| First Author | Toyo-oka K | Year | 1997 |
| Journal | Immunol Lett | Volume | 58 |
| Issue | 1 | Pages | 19-23 |
| PubMed ID | 9436464 | Mgi Jnum | J:40980 |
| Mgi Id | MGI:892699 | Doi | 10.1016/s0165-2478(97)02706-5 |
| Citation | Toyo-oka K, et al. (1997) Synergy between CD28 and CD9 costimulation for naive T-cell activation. Immunol Lett 58(1):19-23 |
| abstractText | Our previous study demonstrated that CD9 is expressed on most mature naive T-cells and delivers a potent costimulatory signal that functions independently of CD28. Here, we investigated whether this CD9-mediated signal is different from the CD28-mediated signal in the mode of costimulation and whether both signals function synergistically for T-cell activation. Anti-CD9 or anti-CD28 monoclonal antibody (mAb) increased [3H]TdR incorporation of naive T-cells in the absence of antigen-presenting cells (APC) when coimmobilized with submitogenic doses of anti-CD3 mAb. The levels of costimulation induced by ligation of CD9 and CD28 were comparable. However, the costimulatory effect differed between soluble anti-CD9 and CD28 mAb. A soluble form of anti-CD28 mAb could costimulate anti-CD3-triggered T-cells, whereas soluble anti-CD9 mAb failed to costimulate. Although anti-CD28 costimulated naive T-cells treated with phorbol myristate acetate (PMA) instead of anti-CD3 mAb, a combination of PMA plus anti-CD9 mAb could not induce T-cell activation. The combined costimulation of anti-CD3-triggered T-cells with anti-CD9 and anti-CD28 mAbs resulted in strikingly enhanced [3H]TdR uptake and lymphokine (IL-2 and IFN-gamma) production when compared to those induced by each costimulation. These results suggest that CD9 and CD28 induce T-cell costimulation using different signaling pathways, thereby inducing synergy in T-cell activation. |
