HOST ANTIBODY RECOGNITION OF SURFACE AND SOMATIC ANTIGENS OF THE PARASITIC DEVELOPMENTAL STAGES OF ANCYLOSTOMA-CEYLANICUM

Exsheathed infective larvae, fourth stage larvae and adult A. ceylanic um were surface labelled with biotin. The surface proteins were extrac ted sequentially with Tris buffer saline, sodium dodecyl sulphate and 2-mercaptoethanol then analysed by SDS-PAGE and Western blotting. It w as found that A. ceylanicum expresses different surface proteins on ea ch of its three parasitic developmental stages and that these proteins vary in their immunogenicity to the host. Most of the proteins on the surface of exsheathed infective larvae were TBS-soluble and some of t hese elicited serum antibody responses in infected hamsters. The antib ody response to surface antigens recognised by post-primary infection sera was not boosted on reinfection but challenge exposure to larvae i nduced antibody reactivity to 3 additional L3 polypeptides. The most i ntense reactivity of post-infection sera was evident with SDS-soluble surface proteins of fourth stage larvae. The post-infection sera showe d weaker recognition of the surface antigens of adult worms compared t o both larval stages, although the same sera were intensely reactive w ith adult worm somatic proteins.