Generation and functional analysis of monoclonal antibodies against the second extracellular loop of human M3 muscarinic acetylcholine receptor
Generation and functional analysis of monoclonal antibodies against the second extracellular loop of human M3 muscarinic acetylcholine receptor
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DOI：
10.3109/s10165-011-0514-8
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发表时间：
2012-04
影响因子：
2.2
通讯作者：
H. Tsuboi;Yumi Nakamura;M. Iizuka;N. Matsuo;I. Matsumoto;T. Sumida
中科院分区：
文献类型：
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作者：
H. Tsuboi;Yumi Nakamura;M. Iizuka;N. Matsuo;I. Matsumoto;T. Sumida
M3乙酰胆碱受体(M3R)在唾液腺和泪腺的激活中起着至关重要的作用。M3R包含四个胞外域(N-末端以及第一、第二和第三个胞外环)，我们最近在Sjögren综合征(SS)患者的一个亚组中检测到针对这四个域中每一个的抗体。功能分析表明，这种抗M3R抗体对唾液分泌的影响可能根据它们结合的表位而有所不同。为了阐明M3R上的B细胞表位与其功能的关系，我们用人唾液腺细胞系HSG，制备了两株产生抗M3R第二细胞外环的单抗的杂交瘤细胞株，并用钙离子内流实验分析了它们的功能。这两种抗M3R2单抗均能抑制西维米林刺激HSG细胞内的钙离子内流，提示抗M3R第二细胞外环的自身抗体可能参与了SS患者唾液功能障碍的发生。
The M3 muscarinic acetylcholine receptor (M3R) plays a crucial role in the activation of salivary and lachrymal glands. The M3R contains four extracellular domains (the N-terminal, and the first, second, and third extracellular loops), and we recently detected antibodies against each of these four domains in a subgroup of patients with Sjögren’s syndrome (SS). Functional analysis indicated that the influence of such anti-M3R antibodies on salivary secretion might differ based on the epitopes to which they bind. To clarify the relationship between B-cell epitopes on the M3R and its function, we generated two hybridomas producing anti-M3R monoclonal antibodies against the second extracellular loop of M3R (anti-M3R2nd mAbs) and analyzed their function by Ca2+-influx assays, using a human salivary gland (HSG) cell line. These two anti-M3R2nd mAbs suppressed Ca2+-influx in the HSG cells induced by cevimeline stimulation, suggesting that autoantibodies against the second extracellular loop of M3R could be involved in salivary dysfunction in patients with SS.