An immunodominant Kb-restricted peptide from the p15E transmembrane protein of endogenous ecotropic murine leukemia virus (MuLV) AKR623 that restores susceptibility of a tumor line to anti-AKR/Gross MuLV cytotoxic T lymphocytes.
An immunodominant Kb-restricted peptide from the p15E transmembrane protein of endogenous ecotropic murine leukemia virus (MuLV) AKR623 that restores susceptibility of a tumor line to anti-AKR/Gross MuLV cytotoxic T lymphocytes.
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来自内源性亲嗜性鼠白血病病毒 (MuLV) AKR623 的 p15E 跨膜蛋白的免疫显性 Kb 限制肽，可恢复肿瘤系对抗 AKR/Gross MuLV 细胞毒性 T 淋巴细胞的敏感性。
DOI：
10.1128/jvi.68.2.897-904.1994
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发表时间：
1994
影响因子：
5.4
通讯作者：
Green,WR
中科院分区：
文献类型：
--
作者：
White,HD;Roeder,DA;Green,WR
表达内源性嗜亲性鼠白血病病毒（EMV）的H-2b肿瘤细胞在C57 BL/6小鼠品系中诱导抗AKR/Gross鼠白血病病毒（MuLV）细胞毒性T淋巴细胞（CTL）应答。EMV克隆AKR 623已被用于感染SC.Kb成纤维细胞，产生SC.Kb/623靶标，其被大量抗AKR/Gross MuLV CTL裂解，其特征与EMV+ AKR.H-2b SL 1肿瘤靶标相似。抗AKR/Gross MuLV CTL受I类Kb抗原的限制，不与抗-莫洛尼-劳舍尔病毒阳性靶标交叉反应。通过计算机搜索AKR 623基因组中与结合Kb的肽的基序FY（FY）XX（VIML）匹配的编码序列。在鉴定的30种八聚体肽中，合成了12种AKR 623特有的且不同于已发表的M-Moloney-Rauscher序列的八聚体肽，并将其结合至EMV阴性SC.Kb细胞，然后将其作为抗AKR/Gross MuLV CTL的靶标进行测定。一种肽，即来自p15 E跨膜蛋白的肽12（KSPWFTTL），可使SC.Kb靶细胞对抗AKR/Gross MuLV CTL的溶解敏感，其特征与AKR.H-2b SL 1肿瘤靶点和SC.Kb/623成纤维细胞靶点的特征相似。低浓度的肽是足够的，半数最大裂解发生在10至100 pg/ml。SC.Kb/肽12靶标以常规I类Kb限制性方式被H-2b限制性本体CTL识别。未标记的SC.Kb/肽12-脉冲靶标在与放射性标记的SC.Kb/623靶标竞争抗AKR/Gross MuLV CTL的裂解中是有效的。这一发现与肽12代表这些抗病毒CTL识别的显性内源性加工表位的概念一致。此外，肽12是免疫原性的，因为它可以刺激来自肿瘤致敏的C57 BL/6应答者脾细胞的抗AKR/Gross MuLV CTL应答的体外产生。最后，肽12的生理学相关性通过其完全恢复AKR.H-2b SL 1克隆18-5肿瘤细胞的识别和裂解的能力而被提出，AKR.H-2b SL 1克隆18-5肿瘤细胞是对抗AKR/Gross MuLV CTL的裂解不敏感的天然存在的变体肿瘤克隆。这些数据表明，由肽12表示的病毒编码的抗原，而不是非病毒肿瘤抗原，是负责C57 BL/6衍生的抗AKR/Gross MuLV CTL识别EMV+肿瘤细胞的免疫显性表位。
H-2b tumor cells expressing the endogenous ecotropic murine leukemia virus (EMV) induce an anti-AKR/Gross murine leukemia virus (MuLV) cytotoxic T-lymphocyte (CTL) response in the C57BL/6 mouse strain. The EMV clone AKR623 has been used to infect SC.Kb fibroblast cells, resulting in SC.Kb/623 targets that are lysed by bulk anti-AKR/Gross MuLV CTL with a profile that is similar to that for the EMV+ AKR.H-2b SL1 tumor target. Anti-AKR/Gross MuLV CTL are restricted by the class I Kb antigen and do not cross-react with Friend-Moloney-Rauscher virus-positive targets. The AKR623 genome was searched by computer for coding sequences that fit the motif XXXX(FY)XX(VIML) for peptides that bind Kb. Of 30 octameric peptides identified, 12 that were unique to AKR623 and different from published Friend-Moloney-Rauscher sequences were synthesized and bound to EMV-negative SC.Kb cells, which were then assayed as targets against anti-AKR/Gross MuLV CTL. One peptide, peptide 12 (KSPWFTTL) from the p15E transmembrane protein, sensitized SC.Kb target cells to lysis by anti-AKR/Gross MuLV CTL with a profile similar to those seen for AKR.H-2b SL1 tumor targets and SC.Kb/623 fibroblast targets. Low concentrations of peptide were sufficient, the half-maximal lysis occurring at 10 to 100 pg/ml. SC.Kb/peptide 12 targets were recognized by the H-2b-restricted bulk CTL in a conventional class I Kb-restricted fashion. Unlabeled SC.Kb/peptide 12-pulsed targets were effective in competing with radiolabeled SC.Kb/623 targets for lysis by anti-AKR/Gross MuLV CTL. This finding is consistent with the notion that peptide 12 represents the dominant endogenously processed epitope recognized by these antiviral CTL. In addition, peptide 12 is immunogenic in that it could stimulate the in vitro generation of an anti-AKR/Gross MuLV CTL response from tumor-primed C57BL/6 responder spleen cells. Finally, the physiological relevance of peptide 12 was suggested by its ability to fully restore the recognition and lysis of AKR.H-2b SL1 clone 18-5 tumor cells, a naturally occurring variant tumor clone that is insusceptible to lysis by anti-AKR/Gross MuLV CTL. These data indicate that a virus-encoded antigen, represented by peptide 12, and not a nonviral tumor antigen, is the immunodominant epitope responsible for the recognition of EMV+ tumor cells by C57BL/6-derived anti-AKR/Gross MuLV CTL.