t22-protein--synthetic and phorbol-12-13-didecanoate

The [Tyr5,12,Lys7]-polyphemusin II peptide (T22) has been shown to inhibit HIV-1 replication in lymphocytes. The mechanism of T22 inhibition of HIV-1 replication is not known but may involve T22 competition with HIV-1 for attachment sites on the plasma membrane of targeted cells. Here we find that three human immunocyte cell lines (H9, Jurkat, and U-937) attach to T22. The phorbol ester, 12-O-tetradecanoylphorbol 13-acetate (TPA), has been shown to activate intracellular protein kinase C and to stimulate lymphocyte attachment to various substrates through specific cell surface receptors. Here we find that TPA treatment enhances attachment of the immunocytes to T22 by three- to four-fold. These data demonstrate that T22 binds to immunocyte cell surfaces and support the hypothesis that T22 may inhibit HIV-1 replication by competing with the virus for a common cell surface receptor(s).

Topics: 1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; Amino Acid Sequence; Antimicrobial Cationic Peptides; Cell Adhesion; Cell Line; HIV-1; Humans; Isoquinolines; Kinetics; Lymphocytes; Molecular Sequence Data; Monocytes; Peptides; Phorbol Esters; Piperazines; Tetradecanoylphorbol Acetate; Tumor Cells, Cultured; Virus Replication