| First Author | Howland KC | Year | 2000 |
| Journal | J Immunol | Volume | 164 |
| Issue | 9 | Pages | 4465-70 |
| PubMed ID | 10779746 | Mgi Jnum | J:110821 |
| Mgi Id | MGI:3641362 | Doi | 10.4049/jimmunol.164.9.4465 |
| Citation | Howland KC, et al. (2000) The roles of CD28 and CD40 ligand in T cell activation and tolerance. J Immunol 164(9):4465-70 |
| abstractText | Costimulation of T cell activation involves both the B7:CD28 as well as the CD40 ligand (CD40L):CD40 pathway. To determine the importance of these pathways to in vitro and in vivo T cell activation, a direct comparison was made of the responses of TCR transgenic T cells lacking either CD28 or CD40L. In vitro, CD28-/- T cells showed a greater reduction in proliferative responses to Ag than did CD40L-/- T cells. The absence of CD28 resulted in defective Th2 responses, whereas CD40L-/- T cells were defective in Th1 development. In vivo, CD28-/- T cells failed to expand upon immunization, whereas CD40L-/- T cells could not sustain a response. These results suggest that CD28 is critical for initiating T cell responses, whereas CD40L is required for sustained Th1 responses. The different functional roles of these costimulatory pathways may explain why blocking B7:CD28 and CD40L:CD40 interactions has an additive effect in inhibiting T cell responses. |
