Abstract
Cytotoxic T lymphocyte antigen 4 (CTLA-4) is an essential negative regulator of T cell immune responses whose mechanism of action is the subject of debate. CTLA-4 shares two ligands (CD80 and CD86) with a stimulatory receptor, CD28. Here, we show that CTLA-4 can capture its ligands from opposing cells by a process of trans-endocytosis. After removal, these costimulatory ligands are degraded inside CTLA-4-expressing cells, resulting in impaired costimulation via CD28. Acquisition of CD86 from antigen-presenting cells is stimulated by T cell receptor engagement and observed in vitro and in vivo. These data reveal a mechanism of immune regulation in which CTLA-4 acts as an effector molecule to inhibit CD28 costimulation by the cell-extrinsic depletion of ligands, accounting for many of the known features of the CD28-CTLA-4 system.
Original language | English |
---|---|
Pages (from-to) | 600-603 |
Number of pages | 4 |
Journal | Science |
Volume | 332 |
Issue number | 6029 |
DOIs | |
Publication status | Published - 29 Apr 2011 |
Bibliographical note
Copyright © 2011, American Association for the Advancement of ScienceKeywords
- antigen
- antigens
- CHO cells
- cricetinae
- cricetulus
- Dendritic cells
- endocytosis
- Jurkat cells
- ligands
- Lymphocyte activation
- T-Cell
- biological models
- ovalbumin
- receptors
- recombinant fusion proteins
- T-lymphocyte subsets
- regulatory T-lymphocytes