BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:CTLA-4 regulation of T-cell immunity - Professor Christopher E. Ru
 dd\, Dept. of Pathology\, University of Cambridge
DTSTART:20071017T153000Z
DTEND:20071017T163000Z
UID:TALK8027@talks.cam.ac.uk
CONTACT:Laurence Tiley
DESCRIPTION:The coreceptor cytotoxic T lymphocyte-associated antigen 4 (CT
 LA-4) is pivotal in regulating the threshold of signals during T cell acti
 vation\, although the underlying mechanism is still not fully understood. 
 Using in vitro migration assays and in vivo two-photon laser scanning micr
 oscopy\, we showed that CTLA-4 increases T cell motility and overrides the
  T cell receptor (TCR)-induced stop signal required for stable conjugate f
 ormation between T cells and antigen-presenting cells. This event led to r
 educed contact periods between T cells and antigen-presenting cells that i
 n turn decreased cytokine production and proliferation. In addition\, CTLA
 -4 ligation prevented TcR complex induction of ZAP-70 microclusters needed
  for the tyrosine phosphorylation cascade in T-cells. These results sugges
 t a fundamentally different model of reverse stop signaling\, by which CTL
 A-4 modulates the threshold for T cell activation and protects against aut
 oimmunity.\n
LOCATION:Lecture Theatre 1\, Department of Veterinary Medicine
END:VEVENT
END:VCALENDAR