Phosphorylcholine antigens from Nippostrongylus brasiliensis. I.--Anti-phosphorylcholine antibodies in infected rats and location of phosphorylcholine antigens.

The anti-phosphorylcholine (PC) antibody synthesis was investigated in the rat after infection with the nematode Nippostrongylus brasiliensis. Serum IgM and IgG antibodies were demonstrated from day 2 or 3 post-infection. Intestinal IgA-antibody synthesis began shortly after the worms reached the intestine. Antigens containing PC were located with the fluorescent antibody technique in L3 infective larvae, adult worms and eggs of the parasites. They were always found to internal structures such as intestinal tract or gonads. It seems, therefore, that the anti-PC antibody synthesis resulted from the release of PC antigens by the parasite (moulting fluids, excretion, secretion or breakage products).