| First Author | Mehlhop-Williams ER | Year | 2014 |
| Journal | J Exp Med | Volume | 211 |
| Issue | 2 | Pages | 345-56 |
| PubMed ID | 24493801 | Mgi Jnum | J:208439 |
| Mgi Id | MGI:5563300 | Doi | 10.1084/jem.20131271 |
| Citation | Mehlhop-Williams ER, et al. (2014) Memory CD8+ T cells exhibit increased antigen threshold requirements for recall proliferation. J Exp Med 211(2):345-56 |
| abstractText | A hallmark of immunological memory is the ability of previously primed T cells to undergo rapid recall responses upon antigen reencounter. Classic work has suggested that memory T cells proliferate in response to lower doses of antigen than naive T cells and with reduced requirements for co-stimulation. In contrast to this premise, we observed that naive but not memory T cells proliferate in vivo in response to limited antigen presentation. To reconcile these observations, we tested the antigen threshold requirement for cell cycle entry in naive and central memory CD8(+) T cells. Although both naive and memory T cells detect low dose antigen, only naive T cells activate cell cycle effectors. Direct comparison of TCR signaling on a single cell basis indicated that central memory T cells do not activate Zap70, induce cMyc expression, or degrade p27 in response to antigen levels that activate these functions in naive T cells. The reduced sensitivity of memory T cells may result from both decreased surface TCR expression and increased expression of protein tyrosine phosphatases as compared with naive T cells. Our data describe a novel aspect of memory T cell antigen threshold sensitivity that may critically regulate recall expansion. |
