Coxsackievirus and adenovirus receptor (CAR) binds immunoglobulins
Coxsackievirus and adenovirus receptor (CAR) binds immunoglobulins
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DOI：
10.1021/bi015571y
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发表时间：
2001-12-04
期刊：
影响因子：
2.9
通讯作者：
Chapman, NM
中科院分区：
文献类型：
--
作者：
Carson, SD;Chapman, NM
柯萨奇病毒和腺病毒受体蛋白（CAR）作为B组柯萨奇病毒和大多数腺病毒的细胞表面受体，但该蛋白的生理功能和配体仍有待描述。用CAR的重组胞外结构域（rECAR）构建亲和柱，以通过亲和层析分离潜在的配体。免疫球蛋白G和M一致地从通过柱的人血清中分离，表明CAR可能是免疫球蛋白结合蛋白。进一步的研究表明，亲和纯化的免疫球蛋白结合rECAR包被的免疫测定板，和过氧化物酶标记的rECAR结合的免疫球蛋白的配体覆盖印迹。将过氧化物酶标记的rECAR掺入亲和纯化的免疫球蛋白和兔抗人免疫球蛋白抗体之间形成的免疫沉淀物中，但不掺入小鼠IgG和兔抗小鼠IgG抗体之间形成的免疫沉淀物中。存在于HeLa细胞裂解物中的CAR也与Immobilon膜上的亲和纯化的免疫球蛋白结合，表明该缔合不限于重组蛋白。这些结果表明CAR结合血清中存在的IgG和IgM，并揭示了柯萨奇病毒和腺病毒受体与免疫系统之间的直接相互作用。
The coxsackievirus and adenovirus receptor protein (CAR) serves as the cell surface receptor for group B coxsackieviruses and most adenoviruses, but the physiological function and ligand for this protein remain to be described. An affinity column was constructed with the recombinant extracellular domain of the CAR (rECAR) to isolate potential ligands by affinity chromatography. Immunoglobulins G and M were consistently isolated from human sera passed through the column, suggesting that the CAR may be an immunoglobulin-binding protein. Further investigation revealed that the affinity-purified immunoglobulins bound to rECAR-coated immunoassay plates, and the peroxidase-labeled rECAR bound the immunoglobulins on ligand-overlay blots. The peroxidase-labeled rECAR was incorporated into immunoprecipitates formed between the affinity-purified immunoglobulins and rabbit antibodies against human immunoglobulins, but not into immunoprecipitates formed between mouse IgG and rabbit antibodies against mouse IgG. The CAR present in HeLa cell lysates also bound to the affinity-purified immunoglobulins on Immobilon membranes, showing that the association is not limited to the recombinant protein. These results demonstrate that the CAR binds IgG and IgM present in serum, and reveal a direct interaction between the coxsackievirus and adenovirus receptor and the immune system.