ANTIGENIC RELATEDNESS OF STOCKS AND CLONES OF TRYPANOSOMA-VIVAX FROM EAST AND WEST-AFRICA

The antigenic relationships of 7 stocks and 7 clones of Trypanosoma vivax from East and West Africa were compared by immune lysis. Sera from goats infected with different stocks and clones of T. vivax, collected on days 40 and 80 after infection, were used in the immune lysis test with homologous and heterologous stocks and clones of trypanosomes. Sera from infected cattle were included to compare stocks and clones from Kenya. The parasites that were used as antigen in the immune lysis tests were collected from infected mice when variable antigen type (VAT) homogeneous populations were used, from goats for infection with stocks and clones from Nigeria, The Gambia and Uganda, and from cattle for Kenyan stocks. Reciprocal cross-reactivity between sera and parasites was found between all the stocks and clones from Nigeria and The Gambia with the exception of one clone from Nigeria that was not recognized by antisera to a clone from The Gambia. There was also cross-reactivity between a stock and clone from Uganda and stocks and clones from Nigeria and The Gambia. Sera from goats infected with stocks and clones from Nigeria, The Gambia and Uganda recognized parasite populations that were homogeneous for one VAT (ILDat 1.2) of the rodent infective stock from Nigeria. Some antisera to West African stocks recognized another stable variant from a Ugandan stock adapted to rodents (ILDat 2.1), indicating that these VATs were expressed in the repertoires of the heterologous stocks. There was no cross-reaction between stocks from Nigeria, The Gambia or Uganda with Kenyan stocks. A stock from Galana (Kenya) and Bamburi (Kenya) showed reciprocal cross-reactivity. Two other Kenyan stocks, from Kilifi and Likoni, also showed cross-reactivity by immune lysis but showed no antigenic relationship with the other Kenyan stocks. © 1990, Cambridge University Press. All rights reserved.