MOLECULAR AND FUNCTIONAL-CHARACTERIZATION OF A RECOMBINANT PROTEIN OFTRICHURIS-TRICHIURA

The pore-forming protein of the human whipworm, Trichuris trichiura, h as been postulated to facilitate invasion of the host gut and enable t he parasite to maintain its syncytial environment. The data presented here describe the first, to our knowledge, molecular characterization of a pore-forming protein in any helminth and provide a unique demonst ration of the functional interaction between a parasite antigen and ho st molecules. Immunological screening of a IT: trichiura cDNA library with IT: trichiura infection sera identified a clone of 1.4 kB, the cD NA consisting of 1495 base pairs encoding a protein of 50 kDa. The seq uence has a highly repetitive nature containing nine four-disulphide-b onded core domains. Structural prediction analyses reveals an amphipat hic nature. TT50 induced pore formation in bilayers in a manner identi cal to that of the native protein. IgG antibody isolated from I: trich iura infection serum was observed to abolish channel activity.