SUMMARY
A range of surface, secreted and somatic antigens from filarial parasites have been studies in order to analyse the response of human infected with these pathogens, and to develop reliable diagnostic and prophylactic agents. Diagnostic procedures, which are urgently required for targetting chemotherapy, are being developed by two techniques. Firstly, detection of host antibody is carried out using selected, specific parasite antigens in the form of recombinant peptides from a filarial DNA library. Secondly, measurement of parasite by a monoclonal antibody "antigen-capture" assay. In addition, a longer-term objective of our collaborative study is to isolate molecules which may stimulate the immune system to mount a protective immune response against filarial parasites. A major focus has been a parasite surface glycoprotein known to be closely conserved between adult worms of Brugia malayi, B. timori and Wuchereria bancrofti. This antigen has been cloned from a cDNA library, and its primary sequence established; in addition to being a constant feature of the adult surface, it is expressed by developing larvae and represents an attractive target for vaccine production. Finally, one of the most intriguing questions in filariasis relates to the genesis of pathological reactions. Although this is a difficult problem, we are now beginning to compare the immune responses of individuals of differing clinical status to certain defined parasite antigens, in an attempt to correlate disease development with particular categories of immune response in infected patients. In this way there is hope to advance the basic understanding of filarial disease, while providing practical means for controlling filariasis at the individual and community levels.