Identification of minor histocompatibility antigens restricted by HLA alleles common in Japanese

对组织表达限于造血细胞的次要组织相容性抗原（mHAg）特异的细胞毒性T淋巴细胞（CTL）可用于异基因造血细胞移植（HCT）后复发性白血病/淋巴瘤的免疫治疗。我们收集了26例接受HCT的患者的外周血样本，并产生了日本人群中常见的HLA等位基因限制性CTL。首先，我们使用320例接受HLA-相同HCT供体对的HLA-A24阳性患者，研究了BCL 2A 1/A24差异对临床结果的影响。结果表明这种差异不太可能增加GVHD，表明这种mHAg可用于HCT后针对血液恶性肿瘤的免疫治疗。接下来，我们尝试使用优先裂解造血细胞的CTL克隆来鉴定编码HLA-A^*3303限制性男性特异性mHAg的基因。使用一组Y染色体缺失突变体LCL，将该基因缩小到Yq11.221。使用RT-PCR的进一步研究， ...更多信息 小基因表达和CTL识别结果表明，mHAg确实位于TMSB 4 Y基因的5 ′ UTR。第三，进行编码HLA-A^*3303和HLA-A ^*3101限制性mHAg的mHAg基因的鉴定。连锁分析表明，两个特异性CTL克隆识别来自单一区域15 q25的相似表位。一个单一的多态性基因，组织蛋白酶H，通过表达克隆的援助。该基因有三个非同义SNP，第一个控制这些CTL克隆的特异性。HLA-A^*3303限制性CTL识别以Arg结尾的10聚体表位，而HLA-A^*3101限制性CTL识别以相同Arg结尾的9聚体表位。用Ag-等位基因编码的Gly取代Arg后，该肽的结合完全消失。组织蛋白酶H在造血细胞中不特异表达，但其功能与癌细胞的转移密切相关。因此，我们目前正在质疑这些表位是否可用于针对实体瘤的免疫治疗。少

Cytotoxic T lymphocytes(CTL) specific for minor histocompatibility antigens(mHAgs) whose tissue expression is limited to hematopoietic cells are useful for immunotherapy of relapsed leukemia/lymphoma following allogeneic hematopoietic cell transplantation(HCT). We have collected peripheral blood samples 26 patients receiving HCT and generated CTL restricted by HLA alleles commonly seen in Japanese population. First we examined the impact of BCL2A1/A24 disparity on clinical outcome using 320 HLA-A24-positive patients receiving HLA-identical HCT.donor pairs. The results indicate the disparity is unlikely to augment GVHD, suggesting this mHAg may be used for immunotherapy against hematological malignancies after HCT. We next attempted to identify a gene encoding HLA-A^*3303 restricted, male specific mHAg using a CTL clone that preferentially lysed hematopoietic cells. Using a panel of Y chromosome deletion mutant LCLs, the gene was narrowed down to Yq11.221. Further studies using RT-PCR, … More minigene expression and CTL recognition, demonstrated that the mHAg was indeed located in the 5'UTR of TMSB4Y gene. Third, identification of mHAg gene(s) encoding HLA-A^*3303 and -A^*3101-restricted mHAgs was conducted. Linkage analysis demonstrated that two CTL clones specific for these mHAgs recognized a similar epitope(s) from a single region, 15q25. A single polymorphic gene, Cathepsin H, was identified by the aid of expression cloning. This gene has three non-synonymous SNPs and the first one controlled the specificity of these CTL clones. HLA-A^*3303-rectricted CTL recognized 10-mer epitope ending Arg while HLA-A^*3101 -rectricted CTL recognized 9-mer epitope ending the same Arg. Substitution of Arg with Gly which is encoded by Ag-negative allele totally abrogated the binding of the peptide. Cathespsin H is not specifically expressed in hematopoietic cells, but its function is tightly correlated with metastasis of cancer cells. Thus we are currently questioning wheather these epitope is useful for immunotherapy against solid tumors. Less