New Methods for Assessing T-Cell Responses

sensitive or provide more information than previously used assays. Importantly, some of these new techniques allow direct ex vivo analysis of T cells without in vitro amplification, thus providing a more accurate picture of the in vivo immune response. In this review, we describe some of the most widely used techniques for immune monitoring of specific T-cell responses. These various assays can be schematically divided into functional assays, which measure the secretion of a particular cytokine (ELISPOT and intracellular cytokines); assays which assess the specificity of the T cells irrespective of their functionality and which are based on structural features of the TCR (tetramers and immunoscope); and assays aimed at detecting T-cell precursors by amplifying cells that proliferate in response to antigenic stimulation. The sensitivity and immunological relevance of these various methods are discussed. Major findings and future applications in basic and clinical immunology are also presented.