Human effector memory T cells express CD86: a functional role in naive T cell priming.
The glycoprotein CD86 expressed on APCs provides a costimulatory signal necessary for an efficient activation of naive T cells. In contrast, there is controversy about the condition of expression and the function of CD86 on T cells. In this study, we have analyzed the phenotype and the biological activity of CD86+ T cells generated from human PBMC. Results show that CD86 expression on T cells is induced by long term stimulation via CD3 and IL-2R and is down-regulated as the cells become quiescent. The CD86-expressing cells are memory effector T cells: 1) they express CD45RO and high levels of the activation markers CD25, CD54, and HLA-Dr; 2) they selectively express CD30, CD40-ligand, and CD70; and 3) in response to stimulation, most of them produce IFN-gamma before dying by apoptosis. We then analyzed whether CD86 expressed on T cells is functional. Results show that paraformaldehyde-fixed CD86+ T cells enhance the proliferation and production of IFN-gamma by anti-CD3 mAb-stimulated naive T cells and induce proliferation of resting allogenic T cells. All these effects are prevented by neutralizing anti-CD86 mAbs. In contrast, we report no autocrine effect of CD86 in CD86+ T cell activation. In conclusion, these data show that human memory effector T cells express a functional form of CD86 that can costimulate naive T cell responses.
Jeannin
P
P
Centre d'Immunologie Pierre Fabre, Saint-Julien en Genevois, France. pascale.jeannin@pierre-fabre.com
Herbault
N
N
Delneste
Y
Y
Magistrelli
G
G
Lecoanet-Henchoz
S
S
Caron
G
G
Aubry
J P
JP
Bonnefoy
J Y
JY
D015703:Antigens, CD / Q000096:biosynthesis* / Q000097:blood / Q000502:physiology; D051940:B7-2 Antigen; D006801:Humans; D007156:Immunologic Memory; D016130:Immunophenotyping; D007399:Interphase / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology*; D007959:Lymphocyte Culture Test, Mixed; D008562:Membrane Glycoproteins / Q000096:biosynthesis* / Q000097:blood / Q000502:physiology; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology* / Q000378:metabolism*