PROLIFERATIVE RESPONSIVENESS OF LYMPHOCYTES FROM CRYPTOSPORIDIUM-PARVUM EXPOSED MICE TO 2 SEPARATE ANTIGEN FRACTIONS FROM OOCYSTS

We assessed lymphoproliferative responsiveness of lymphocytes from the spleen and lymph nodes of inbred neonatal SWR/J H-2q mice at various times postinoculation (PI) using Cryptosporidium parvum oocysts. The l ymphocytes were cultured in vitro with a water-soluble (SO) and a wate r-insoluble (IN) antigen fraction. The IN fraction was prepared by sol ubilizing particulates, the sediment obtained after centrifuging disru pted oocysts in urea. Both fractions were characterized using silver s tain and enzyme-linked immunoelectrotransfer blot (EITB) with hyperimm une rabbit anti-oocyst serum, monoclonal antibody specific to a 23-kD antigen, and serum from patients with symptoms of cryptosporidiosis. T he EITB showed that the antigens in the IN fraction differed both quan titatively and qualitatively from those in the SO fraction. Lymphocyte s from lymph nodes of exposed mice cultured with the SO fraction exhib ited a significant (P < 0.05) and antigen-specific response compared w ith those from unexposed mice at days 10, 19, 22, and 28 PI. The respo nse to the IN fraction of lymphocytes from lymph nodes of exposed mice was not as consistent as that to the SO fraction but showed a signifi cant (P < 0.05) and antigen-specific response at days 10 and 19 PI. No significant response occurred when splenic lymphocytes were cultured with SO or IN fractions. These results show that lymphocytes from lymp h nodes of mice exposed to Cryptosporidium parvum oocysts proliferate when cultured in vitro with soluble or particulate antigens prepared f rom oocysts.