Human Effector Memory T Cells Express CD86: A Functional Role in Naive T Cell Priming

• Published in: The Journal of immunology (1950) 1999-02, Vol.162 (4), p.2044-2048
• Main Authors: Jeannin, Pascale, Herbault, Nathalie, Delneste, Yves, Magistrelli, Giovanni, Lecoanet-Henchoz, Sybille, Caron, Gersende, Aubry, Jean-Pierre, Bonnefoy, Jean-Yves
• Format: Article
• Language: English
• Subjects: Antigens, CD - biosynthesis; Antigens, CD - blood; Antigens, CD - physiology; B7-2 Antigen; Humans; Immunologic Memory; Immunophenotyping; Interphase - immunology; Lymphocyte Activation - immunology; Lymphocyte Culture Test, Mixed; Membrane Glycoproteins - biosynthesis; Membrane Glycoproteins - blood; Membrane Glycoproteins - physiology; T-Lymphocyte Subsets - cytology; T-Lymphocyte Subsets - immunology; T-Lymphocyte Subsets - metabolism
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.162.4.2044

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.