Macrophages as Mediators of Immunosuppression in Murine African Trypanosomiasis
African trypanosomes cause serious infections in man and cattle and can escape immune control by two means: (1) by their ability to change their surface glycoprotein coat to which protective antibodies are directed; thus once one wave of parasites has been controlled, further waves of variant trypanosomes with serologically distinct surface antigens arise (Vickerman 1978). (2) By inducing a general immunosuppression which affects antibody responses as well as T-cell-mediated immune responses to the parasite- and to non-parasite-related antigens. Hosts succumb in the long term, either to very heavy parasite loads or to secondary infections to which they become more susceptible through their defective immune function. Once more infected, hosts show impaired responses to vaccination (e.g. Greenwood 1974a; Rurangirwa et al. 1980). Thus immunosuppression is an important feature in this infection and affects the outcome of the disease. Since antigenic variation presents problems for vaccination strategies, it becomes important to understand the basis of immunosuppression.
KeywordsPeritoneal Macrophage Accessory Cell African Trypanosome Macro Phage Parasite Product
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- Bancroft GJ, Askonas BA (1982) Regulation of antibody production in protozoal infections. Clin Immunol Allergy 2: 511–539Google Scholar
- Bancroft GJ, Askonas BA (1985) Immunobiology of African trypanosomes in Laboratory rodents. In: Tizard I (ed) Immunology and pathogenesis of trypanosomiasis. CRC Florida, pp. 102–275Google Scholar
- Beller DI, Unanue ER (1982) Reciprocal regulation of macrophages and T-cell function by way of soluble mediators. Lymphokines 6: 25–46Google Scholar
- Fierer J, Salmon JA, Askonas BA (1984) African trypanosomiasis alters prostaglandin production by murine peritoneal macrophages. Clin Exp Med 58: 548–556Google Scholar
- Goodwin LG (1974) The African Scene mechanism of pathogenesis in trypanosomiasis. In: Elliott K, O’Connor M, Wolstenholme GEW, eds. Trypanosomiasis and leishmaniasis. Ciba Found Symp 20: 107–119Google Scholar
- Greenwood BM (1974a) Immunosuppression in malaria and trypanosomiasis. In: Porter R, Knight J (eds) Parasites in the immunised host: mechanisms of survival. Ciba Found Symp 25: 137–145Google Scholar
- Mansfield JM (1981) Immunology and immunopathology of African trypanosomiasis. In: Mansfield JH (ed) Parasitic diseases, vol 1. The immunology. Marcel Dekker, Basel, pp 167–226Google Scholar
- Moore M (1983) Interferon and the immune system. In: Burke DC, Morris AG (eds) Interferons, Symposium 35. Cambridge University Press, Cambridge, pp 181–210Google Scholar
- Rurangirwa FR, Mushi EZ, Tabel H, Tizard IR (1980) The effect of T. congolense and T. vivax infections on the antibody response of cattle to live rinderpest virus vaccine. Res Vet Sci 281: 264–266Google Scholar
- Sacks DL, Bancroft GJ, Evans WH, Askonas BA (1982) Incubation of trypanosome-derived myogenic and immunosuppressive products with peritoneal macrophages allows recovery of biological activities from soluble parasite fractions. Infect Immunol 36: 160–168Google Scholar