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The N‐terminal X‐X‐Pro sequence of the HIV‐1 Tat protein is important for the inhibition of dipeptidyl peptidase IV (DP IV/CD26) and the suppression of mitogen‐induced proliferation of human T cells
Author(s) -
Wrenger Sabine,
Reinhold Dirk,
Hoffmann Torsten,
Kraft Margot,
Frank Rainer,
Faust Jürgen,
Neubert Klaus,
Ansorge Siegfried
Publication year - 1996
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(96)00221-9
Subject(s) - dipeptidyl peptidase , chemistry , human immunodeficiency virus (hiv) , terminal (telecommunication) , microbiology and biotechnology , biochemistry , biology , enzyme , immunology , computer science , computer network
Recent data in the literature suggest that the HIV‐1 Tat(1–86) protein exhibits immunosuppressive effects. Moreover, Tat was found to interact with dipeptidyl peptidase IV (DP IV), which is identical to the T cell activation marker CD26. Here we show that the N‐terminal amino acid sequence of Tat is essential for the inhibition of DP IV‐catalyzed IL‐2(1–12) degradation. N‐terminal modification of Tat with rhodamine prevented inhibition of enzymatic activity of DP IV as well as suppression of DNA synthesis of mitogen‐stimulated human T cells. Moreover, natural peptides containing the X‐X‐Pro N‐terminal motif of Tat also inhibited DP IV activity. These data suggest the existence of endogenous immunomodulatory oligopeptides which influence immune cell proliferation and differentiation via DP IV as does HIV‐1 Tat.