Global Advanced Research Journal of Medicine and Medical Sciences (GARJMMS) ISSN: 2315-5159
May 2015 Vol. 4(5), pp. 218-230
Copyright © 2015 Global Advanced Research Journals

Review

Immunology and immunopathology of African Trypanosomiasis

D. Musa, A.O. Fajinmi, R. Abdullahi, T. Tese, A. E. Irhue

Nigerian Institute for Trypanosomiasis Research PMB 2077, Kaduna, Nigeria.

*Corresponding Author E-mail: musakaus@yahoo.com

Accepted 28 May, 2015

Abstract

Major modifications of immune system have been observed in Human African Trypanosomiasis. These immune reactions do not lead to protection and are also involved in immunopathology disorders. The major surface component (variable surface glycoprotein, VSG) is associated with escape to immune reactions, cytokine network dysfunctions and autoantibody production. Most of our knowledge result from experimental trypanosomiasis. Innate resistance elements have been characterized. In infected mice, VSG preferentially stimulates a Th1-cellsubset. A response of γ δ and CD8T cells to trypanosome antigens was observed in trypanotolerant cattle. An increase in CD5B cells, responsible for most serum IgM and production of auto antibodies has been noted in infected cattle. Macrophages play important roles in trypanosomiasis, in synergy with antibodies (phagocytosis) and by secreting various molecules (radicals, cytokines, prostaglandins etc.). Trypanosomes are highly sensitive to TNF-α, reactive oxygen and nitrogen intermediates. TNF-α is also involved in cachexia. IFN-γ acts as a parasite growth factor. These various elements contribute to immunosuppression. Trypanosomes have learnt to use immune mechanisms to its own profit. Recent data show the importance of alternative macrophage activation, including arginase induction. L-ornithine produced by host arginase is essential to parasite growth. All these data reflect the deep insight into the immune system realized by trypanosome sand might suggest interference therapeutic approaches.

Keywords: Trypanosome, Human African trypanosomiasis, immunology, macrophage, lymphocytes, nitricoxide, cytokine, auto antibodies.