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An Immunoaffinity‐Purified Trypanosoma cruzi Antigen Suppresses Cellular Proliferation through a TGF‐β‐Mediated Mechanism
Author(s) -
Richard A. Hansen,
VillacresEriksson,
Åkerblom,
Hellman,
Segura,
Carlomagno,
Morein
Publication year - 1998
Publication title -
scandinavian journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.934
H-Index - 88
eISSN - 1365-3083
pISSN - 0300-9475
DOI - 10.1046/j.1365-3083.1998.00340.x
Subject(s) - trypanosoma cruzi , concanavalin a , splenocyte , microbiology and biotechnology , monoclonal antibody , in vitro , biology , antigen , transforming growth factor , affinity chromatography , in vivo , antibody , biochemistry , immunology , parasite hosting , world wide web , computer science , enzyme
Two subfractions with opposite immunological properties were obtained from the flagellar antigens (FF) of Trypanosoma cruzi epimastigotes by immunoaffinity chromatography. The ligand‐bound material (Ag 123) contained four polypeptide bands of 97, 55, 38 and 14 kDa. The nonretained flow‐through (FT), induced a potent proliferation of murine naive splenocytes. In contrast, Ag 123 inhibited the proliferative capacity of the FT as well as the proliferation mediated by the mitogen Concanavalin A (Con A). The suppressive effect of Ag 123 on the Con A‐mediated proliferation was neutralized by an anti‐TGF‐β monoclonal antibody. Both Ag 123 and FF stimulated high serum levels of TGF‐β in injected mice. Ag 123 also induced in vitro secretion of TGF‐β by murine splenocytes. These results demonstrate that Ag 123 is a potent stimulator of TGF‐β both in vivo and in vitro . Oligopeptides derived from the 38 kDa protein present in Ag 123 showed homology with human and rat alpha‐fetoproteins (AFP). Ag 123 seems to have a key role in the immunosuppression that develops during early stages in the infection with T. cruzi .