Adhesion of human T cells to antigen-presenting cells through SIRPbeta2-CD47 interaction costimulates T-cell proliferation.
Signal-regulatory proteins (SIRPs) are transmembrane glycoproteins belonging to the immunoglobulin (Ig) superfamily that are expressed in the immune and central nervous systems. SIRPalpha binds CD47 and inhibits the function of macrophages, dendritic cells, and granulocytes, whereas SIRPbeta1 is an orphan receptor that activates the same cell types. A recently identified third member of the SIRP family, SIRPbeta2, is as yet uncharacterized in terms of expression, specificity, and function. Here, we show that SIRPbeta2 is expressed on T cells and activated natural killer (NK) cells and, like SIRPalpha, binds CD47, mediating cell-cell adhesion. Consequently, engagement of SIRPbeta2 on T cells by CD47 on antigen-presenting cells results in enhanced antigen-specific T-cell proliferation.
Piccio
Laura
L
Department of Pathology and Immunology, Washington University School of Medicine, 660 S Euclid, St Louis, MO 63110, USA.
Vermi
William
W
Boles
Kent S
KS
Fuchs
Anja
A
Strader
Carey A
CA
Facchetti
Fabio
F
Cella
Marina
M
Colonna
Marco
M
D051928:CD47 Antigen / Q000276:immunology*; D002448:Cell Adhesion / Q000276:immunology; D049109:Cell Proliferation; D002478:Cells, Cultured; D002490:Central Nervous System / Q000166:cytology / Q000276:immunology; D003713:Dendritic Cells / Q000166:cytology / Q000276:immunology*; D006098:Granulocytes / Q000166:cytology / Q000276:immunology; D006801:Humans; D007694:Killer Cells, Natural / Q000166:cytology / Q000276:immunology; D008213:Lymphocyte Activation / Q000276:immunology*; D008264:Macrophages / Q000166:cytology / Q000276:immunology; D008562:Membrane Glycoproteins / Q000276:immunology*; D019006:Neural Cell Adhesion Molecules / Q000276:immunology*; D013601:T-Lymphocytes / Q000166:cytology / Q000276:immunology*
D051928:CD47 Antigen; D008562:Membrane Glycoproteins; D019006:Neural Cell Adhesion Molecules; C423651:SIRPB2 protein, human