利用海绵移植模型,将Friend小鼠白血病病毒gag编码的二个多肽CCLCLTVFL(gPr80 gag 85-93)和RSPTNLAKV(Pr65 gag P30 131-139)分别注入正常或经FBL-3肿瘤细胞免疫过的C57BL/6小鼠皮下的植入海绵中,10天后,收集海绵中浸润淋巴细胞,在体外用免疫肽周期性刺激培养扩增。实验结果表明:用多肽体内免疫正常或经FBL-3免疫的B6小鼠均能诱导出对免疫多肽特异的CD8~ CTL。其中,P85-93多肽诱导的CD8~ CTL除能杀伤该多肽致敏的同系靶细胞外,还能特异性杀伤FBL-3瘤细胞.抗原多肽诱导的CD8~ CTL在体外经用免疫多肽致敏的同系小鼠脾细胞作周期性刺激并在低浓度IL-2的条件下培养,可长期生长并大量扩增。用体外培养扩增的P85-93多肽特异性CD8~ CTL过继转输治疗FBL-3荷瘤小鼠,能有效治愈FBL-3白血病荷瘤小鼠。上述结果表明,用肿瘤抗原多肽替代肿瘤细胞体内免疫动物可诱导特异性抗瘤效应的CD8~ CTL,并可在体外扩增用于肿瘤过继性免疫治疗。

The aim of the current study was to determine whether tumor-specific T cells can be primed in and obtained from sponge implants loaded with tumor associated peptides. Naive C57BL/6 mice as well as C57BL/6 mice previously primed with FBL-3 tumor cells were implanted with small polyurethane sponges containing FBL-3 gag peptides CCLCLTVFL(gPr80 gag 85-93)or RSPTNLAKV(Pr65 gag p30 131-139). Both FBL-3 gag peptides were shown could bind to H-2 Db molecules. Ten days later, cells that had accumulated in the sponges were harvested, stimulated in vitro with the immunizing peptide, and tested for cytolytic activity against FBL-3 tumor and FBL-3 gag peptides. The results demonstrated that peptide-specific CD8 CTL could be elicited and obtained from the sponge implants of both naive and immune mice. The FBL-3 gag p85-93 peptide induced CTL could specifically lyse syngeneic targets pulsed with the FBL-3 gag p85-93 peptide as well as FBL-3 tumor. However, the FBL-3 gag p131-139 peptide induced CTL lysed only the FBL-3 gag p131- 139 peptide pulsed syngeneic targets but not the FBL- 3 tumor. Tumor-specific T cells obtained from peptide-loaded sponge implants could be induced to grow to large numbers in vitro by periodic restimulation with the immunizing peptide plus syngeneic APC and low concentrations of IL- 2. Adoptive transfer of the resultant expanded FBL-3 gag p85-93 peptide-induced CTL into mice with disseminated FBL-3 could mediate effective anti-tumor therapy. Thus,in vivo immunization with peptide-loaded sponges provides a potentially useful technique for procuring primed peptide- specific T cells for tumor therapy.

国家自然科学基金资助项目(3937076g)