1994 Volume 4 Issue 3 Pages 88-97
Inter and intra-specific developmentally regulated antigenic polymorphisms and some metabolic differences between promastigotes of Leishmania donovani and L. major have been characterized. There was an increase in optical density values from logarithmic to stationary phase antigen of both species justifying the increased infectivity of stationary phase promastigotes. Immunoblot analysis showed few antigens as species and stage-specific, viz., 105 KDa unique to L. donovani logarithmic phase, 140 KDa to logarithmic phase of L. major and 115 KDa to L. major stationary phase promastigotes, whereas antigen of 50 KDa was only present in logarithmic phase of both L. donovani and L. major strain. Bands at 20, 95 and 120 KDa were present both in logarithmic and stationary phase L. donovani antigen when they reacted with homologous antibody. On the other hand, no common shared antigens were detected in the case of homologous reaction of two phases of L. major strain. Fewer peptides on western blots of stationary phase than of logarithmic phase promastigotes confirmed the concept that the former phase may be less immunogenic but much more infective to its vertebrate host. Of the amino acids and sugars tested, proline was found to have the maximum role in the transformation to metacyclic form. The role of the other sugars were negligible.