Animated Immunity

Abstract

Our current understanding of the complex cellular interactions required for immune responses has come largely from in vitro manipulation or from snapshots of events within fixed tissues. Three reports now describe real-time analysis of immune cell responses within living tissues (see the Perspective by von Adrian). Using two-photon technology to compare migration of T and B cells within organized lymphoid tissue, Miller et al. observed that T cells roam considerably further and at faster rates than B cells. This explorative behavior shifted toward focused clustering upon inclusion of antigen. Stoll et al. used modified single-photon confocal imaging to investigate interactions of naïve T cells with antigen on dendritic cell (DC) in lymph nodes. Extended periods of connection, with the formation of immune synapses and eventual departure of activated T cells, were observed in the presence of antigen-loaded DCs. Bousso et al. used two-photon imaging to study thymocyte interactions with thymic stromal cells in a reaggregated thymic organ culture. Recognition events that resulted in positive selection of thymocytes promoted thymocyte motility and increased the duration of thymocyte-thymic stromal cell contacts. U. H. von Andrian, T cell activation in six dimensions. Science 296, 1815-1817 (2002). [Summary] [Full Text] M. J. Miller, S. H. Wei, I. Parker, M. D. Cahalan, Two-photon imaging of lymphocyte motility and antigen response in intact lymph node. Science 296, 1869-1873 (2002). [Abstract] [Full Text] S. Stoll, J. Delon, T. M. Brotz, R. N. Germain, Dynamic imaging of T cell-dendritic cell interactions in lymph nodes. Science 296, 1873-1876 (2002). [Abstract] [Full Text] P. Bousso, N. R. Bhakta, R. S. Lewis, E. Robey, Dynamics of thymocyte-stromal cell interactions visualized by two-photon microscopy. Science 296, 1876-1880 (2002). [Abstract] [Full Text]