VACCINATION WITH RECOMBINANT PARASITE SURFACE-ANTIGEN-2 FROM LEISHMANIA-MAJOR INDUCES A TH1 TYPE OF IMMUNE-RESPONSE BUT DOES NOT PROTECT AGAINST INFECTION

Vaccination with the native Parasite Surface Antigen 2 of Leishmania m ajor with Corynebacterium parvum as adjuvant protects mice from leishm aniasis through a Th1 mediated response. Here we show that vaccination with a recombinant form of this protein, purified from Escherichia co li and administered in iscoms or with C. parvum as adjuvant, does not induce protective immunity despite the induction of Th1 responses. The results suggest that protective immunity depends on the ability of th e vaccinating antigen to induce Th1-like T cells with ability to be re called by infection, Therefore, the conformation of antigens may play a more major role fop the induction of T cell mediated immunity than o riginally considered. (C) 1998 Elsevier Science Ltd. All rights reserv ed.