IgE Antibody Formation and Aging

Abstract

Abstract The IgE, IgG, and IgM antibody responses to DNP-As were assessed in young adult and aged C57BL/6J mice. The primary IgE anti-DNP antibody response was significantly reduced in aged mice; however, the secondary response of 54-week-old mice was comparable to that of young adult mice, although the decline of the antibody level was more rapid in aged mice compared to young adult mice. Multiple booster injections could not restore the depressed immune response of 66-week-old mice to the level of the immune response of young adult mice in terms of IgE antibody responses to DNP-As. The IgE anti-carrier response was considerably lower than the IgE anti-hapten response, and more transient and significantly lower in aged mice than in young adult mice. The avidity of IgE antibody for DNP-determinant was invariably higher in young adult mice than in aged mice. Booster injections increased the avidity of IgE antibody in both groups of mice. Moreover, the hemagglutinating antibody response was also impaired in aged mice, which mounted minute or no amounts of IgG antibody. Upon transfer of the thymocytes from young syngeneic donor mice, the aged mice could restore substantially the IgE and hemagglutinating antibody responses to DNP-As. It became clear in the study of individual mice that the variability of the IgE anti-DNP antibody response increased with advancing age, but the variability within aged mice decreased and deviation from young adult mice was less after the secondary immunization.