IL6 and infection: To evaluate whether the clinical outcome of mice assigned to the different coinfection conditions would be associated with changes in cytokine production compared to single infections, we measured the levels of IFN-γ, IL-1α, IL-1β, IL-6, IL-10, and TNF-α in lung homogenates by magnetic microbead immunoassays on day 4 after the last infection (Fig. 6).