In the absence of its cytosolic domain, the CD28 molecule still contributes to T cell activation.
The CD28 costimulatory receptor has a pivotal role in T cell biology as this molecule amplifies T cell receptor (TCR) signals to provide an efficient immune T cell response. There is a large debate about how CD28 mediates these signals. Here, we designed a CD28 gene-targeted knock-in mouse strain lacking the cytoplasmic tail of CD28. As is the case in CD28-deficient (CD28 knock-out) mice, regulatory T cell homeostasis and T cell activation are altered in these CD28 knock-in mice. Unexpectedly, the presence of a CD28 molecule deprived of its cytoplasmic tail could partially induce some early activation events in T cells such as signaling events or expression of early activation markers. These results unravel a new mechanism of T cell costimulation by CD28, independent of its cytoplasmic tail.
Centre de Recherche en Cancérologie de Marseille (CRCM), 27 Bd Leï Roure, BP 30059, 13273, Marseille Cedex 09, France.
Stéphanie O
SO
Morin
Valentin
V
Giroux
Cédric
C
Favre
Yassina
Y
Bechah
Nathalie
N
Auphan-Anezin
Romain
R
Roncagalli
Jean-Louis
JL
Mège
Daniel
D
Olive
Marie
M
Malissen
Jacques A
JA
Nunès
D000818:Animals; D018106:CD28 Antigens / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D055879:Gene Knock-In Techniques; D008213:Lymphocyte Activation / Q000235:genetics / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D017434:Protein Structure, Tertiary; D011778:Q Fever / Q000276:immunology; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology*
D018106:CD28 Antigens