Trypanosoma lewisi: characteristics of an antigen which induced ablastic antibody

The antigen-inducing ablastic antibody was found in the plasma of Trypanosoma letwsi-infected rats which were treated with high doses of hydrocortisone acetate.The antigen (ablastinogen) was demonstrated by immunizing normal rats with hydrocortisone treated, infected rat plasma (TIRP) and testing their antiserum for ablastic antibody. Plasma from either hydrocortisone treated, uninfected rats or from untreated, uninfected rats did not induce detectable ablastic antibody.Ablastinogen in TIRP was stable to ether treatment, to heating at 37 C for 4 hr, and to heating at 56 C for 45 min, but was inactivated by heating at 100 C for 15 min. Pronase treatment (2 mg/ml TIRP) for 4 hr at 37 C inactivated the antigen in 2 out of 3 samples.Ablastinogen was not dialyzable, and gel filtration of TIRP on Sephadex G-200 in aqueous buffer (1.0 M NaCl, 0.1 M Tris-hydrochloride, pH 8.0) separated the antigen into at least 2 components. The separate components did not induce ablastic antibody, however, recombinations of the components did induce ablastic antibody in immunized rats.