ABSTRACT
Innate immunity plays a key role in the control of microbial infections in both vertebrates and invertebrates. Haemolymph samples from Shistocerca gregaria, obtained after Trypanosoma brucei brucei challenge were analyzed for their protein profiles using SDS and 2D-PAGE and also evaluated for antitrypanosomal activity in vitro. Protein induction was found to increase with time, peaking at about 18 hours. In SDS-PAGE, the intensity levels of five polypeptides were found to vary from prechallenge levels. Further analysis of the polypeptides on 2D-PAGE showed variations in their induction pattern with some being induced, upregulated or suppressed with time of induction. Samples collected from insects challenged with parasites followed by sugars, D-glucosamine had the highest inhibitory effect on the level of protein induction while D-galactose had the least effect. When screened for trypanolytic activity against T. brucei brucei, the samples had pronounced antitrypanosomal activity which peaked with the 18 hour sample. Antibodies raised against Glossina proteolytic lectin [Gpl], showed no cross-reactivity to Shistocerca gregaria induced haemolymph proteins in Western blots. Antitrypanosoma proteins induced during vector-parasite interaction have the potential of being used to modulate tsetse fly vectorial capacity