Eisenberg R A, Winfield J B, Cohen P L
J Immunol. 1982 Nov;129(5):2146-9.
The subclass distribution of anti-Sm antibodies in the serum of MRL/Mp-Ipr/Ipr and MRL/Mp- +/+ mice was investigated with a sensitive ELISA technique. In both strains, but particularly in the Ipr mice, anti-Sm antibodies were predominantly of the IgG2a isotype. This preponderance was not an artifact of the sensitivity or specificity of the subclass-specific anti-Sm ELISA, nor did it reflect the subclass distribution of total serum IgG. A plaque-forming cell assay for anti-Sm antibodies also showed a predominance of the IgG2a isotype, indicating that the serum findings could not be explained by differential catabolism of IgG subclasses. Finally, antibodies to double-stranded DNA, as detected by the Crithidia luciliae assay, did not show a restricted subclass distribution. The isotype expression of anti-Sm antibodies in MRL mice must reflect in vivo mechanisms regulating the production of these autoantibodies. The IgG2a restriction in particular suggests an important in vivo role for T cells.
采用灵敏的酶联免疫吸附测定（ELISA）技术，研究了MRL/Mp-Ipr/Ipr和MRL/Mp- +/+小鼠血清中抗Sm抗体的亚类分布。在这两种品系中，尤其是在Ipr小鼠中，抗Sm抗体主要为IgG2a同种型。这种优势并非亚类特异性抗Sm ELISA敏感性或特异性的人为结果，也不反映总血清IgG的亚类分布。抗Sm抗体的空斑形成细胞试验也显示IgG2a同种型占优势，表明血清结果不能用IgG亚类的不同分解代谢来解释。最后，通过利什曼原虫检测的抗双链DNA抗体未显示出受限的亚类分布。MRL小鼠中抗Sm抗体的同种型表达必定反映了调节这些自身抗体产生的体内机制。特别是IgG2a的限制表明T细胞在体内具有重要作用。
