Pathomechanisms of paraneoplastic neurological syndrome-neuronal damege mediated by cytotoxic T cells

副肿瘤神经综合征的一部分可以用特有的抗神经元抗体来诊断，这也给出了潜在癌症的预测。尽管在患者的血清和CSF中发现的这些抗体被认为是疾病特异性的，但没有直接证据表明在神经元丢失中起到了作用。副肿瘤性小脑变性(PCD)和抗Yo抗体阳性或抗Hu抗体阳性的脑脊髓神经病(抗Hu综合征)患者病变组织中CD8阳性T细胞浸润，提示HLAI类限制性细胞毒性T细胞(CTL)可能参与了这些疾病的发生。首先，我们用RT-PCR和单链构象多态性方法检测了浸润性淋巴细胞中T细胞受体的VB基因，这表明肿瘤中的T细胞和PCD/抗HU综合征的小脑/后神经节中的T细胞分别发生了寡克隆扩张。然后，我们检测了具有HLAA24特异性多肽结合基序的YoProtein或具有B7超型特异性多肽结合基序的Hu蛋白的某些多肽对HLAI类限制性细胞毒性T淋巴细胞(CTL)的活性。PCD/抗-Hu综合征患者外周血经特异性多肽刺激后，可诱导CTL活性，以对抗其表面表达各种多肽的自体成纤维细胞。为了阐明CTL可能确实与神经元损伤有关，需要建立CTL诱导的动物模型。为此，我们用这些多肽和自体树突状细胞免疫具有共同MHC基序的小鼠，获得了对每种多肽都有反应的T细胞克隆。

A part of the paraneoplastic neurological syndrome could be diagnosed with characteristic anti-neuronal antibodies which also give the prediction for underlying cancer. Although these antibodies found in the sera and CSFs of patients is thought to be disease- specific, there is no direct evidence of a role in neuronal loss. Infiltration of CD8-positive T cells in the affected tissue was found in the patient with paraneoplastic cerebellar degeneration(PCD)and anti-Yo antibody or encepahlomyeloneuropathy with anti-Hu antibody(anti-Hu syndrome)which suggested HLA class I restricted cytotoxic T cells(CTL)may be involved in these disorders. First, we examined Vb genes of T cell receptors of infiltrated lymphocytes with RT-PCR and single strand conformational polym orphism method, that suggested the oligoclonal expansions of T cells in the tumor and the cerebellum/posterior ganglions of PCD/anti-Hu syndrome, respectively.Then we examined HLA-class I- restricted cytotoxic T lymphocyte(CTL)activity against a peptid of the Yoprotein with the HLA A24-specific peptide-binding motifs or some peptides of the Hu protein with the B7 supertype-specific peptide binding motifs. CTL activity was induced in the peripheral blood of patients with PCD/anti-Hu syndrome after stimulated with specific peptides against autologous fibroblasts expressing each peptide on their surface. To clarify that CTL might really related to the neuronal damage, CTL induced animal models should be raised.For this purpose, we immunized the mice bering common MHC motifs with these peptides and autologous dendritic cells and obtained T cell clones reactive to each peptides.