Use of Immobilized HLA-A2:Ig Dimeric Proteins to Determine the Level of Epitope-Specific, HLA-Restricted CD8⁺ T-Cell Response

A novel assay to assess antigen-specific cytokine release from stimulated CD8⁺ T cells derived from the mucosal and peripheral blood compartments has been developed and standardized using the influenza A virus matrix protein (MP) peptide, GILGFVFTL. This technology is based on the capacity for the human leucocyte antigen (HLA)-A2:Ig dimeric protein to stimulate CD8⁺ T cells in a major histocompatibility complex (MHC) class I-restricted fashion without the necessity for antigen presenting cells (APC). This assay has been optimized utilizing a 9-amino acid residue (9mer) peptide, the optimal peptide length for presenting an epitope to CD8⁺ T cells. Compared to existing assays, this more sensitive and specific methodology requires fewer cells, enabling easier and more accurate monitoring of the CD8⁺ T-cell response in biological compartments, such as the mucosa during the course of viral infection and may be utilized to assess epitope-specific CD8⁺ T-cell responses in vaccine trials.