Fig. 2
MoPn-specific IgG2a and IgG1 responses following chlamydial infection.
Age- and sex-matched interleukin (IL)-18 knockout (KO), IL-12 KO and wild type (WT) mice were intranasally infected with mouse pneumonitis (MoPn) (1 × 104 inclusion forming units (IFU)/mouse). Sera were collected at 10 days postinfection for determination of MoPn-specific immunoglobulin G (IgG)2a and IgG1 using ELISA assays described in “Materials and Methods.” The data are expressed as mean ± standard error of the mean (SEM) of the titers (log10 transformed) of all the sera in the same mouse group (A). The ratio of MoPn-specific IgG2a/IgG1 is shown in (B). *p < 0.05, compared with those in WT and IL-18 KO mice.