Protein microarrays have shown great potential in high-throughput screening of protein-protein interactions in medical diagnostics, drug and vaccine development, and treatment of cancers, autoimmune and infectious diseases. The adaptive immune response against viral infections is triggered by a molecular recognition event in which a T cell receptor on the surface of cytotoxic T lymphocytes (CTL) recognizes an 8-10 amino acid long peptide bound to a major histocompatibility complex (MHC) presented on the surface of an antigen-presenting cell (APC). We are developing a protein microarray technology to rapidly screen and characterize diverse human T cell populations based on this molecular recognition event.

These microarrays are printed uniformly with dimeric MHCs on each spot, but with different peptides bound to the MHC (pMHC) on each spot. Thus, the spots will selectively capture T cells based on the specificity of the peptide-mediated interaction of their TCRs with the pMHC. When co-spotted with antibodies that capture secreted cytokines, the microarray enables the simultaneous detection of a functional response of antigen-specific CTLs. Optimization of spot-to-spot uniformity and morphology, sensitivity, accuracy, and reliability have been made to improve the technique for high throughput screening. In addition, the spot size has been systematically reduced to enhance the high-throughput capability of the technique. These improvements will be discussed within the context of characterizing the human immune response to influenza virus.