Induced proteins profile in the haemolymph of desert locust, schistocerca gregaria, following trypanosoma brucei brucei challenge

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.

Key words: Haemolymph proteins, Schistocerca gregaria,
Trypanosomes, two-dimensional gel electrophoresis