Single cell characterization of early innate immune responses induced by acute and chronic viral infections 2267604

Abstract Introduction Lymph-borne viruses penetrate the host through the skin or mucosa barriers and drain to the nearest lymph node. The innate immune response induced at the infection site and draining lymph node curb virus systemic dissemination and activate adaptive lymphocytes. However, acute and chronic infections caused, respectively, by the mouse pathogens poxvirus ectromelia virus (ECTV) and the murine cytomegalovirus (MCMV) induce very dissimilar immune responses. Thus, we compared the innate immune responses induced at early stages of infection with these two DNA viruses in the draining lymph nodes of wild-type C57BL/6 inbred strain infected with ECTV or MCMV by footpad inoculation. Methods For that, we used We used unbiased cellular indexing of transcriptome and epitope single cell sequencing (CITEseq) to characterized changes induced by infection and infected populations. Results We found that ECTV induced expansion and activation of Natural Killer (NK) cell populations and inflammatory monocytes while MCMV did not. We also observed the presence of a distinct infected cluster in dLN of mice infected ECTV while MCMV was dispersed throughout multiple cell populations that presented low MCMV transcripts. Conclusion Overall, we dissected that acute infection with ECTV induces innate immune responses that correlate with survival while infection with MCMV induced poor innate immune responses. Funding Source n/a Topic Categories Viral Immunology (VIR)