Efficiency of T-cell costimulation by CD80 and CD86 cross-linking correlates with calcium entry.
Costimulation is a fundamental principle of T-cell activation. In addition to T-cell receptor engagement, the interaction between CD80 and/or CD86 with CD28 and/or cytotoxic T-lymphocyte antigen 4 (CTLA-4) receptors is required to regulate T-cell activation and tolerance. While the importance of costimulation is clearly established, the exact molecular mechanism is unknown. We demonstrate that T-cell proliferation and the ability of CD8(+) T-effector cells to kill were enhanced slightly by CD80 but dramatically by CD86 costimulation. To further analyse the cellular process of costimulation, we developed a single-cell assay to analyse Ca(2+) signals following costimulation with bi-specific antibodies. We found that this stimulation method worked in every human T-cell that was analysed, making it one of the most efficient T-cell activation methods to date for primary human T cells. The enhanced proliferation and killing by costimulation was paralleled by an increase of Ca(2+) influx following CD86 costimulation and it was dependent on CD28/CTLA-4 expression. The enhanced Ca(2+) influx following CD86 costimulation was abrogated by an antibody that interfered with CD28 function. The differences in Ca(2+) influx between CD80 and CD86 costimulation were not dependent on the depletion of Ca(2+) stores but were eliminated by the application of 10 mum 2-aminoethyldiphenyl borate which has recently been shown to enhance stromal interaction molecule 2 (STIM2)-dependent Ca(2+) entry while reducing STIM1-dependent Ca(2+) entry. Our data indicate that differences in the efficiency of costimulation are linked to differences in Ca(2+) entry.
Thiel
Markus
M
Klinik und Poliklinik für Onkologie, Universitäts-Spital Zürich, Zürich, Switzerland.
Wolfs
Melodie-Jo
MJ
Bauer
Stefan
S
Wenning
Anna S
AS
Burckhart
Tanja
T
Schwarz
Eva C
EC
Scott
Andrew M
AM
Renner
Christoph
C
Hoth
Markus
M
D000911:Antibodies, Monoclonal; D018122:B7-1 Antigen / Q000276:immunology / Q000378:metabolism*; D051940:B7-2 Antigen / Q000276:immunology / Q000378:metabolism*; D001896:Boron Compounds / Q000494:pharmacology; D017252:CD3 Complex / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D020013:Calcium Signaling / Q000187:drug effects / Q000276:immunology; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism; D049109:Cell Proliferation; D003602:Cytotoxicity, Immunologic; D006801:Humans; D019169:Jurkat Cells; D008213:Lymphocyte Activation / Q000187:drug effects / Q000276:immunology; D015202:Protein Engineering; D011993:Recombinant Fusion Proteins; D000071738:Stromal Interaction Molecule 2
D000911:Antibodies, Monoclonal; D018122:B7-1 Antigen; D051940:B7-2 Antigen; D001896:Boron Compounds; D017252:CD3 Complex; D015815:Cell Adhesion Molecules; D011993:Recombinant Fusion Proteins; C513279:STIM2 protein, human; D000071738:Stromal Interaction Molecule 2; C109986:2-aminoethoxydiphenyl borate