CD11b+Ly6g+CD69+CD74+ cells produce interferon-α in Mycobacterium tuberculosisinfected alcohol diet-fed mice

Abstract

Abstract Chronic alcohol consumption is associated with significant mortality and morbidity in people affected by Mycobacterium tuberculosis (Mtb) infection. Our Lab previously reported that alcohol diet increased mortality in young mice infected with Mtb in an Interferon-α (IFN-α) dependent manner. We also found CD11b+Ly6g+ cells are major source for IFN-α. In the current study, using single cell RNA sequencing, we further characterized IFN-α producing CD11b+Ly6g+ cells in the lungs of Mtb infected alcohol-diet fed mice. Our analysis revealed ‘6’ distinct clusters in CD11b+Ly6g+ cell population based on gene signatures. We identified cluster ‘6’, through gene-set scoring and expression of interferon related genes such as IRF1, IRF5 to be responsible for type I interferon production. Pseudotime analysis along with KEGG enrichment, revealed transcriptome of cluster ‘6’ to be in a separate trajectory compared to the core of the cluster, suggesting a differentiated phenotype. Similarly, we identified CD69 and CD74 as a surface marker for this unique cell population which was subsequently verified with t-sne analysis using flow cytometry. We are currently characterizing the cellular mechanisms regulating the expansion of these cells in Mtb infected alcohol-diet fed mice to be able to target them for effective early Interferon-α neutralization.