Study of tsetse-host immunity relationships with respect to mass rearing and tsetse eradication

The influence of repeated exposition of alternative hosts (rabbits, mice) to flies was characterized by two different types of adaptive response mechanisms: the induction of serum ''killing factor'', and the induction of high titre of circulating IgG cross-reacting with relatively wide spectrum of tsetse (glyco) proteins isolated either from various tissues, or whole body homogenates. The question remains how these pathways are involved in host-vector interaction under natural conditions. ''Killing factor''seems to be responsible for dramatic increase of fly mortality following sucking. It is passively transferable but its effect disappears during about 5 days following sucking or passive immunization. On the contrary, the immunoglobulins persist in host blood for at least 70 days but they are probably not responsible for direct killing of biting flies. However, their role in fly longevity, reproduction, and vector-parasite interaction was determined. (author). 18 refs, 7 figs, 1 tab