A similarity in peptide cross-reactivity between alloantigen- and nominal antigen-induced CD8+ T cell responses in vitro
A similarity in peptide cross-reactivity between alloantigen- and nominal antigen-induced CD8+ T cell responses in vitro
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DOI：
10.1007/s00251-012-0668-3
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发表时间：
2013-03-01
期刊：
影响因子：
3.2
通讯作者：
Wu, Xiongwen
中科院分区：
文献类型：
--
作者：
Yu, Qian;Zhang, Li;Wu, Xiongwen
在体外培养肿瘤特异性同种异体限制性T细胞用于过继性输血有望规避宿主肿瘤耐受。然而，已经假定，同种异体反应性T细胞克隆在体外活化的范围从具有高亲合力的肽特异性到具有低亲合力的肽简并。在这项研究中，我们研究了肽的特异性和交叉反应性的T细胞反应在体外同种异体表位和名义表位与淋巴细胞和自体单核细胞的改良共培养。在通过其Fc部分与细胞表面IgG Fc受体I型（Fc γ RI）的相互作用与单核细胞结合后，由HLA-A2分子的胞外结构域和IgG 1的Fc区（二聚体）组成的融合蛋白将单个表位引入共培养物中。二聚体包被的单核细胞在共培养后刺激自体CD 8（+）T细胞增殖。对于HLA-A2阳性（HLA-A2+ve）样本，CD 8（+）T细胞应答是自身HLA限制性的，对于HLA-A2阴性（HLA-A2-ve）样本，CD 8（+）T细胞应答是同种HLA限制性的，因为用HLA-A2四聚体染色的共培养物、响应T细胞受体（TCR）配体的人干扰素-γ（IFN-γ）产生以及对一组靶细胞的细胞毒性表现出肽特异性。包括两个具有序列同源性的HLA-A2限制性肽，允许比较同种抗原和标称抗原诱导的CD 8（+）T细胞应答之间的交叉反应性。有趣的是，同种异体和自身HLA限制性CD 8（+）T细胞反应在肽交叉反应性方面相似，尽管同种异体限制性T细胞反应总体上似乎更强烈，并且对特异性四聚体具有更高的结合亲和力。结果表明，体外共培养的同种异体反应性T细胞与自身HLA限制性T细胞一样具有肽特异性和交叉反应性。
Raising tumor-specific allorestricted T cells in vitro for adoptive transfusion is expected to circumvent host tumor tolerance. However, it has been assumed that alloreactive T cell clones activated in vitro ranges from peptide-specific with high avidity to peptide-degenerate with low avidity. In this study, we examined the peptide specificity and cross-reactivity of T cell responses in vitro to an allogeneic epitope and a nominal epitope with a modified co-culture of lymphocytes and autologous monocytes. After binding to the monocyte via the interaction of its Fc part and the cell surface IgG Fc receptor type I (Fc gamma RI), a fusion protein consisting of the extracellular domains of HLA-A2 molecule and the Fc region of IgG1 (the dimer) introduced a single epitope into the co-culture. The dimer-coated monocytes stimulated the proliferation of autologous CD8(+) T cells after co-culturing. The CD8(+) T cell responses were self-HLA-restricted for HLA-A2-positive (HLA-A2+ve) samples and allo-HLA-restricted for HLA-A2-negative (HLA-A2-ve) samples, since the co-cultural bulks stained with HLA-A2 tetramers, human interferon-gamma (IFN-gamma) production in response to T cell receptor (TCR) ligands, and cytotoxicity against a panel of target cells exhibited peptide-specific properties. Two HLA-A2-restricted peptides with sequence homology were included, allowing the comparison of cross-reactivity between allo-antigen-and nominal antigen-induced CD8(+) T cell responses. Interestingly, the allo-and self-HLA-restricted CD8(+) T cell responses were similar in the peptide cross-reactivity, although the allorestricted T cell response seemed, overall, more intensive and had higher binding affinity to specific tetramer. Our findings indicated the alloreactive T cells raised by the co-culture in vitro were as peptide specific and cross-reactive as the self-HLA-restricted ones.