Phipps R P, Mitchell G F, Mandel T E, Tew J G
Immunology. 1980 Jul;40(3):459-66.
Antibody isotypes vary in their capacity to mediate retention of a readily catabolized protein antigen, human serum albumin (HSA) in spleen, popliteal lymph node (PLN) and hind foot. Hyperimmune anti-HSA mouse sera were separated into fractions highly enriched for IgM, IgG1 and IgG2 via differential elution from protein A-Sepharose. These fractions were used to immunize normal mice passively. Twenty-four hours later the mice were injected with radio-iodinated HSA into the hind footpad. When the amount of HSA retained in the spleen 6 days later was determined, the potency of various antibody fractions to mediate retention could be ranked IgG2=IgG1 > IgM. The amount of HSA retention mediated by various fractions correlated well with autoradiographic evidence demonstrating localization of HSA in splenic follicles. The localization pattern in PLN was similar to the spleen except that the IgM-containing fraction mediated follicular localization of HSA to a considerable degree. In tendons of the hind foot, IgG1 mediated HSA retention five times better than IgG2 or IgM fractions. The amount of radioactivity found in the liver varied inversely with HSA retention in other locations. The results demonstrate differences in antibody isotype requirements for antigen localization in spleen, regional lymph node and collagenous sites of the hind foot.
抗体同种型在介导一种易于分解代谢的蛋白质抗原——人血清白蛋白（HSA）在脾脏、腘淋巴结（PLN）和后足中潴留的能力方面存在差异。通过从蛋白A-琼脂糖上进行差异洗脱，将超免疫抗HSA小鼠血清分离成高度富集IgM、IgG1和IgG2的组分。这些组分用于被动免疫正常小鼠。24小时后，将放射性碘化的HSA注射到小鼠后足垫中。当测定6天后脾脏中潴留的HSA量时，各种抗体组分介导潴留的效力可排序为IgG2 = IgG1 > IgM。各种组分介导的HSA潴留量与放射自显影证据密切相关，该证据表明HSA在脾滤泡中的定位。PLN中的定位模式与脾脏相似，只是含IgM的组分在很大程度上介导了HSA在滤泡中的定位。在后足的肌腱中，IgG1介导HSA潴留的能力比IgG2或IgM组分强五倍。肝脏中发现的放射性量与其他部位的HSA潴留量呈反比。结果表明，在脾脏、局部淋巴结和后足胶原部位，抗原定位对抗体同种型的要求存在差异。
