansion of an alternative Tex cell subset characterized by high expression of T cell exhaustion markers, and this was accompanied by elevated viremia. HDAC1 knockout altered the chromatin landscape in progenitor Tex cells, abrogated the expression of effector-like signature genes and interfered with cell fate specification toward the CX3CR1+ Tex cell subset. We conclude that HDAC1 is functionally required for controlling viral load during chronic infection by ensuring adequate CX3CR1+ Tex cell subset differentiation. HighlightsO_LIHDAC1 promotes the generation of CX3CR1+ effector-like Tex cell subsets in chronic viral infection in a CD8+ T cell-intrinsic manner. C_LIO_LIDeletion of HDAC1 leads to an increase of a cell subset enriched in exhaustion markers and is accompanied with elevated viremia. C_LIO_LIHDAC1 is required for the maintenance of the CX3CR1+ Tex cell pool. C_LIO_LIHDAC1 deletion alters the chromatin landscape at effector-like signature gene loci in progenitor Tex cells. C_LI

immunology↗

bioRxiv2022

The guanine nucleotide exchange factor Rin-like acts as a gatekeeper for T follicular helper cell differentiation via regulating CD28 signaling

T follicular helper (Tfh) cells are essential for the development of germinal center B cells and high-affinity antibody producing B-cells in human and mice. Here, we identify the guanine nucleotide exchange factor (GEF) Rin-like (Rinl) as a negative regulator of Tfh generation. Loss of Rinl leads to an increase of Tfh in aging, upon in vivo immunization and acute LCMV Armstrong infection in mice, and in human CD4+ T cell in vitro cultures. Further, adoptive transfer experiments using WT and Rinl-KO naive CD4+ T cells unraveled T cell-intrinsic functions of Rinl. Mechanistically, Rinl regulates CD28 internalization and signaling, thereby shaping CD4+ T cell activation and differentiation. Thus, our results identify the GEF Rinl as a negative regulator of global Tfh differentiation in an immunological context and species-independent manner, and furthermore connect Rinl with CD28 internalization and signaling pathways in CD4+ T cells, demonstrating for the first-time the importance of endocytic processes for Tfh differentiation. HighlightsO_LIRinl-KO CD4+ T cells show increased Tfh differentiation in a context independent manner C_LIO_LIThe regulation of Tfh differentiation is T cell-intrinsic C_LIO_LIRinl controls CD28 endocytosis and shapes Tfh-specific CD28 signal transduction C_LIO_LIHuman Tfh differentiation is regulated by Rinl C_LI

immunology↗

bioRxiv2021

24-Nor-Ursodeoxycholic acid reshapes immunometabolism in CD8+ T cells and alleviates hepatic inflammation

Background & Aims24-NorUrsodeoxycholic acid (NorUDCA) is novel therapy for immune-mediated liver diseases such as primary sclerosing cholangitis (PSC) where dysregulated T cells including CD8+ T cells cause liver immunopathology. We hypothesized that NorUDCA may directly modulate CD8+ T cell effector function thus contributing to its therapeutic efficacy independent of anti-cholestatic effects. MethodsNorUDCA effects on CD8+ T cell function in vivo were investigated in a hepatic injury model system induced by excessive CD8+ T cell immune response upon non-cytolytic lymphocytic choriomeningitis virus (LCMV) infection. Mechanistic studies included molecular and biochemical approaches, flow cytometry and metabolic assays in mouse CD8+ T cells in vitro. Mass spectrometry (MS) was used to identify potential targets modulated by NorUDCA in CD8+ T cells. NorUDCA signaling effects observed in murine systems were validated in peripheral T cells from healthy volunteers and PSC patients. ResultsIn vivo NorUDCA ameliorated hepatic injury and systemic inflammation upon LCMV infection. Mechanistically, NorUDCA demonstrated a strong immunomodulatory efficacy in CD8+ T cells affecting lymphoblastogenesis, mTORC1 signaling and glycolysis of CD8+ T cells. With MS, we identified that NorUDCA regulates CD8+ T cells via targeting mTORC1. NorUDCAs impact on mTORC1 signaling was further confirmed in circulating human CD8+ T cells. ConclusionsNorUDCA possesses a yet-unrecognized direct modulatory potency on CD8+ T cells and attenuates excessive CD8+ T cell hepatic immunopathology. These findings may be relevant for treatment of immune-mediated liver diseases such as PSC and beyond.

molecular biology↗