HIV-1 Gag protein (77-85) peptide presented by Human Leukocyte Antigen A*02:01 (SL9/HLA-A*02:01)

The HIV-1 Gag 77-85 peptide presented by HLA-A*02:01 is a specific peptide-major histocompatibility complex (pMHC) found on the surface of cells infected with Human Immunodeficiency Virus type 1. The peptide, often referred to as SL9 (sequence SLYNTVATL), is derived from the Gag p17 matrix protein and is one of the most immunodominant epitopes recognized by CD8+ cytotoxic T lymphocytes in HLA-A*02:01-positive individuals (PubMed: 15141001). This complex is a primary target for novel immunotherapies, including TCR-engineered T cells and bispecific T-cell engagers like ImmTAVs (e.g., GSK3903371), which aim to clear the latent HIV reservoir (PubMed: 31932453). Because the SL9 epitope is critical for viral fitness, mutations here often incur a fitness cost, though "escape" variants still occur and can hinder immune recognition (PubMed: 11160736). Therapeutic targeting of this pMHC complex represents a major strategy in "shock and kill" or "reduce and control" HIV cure research. The interaction between the T-cell receptor and this pMHC complex is a cornerstone of the natural immune response to HIV, making it a high-priority template for synthetic biology applications.

Other names

SLYNTVATL-HLA-A*02:01 complexHIV-1 Gag p17 (77-85) epitopeGag SL9-MHC complexHLA-A*02:01-restricted HIV-1 Gag 77-85

Redirection of T-cells to recognize and lyse HIV-infected cells through high-affinity T-cell receptor (TCR) binding to the peptide-MHC complex.