Suppression of cyclical development of Trypanosoma brucei brucei in Glossina morsitans centralis by an anti-procyclics monoclonal antibody.

Five hundred and sixty teneral male Glossina morsitans centralis were fed, at the height of parasitaemia, on a goat infected with Trypanosoma brucei brucei. Thereafter, the tsetse were divided into 4 equal groups. Group I was fed in vitro once weekly for 4 weeks and Group II twice weekly for 4 weeks on fresh defibrinated ox blood containing 2 mg/ml purified monoclonal antibody against T. b. brucei procyclics, while Group III was fed twice a week for 4 weeks on blood containing 2 mg/ml anti-T. vivax monoclonal antibody. The last group was fed on a rabbit. The tsetse were dissected on day 31 and the percent salivary gland infection rates observed were 18.2, 18.6, 39.8 and 40.8, respectively. In another experiment, 2 groups of tsetse, 120 per group, were fed on fresh defibrinated ox blood containing 2 mg/ml anti-T. b. brucei (test group) or anti-T. vivax (control group), on days 3, 6 and 9 following the infected feed. Dissection of the tsetse on day 31 revealed salivary gland infection rates of 0% in the test group and 6.5% in the control group. Thus the monoclonal antibody had a marked, specific suppression of the cyclical development of T. b. brucei in the tsetse vector.