Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain
the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in
Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles
and JavaScript.
Chemokines not only act as chemotactic and chemokinetic molecules but also are inducers of integrin-dependent adhesion. Analysis of an immunological synapse now demonstrates an additional function for chemokines as costimulatory molecules.
Chemokines 'trigger' the integrin LFA-1 to different conformational and affinity states. Elegant experiments provide new insights into the involvement of different LFA-1 affinity states in rapid lymphocyte arrest under flow.
Inflammatory signals must be resolved to avoid excessive tissue damage. The D6 chemokine receptor acts in this process by 'mopping up' proinflammatory β-chemokines.
The MAP kinase p38 is normally regulated by the MAPKKK-MAPKK pathway in mammalian cells. However, analysis of T cell signaling shows an alternative pathway for p38 activation exists.
Double-positive thymocytes are selected into the CD4 or CD8 lineage on the basis of their T cell receptor specificity. The transcription factor cKrox has been identified as being both required and sufficient to direct thymocytes undergoing positive selection to the CD4 lineage.
Different peptide antigens induce T cell repertoires of very different diversity. An analysis of the effect on T cell receptor usage of re-engineering peptide features indicates that a lack of prominent side chains presented for recognition limits the T cell repertoire.
Gene reassortment confers immunoglobulin diversity. Functional diversity occurs by use of distinct heavy chains. Identification of a previously unknown immunoglobulin gene in zebrafish suggests such functional specialization also occurs in this species and probably in all bony fish.
A new study uses experimental infection of naive macaques with simian immunodeficiency virus containing known cytotoxic T lymphocyte escape mutations to examine the host and viral forces governing reversion or persistence of escape during transmission between hosts.
Self-renewal of hematopoietic stem cells allows life-long production of blood cells. Notch signaling is critically involved in this process by maintaining a pool of self-renewing hematopoietic stem cells.
Calcium signaling is essential during thymocyte development. It seems that calcium oscillations trigger thymocytes to become immotile, prolonging interactions with stromal cells that are critical for positive selection.
Specific docking of the three T cell receptor complementary-determining regions (CDRs) onto the peptide-MHC complex is the basis of immune recognition. However, the contribution of each CDR to peptide-MHC binding is not routine.
It is not clear how lymphocytes establish monoallelic gene expression of antigen receptor genes. New data linking local chromatin modifications with nuclear movements provide a framework for deciphering this process.
The definition of the physiological functions of dendritic cells is undergoing refinement, as specialization of dendritic cell labor depends on their previous encounters.
Dendritic cells have the unique capacity of processing soluble exogenous proteins for presentation to killer T lymphocytes. Now Cresswell and associates show that this is possible because pinocytosed material gains access to the perinuclear endoplasmic reticulum of dendritic cells.
