부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.imlet.2006.05.003 Byline: Robert S. Liwski (a), Jennifer C. Chase (b), William H. Baldridge (c), Irene Sadek (a), Geoffrey Rowden (a)(d), Kenneth A. West (a)(b)(d) Keywords: Dendritic cells; Costimulation; Cell cycle Abbreviations: DC, dendritic cells; IS, immunological synapse; LPS, lipopolysaccaride Abstract: Costimulation by members of the B7 family of molecules is critical for the activation of naive CD4.sup.+ T cells. While prolonged TCR signaling is necessary for T cell activation, the duration of costimulatory signals required has not been established. In this study, murine bone marrow-derived dendritic cells (DC) and naA[macron]ve CD4.sup.+ T cells were used to determine the temporal costimulatory requirements for naive T cell activation. By blocking CD80/CD86 costimulation at various time points during DC-T cell interaction and using the CFSE technique to assess the dynamics of T cell proliferation, we found that prolonged costimulation was required for naive T cells to enter and progress through the cell cycle over a wide range of peptide concentrations. Prolonged costimulation was also important for IL-2 production and CD25/CD69 expression by naive T cells. Video microscopy demonstrated that DC and naive T cells formed stable conjugates that persisted for more than 6h. Thus, persistent CD80/CD86 signaling during prolonged interactions with DC allows naive T cells to enter the cell cycle and programs the daughter cells to undergo subsequent divisions. Author Affiliation: (a) Department of Pathology, Dalhousie University, Halifax, NS, Canada (b) Department of Microbiology and Immunology, Dalhousie University, Halifax, NS, Canada (c) Department of Anatomy and Neurobiology, Dalhousie University, Halifax, NS, Canada (d) Department of Medicine, Dalhousie University, Halifax, NS, Canada Article History: Received 23 January 2006; Revised 20 April 2006; Accepted 1 May 2006