The CD28 ligand, B7, enhances IL-2 production by providing a costimulatory signal to T cells.
Previous studies demonstrated that a human pre-B acute lymphoblastic leukemia cell line, NALM-6, failed to stimulate a primary MLR, despite expression of class II MHC and adhesion molecules. Here we demonstrate that this is the result of the fact that NALM-6 cells do not express the ligand for CD28, namely B7. NALM-6 transfectants that expressed high levels of B7 gained the capacity to stimulate IL-2 production by class II MHC molecule-specific alloreactive T cells and to costimulate a polyclonal population of purified T cells cultured with immobilized anti-CD3 mAb. In the presence of PMA, NALM-6 cells transfected with B7 polyclonally stimulated T cells in a cyclosporine A-resistant fashion, a property previously attributed only to agonistic anti-CD28 mAb. The gain of these functions could not be explained solely by an increased capacity of the transfectants to form conjugates with T cells, suggesting that the CD28/B7 interaction transduces a costimulatory signal in T cells.
Norton
S D
SD
Department of Microbiology, University of Minnesota Medical School, Minneapolis 55455.
Zuckerman
L
L
Urdahl
K B
KB
Shefner
R
R
Miller
J
J
Jenkins
M K
MK
D000938:Antigen-Presenting Cells / Q000502:physiology; D015703:Antigens, CD / Q000502:physiology*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000502:physiology*; D000954:Antigens, Surface / Q000502:physiology*; D018122:B7-1 Antigen; D018106:CD28 Antigens; D002448:Cell Adhesion; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis*; D008213:Lymphocyte Activation; D011948:Receptors, Antigen, T-Cell / Q000502:physiology; D013601:T-Lymphocytes / Q000276:immunology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014162:Transfection
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D000954:Antigens, Surface; D018122:B7-1 Antigen; D018106:CD28 Antigens; D007376:Interleukin-2; D011948:Receptors, Antigen, T-Cell; D013755:Tetradecanoylphorbol Acetate