Suppression of the IgE antibody response by glutaraldehyde-modified ovalbumin: dissociation between loss of antigenic reactivity and ability to induce suppression.

Ovalbumin (OA) was substituted with glutaraldehyde (GA) at various GA:OA ratios and several preparations were isolated by gel filtration according to molecular weight. Two GA-substituted but unpolymerized preparations (OA1-L and OA1-H) and 3 polymerized preparations of increasing molecular weight (OA4, OA175 and OA-POL) were obtained and were assessed for their ability to react with IgG and IgE antibodies directed against the native OA molecule, as well as for their ability to suppress the IgE antibody response. The results show that while both polymerized and unpolymerized GA-modified preparations lost their reactivity towards antinative OA antibodies, to a considerable extent, their ability to suppress the OA/IgE antibody response was directly dependent on polymerization. Pretreatment of CBA mice with unpolymerized OA preparations was ineffective while the effect of pretreatment with three polymers (OA4, OA175 and OA-POL) was directly dependent on the size of the polymer. The ability to induce IgG antibodies or delayed hypersensitivity to OA was not suppressed.