Quantitative Studies of the Immunoglobulin Sequence in the Response of the Rabbit to a Somatic Antigen

Abstract

Employing a sensitive and immunoglobulin-specific assay method based upon antiglobulin augmentation, quantitative and qualitative aspects of the primary and secondary response of the rabbit to Salmonella typhimurium O antigens have been evaluated. These studies examine the validity of the method of assay for detecting and measuring γG- and γM-antibodies produced in response to whole organisms or its lipopolysaccharide. The results show that during the primary response γG-antibodies, not detectable by usual techniques, are produced in a pattern similar to that reported in animals stimulated by other classes of antigens. Moreover, the γG response following reinjection is characteristic of a secondary-type response. In contrast, γM-antibody levels after both primary and secondary stimulation rose equally to levels between 1 and 4 mg/ml. Despite increased sensitivity of detection and quantitative estimates of the actual molar concentration of each immunoglobulin, the minimal interval between γM and γG appearance in serum was not less than 1.5 days. The variable degree of augmentation of agglutination by antiglobulin reagent found during the immune response severely limits the quantitative usefulness of the methods developed. However, the data suggest that qualitative changes in anti-O antibodies interpretable as changes in avidity occur regularly during the immune response.

Natural Antibodies to <i>Salmonella enteritidis </i>Endotoxin in Maternal and Cord Sera and in Sera of Patients with Immunologic Deficiency Diseases

“…These observations confirm previous reports [1,2,3] that the antibody to gram negative endotoxin includes 7S as well as 19S immunoglobu lins both before and after immunization. It is known that the mode of passive transfer of antibodies from the mother to the fetus varies among species of animals.…”

“…Most animals have natural bactericidal antibody against gram negative bacteria reacting with the cell wall lipopolysaccharides, but newborn animals have less of this antibody than adults [4], Natural antibody has generally been considered to be primarily IgM but recently IgG antibody has been found also [1,2,3].…”

The Antibody Response in Rabbits to <i>E. coli</i> O Antigen

“…The existence of immunologic memory for the antibody response to endotoxins has earlier been denied by several authors [i.a. 4,27] but demonstrated by others [1,24].…”

Sequential Changes in the Relative Affinity of Antibodies Synthesized During the Immune Response

“…Gel FCltration of ~tt-Proteins.--In the rabbit, as well as in other species, the immune response to a variety of immunogens is characterized by the production of antibodies of high molecular weight (3,M-immunoglobulins) in the early period after immunization (13)(14)(15)(16)(17)(18)(19)(20)(21)(22). Since the anti-DNP antibodies formed in the first 2 wk after antigen administration were lower in average affinity than the antibodies formed later, it seemed possible that the variation in affinity might be related to a shift in the proportions of ~/M-and ~/G-immunoglobulins.…”