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The main lytic factor of Trypanosoma brucei brucei in normal human serum is not high density lipoprotein

Natural immunity of humans to the cattle pathogen Trypanosoma brucei brucei has been attributed to the presence in normal human serum (NHS) of lytic factors for the parasites. We and others have shown that NHS contains two trypanolytic factors (herein termed TLF1 and TLF2) that can be separated by g...

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Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1996
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Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2192309/
https://www.ncbi.nlm.nih.gov/pubmed/8642243
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collection PubMed
description Natural immunity of humans to the cattle pathogen Trypanosoma brucei brucei has been attributed to the presence in normal human serum (NHS) of lytic factors for the parasites. We and others have shown that NHS contains two trypanolytic factors (herein termed TLF1 and TLF2) that can be separated by gel filtration. TLF1 copurifies with a subclass of high density lipoprotein (HDL), whereas TLF2 has a much higher molecular weight and does not appear to be a lipoprotein. We find that the trypanolytic activity of purified TLF1 is totally inhibited by exogenous haptoglobin (Hp) at concentrations (0.1 mg/ml) lower than those present in NHS (0.2-2 mg/ml). In contrast, exogenous Hp (up to 2.5 mg/ml) has no effect on the lytic activity of either NHS or isolated TLF2. Hp-depleted sera from patients with intravascular hemolysis is severalfold more trypanolytic than NHS. These sera contain only TLF1, and their lytic activity is totally abolished upon the addition of Hp (0.1 mg/ml). When NHS containing different Hp allotypes is fractionated by gel filtration, TLF1 activity is either revealed or remains masked, depending on whether it coelutes with Hp. Masked TLF1 activity in the column fractions is revealed if Hp is removed by density gradient ultracentrifugation. We conclude that endogenous Hp inhibits TLF1 activity, and that TLF2 is the main trypanolytic factor in NHS.
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spelling pubmed-21923092008-04-16 The main lytic factor of Trypanosoma brucei brucei in normal human serum is not high density lipoprotein J Exp Med Articles Natural immunity of humans to the cattle pathogen Trypanosoma brucei brucei has been attributed to the presence in normal human serum (NHS) of lytic factors for the parasites. We and others have shown that NHS contains two trypanolytic factors (herein termed TLF1 and TLF2) that can be separated by gel filtration. TLF1 copurifies with a subclass of high density lipoprotein (HDL), whereas TLF2 has a much higher molecular weight and does not appear to be a lipoprotein. We find that the trypanolytic activity of purified TLF1 is totally inhibited by exogenous haptoglobin (Hp) at concentrations (0.1 mg/ml) lower than those present in NHS (0.2-2 mg/ml). In contrast, exogenous Hp (up to 2.5 mg/ml) has no effect on the lytic activity of either NHS or isolated TLF2. Hp-depleted sera from patients with intravascular hemolysis is severalfold more trypanolytic than NHS. These sera contain only TLF1, and their lytic activity is totally abolished upon the addition of Hp (0.1 mg/ml). When NHS containing different Hp allotypes is fractionated by gel filtration, TLF1 activity is either revealed or remains masked, depending on whether it coelutes with Hp. Masked TLF1 activity in the column fractions is revealed if Hp is removed by density gradient ultracentrifugation. We conclude that endogenous Hp inhibits TLF1 activity, and that TLF2 is the main trypanolytic factor in NHS. The Rockefeller University Press 1996-03-01 /pmc/articles/PMC2192309/ /pubmed/8642243 Text en This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/).
spellingShingle Articles
The main lytic factor of Trypanosoma brucei brucei in normal human serum is not high density lipoprotein
title The main lytic factor of Trypanosoma brucei brucei in normal human serum is not high density lipoprotein
title_full The main lytic factor of Trypanosoma brucei brucei in normal human serum is not high density lipoprotein
title_fullStr The main lytic factor of Trypanosoma brucei brucei in normal human serum is not high density lipoprotein
title_full_unstemmed The main lytic factor of Trypanosoma brucei brucei in normal human serum is not high density lipoprotein
title_short The main lytic factor of Trypanosoma brucei brucei in normal human serum is not high density lipoprotein
title_sort main lytic factor of trypanosoma brucei brucei in normal human serum is not high density lipoprotein
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2192309/
https://www.ncbi.nlm.nih.gov/pubmed/8642243