Fig. 1

Lung clearance and body weight changes after intranasal chlamydial infection.

Three to four age- and sex-matched interleukin (IL)-18 knockout (KO), IL-12 KO and wild type (WT) mice were intranasally infected with 10⁴ inclusion forming units (IFU) of C. trachomatis mouse pneumonitis (MoPn) biovar and monitored daily for body weight changes. The mice were sacrificed at 10 days postinfection and the lung homogenates were analyzed for in vivo chlamydia growth as described in “Materials and Methods.” The data represent the mean ± standard error of the mean (SEM) of the percentages of body weight loss (A) or chlamydial IFU (log10) per lung (B) from one of three separated experiments with similar results. *p < 0.05 or **p < 0.01, compared with those in WT mice.