HLA-DRA1*0101 & HLA-DRB1*0401 & Influenza HA (PKYVKQNTLKLAT)

The peptide PKYVKQNTLKLAT, derived from the hemagglutinin (HA) protein of influenza virus, is presented by the MHC class II molecule HLA-DRA1*01:01/HLA-DRB1*04:01. This complex serves as a prototypical target for virus-specific CD4⁺ T helper cells, which are crucial for generating effective antibody responses and cytotoxic T lymphocyte (CTL) memory during influenza infection and vaccination. Studying this epitope has been fundamental to understanding adaptive immunity to viral pathogens and HLA-restricted immune recognition.