Skip to main content Accessibility help

Identification of a trypanocidal factor against Trypanosoma equiperdum in normal human serum

  • G. Verducci (a1), S. Perito (a1), R. Rossi (a2), E. Mannarino (a3), F. Bistoni (a1) and P. Marconi (a1)...


Normal human serum (HS) contains trypanolytic activity and agglutinins to Trypanosoma equiperdum, while such activities are not found in sera from a range of animals susceptible to infection. HS given to T. equiperdum-infected mice caused a rapid decrease in the number of circulating trypanosomes and protection from lethal infection. Trypanolytic activity of human serum was found to be associated, after DEAE chromatography and Sephadex G-200 gel filtration, with the fraction containing 19S antibodies. Immunofluorescence assays confirmed a binding of human IgM and C1q complement component onto the surface of T. equiperdum. Anti-T. equiperdum activity of HS was specifically directed to T. equiperdum surface components and not to some mouse serum components adsorbed on parasites during the growth in the host, because HS adsorbed in vivo in CD-1 mice retained full protective and agglutinating properties. Trypanocidal activity appears in human serum about the 7th month after birth and persists until late in life. On the contrary, human purified high-density lipoprotein had no significant in vitro or in vivo trypanocidal activity. In conclusion, strong natural anti-T. equiperdum activity in human serum was mainly mediated by natural antibodies of the IgM class. The presence of natural IgM active against T. equiperdum in HS could represent one of the natural mechanisms of resistance of refractory hosts against trypanosome infections. This phenomenon provides further evidence that host specificity of trypanosomes may be partly conditioned by the presence of natural antibodies.



Hide All
Albright, J. W. & Albright, J. F. (1981). Basis of the specificity of rodent trypanosomes for their natural hosts. Infection and Immunity 33, 355–63.
Balber, A. E. & Sturtevant, J. E. (1986). A surface glycoprotein of Trypanosoma lewisi binds immunoglobulin G from the serum of uninfected rats. Infection and Immunity 53, 420–6.
Cooper, M. D. & Lawton, A. R. (1972). Circulating B-cells in patients with immunodeficiency. American Journal of Pathology 69, 513–28.
Ferrante, A. (1984). The role of natural agglutinins and trypanolytic activity in host specificity of Trypanosoma musculi. Parasite Immunology 6, 509–17.
Ferrante, A. (1985). Trypanolytic activity, agglutinins, and opsonins in sera from animals refractory to Trypanosoma lewisi. Infection and Immunity 49, 378–82.
Ferrante, A. & Allison, A. C. (1983). Natural agglutinins to African trypanosomes. Parasite Immunology 5, 539–46.
Ferrante, A. & Jenkin, C. R. (1979). The role of the macrophage in immunity to Trypanosoma lewisi infections in the rat. Cellular Immunology 42, 327–35.
Giannini, S. H. & D'alesandro, P. A. (1979). Trypanosoma lewisi: accumulation of antigen-specific host IgG as a component of the surface coat during the course of infection in the rat. Experimental Parasitology 47, 342–55.
Gidez, L. I., Miller, G. J., Burstein, M., Slagle, S. & Eder, H. A. (1982). Separation and quantitation of subclasses of human plasma high density lipoproteins by a simple precipitation procedure. Journal of Lipid Research 23, 1206–23.
Greenblatt, H. T., Diggs, C. L. & Aikawa, M. (1983). Antibody-dependent phagocytosis of Trypanosoma rhodesiense by murine macrophages. American Journal of Tropical Medicine and Hygiene 32, 3445.
Hawking, F. (1977). The resistance to human plasma of Trypanosoma brucei and T. gambiense. I. Analysis of the composition of trypanosome strains. Transactions of the Royal Society of Tropical Medicine and Hygiene 70, 504–12.
Herbert, W. J. & Lumsden, W. H. R. (1976). Trypanosoma brucei: a rapid ‘matching’: method for estimating the host's parasitemia. Experimental Parasitology 40, 427–31.
Lowry, O. H., Rosebrough, N. J., Farr, A. L. & Randall, A. J. (1951). Protein measurement with the Folin phenol reagent. Journal of Biological Chemistry 193, 265–75.
Rickman, L. R. & Robson, J. (1970). The testing of proven Trypanosoma brucei and T. rhodesiense strains by the blood incubation infectivity test. Bulletin of the World Health Organization 42, 911–16.
Rifkin, M. R. (1978). Identification of the trypanocidal factor in normal human serum: high density lipoprotein. Proceedings of the National Academy of Sciences, USA 75, 3450–4.
Takayanagi, T., Nakatake, Y. & Enriquez, G. L. (1974). Attachment and ingestion of Trypanosoma gambiense to the rat macrophage by specific antiserum. Journal of Parasitology 60, 336–9.
Terry, R. J. (1976). Innate resistance to trypanosoma infections. In Biology of the Kinetoplastida (ed. Lumsden, W. H. R. and Evans, D. A.), pp. 477–92. New York: Academic Press.
Vincendeau, P., Caristan, A. & Pautrizel, R. (1981). Macrophage function during Trypanosoma musculi infection in mice. Infection and Immunity 34, 378–81.
Vincendeau, P., Daëron, M. & Daulouede, S. (1986). Identification of antibody classes and Fc receptors responsible for phagocytosis of Trypanosoma musculi by mouse macrophages. Infection and Immunity 53, 600–5.


Identification of a trypanocidal factor against Trypanosoma equiperdum in normal human serum

  • G. Verducci (a1), S. Perito (a1), R. Rossi (a2), E. Mannarino (a3), F. Bistoni (a1) and P. Marconi (a1)...


Full text views

Total number of HTML views: 0
Total number of PDF views: 0 *
Loading metrics...

Abstract views

Total abstract views: 0 *
Loading metrics...

* Views captured on Cambridge Core between <date>. This data will be updated every 24 hours.

Usage data cannot currently be displayed