Basic and clinical studies on the immunopathogenesis of viral infection

1. IL-1的研究：猫传染性腹膜炎（FIP）的腹膜渗出细胞（PEC）培养上清显示出显著的IL-1活性，也被发现对健康猫的外周血中性粒细胞（PBN）具有趋化作用。趋化活性的大小约为健康猫鲜血清（ZAS）的10倍，健康猫PBN在PEC培养上清和ZAS之间的迁移情况略有不同。这些发现提示趋化作用。在PEC培养上清中检测到的活性与在zas中不同。IL-6的研究：通过两个IL-6依赖的小鼠杂交瘤细胞克隆B3BI和MH 60的增殖反应，研究IL-6参与FIP血管炎和多克隆γ病的发展。BSF-2细胞：在FIP猫的血清和腹水中发现了显著的IL-6活性，而在健康猫的血清中没有检测到IL-6活性。在这些FIP猫中，腹水中的IL-6活性明显高于血清。FIP猫的PEC也被发现向培养上清中释放高水平的IL-6。凝胶过滤将腹水IL-6活性洗脱为分子量为30000 ~ 40000的馏分，阴离子交换层析将腹水IL-6活性洗脱为盐浓度为0.2 ~ 0.3 M NaCl的馏分。在这些FIP猫中，腹水IL-6活性水平与血清白蛋白/球蛋白比呈负相关。这些发现表明，积存在腹水中的IL-6可能会渗漏到体循环中，并与免疫球蛋白和急性期蛋白合成增强等系统性改变有关。IL-2受体的研究：制备了针对猫IL-2受体（IL-2R） A链亚基的单克隆抗体9F23，并研究了IL-2R α链在猫白血病病毒（FeLV）产生淋巴瘤细胞株上的表达。9F23特异性免疫沉淀IL-2/IL-2R α链复合物，该复合物来自豆豆蛋白a刺激的猫淋巴细胞的细胞提取物，但不影响IL-2驱动的淋巴细胞增殖或IL-2结合。利用9F23检测了部分产生felv的淋巴瘤细胞系细胞表面IL-2R α链的表达，其中源自大颗粒淋巴细胞的FGL细胞表达了高亲和力的IL-2R。IL-2R α链在FGL细胞上的表达也被证实通过外源IL-2的加入而上调。少

1. Studies on IL-1: The culture supernatant of peritoneal exudate cells (PEC) from cats with feline infectious peritonitis (FIP), which exhibits significant IL-1 activity, was also found to be chemotactic for peripheral blood neutrophils (PBN) from healthy cats. The magnitude of the chemotactic activity was approximately 10-fold lower than that in zymosan-activated fresh serum of healthy cats (ZAS), and the migration profile of PBN from healthy cats was slightly different between the PEC culture supernatant and ZAS. These findings suggest that the chemotactic.activity detected in the PEC culture supernatant-is distinct from that in ZAS.2. Studies on IL-6: Involvement of IL-6 in the development of vasculitis and polyclonal gammopathy in FIP was investigated, by using the proliferative responses of two IL-6-dependent -murine hybridoma cell'clones, B3BI and MH 60.BSF-2 cells: A significant IL-6 activity was found in sera and ascitic fluids of cats with FIP, whereas no IL-6 activity was de … More tected in sera from healthy cats. In these FIP cats, IL-6 activity in ascitic fluids was significantly higher-than in sera. PEC from FIP cats were also found to be release a high level of IL-6 to the culture supernatant. The ascitic IL-6 activity was eluted into the fractions corresponding to the molecular weight of 30000 to 40000 in gel filtration, and into the fractions at the salt concentration from 0.2 to 0.3 M NaCl in anion exchange chromatography. The level of ascitic IL-6 activity was inversely correlated to'serum albumin/globulin ratio in these FIP cats. These findings indicate that IL-6 accumulated in the ascites might be leaked into the systemic circulation, and be linked to systemic alterations such as enhanced synthesis of immunoglobulins and-acute phase proteins.3. Studies on IL-2 receptors: A monoclonal antibody termed 9F23 directed against feline IL-2 receptor (IL-2R) a-chain subunit was prepared, and then the expression of IL-2R alpha-chain on feline leukemia virus (FeLV)-producing lymphoma cell lines was studied. 9F23 specifically immunoprecipitated the IL-2/IL-2R alpha-chain complex in a cell extract from concanavalin A-stimulated feline lymphocytes, and did not affect either IL-2-driven proliferation of the lymphocytes or IL-2 binding. By using 9F23, the expression of IL-2R alpha-chain was detected on the cell surface of some FeLV-producing lymphoma cell lines, and one of these cell lines, FGL cells, which derives from large granular lymphocytes, expressed high affinity IL-2R. The expression of IL-2R alpha-chain on FGL cells was also confirmed to be up-regulated by the addition of exogenous IL-2. Less