Florence: cytokines and T-cell subsets.

The second international congress on cytokines, held in Florence (March 23-25, 1992), has been marked by the presentation of recent data about cytokine-deficient mice obtained by homologous recombination which, contrary to expectation, exhibit normal T and B cell development. The cloning of a few new cytokines and receptors were also reported as well as recent advances in the knowledge of the oldest members of this quickly growing family. The meeting has also been marked by a great number of reports providing insights into T cell-dependent immune response. Participants provided evidence, through their different experimental models, that functional T helper dichotomy, TH1 versus TH2, was of physiological relevance both in mice and humans, while other reports highlighted the differential regulation of these T lymphocytes subsets. An interesting discussion took place about their differentiation process and the harmonization of the concepts of naive, memory and effector T cells with the T subset classification according to cytokine production profile.