DIFFERENTIAL ANTIGEN-STIMULATED PROLIFERATION OF HUMAN MONONUCLEAR-CELLS BY RECOMBINANT SCHISTOSOMA-JAPONICUM ANTIGENS IN A CHINESE POPULATION

Peripheral blood mononuclear cells (PBMC) from 117 individuals living on two islands in an area (Dongting Lake) endemic for schistosomiasis japonica in China, and 15 control individuals from a nonendemic area o f China, were assessed for antigen-stimulated proliferation against fi ve recombinant Schistosoma japonicum antigens of recognized interest i n the development of immunity to schistosomiasis. Two recombinant anti gens, paramyosin and 28-kD glutathione-S-transferase, stimulated cellu lar proliferation (stimulation index greater than or equal to 3.0) in 38.5% and 42.5% of subjects, respectively, a level similar to that ind uced by a soluble whole parasite extract (51.3%). In contrast, three o ther recombinant antigens tested-a fatty acid binding protein, 22-kD t egumental membrane-associated antigen, and glyceraldehyde-3-phosphate dehydrogenase-stimulated PBMC proliferation in only 3-8% of subjects. More over, we also identified a positive association between the degre e of exposure, and cellular proliferation following stimulation with r ecombinant paramyosin or whole parasite extract. Highly significant di fferences in antigen-stimulated proliferation were also observed betwe en the two islands, Niangashan and Qingshan. The whole parasite extrac t stimulated proliferation in 90% of subjects from Niangashan island c ompared with only 42.1% of subjects from Qingshan island (chi(2) = 16. 88, P = 0.00004), while glutathione-S-transferase stimulated prolifera tion in 77.3% of subjects from Niangashan island compared with only 34 .7% of subjects from Qingshan island (chi(2) = 16.88, P = 0.003). A si milar but not significant, trend was observed for paramyosin and the f atty-acid binding protein. The identification of differential cellular proliferative responses to specific schistosome antigens within an in fected human population may have important practical implications for vaccine development against schistosomiasis japonica.