Nair T S, Prieskorn D M, Miller J M, Mori A, Gray J, Carey T E
Cell Biology and Immunology Laboratory, Kresge Hearing Research Institute, University of Michigan, Ann Arbor 48109-0506, USA.
Hear Res. 1997 May;107(1-2):93-101. doi: 10.1016/s0378-5955(97)00024-5.
The IgG1 mouse monoclonal antibody (MAb) KHRI-3, binds to an antigen of 65-68 kDa expressed on inner ear supporting cells in guinea pigs. We previously showed [Nair et al. (1995) Monoclonal antibody induced hearing loss. Hear. Res. 83, 101-113] that mice carrying the KHRI-3 hybridoma develop high frequency hearing loss and loss of hair cells in the basal turn suggesting that this MAb causes immune-mediated sensorineural hearing loss. To evaluate the specificity of this effect, sterile KHRI-3 and control IgG1 preparations were infused directly into the guinea pig cochlea using Alzet mini-osmotic pumps. Assessments included: (1) hearing, measured by click auditory brain stem responses (ABRs); (2) in vivo antibody binding; and (3) the structural integrity of the organ of Corti. Nine animals were infused with KHRI-3 preparations and 5 controls were infused with control IgG1. Four guinea pigs given KHRI-3 developed 25-55 dB hearing loss. Control animals showed no difference from baseline. In vivo binding of KHRI-3 was detected in the organ of Corti in 6 of the 9 animals, including all 4 that had hearing loss. No staining was observed with control antibody. Confocal microscopy revealed that the in vivo KHRI-3 antibody binding pattern was identical to that obtained by incubating fixed tissue in vitro with KHRI-3. Histologic examination revealed an increased frequency of hair cell loss in KHRI-3 treated ears when compared to either the contralateral ears of the same guinea pigs or the IgG1 treated ears of control animals. The lesions in the infused ears of guinea pigs were scattered throughout the cochlea from base to apex. These experiments demonstrate the following points: (1) Antibodies can be chronically infused directly into the cochlea of living animals. (2) The KHRI-3 antibody binds to live supporting cells within the organ of Corti. (3) Infusion of an inner ear specific antibody affects auditory function. (4) The infusion of irrelevant antibody had no effect on the structure or function of the ear. This system provides an animal model for further studies of antibody-induced sensorineural hearing loss.
IgG1小鼠单克隆抗体（MAb）KHRI-3与豚鼠内耳支持细胞上表达的一种65 - 68 kDa的抗原结合。我们之前的研究显示[奈尔等人（1995年）。单克隆抗体诱导的听力损失。听觉研究。83，101 - 113]，携带KHRI-3杂交瘤的小鼠出现高频听力损失以及基底转毛细胞缺失，这表明该单克隆抗体导致了免疫介导的感音神经性听力损失。为了评估这种效应的特异性，使用Alzet微型渗透泵将无菌的KHRI-3和对照IgG1制剂直接注入豚鼠耳蜗。评估内容包括：（1）听力，通过短声听觉脑干反应（ABR）测量；（2）体内抗体结合；以及（3）柯蒂氏器的结构完整性。9只动物被注入KHRI-3制剂，5只对照动物被注入对照IgG1。4只接受KHRI-3注射的豚鼠出现了25 - 55 dB的听力损失。对照动物与基线相比无差异。在9只动物中的6只动物的柯蒂氏器中检测到了KHRI-3的体内结合，包括所有4只出现听力损失的动物。对照抗体未观察到染色。共聚焦显微镜显示，体内KHRI-3抗体结合模式与用KHRI-3体外孵育固定组织所获得的模式相同。组织学检查显示，与同一只豚鼠的对侧耳或对照动物接受IgG1治疗的耳相比，接受KHRI-3治疗的耳中毛细胞缺失频率增加。豚鼠注入侧耳的病变从基底到顶端散在于整个耳蜗。这些实验证明了以下几点：（1）抗体可以长期直接注入活体动物的耳蜗。（2）KHRI-3抗体与柯蒂氏器内的活支持细胞结合。（3）注入内耳特异性抗体影响听觉功能。（4）注入无关抗体对耳朵的结构或功能没有影响。该系统为进一步研究抗体诱导的感音神经性听力损失提供了一个动物模型。
