Interaction in Vivo of Homocytotropic Antibodies Belonging to Two Different Rat Immunoglobulin Classes: Effect of IgE on the Passive Cutaneous Anaphylactic Reaction Mediated by IgGa Antibodies

[摘要] Rat anti- Nippostrongylus brasiliensis antiserum was considerably more effective than normal rat serum in inhibiting the passive cutaneous anaphylactic (PCA) reaction mediated by an IgGa anti-dinitrophenyl (DNP) antiserum fraction. The inhibitory activity had the chromatographic, gel filtration and heat lability characteristics of rat IgE. The IgGa fraction, isolated from hyperimmune rat anti-DNP antiserum, devoid of IgE anti-DNP activity, yielded stronger 6-hr PCA reactions than did whole antiserum. The inhibitory activity in whole antiserum was attributed to nonspecific IgE, although the existence of other, minor, inhibitors could not be excluded. Rats repeatedly infected with N. brasiliensis larvae failed to undergo PCA reactions at sites prepared with certain IgGa or IgE antibody-containing fractions; it is presumed that in these animals mast cell receptors are occupied by autologous IgE anti-worm antibodies. These experiments provide in vivo confirmation of the interaction of rat IgE and IgGa antibodies at a common receptor on target cells.

[学科分类] 生物科学（综合）