本帖最后由 爱康得 于 2015-8-30 11:28 编辑 |
Identification and selectiveexpansion of functionally superior T cells expressing chimeric antigenreceptors
T cells expressing chimeric antigen receptors (CARs)have shown exciting promise in cancer therapy, particularly in the treatment ofB-cell malignancies. However, optimization of CAR-T cell production remains atrial-and-error exercise due to a lack of phenotypic benchmarks that areclearly predictive of anti-tumor functionality. A close examination of thedynamic changes experienced by CAR-T cells upon stimulation can improveunderstanding of CAR–T-cell biology and identify potential points foroptimization in the production of highly functional T cells.
Methods Primary human T cells expressing asecond-generation, anti-CD19 CAR were systematically examined for changes inphenotypic and functional responses to antigen exposure over time. Multi-colorflow cytometry was performed to quantify dynamic changes in CAR-T cell viability,proliferation, as well as expression of various activation and exhaustionmarkers in response to varied antigen stimulation conditions.
Stimulated CAR-T cells consistently bifurcate into two distinct subpopulations, only one ofwhich (CARhi/CD25+) exhibit anti-tumor functions. The use of central memory Tcells as the
starting population and the resilience—but not antigendensity—of antigen-presenting cells used to expand CAR-T cells were identifiedas critical parameters that augment the production of functionally superior Tcells. We further demonstrate that the CARhi/CD25+subpopulation upregulatesPD-1 but is resistant to PD-L1-induced dysfunction.
CAR-T cells expanded ex vivo for adoptive T-cell therapy undergo dynamic phenotypic changesduring the expansion process and result in two distinct populations withdramatically different functional capacities. Significant and sustained CD25and CAR expression upregulation is predictive of robust anti-tumor functionalityin antigen-stimulated T cells, despite their correlation with persistent PD-1upregulation. The functionally superior subpopulation can be selectivelyaugmented by careful calibration of antigen stimulation and the enrichment ofcentral memory T-cell type.
经抗原激活的CAR-T细胞最终分化成两个不同的亚群，但只有CARhi/CD25 +亚群表达出抗肿瘤的作用，中枢记忆T细胞被认为是生产功能优越T细胞的关键点。我们进一步证明CARhi/ CD25 +亚群会上调的PD-1的表达，但是会耐受PD-L1引起的免疫抑制。