Isolation of protective antigens from Trypanosoma lewisi by using trypanostatic (ablastic) immunoglobulin G from the surface coat.

摘要: Antigens were purified from extracts of Trypanosoma lewisi on immunoadsorbent columns trypanostatic immunoglobulin G eluted parasite surface coats at 8 days postinfection. Eight absorbed proteins, with molecular weights between 15,000 and 70,000, identified. These coat antigens (SCAgs) then used to immunize rats. After immunization, sera assayed in vitro for levels circulating trypanocidal antibodies. Approximately half the immune had higher antibody, compared control sera; no antibodies (agglutinins) detected any sera. The rats challenged intraperitonally, parasitemias division rates parasites monitored. Parasitemias all immunized significantly (P less than 0.01) lower shorter duration those controls. Division trypanosomes also times before total cessation A clear dose-response effect was observed, greater amounts SCAg eliciting protection. Purified SCAgs more effective immunogens crude trypanosome which they been purified, other proteins addition present. data provide conclusive evidence that T. lewisi, adsorbed during course infection, is specific it can be isolate elicit a response them.