Copresentation of natural HIV-1 agonist and antagonist ligands fails to induce the T cell receptor signaling cascade.

Journal article

It is not known how human immunodeficiency virus type 1 (HIV-1)-derived antagonist peptides interfere with intracellular activation of cytotoxic T lymphocytes (CTL). We identified Gag epitope variants in HIV-1-infected patients that act as antagonists of CTL responses to unmutated epitopes. We then investigated the effect that presentation of each variant has on the early events of T cell receptor (TCR) signal transduction. We found that altered peptide ligands (APL) failed to induce phosphorylation of pp36, a crucial adaptor protein involved in TCR signal transduction. We further investigated the effect that simultaneous presentation of APL and native antigen at low, physiological, peptide concentrations (1 nM) has on TCR signal transduction, and we found that the presence of APL can completely inhibit induction of the protein tyrosine phosphorylation events of the TCR signal transduction cascade.

Authors: Purbhoo, M; Sewell, A; Klenerman, P; Goulder, P; Hilyard, K

• Publication status: Published
• Journal: Proceedings of the National Academy of Sciences of the United States of America
• Volume: 95
• Issue: 8
• Pages: 4527-4532
• Publication date: 1998-04-01
• DOI: 10.1073/pnas.95.8.4527
• EISSN: 1091-6490
• ISSN: 0027-8424
• Language: English
• Keywords: Amino Acid Sequence; Epitopes; B-Lymphocytes; Antigen-Presenting Cells; Receptors, Antigen, T-Cell; Cytotoxicity, Immunologic; Recombinant Fusion Proteins; Cell Line; Genetic Variation; Acquired Immunodeficiency Syndrome; Peptide Fragments; Signal Transduction; Gene Products, gag; Humans; Lymphocyte Activation; T-Lymphocytes, Cytotoxic; HIV-1