Zhang Hua, Snyder Kristen M, Suhoski Megan M, Maus Marcela V, Kapoor Veena, June Carl H, Mackall Crystal L
Pediatric Oncology Branch, National Cancer Institute, Bethesda, MD 20892, USA.
J Immunol. 2007 Oct 1;179(7):4910-8. doi: 10.4049/jimmunol.179.7.4910.
Artificial APCs (aAPCs) genetically modified to express selective costimulatory molecules provide a reproducible, cost-effective, and convenient method for polyclonal and Ag-specific expansion of human T cells for adoptive immunotherapy. Among the variety of aAPCs that have been studied, acellular beads expressing anti-CD3/anti-CD28 efficiently expand CD4+ cells, but not CD8+ T cells. Cell-based aAPCs can effectively expand cytolytic CD8+ cells, but optimal costimulatory signals have not been defined. 4-1BB, a costimulatory molecule expressed by a minority of resting CD8+ T cells, is transiently up-regulated by all CD8+ T cells following activation. We compared expansion of human cytolytic CD8+ T cells using cell-based aAPCs providing costimulation via 4-1BB vs CD28. Whereas anti-CD3/anti-CD28 aAPCs mostly expand naive cells, anti-CD3/4-1BBL aAPCs preferentially expand memory cells, resulting in superior enrichment of Ag-reactive T cells which recognize previously primed Ags and efficient expansion of electronically sorted CD8+ populations reactive toward viral or self-Ags. Using HLA-A2-Fc fusion proteins linked to 4-1BBL aAPCs, 3-log expansion of Ag-specific CD8+ CTL was induced over 14 days, whereas similar Ag-specific CD8+ T cell expansion did not occur using HLA-A2-Fc/anti-CD28 aAPCs. Furthermore, when compared with cytolytic T cells expanded using CD28 costimulation, CTL expanded using 4-1BB costimulation mediate enhanced cytolytic capacity due, in part, to NKG2D up-regulation. These results demonstrate that 4-1BB costimulation is essential for expanding memory CD8+ T cells ex vivo and is superior to CD28 costimulation for generating Ag-specific products for adoptive cell therapy.
经过基因改造以表达选择性共刺激分子的人工抗原提呈细胞（aAPC）为过继性免疫治疗中人类T细胞的多克隆和抗原特异性扩增提供了一种可重复、经济高效且便捷的方法。在已研究的多种aAPC中，表达抗CD3/抗CD28的无细胞微珠能有效扩增CD4+细胞，但不能扩增CD8+ T细胞。基于细胞的aAPC能有效扩增细胞毒性CD8+细胞，但尚未确定最佳共刺激信号。4-1BB是少数静止CD8+ T细胞表达的共刺激分子，所有CD8+ T细胞激活后会短暂上调表达。我们比较了通过4-1BB与CD28提供共刺激的基于细胞的aAPC对人类细胞毒性CD8+ T细胞的扩增情况。抗CD3/抗CD28 aAPC主要扩增初始细胞，而抗CD3/4-1BBL aAPC优先扩增记忆细胞，从而能更好地富集识别先前致敏抗原的抗原反应性T细胞，并有效扩增对病毒或自身抗原具有反应性的经电子分选的CD8+群体。使用与4-1BBL aAPC连接的HLA-A2-Fc融合蛋白，在14天内可诱导抗原特异性CD8+ CTL进行3个对数级的扩增，而使用HLA-A2-Fc/抗CD28 aAPC则不会发生类似的抗原特异性CD8+ T细胞扩增。此外，与使用CD28共刺激扩增的细胞毒性T细胞相比，使用4-1BB共刺激扩增的CTL介导的细胞溶解能力增强，部分原因是NKG2D上调。这些结果表明，4-1BB共刺激对于体外扩增记忆CD8+ T细胞至关重要，并且在为过继性细胞治疗生成抗原特异性产物方面优于CD28共刺激。
