Ho J, Chan H, Liang Y, et al. - Researchers investigated the role of cathelicidin in polymicrobial sepsis in this study with experimental models. They performed cecal-ligation and puncture (CLP) on cathelicidin wild-(Cnlp+/+) and knockout (Cnlp−/−) mice, followed by the evaluation of septic mortality and morbidity as well as histological, biochemical, immunological, and transcriptomic analyses in the ileal tissues. A rise in the ileal expression of cathelicidin by three-fold was noted following CLP, peaking at 4 h. A significantly increased 7-day mortality, as well as a higher murine sepsis score, was observed in relation to knockout of Cnlp. Reduced 7-day mortality and significantly less severe symptoms were seen in mice pre-treated with cholecalciferol or treated with 1alpha, 25-dihydroxyvitamin D₃. The identified roles of endogenous cathelicidin in polymicrobial sepsis were: promotion of intestinal barrier integrity along with modulating the infiltration of neutrophils and macrophages. As per the findings, a potential treatment agent for treating sepsis is 1alpha, 25-dihydroxyvitamin D₃ but not cholecalciferol.