CD28 costimulation is essential for human T regulatory expansion and function

J Immunol. 2008 Aug 15;181(4):2855-68. doi: 10.4049/jimmunol.181.4.2855.


The costimulatory requirements required for peripheral blood T regulatory cells (Tregs) are unclear. Using cell-based artificial APCs we found that CD28 but not ICOS, OX40, 4-1BB, CD27, or CD40 ligand costimulation maintained high levels of Foxp3 expression and in vitro suppressive function. Only CD28 costimulation in the presence of rapamycin consistently generated Tregs that consistently suppressed xenogeneic graft-vs-host disease in immunodeficient mice. Restimulation of Tregs after 8-12 days of culture with CD28 costimulation in the presence of rapamycin resulted in >1000-fold expansion of Tregs in <3 wk. Next, we determined whether other costimulatory pathways could augment the replicative potential of CD28-costimulated Tregs. We observed that while OX40 costimulation augmented the proliferative capacity of CD28-costimulated Tregs, Foxp3 expression and suppressive function were diminished. These studies indicate that the costimulatory requirements for expanding Tregs differ from those for T effector cells and, furthermore, they extend findings from mouse Tregs to demonstrate that human postthymic Tregs require CD28 costimulation to expand and maintain potent suppressive function in vivo.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adoptive Transfer
  • Animals
  • CD28 Antigens / metabolism*
  • CD28 Antigens / physiology
  • Cell Culture Techniques
  • Female
  • Graft vs Host Disease / immunology
  • Graft vs Host Disease / therapy
  • Humans
  • K562 Cells
  • Lymphocyte Activation / immunology*
  • Male
  • Mice
  • Mice, Inbred NOD
  • Mice, SCID
  • Signal Transduction / immunology
  • T-Lymphocytes, Regulatory / cytology*
  • T-Lymphocytes, Regulatory / immunology*
  • T-Lymphocytes, Regulatory / transplantation
  • Thymus Gland / cytology
  • Thymus Gland / immunology
  • Thymus Gland / metabolism


  • CD28 Antigens