Crisscross CTL induction by SYT-SSX junction peptide and its HLA-A*2402 anchor substitute
Crisscross CTL induction by SYT-SSX junction peptide and its HLA-A*2402 anchor substitute
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DOI：
10.4049/jimmunol.173.2.1436
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发表时间：
2004-07-15
影响因子：
4.4
通讯作者：
Sato, N
中科院分区：
文献类型：
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作者：
Ida, K;Kawaguchi, S;Sato, N
为了研究SYT-SSX连接肽中锚取代的作用，根据HLA-A24结合基序，将SYT-SSX B肽（GYDQIMPKK）的HLA-A24锚残基（位置9）取代为更有利的残基。在所构建的四种替代物中，以异亮氨酸（称为K9 I肽）的替代物对HLA-A24分子的亲和力增强最明显。随后使用15名HLA-A24（+）滑膜肉瘤患者的PBMC进行的体外CTL诱导分析显示，原始B肽允许从7名患者（47%）诱导滑膜肉瘤特异性CTL，而K9 I肽可从12名患者（80%）诱导此类CTL。此外，K9 I肽诱导的CTL对HLA-A24（+）滑膜肉瘤细胞系的细胞毒性程度高于B肽诱导的CTL。通过针对自体细胞的细胞毒性测定和四聚体分析来评价锚取代对肽/TCR相互作用的影响。使用K9 I肽从滑膜肉瘤患者诱导的CTL不裂解自体PHA母细胞或EBV感染的B细胞。用K9 I肽体外刺激5例HLA-A24（+）滑膜肉瘤患者的PBMC，可增加与HLA-A24/K9 I肽四聚体和HLA-A24/B肽四聚体反应的T细胞频率。相反，与HLA/HIV衍生肽四聚体反应的T细胞的频率仍然很低。这些发现支持了SYT-SSX融合基因衍生肽中锚残基取代设计的有效性，并为融合基因衍生天然连接肽的疫苗接种试验目前的停滞提供了潜在的线索。
To investigate the effects of anchor substitutions in SYT-SSX junction peptide, an HLA-A24 anchor residue (position 9) of the SYT-SSX B peptide (GYDQIMPKK) was substituted to more favorable residues according to the HLA-A24-binding motif. Among four substitutes constructed, a substitute with isoleucine (termed K9I peptide) most apparently enhanced the affinity for HLA-A24 molecule. Subsequent in vitro CTL induction analysis using PBMCs of 15 HLA-A24(+) synovial sarcoma patients revealed that the original B peptide allowed to induce synovial sarcoma-specific CTLs from 7 patients (47%), whereas such CTLs were inducible from 12 patients (80%) with K9I peptide. Moreover, the extent of cytotoxicity against HLA-A24(+) synovial sarcoma cell lines was higher in K9I peptide-induced CTLs than B peptide-induced CTLs. Influence of anchor substitution on peptide/TCR interaction was evaluated by cytotoxicity assays against autologous cells and tetramer analysis., CTLs induced from a synovial sarcoma patient using K9I peptide did not lyse autologous PHA blasts or EBV-infected B cells. In vitro stimulations of PBMCs from 5 HLA-A24(+) synovial sarcoma patients with K9I peptide increased the frequency of T cells reacting with both HLA-A24/K9I peptide tetramer and HLA-A24/B peptide tetramer. In-contrast, the frequency of T cells reacting with HLA/HIV-derived peptide tetramer remained low. These findings support the validity in design of anchor residue substitution in SYT-SSX fusion gene-derived peptide, and provide a potential clue to the current stagnation in vaccination trials of fusion gene-derived natural junction peptides.