A tissue specific approach for analysis of membrane and secreted protein antigens from Haemonchus contortus gut and its application to diverse nematode species

General methods to conduct tissue specific analysis are largely lacking for nematodes. An approach is described that focused on isolation of membrane and secreted protein genes from the gut of the parasitic nematode Haemonchu s contortus. The approach capitalized on a monoclonal antibody that recogni zes multiple membrane and secreted worm proteins. Polyclonal antisera made against these proteins were used to screen expression cDNA libraries made e ither from adult worm gut or whole worm. The genes identified encode predic ted or known membrane and secreted proteins from gut, including a cysteine protease, a zinc metallopeptidase and a previously described GA1 protein. A nother gene, Hc40, was isolated from the whole worm cDNA library and is nea rly identical to a vaccine patent sequence pBTA879. Tissue analysis demonst rated the intended focus on membrane and secreted proteins from parasite gu t was achieved. Proteins related to each of those described were identified from other nematode species through data base analysis. Additionally, this analysis led to (1) identification of homologues of each gene in C. elegan s; (2) deduction of a dimorphic structure in the Hc40 protein; (3) recognit ion of both monomorphic and dimorphic families of Hc40-related proteins; an d (4) detection of two apparent classes of transcripts (mep1a and mep1b) th at would each encode a divergent version of the putative zinc metallopeptid ase MEP1. The tissue specific approach and information base described shoul d generally contribute to investigations on nutrient digestion and related secretory processes in nematode gut. (C) 1998 Elsevier Science B.V. All rig hts reserved.