Human Anti-Human-Gammaglobulins, Their Specificity and Function. Genetic Ig Factors and Tolerance

Abstract

The definition of an anti-human-gammaglobulin used here is operational: An anti-human-gammaglobulin is an immunoglobulin capable of interacting directly with human immunoglobulin or an immunoglobulin preparation. The requirement that the antiglobulin itself must be an Ig excludes a number of “factors” or conditions capable of agglutinating Ig-coated red cells, such as various enzymes (which might be present in human plasma) or a number of substances capable of increasing the dielectric constant of the suspension medium (Leikola, 1967). It is known that protein A from strains of Staphylococcus aureus interacts with the Fc fragments of the majority of Ig molecules (see Forsgren, 1968). The requirement that the antiglobulin should interact directly with immunoglobulin excludes immunoglobulins which interact with accessory factors, especially components of the complement system. Conglutinin, immunoconglutinin (see Coombs et al., 1961) and the 11S factor or C_1q (Müller-Eberhard and Kunkel, 1961; Lepow et al., 1963; Ewald and Schubart, 1966; Gewurz et al., 1968) are at present the best-understood examples of this type. It is important to realize that several types of “agents” may agglutinate coated red cells. It has not, in fact, been adequately excluded that some of the “anti-globulins” or “anti-antibodies” which have been described are of the character of those just mentioned.