Fig. 2.
Total anti-influenza serum IgG and isotype profiles after intranasal prime and boost. (A) Serum IgG titers. (B) Serum IgG1 and IgG2a isotypes. (C) Serum IgG2b titers; (D) serum IgG3 titers; (E) Serum IgM titers; (F) Serum IgA titers; Sera were collected at 2 weeks after each immunization; IgG, IgG isotypes and IgM were determined with quantitative ELISA and expressed as ng/ml. IgA titers were recorded as O.D. values at 450 nm. PR8, inactivated influenza virus alone; PR8+mFliC, inactivated virus plus 10 μg monomeric recombinant flagellin (mFliC); PR8+pFlag, inactivated virus plus 1 μg polymeric flagellin (pFlag); mFliC, 10 μg monomeric recombinant flagellin; pFlag, 1 μg polymeric flagellin. The results are the average of two independent experiments. Bars represent averages and standard errors from six mice per group.