| First Author | Lucas PJ | Year | 1995 |
| Journal | J Immunol | Volume | 154 |
| Issue | 11 | Pages | 5757-68 |
| PubMed ID | 7751626 | Mgi Jnum | J:25536 |
| Mgi Id | MGI:73252 | Doi | 10.4049/jimmunol.154.11.5757 |
| Citation | Lucas PJ, et al. (1995) Naive CD28-deficient T cells can initiate but not sustain an in vitro antigen-specific immune response. J Immunol 154(11):5757-68 |
| abstractText | Naive T cells require an Ag-specific signal, as well as a costimulatory signal to mount a primary Ag-specific response. Because of their low precursor frequency, it has been difficult to study costimulatory requirements of these Ag-specific T cells. We have generated a CD28-deficient mouse that has been bred to a TCR transgenic (Tg) mouse to better study the function of CD28 during CD4+ T cell responses to Ag. In the absence of CD28, naive TCR Tg T cells responded vigorously to peptide, but responded poorly to mitogen activation. Comparison of activation-induced cell-surface molecules, including CD25, CD44, CD69, and CD71, showed no significant differences between CD28+ and CD28- TCR Tg T cells during the first 24 to 48 h after Ag stimulation. Despite relatively normal surface phenotype and normal proliferative response to Ag, CD28- T cells produced little IL-2, had a decreased sensitivity to lower Ag concentrations, and were unable to maintain their proliferative response. These results suggest that naive T cells are able to utilize other costimulatory signals to initiate a primary Ag-specific response, but require CD28 for optimal, sustained proliferation. |
