A Preliminary characterisation of a possible non-surface variant specific 42Kda antigen in Trypanosoma Evansi

The objective of this study was to investigate the antigenic components of Trypanosoma evansi (T. evansi) during infection. The antigenic components of intact and trypsin-treated T. evansi were identified using a combination of SDS-PAGE and Western immunoblotting against sera from infected rabbits and rabbits immunised with a soluble extract of the parasite. These sera recognised 14 components ranging from ∼ 172kDa to ∼21.5kDa. A non-trypsin-sensitive component of ∼ 42kDa, recognised strongly by sera from infected rabbits and rabbits immunised with the parasite soluble extract was, selected for further studies. This antigen purified by electro elution from acrylamide gels and mono-specific serum produced and used in both Western immunoblotting and enzyme linked immunosorbent assay (ELISA). Serum raised against this antigen recognised only antigenic materials in the homologous T. evansi population by both Western immunoblotting and ELISA. Being a non-trypsin-sensitive antigen that was not, cleaved from the parasite by the process of trypsinisation, possibly indicate a non-surface association, yet a variant-specific antigen. The presence of such antigens in T. evansi parasites and their role in the process of antigenic variation is discussed. Conclusions were drawn and recommendations were suggested.