CTSL-2 upon specifically recognizing Vibrio splendidus directly cleaves complement C3 to promote the bacterial phagocytosis and degradation in oyster.

ABSTRACT: Cathepsin L (CTSL) as a cysteine cathepsin protease mediates complement C3 cleavage and pathogen degradation. In the present study, a CTSL homolog was identified from Crassostrea gigas (designated as CgCTSL-2). Its mRNA expression increased significantly in hemocytes after Vibrio splendidus stimulation. The activity of rCgCTSL-2 was induced after incubation with LPS or V. splendidus in Ca²⁺-dependent manner. rCgCTSL-2 could specifically bound V. splendidus in Ca²⁺-dependent manner. The co-localization of rCgCTSL-2 and V. splendidus was observed in cell-free hemolymph. Upon binding V. splendidus, CgCTSL-2 interacted with CgC3 in cell-free hemolymph and hemocytes. CgC3 fragments in CgCTSL-2-RNAi oysters and full length CgC3 in rCgCTSL-2-treated oysters were both reduced

SUBMITTER: Guo Q 

PROVIDER: S-EPMC12023428 | biostudies-literature | 2025 Apr

REPOSITORIES: biostudies-literature