Characterization of a monoclonal antibody to cis-urocanic acid: detection of cis-urocanic acid in the serum of irradiated mice by immunoassay.
Characterization of a monoclonal antibody to cis-urocanic acid: detection of cis-urocanic acid in the serum of irradiated mice by immunoassay.
复制标题
顺式尿刊酸单克隆抗体的表征：通过免疫测定法检测受辐射小鼠血清中的顺式尿刊酸。
作者：
A. Moodycliffe;M. Norval;I. Kimber;T. J. Simpson
顺式尿苷酸(cis-UCA)是紫外线(UV)照射下天然生成的反式异构体，被认为是紫外线照射抑制全身免疫反应的光感受器和介体。反式尿酸主要位于角质层，顺式尿酸的异构化程度可以通过皮肤提取物的高效液相分析。这样的分析不适用于其他组织。本研究制备了小鼠抗顺式UCA的单抗，并以蛋白质偶联的UCA异构体为抗原，用EL ISA进行检测。竞争抑制酶联免疫吸附试验检测抗体与UCA结构类似物的相互作用，表明该抗体对顺式UCA具有高度的特异性。用竞争抑制ELISA法对小鼠UVB照射后不同时间的血清进行筛选，结果表明，UVB照射后至少2天内，顺式UCA可能以游离形式存在。因此，紫外线照射后在表皮中产生的顺式尿酸在几小时后到达血清。这一发现对抑制免疫反应的产生的意义进行了讨论。
Cis-urocanic acid (cis-UCA), which is formed from the naturally occurring trans-isomer on ultraviolet (UV) irradiation, has been suggested as a photoreceptor for and mediator of the suppressive effects of UV irradiation on systemic immune responses. Trans-UCA is located predominantly in the stratum corneum, and the extent of isomerization to cis-UCA may be analysed by high-performance liquid chromatography (HPLC) of skin extracts. Such an analysis is not suitable for other tissues. In this study a murine monoclonal antibody to cis-UCA was prepared and tested by ELISA using UCA isomers conjugated to protein as antigens. The interaction of the antibody with structural analogues of UCA was assessed by competitive inhibition ELISA which indicated that the antibody had a high specificity for cis-UCA. Screening of sera at various times after UVB irradiation of mice by competitive inhibition ELISA using the monoclonal antibody showed that cis-UCA was present, probably in an unbound form, for at least 2 days after the exposure. Thus, cis-UCA produced in the epidermis following UVB irradiation reaches the serum a few hours later. The implications of this finding for the generation of suppressed immune responses are discussed.