HARBOE M, RAU B, AHO K
J Exp Med. 1965 Apr 1;121(4):503-19. doi: 10.1084/jem.121.4.503.
The serological and physicochemical properties of the following three forms of human anti-gamma-globulin factors were compared: (a) rheumatoid factors; (b) Milgrom type anti-gamma-globulin factors; and (c) factors directed against an antigen in human gammaG-globulin that is hidden in the intact molecule and revealed by enzymatic digestion at low pH. The property common to these factors is ability to interact with human gammaG-globulin; they are distinguishable because they react with different antigenic groups on this molecule. In all of five sera, the Milgrom type anti-gamma-globulin factors were gammaM-globulins. They reacted with various human gammaG-globulin antibodies but failed to interact with gammaM-globulin type antibodies in agglutination and absorption experiments. When isolated from other anti-gamma-globulin factors, they agglutinated red cells coated with intact anti-Rh antibodies, but failed to react with cells cells coated with pepsin-digested anti-Rh antibody. These observations indicate that the agglutinator reacts with the crystallizable, inert fragment of gammaG-globulin. Anti-gamma-globulin activity directed against an antigen in human gammaG-globulin revealed by pepsin digestion was demonstrated in gammaG-, gammaA-, and gammaM-globulins. This anti-gamma-globulin factor could be absorbed by antigen-antibody precipitates containing human antibody, which shows that the hidden antigen in human gammaG-globulin is revealed not only by enzymatic digestion at low pH, but also when gammaG-globulin is present as antibody in an antigen-antibody precipitate. Rheumatoid factors and Milgrom type anti-gamma-globulin factors were also absorbed by antigen-antibody precipitates containing human antibody. The results indicate that the three distinct forms of antigamma-globulin factors may all be produced as a result of antigenic stimulation by autologous antigen-antibody complexes.
对以下三种形式的人抗γ球蛋白因子的血清学和物理化学性质进行了比较：(a)类风湿因子；(b)米尔格罗姆型抗γ球蛋白因子；(c)针对人γG球蛋白中一种抗原的因子，该抗原隐藏在完整分子中，在低pH值下经酶消化后暴露。这些因子的共同特性是能够与人γG球蛋白相互作用；它们是可区分的，因为它们与该分子上不同的抗原基团发生反应。在所有五份血清中，米尔格罗姆型抗γ球蛋白因子均为γM球蛋白。它们与各种人γG球蛋白抗体发生反应，但在凝集和吸收实验中未能与γM球蛋白型抗体相互作用。当从其他抗γ球蛋白因子中分离出来时，它们能凝集包被完整抗Rh抗体的红细胞，但不能与包被胃蛋白酶消化的抗Rh抗体的细胞发生反应。这些观察结果表明，凝集剂与γG球蛋白的可结晶惰性片段发生反应。在γG、γA和γM球蛋白中均证明了针对经胃蛋白酶消化后暴露的人γG球蛋白中一种抗原的抗γ球蛋白活性。这种抗γ球蛋白因子可被含有人抗体的抗原-抗体沉淀物吸收，这表明人γG球蛋白中的隐藏抗原不仅在低pH值下经酶消化后暴露，而且当γG球蛋白作为抗体存在于抗原-抗体沉淀物中时也会暴露。类风湿因子和米尔格罗姆型抗γ球蛋白因子也可被含有人抗体的抗原-抗体沉淀物吸收。结果表明，这三种不同形式的抗γ球蛋白因子可能都是由自体抗原-抗体复合物的抗原刺激产生的。
