Krasny S A, Gorzynski E A
Immunopharmacology. 1979 Dec;2(1):1-8. doi: 10.1016/0162-3109(79)90014-6.
Livers, sera, and erythrocytes of MAXX, BN, and Wistar rats were examined for an antigen (CRA) that cross-reacts with enterobacterial common antigen (ECA). Extracts of these tissues were tested for their capacity to reduce anti-ECA titers. By this parameter, CRA was present in certain, although not all, extracts of rat tissue. None of the extracts modified red blood cells (RBC) for agglutination by anti-ECA antisera, nor did MAXX liver extracts engender anti-ECA activity in rabbits. It was speculated that a repressor is present in rat tissue that affects both antigenicity and immunogenicity of CRA. To test this concept, extracts of mixtures of enterobacterial suspensions and liver homogenates were prepared. ECA in the presence of tissue did not modify RBC for anti-ECA activity as did ECA alone, nor did enterobacteria-liver extracts significantly reduce anti-ECA titers. Administration of ethanol-soluble fractions of enterobacteria-liver mixtures to rabbits did not elicit an anti-ECA antibody response as did ECA alone. The finding of CRA in certain rat tissues, sera, and erythrocytes may account, in part, for rats being refractory to immunization with ECA. It is proposed that repressors may mask or abrogate the expression of CRA in animal tissue.
对MAXX、BN和Wistar大鼠的肝脏、血清及红细胞进行检测，寻找一种与肠杆菌共同抗原（ECA）发生交叉反应的抗原（CRA）。检测这些组织提取物降低抗ECA滴度的能力。通过该参数发现，CRA存在于大鼠组织的某些提取物中，但并非全部。没有一种提取物能使红细胞（RBC）被抗ECA抗血清凝集，MAXX肝脏提取物也未在兔体内产生抗ECA活性。据推测，大鼠组织中存在一种抑制因子，它会影响CRA的抗原性和免疫原性。为验证这一概念，制备了肠杆菌悬浮液与肝脏匀浆混合物的提取物。与单独的ECA不同，在有组织存在时，ECA不会改变RBC的抗ECA活性，肠杆菌 - 肝脏提取物也不会显著降低抗ECA滴度。给兔注射肠杆菌 - 肝脏混合物的乙醇可溶部分，不会像单独注射ECA那样引发抗ECA抗体反应。在某些大鼠组织、血清和红细胞中发现CRA，可能部分解释了大鼠对ECA免疫不敏感的原因。有人提出，抑制因子可能会掩盖或消除动物组织中CRA的表达。
