CELLULAR IMMUNOLOGY OF PATHOGENIC TRYPANOSOMES

Abstract

Pathogenic trypanosomes are the cause of a variety of disease syndromes kown collectively as trypanosomiases of man and animals. The association of the tsetse fly (Glossina species) with the transmission of the disease in Africa, and not elsewhere, has led to the adoption of the title "African trypanosomiases" for the disease on the continent. For the same reason, African trypanosomiases have often been described as an entomological problem. But no one will deny that protozoologists, epidemiologists, biochemists, pathologists and immunologists have their parts to play if the problem is to be resolved, eventually. This study is concerned with immunological aspects.

Immunological studies of trypanosomiases are traditionally aimed at elucidating the nature of trypanosomal antigens, the biological properties of trypanosomal antibodies, the mechanism of pathogenesis and the kinetics of resistance. In addition, improved methods of diagnosis and practica1 immunization procedures, are eagerly sought. Much effort has been directed towards studies of antigens and antibodies, and the achievements in the knowledge of these aspects are very impressive. It is, however, becoming increasingly evident that investigations into cellular parameters of the host-parasite interactions leading to the diseased state will be necessary to place the nature of the problem in proper perspective. In this thesis both the role and the fate of immunologically active cell lines, and the nature of their involvement in the lesions and the outcome of the infections will be considered. This is important, since the role of the cells must be related to the host resistance and their fate to host susceptibility. However, with the present improved methods available for investigating cellular immunity, it may be rewarding to apply the available knowledge to the study of the neglected aspect of the diseases caused by pathogenic trypanomes.