IgA attenuates anaphylaxis and subsequent immune responses in mice: possible application of IgA to vaccines

Administration of the influenza vaccination to patients with an egg allergy is major health concern. Contaminating egg antigens occasionally induce severe anaphylactic shock in these patients following administration of the vaccination; therefore, the development of a safer vaccination is needed. In the present study, we investigated whether a mixture of four newly and previously generated anti-ovalbumin (OVA) IgA monoclonal antibodies (mAbs) could inhibit both anaphylactic shock upon a subcutaneous OVA challenge and subsequent further sensitization against OVA in passively anti-OVA IgE-sensitized mice and actively sensitized mice with an injection of OVA. The prevention of anaphylaxis by anti-OVA IgA mAbs was suggested to be mediated through the inhibition of OVA binding to allergenic antibodies such as anti-OVA IgE on mast cells and deceleration of the rate of OVA penetration from the injected site into the systemic circulation. Anti-OVA IgA mAbs inhibited further sensitization against OVA in mice actively sensitized with OVA, but did not affect sensitization against the unrelated antigen, phosphorylcholine-keyhole limpet hemocyanin co-injected with OVA. Our findings indicate that adding the anti-egg antigen IgA to the influenza vaccine should reduce not only the risk of inducing anaphylactic shock, but also undesired further sensitization against egg antigens following the vaccination without affecting the intended beneficial effect of the vaccine, namely the upregulation of immune responses to influenza viruses.