Leishmania Donovani; Partial Characterization of Some Flagellate Cytoplasmic Immunogens

[摘要] Leishmania donovani promastigotes were cultured in Millipore-filtered medium and subjected to freeze-thaw and homogenization regimens. The resulting homogenate was centrifuged, and the supernatant, consisting mainly of the cytoplasmic portion, was injected into rabbits. The rabbit anti-promastigote antibody was used to study promastigote immunogens by immunoelectrophoresis and by our modification of thin-layer immunochromatography (ICG). Both procedures revealed nine distinct precipitin lines; however, ICG disclosed the approximate molecular weights of the cytoplasmic immunogens ranging from 8637 to 112,250. In other characterization studies, promastigote homogenate in CFA was used to sensitize 16 guinea pigs. After 7 days the animals were challenged with individual cytoplasmic fractions (3 to 4 µg protein) separated by G-200 Sephadex. Intradermal challenge sites were measured, for diameters of erythema at 10 min; 4, 7, 24, 48 and 96 hr. Erythema appeared at 4 hr post-challenge, peaking at 24 hr and thereafter decreasing in intensity. Two distinct fractions from the separated homogenate were responsible for the most intense delayed skin responses. Used culture medium produced delayed skin reactions; whereas, unused medium provoked no response.

[学科分类] 生物科学（综合）