MHC class I multimers

T lymphocytes play a key role in the immune response to both foreign and se lf peptide antigens, which they recognize in combination with MHC molecules . In the past it has been difficult to analyse objectively the specificity, frequency and intensity of T cell responses. The recent application of flu orescent-labelled MHC class I multimers, however, has provided a powerful e xperimental approach to the direct visualisation of antigen-specific T cell s. As a result, our perspective of how T cells respond to both viruses and other antigens in vivo has been greatly enhanced.