Han S H, Chang Z N, Chang H H, Chi C W, Wang J Y, Lin C Y
Institute of Microbiology and Immunology, National Yang-Ming Medical College, Taipei, Taiwan, Republic of China.
J Allergy Clin Immunol. 1993 May;91(5):1035-41. doi: 10.1016/0091-6749(93)90217-4.
We identified three epitopes on Cyn d I by using four anti-Cyn d I monoclonal antibodies (MoAbs).
In a cross-inhibition binding assay, the binding of MoAbs 1-61 and 10-7 to Cyn d I was completely blocked by each other but not by MoAbs 4-37 and 11-7; the binding of MoAb 4-37 and MoAb 11-7 to Cyn d I was inhibited by themselves but not by other MoAbs. The epitope recognized by MoAbs 1-61 and 10-7 is designated as E1, and those recognized by MoAbs 4-37 and 11-7 are designated as E2 and E3, respectively.
In a radioallergosorbent inhibition assay, we found that MoAbs 1-61 and 4-37 (1:50 diluted) can inhibit the binding of human Immunoglobulin Es to Cyn d I by more than 30%, whereas MoAb 11-7 was less efficient (reduced by only 6%). These results suggest that both E1 and E2 are major allergenic epitopes but that E3 is only a minor one. Further characterization of E1 and E2 reveals that they are labile in alkaline but resistant to acid and sodium periodate treatments. Moreover, E1 is heat-labile, but guanidine- and urea-sensitive, whereas E2 is not. Both E1 and E2 lost their antigenicity after reduction and alkylation.
Results of the present study provide important information on the physicochemical properties of major allergenic epitopes on Cyn d I, which may be useful for future development of therapeutic peptides for patients allergic to Bermuda grass pollen.
我们使用四种抗Cyn d I单克隆抗体（MoAbs）鉴定出了Cyn d I上的三个表位。
在交叉抑制结合试验中，单克隆抗体1 - 61和10 - 7与Cyn d I的结合可被彼此完全阻断，但不能被单克隆抗体4 - 37和11 - 7阻断；单克隆抗体4 - 37和单克隆抗体11 - 7与Cyn d I的结合可被自身抑制，但不能被其他单克隆抗体抑制。单克隆抗体1 - 61和10 - 7识别的表位被命名为E1，单克隆抗体4 - 37和11 - 7识别的表位分别被命名为E2和E3。
在放射变应原吸附抑制试验中，我们发现单克隆抗体1 - 61和4 - 37（1:50稀释）可抑制人免疫球蛋白E与Cyn d I的结合达30%以上，而单克隆抗体11 - 7的抑制效果较差（仅降低6%）。这些结果表明E1和E2都是主要的过敏原表位，但E3只是次要表位。对E1和E2的进一步表征显示，它们在碱性条件下不稳定，但对酸和高碘酸钠处理具有抗性。此外，E1对热不稳定，但对胍和尿素敏感，而E2则不然。E1和E2在还原和烷基化后均失去抗原性。
本研究结果提供了关于Cyn d I主要过敏原表位物理化学性质的重要信息，这可能有助于未来开发针对百慕大草花粉过敏患者的治疗性肽。
