GENERIC APPROACHES TO OBTAINING EFFICACIOUS ANTIGENS FROM VECTOR ARTHROPODS

Generic approaches to obtaining efficacious antigens from vector arthr opods. International Journal for Parasitology 24: 67-79. The developme nt of vaccines to control ectoparasites is dependent upon the identifi cation of key parasite antigens. While a rational, pragmatic approach to antigen identification has yielded a successful vaccine candidate f rom ticks, there may be problems with such an approach when dealing wi th other ectoparasites. As an alternative approach, the search for vac cine candidates may be facilitated by cloning and expressing parasite genes encoding proteins involved in key physiological roles. A number of criteria may be applied to short-list candidate vaccines, these bei ng; (a) host antibodies should be able to gain access to the parasite antigen; (b) sufficient antibody must gain access to the antigen targe t; (c) the formation of antibody-antigen complex should disrupt the no rmal function of the parasite antigen (d) the antigen should share con served structural/sequence motifs with related, characterised, protein s, thus allowing the use of recombinant DNA methods to clone and expre ss the candidate antigen. We propose three major groups of parasite an tigens which may fulfill these criteria; serine proteases, chemorecept ors/ion channels and neuropeptides.