Parasite development and host responses during the establishment of Trypanosoma brucei infection transmitted by tsetse fly.
Following inoculation of Trypanosoma brucei into large mammals by the tsetse fly a local skin reaction, the 'chancre', develops due to trypanosome proliferation. We have cannulated the afferent and efferent lymphatics of the draining lymph node in goats and examined the onset of a cellular reaction, the emigration of the parasite from the chancre and the development of both antigenic variation and the specific immune response. The chancre first became detectable by day 3 post-infection, peaked by day 6 and then subsided. Lymphocyte output increased 6- to 8-fold by day 10 and the number of lymphoblasts increased 50-fold in this period. Both then declined. Trypanosomes were detected in lymph 1-2 days before the chancre, peaked by days 5-6, declined during development of the chancre and then peaked again. The bloodstream population appeared by days 4-5 and displayed different kinetics from that in lymph. Recirculation of parasites through the lymphatics ensued. Lymph-borne trypanosome populations were highly pleomorphic. Parasites in lymph expressed firstly a mixture of the Variable Antigen Types (VATs) which are found characteristically in the tsetse fly, this being followed by a mixture of other VATs. The two groups overlapped in appearance. In the bloodstream the same sequence of events occurred although 2 or 3 days later. The specific antibody response, as measured by radioimmunoassay and agglutination, arose within a few days of the first detection of each VAT. Activities appeared first in the lymph and then in plasma.
D000818:Animals; D000917:Antibody Formation; D000941:Antigens / Q000032:analysis; D006041:Goats; D007303:Insect Vectors; D007630:Kenya; D008198:Lymph Nodes / Q000276:immunology / Q000469:parasitology; D008297:Male; D012867:Skin / Q000276:immunology; D014346:Trypanosoma brucei brucei / Q000254:growth & development* / Q000276:immunology; D014353:Trypanosomiasis, African / Q000276:immunology / Q000469:parasitology / Q000635:transmission / Q000662:veterinary*; D014370:Tsetse Flies
D000941:Antigens