Pontesilli O, Carotenuto P, Hayward A R, Prowse S J
Barbara Davis Center for Childhood Diabetes, Department of Microbiology and Immunology, University of Colorado Health Sciences Center, Denver 80262.
J Clin Lab Immunol. 1989 Apr;28(4):161-8.
Monoclonal antibody (Mab) 1.93B7 was obtained by fusion of spleen cells from a diabetic NOD mouse with P3X63Ag8.653 myeloma cells and screening for complement mediated lysis of rat insulinoma (RIN) cells. Immunofluorescence studies revealed that this Mab binds to RIN cells but not to the rat pituitary tumour line GH3. The binding of Mab 1.93B7 to RIN cells was abolished by trypsin but not by neuraminidase treatment of the cells, suggesting that the antigen recognized is a protein. Mab 1.93B7 bound to approximately 30% of mouse (BALB/c) and rat islet cells which had been subjected to trypsin digestion and incubated as a single cell suspension for 12h to allow reexpression of trypsin sensitive antigens. Since Mab 1.93B7 is potentially pathogenic, as suggested by its reactivity to primary islet cells and its complement fixing capacity, we injected it into BALB/c and NOD mice. Cytotoxic activity against RIN cells was detected in the serum of the animals injected with Mab 1.93B7, but the Mab did not exert a diabetogenic action and failed to reverse diabetes when administered at onset in NOD mice. No modification of the course of spleen cell mediated transfer of diabetes in NOD mice was observed when the Mab was administered from the time of spleen cell inoculation to the appearance of glycosuria. The implications of the lack of an effect in vivo of Mab 1.93B7 under the conditions employed are discussed.
单克隆抗体（Mab）1.93B7是通过将糖尿病NOD小鼠的脾细胞与P3X63Ag8.653骨髓瘤细胞融合，并筛选能介导大鼠胰岛素瘤（RIN）细胞补体溶解的细胞而获得的。免疫荧光研究表明，这种单克隆抗体与RIN细胞结合，但不与大鼠垂体肿瘤细胞系GH3结合。用胰蛋白酶处理细胞可消除Mab 1.93B7与RIN细胞的结合，但用神经氨酸酶处理细胞则不能消除，这表明所识别的抗原是一种蛋白质。Mab 1.93B7与大约30%的小鼠（BALB/c）和大鼠胰岛细胞结合，这些细胞已经过胰蛋白酶消化，并作为单细胞悬液孵育12小时，以使胰蛋白酶敏感抗原重新表达。由于Mab 1.93B7对原代胰岛细胞有反应性且具有补体固定能力，提示其可能具有致病性，我们将其注射到BALB/c和NOD小鼠体内。在注射了Mab 1.93B7的动物血清中检测到了针对RIN细胞的细胞毒性活性，但该单克隆抗体没有产生致糖尿病作用，并且在NOD小鼠发病时给药也未能逆转糖尿病。当从接种脾细胞到出现糖尿期间给予该单克隆抗体时，未观察到NOD小鼠中脾细胞介导的糖尿病转移过程有任何改变。讨论了在所采用的条件下Mab 1.93B7在体内缺乏作用的意义。
