Roles of Pathways in the B7:CD28 Family in Regulating T Cell Activation and Tolerance |
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| Launch in standalone player | |
| Air date: | Wednesday, December 19, 2007, 3:00:00 PM |
| Category: | Wednesday Afternoon Lectures |
| Runtime: | 65 minutes |
| NLM Title: | Roles of pathways in the B7:CD28 family in regulating T cell activation and tolerance [electronic resource] / Arlene Sharpe. |
| Series: | Roles of PD-1:PD-L in regulating T cell activation and tolerance |
| Author: | Sharpe, Arlene. National Institutes of Health (U.S.) |
| Publisher: | [Bethesda, Md. : National Institutes of Health, 2007] |
| Other Title(s): | Roles of PD-1:PD-L in regulating T cell activation and tolerance |
| Abstract: | (CIT): Dr. Sharpe's laboratory is interested in analyzing the role of costimulatory molecules in T cell activation in vivo. Costimulation is a pivotal event for T cell activation, determining the functional outcome of T cell interaction with antigen presenting cells (activation versus anergy). Her laboratory's work has focused on the obligatory in vivo role of costimulators using targeted gene disruption and have revealed striking and unexpected functions of costimulatory pathways. Analysis of B7-1 deficient mice provided the first evidence for the existence of additional functional CD28/CTLA-4 counter-receptors in vivo. As a result of these findings, a second CTLA-4 counter-receptor, B7-2, was cloned and revealed as the major early activating costimulator in this pathway. Mice lacking both B7-1 and B7-2 exhibit profound immunologic deficits. Together, these 3 B7 deficient strains have facilitated a comparative analysis of the in vivo functions of B7-1 and B7-2, as well as definitive tools for determining when the B7:CD28/CTLA-4 pathway is essential for T cell activation. Her CTLA-4 deficient mouse revealed a critical role for CTLA-4 in turning off activated T cells. This critical negative immunoregulatory function of CTLA-4 provides a previously unsuspected means by which costimulation can regulate responses to self antigens and potentially offers new approaches for manipulating activated T cells. More recently, she has studied the functions of newly discovered members of the B7-CD28 superfamily (ICOS:B7h and PD-1:PD-L1/PD-L2 pathways) and helped identify the P-D-1:PD-L1 pair as playing a key inhibitory role in immune suppression during chronic viral infection. Her talk today will focus on the role of PD-1 and its ligands in regulating T cell activation and tolerance, as well as the new PD-L1:B7-1 pathway. |
| Subjects: | Antigens, CD80--metabolism Immune Tolerance Lymphocyte Activation Mice, Transgenic T-Lymphocytes--immunology |
| Publication Types: | Government Publications Lectures |
| Download: | Download
Video How to download a Videocast |
| NLM Classification: | QW 573 |
| NLM ID: | 101465426 |
| CIT File ID: | 14220 |
| CIT Live ID: | 6204 |
| Permanent link: | http://videocast.nih.gov/launch.asp?14220 |
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Enhanced Audio Podcast | 1:01:12 |
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Enhanced Video Podcast | 1:01:12 | |