Cathelicidin LL-37 level in presence and absence of vitamin D in cultured macrophages isolated from elderly women

Introduction: Vitamin D deficiency and frequent infections are the two common worldwide phenomenon among elderly. Recent studies have demonstrated that vitamin D regulates the expression of specific endogenous antimicrobial peptides like cathelicidin LL-37 of macrophages and neutrophils, which is active against a broad spectrum of infectious agents. Therefore, the objective of the present study was to determine the level of cathelicidin LL-37 in macrophages of elderly women (classified according to serum 25(OH)D level) after exposure to Vibrio cholera infection and to find out the effect of 1,25(OH)2D added in vitro. Methods: This study was conducted among 40 randomly selected rural elderly women aged between 60 to 70 years of age. Their vitamin D status was assessed by the estimation of serum 25(OH)D and classified into three groups viz. sufficient (14 members), insufficient (13 members), and deficient (13 members). Later, their peripheral blood mononuclear cells (PBMC) were isolated and cultured from fresh blood. 1,25(OH)2D supplementation was given selectively at a dose of 10 ×10-8 M for 72 hours in the culture media; then exposed to infection and screened according to the objectives of this study. Results: Macrophages in all groups, except vitamin D deficient group, responded significantly in terms of LL-37 release during exposure to Vibrio cholera infection. Considering in vitro 1,25(OH)2D, supplementation responded significantly (p<0.05) in all three groups. Conclusion: Vitamin D can be used as a prophylaxis to enhance cathelicidin LL-37 release for all three groups as in the present study.