STAR™ multimers represent a break-through technology allowing for the first time the direct and quantitative detection of endogenous peptide antigen presentation on diseased cells and tissues. STAR™ multimers generated by our proprietary technology have been used to stain human tumor cells by flow cytometry and human tissue arrays by immunohistochemistry. In many cases staining with STAR™ multimers detected peptide-MHC complexes in tumor samples that would not be identified solely using antigen specific antibodies. Thus, STAR™ technology could provide a powerful tool to elucidate which tumor or viral antigens may be broadly applicable targets for immunotherapy.

Study demonstrating peptide antigen presentation in human tumor tissue samples using p53-specific STAR™ multimer (264scTCR/multimer) by immunohistochemistry

STAR™ multimers also have uses in characterizing antigen-presenting cells such as dendritic cells. Vaccination with dendritic cells presenting tumor antigens has been shown to induce tumor-specific immunity and provide clinical benefit in some cancer patients. However, optimization and standardization of these approaches generally relies on indirect and lengthy methods, such as CTL-based cytotoxicity assays, to assess antigen presentation. We have found that STAR™ multimer staining methods are as sensitive as other current methods for detecting antigen presentation on cells and could provide a more general and direct approach to optimizing and validating the production of antigen presenting cell therapies.

Study comparing level of STAR™ multimer staining with amount of peptide used in loading antigen presenting cell preparation.