caa a22 4500 386400547 CHVBK 20180307112157.0 cr unu---uuuuu 161130e198906 xx s 000 0 eng 10.1017/S0031182000061485 doi S0031182000061485 pii (NATIONALLICENCE)cambridge-10.1017/S0031182000061485 Identification of a trypanocidal factor against Trypanosoma equiperdum in normal human serum [Elektronische Daten] 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. Copyright © Cambridge University Press 1989 Trypanosoma equiperdum nationallicence trypanocidal factor nationallicence natural antibodies nationallicence human IgM nationallicence Verducci G. Department of Experimental Medicine and Biochemical Sciences, Microbiology Section, Policlinico, Monteluce, University of Perugia, 06100 Perugia, Italy Perito S. Department of Experimental Medicine and Biochemical Sciences, Microbiology Section, Policlinico, Monteluce, University of Perugia, 06100 Perugia, Italy Rossi R. Institute of General Pathology, Via del Giochetto and Division of Internal Medicine, Policlinico, Monteluce, University of Perugia, 06100 Perugia, Italy Mannarino E. Division of Internal Medicine, Policlinico, Monteluce, University of Perugia, 06100 Perugia, Italy Bistoni F. Department of Experimental Medicine and Biochemical Sciences, Microbiology Section, Policlinico, Monteluce, University of Perugia, 06100 Perugia, Italy Marconi P. Department of Experimental Medicine and Biochemical Sciences, Microbiology Section, Policlinico, Monteluce, University of Perugia, 06100 Perugia, Italy Parasitology Cambridge University Press 98/3(1989-06), 401-407 0031-1820 98:3<401 1989 98 PAR https://doi.org/10.1017/S0031182000061485 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0031182000061485 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Verducci G. Department of Experimental Medicine and Biochemical Sciences, Microbiology Section, Policlinico, Monteluce, University of Perugia, 06100 Perugia, Italy NATIONALLICENCE 700 1- Perito S. Department of Experimental Medicine and Biochemical Sciences, Microbiology Section, Policlinico, Monteluce, University of Perugia, 06100 Perugia, Italy NATIONALLICENCE 700 1- Rossi R. Institute of General Pathology, Via del Giochetto and Division of Internal Medicine, Policlinico, Monteluce, University of Perugia, 06100 Perugia, Italy NATIONALLICENCE 700 1- Mannarino E. Division of Internal Medicine, Policlinico, Monteluce, University of Perugia, 06100 Perugia, Italy NATIONALLICENCE 700 1- Bistoni F. Department of Experimental Medicine and Biochemical Sciences, Microbiology Section, Policlinico, Monteluce, University of Perugia, 06100 Perugia, Italy NATIONALLICENCE 700 1- Marconi P. Department of Experimental Medicine and Biochemical Sciences, Microbiology Section, Policlinico, Monteluce, University of Perugia, 06100 Perugia, Italy NATIONALLICENCE 773 0- Parasitology Cambridge University Press 98/3(1989-06), 401-407 0031-1820 98:3<401 1989 98 PAR CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge