IgE Response to Bordetella pertussis Components

[摘要] Pertussis vaccine and pertussis toxin (PT) are well known as IgE adjuvants for a variety of protein antigens. However, there is very little information on whether PT acts as an IgE adjuvant for the antigens of B. pertussis itself, as studied in this investigation. Initial experiments with ovalbumin (0a) showed that an anti-0a IgE response in mice was produced after both one-dose and three-dose immunization schedules, with PT as adjuvant for the first doses only. The one-dose schedule involved injected 0a and bioactive PT as adjuvant on day 0, then bleeding on day 10, 21 or 28. The sera in the one-dose immunization were IgE-positive only when tested individually, and became unreactive when pooled. The mice, in this instance, thus acted as high or low responders for IgE production. The optimal concentration of PT in this one-dose sheme was I mug per mouse. This adjuvant dose of PT was kept constant in subsequent experiments with the three-dose immunization schedule A persistent boosterabie IgE response was detected with a three-dose immunization schedule, which involved injecting antigen (Ag) and adjuvant (Adj) on Day 0, then boosting on days 28 and 56, with Ag alone, and bleeding on day 63 The sera, when pooled, contained a high IgE titre but only from mice given the 0.1 mug and 1 mug 0a immunization doses. These titrations for anti-0a IgE were done by passive cutaneous anaphylaxis (PCA) test and by ELISA. The PCA test, with anti-0a IgE. was optimal with a two-day sensitization interval after the intracutaneous injection of the serum and with a challenge dose of 1 mg of antigen with Evans blue. The usual 30 min heating at 56

[发布机构] University:University of Glasgow

[关键词] Microbiology, Immunology