{Reference Type}: Journal Article {Title}: Antileishmanial activity of cathelicidin and its modulation by Leishmania donovani in a CREM-dependent manner for establishing infection. {Author}: Roy S;Roy S;Banerjee M;Madbhagat P;Chande A;Ukil A; {Journal}: J Infect Dis {Volume}: 0 {Issue}: 0 {Year}: 2024 Mar 27 {Factor}: 7.759 {DOI}: 10.1093/infdis/jiae158 {Abstract}: Concerns regarding toxicity and resistance of current drugs have been reported in visceral leishmaniasis. Anti-microbial peptides are considered as new promising candidates and amongst them, human cathelicidin hCAP18/LL-37 showed significant parasite killing on drug-sensitive and resistant Leishmania promastigotes, coupled with its apoptosis-inducing role. Administration of hCAP18/LL-37 in infected macrophages also decreased parasite survival and increased the host favorable cytokine IL-12. However, 1,25-dihydroxyvitamin D3 (VitD3)-induced endogenous hCAP18/LL-37 production was hampered in infected THP-1 cells. Infection also suppressed the VitD3-receptor (VDR), transcription factor of hCAP18/LL-37. cAMP response element modulator (CREM), the repressor of VDR, was induced in infection resulting in suppression of both VDR and cathelicidin expression. PGE2/cAMP/PKA axis was found to regulate CREM induction during infection and silencing CREM in infected cells and BALB/c mice led to decreased parasite survival. Present study thus documents the anti-leishmanial potential of cathelicidin and further identifies CREM as a repressor of cathelicidin in Leishmania infection.