ABSTRACT
BACKGROUNDCOVID-19 remains a global health emergency with limited treatment options, lagging vaccine rates, and inadequate healthcare resources in the face of an ongoing calamity. The disease is characterized by immune dysregulation and cytokine storm. Cyclosporine A (CSA) is a calcineurin inhibitor that modulates cytokine production and may have direct antiviral properties against coronaviruses.METHODSTo test whether a short course of CSA was safe in patients with COVID-19, we treated 10 hospitalized, oxygen-requiring, noncritically ill patients with CSA (starting at a dose of 9 mg/kg/d). We evaluated patients for clinical response and adverse events, measured serum cytokines and chemokines associated with COVID-19 hyperinflammation, and conducted gene-expression analyses.RESULTSFive participants experienced adverse events, none of which were serious; transaminitis was most common. No participant required intensive care unit-level care, and all patients were discharged alive. CSA treatment was associated with significant reductions in serum cytokines and chemokines important in COVID-19 hyperinflammation, including CXCL10. Following CSA administration, we also observed a significant reduction in type I IFN gene expression signatures and other transcriptional profiles associated with exacerbated hyperinflammation in the peripheral blood cells of these patients.CONCLUSIONShort courses of CSA appear safe and feasible in patients with COVID-19 who require oxygen and may be a useful adjunct in resource-limited health care settings.TRIAL REGISTRATIONThis trial was registered on ClinicalTrials.gov (Investigational New Drug Application no. 149997; ClinicalTrials.gov NCT04412785).FUNDINGThis study was internally funded by the Center for Cellular Immunotherapies.
Subject(s)
COVID-19 Drug Treatment , Cyclosporine/therapeutic use , Cytokines , Humans , Oxygen , SARS-CoV-2ABSTRACT
T cell receptor (TCR) stimulation of naive CD8+ T cells initiates reprogramming of cis-regulatory landscapes that specify effector and memory cytotoxic T lymphocyte (CTL) differentiation. We mapped regions of hyper-accessible chromatin in naive cells during TCR stimulation and discovered that the transcription factor (TF) Runx3 promoted accessibility to memory CTL-specific cis-regulatory regions before the first cell division and was essential for memory CTL differentiation. Runx3 was specifically required for accessibility to regions highly enriched with IRF, bZIP and Prdm1-like TF motifs, upregulation of TFs Irf4 and Blimp1, and activation of fundamental CTL attributes in early effector and memory precursor cells. Runx3 ensured that nascent CTLs differentiated into memory CTLs by preventing high expression of the TF T-bet, slowing effector cell proliferation, and repressing terminal CTL differentiation. Runx3 overexpression enhanced memory CTL differentiation during iterative infections. Thus, Runx3 governs chromatin accessibility during TCR stimulation and enforces the memory CTL developmental program.
Subject(s)
Chromatin/metabolism , Core Binding Factor Alpha 3 Subunit/metabolism , Immunologic Memory/immunology , Receptors, Antigen, T-Cell/immunology , T-Lymphocytes, Cytotoxic/cytology , T-Lymphocytes, Cytotoxic/immunology , Animals , Binding Sites/immunology , Cell Differentiation/immunology , Cell Line , Cell Proliferation , Chlorocebus aethiops , Cricetinae , Enzyme Activation/immunology , Female , Humans , Interferon Regulatory Factors/biosynthesis , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Positive Regulatory Domain I-Binding Factor 1/biosynthesis , Vero CellsABSTRACT
The conserved Paf1 complex localizes to the coding regions of genes and facilitates multiple processes during transcription elongation, including the regulation of histone modifications. However, the mechanisms that govern Paf1 complex recruitment to active genes are undefined. Here we describe a previously unrecognized domain within the Cdc73 subunit of the Paf1 complex, the Cdc73 C-domain, and demonstrate its importance for Paf1 complex occupancy on transcribed chromatin. Deletion of the C-domain causes phenotypes associated with elongation defects without an apparent loss of complex integrity. Simultaneous mutation of the C-domain and another subunit of the Paf1 complex, Rtf1, causes enhanced mutant phenotypes and loss of histone H3 lysine 36 trimethylation. The crystal structure of the C-domain reveals unexpected similarity to the Ras family of small GTPases. Instead of a deep nucleotide-binding pocket, the C-domain contains a large but comparatively flat surface of highly conserved residues, devoid of ligand. Deletion of the C-domain results in reduced chromatin association for multiple Paf1 complex subunits. We conclude that the Cdc73 C-domain probably constitutes a protein interaction surface that functions with Rtf1 in coupling the Paf1 complex to the RNA polymerase II elongation machinery.
