4-1BB costimulation ameliorates T cell exhaustion induced by tonic signaling of chimeric antigen receptors. # c$ ~- Y A3 j, ~ http://www.nature.com/nm/journal/vaop/ncurrent/full/nm.3838.html 3 q$ s1 a6 K6 \* x3 o+ |' ?" D. \0 l白血病治疗的奇效是一种巧合：CD19与CAR结合没有引起T细胞的耗竭效应。' m3 M& U& ?" ^+ F& [
Chimeric antigen receptors (CARs) targeting CD19 have mediated dramatic antitumor responses in hematologic malignancies, but tumor regression has rarely occurred using CARs targeting other antigens. It remains unknown whether the impressive effects of CD19 CARs relate to greater susceptibility of hematologic malignancies to CAR therapies, or superior functionality of the CD19 CAR itself. We show that tonic CAR CD3-ζ phosphorylation, triggered by antigen-independent clustering of CAR single-chain variable fragments, can induce early exhaustion of CAR T cells that limits antitumor efficacy. Such activation is present to varying degrees in all CARs studied, except the highly effective CD19 CAR. We further determine that CD28 costimulation augments, whereas 4-1BB costimulation reduces, exhaustion induced by persistent CAR signaling. Our results provide biological explanations for the antitumor effects of CD19 CARs and for the observations that CD19 CAR T cells incorporating the 4-1BB costimulatory domain are more persistent than those incorporating CD28 in clinical trials.. C- `5 `: J! A- X4 k 作者: 杏色玻璃 时间: 2015-5-14 14:49
本帖最后由 细胞海洋 于 2015-5-15 09:33 编辑 ) K% i7 c s S$ O8 U- D4 u 4 E8 Z0 [& s, G# d3 A8 |3 e. A. \收吧作者: helong 时间: 2015-5-14 14:56