Evidence for the Involvement of a Tsetse Midgut Lectin-Trypsin Complex in Differentiation of Bloodstream-Form Trypanosomes

Autor: Francis Mulaa, C. Wells, G. Zimba, L. U. Abubakar, Ellie O. Osir
Rok vydání: 2003
Předmět:
Zdroj: International Journal of Tropical Insect Science. 23:197-205
ISSN: 1742-7592
1742-7584
DOI: 10.1017/s1742758400023596
Popis: We have previously described a bloodmeal-induced molecule (lectin-trypsin complex) from the midgut of the tsetse fly, Glossina longipennis, with both lectin and trypsin activities (Osir et al., 1995). In this paper, we report on the isolation of a similar molecule from the midguts of Glossina fuscipes fnscipes and provide direct evidence for its involvement in the development of African trypanosomes. The molecule (native Mr ∼65,700) has two non-covalently linked subunits, Mr ∼28,800 and Mr ∼35,700. The native molecule was found to be capable of inducing differentiation of bloodstream-form trypanosomes into procyclic (midgut forms) in vitro. In the assays, specific antibodies against procyclin were used to monitor the transformation of the bloodstream-form trypanosomes into procyclic forms. This induction was specifically inhibited by D-glucosamine. Cis-aconitate was also capable of inducing the transformation process with the same efficiency as that of the lectin-trypsin complex. While increasing the concentrations of the lectin-trypsin complex (≥100 μg protein/ml) in the incubation assays resulted into higher transformation rates, it also led to high parasite mortality. These results provide evidence for the involvement of the midgut lectin-trypsin complex in the differentiation of bloodstream-form trypanosomes within tsetse midgut.
Databáze: OpenAIRE
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