Molecular characterization of a novel cathepsin L from Trichinella spiralis and its participation in invasion, development and reproduction

•A novel Trichinella spiralis cathepsin L (TsCL) was cloned and expressed.•TsCL is expressed in various stage and mainly located in cuticle, stichosome, midgut and embryos.•rTsCL has the capacity to specially bind with intestinal epithelial cells (IECs).•rTsCL promoted the larval invasion of IECs.•RNAi impaired larval invasive ability, development and female fecundity.