FIG 3.

Early proinflammatory cytokines and colonization of the lungs are MyD88 dependent. Groups of 5 C57BL/6 (filled bars) or Myd88^−/− (open bars) mice were challenged by intranasal infection with 2,000 CFU of Y. pestis CO92. (A to D) After 18 h of infection, the mice were euthanized, and lungs were collected for cytokine and CFU analyses: IL-6 (A), IFN-γ (B), KC (C), and CFU (D). (E) Representation of mouse colonization from panel D data. Data were collected in 2 independent trials; n = 10. Bars represent standard errors. Combined data were analyzed by an unpaired t test (A to C), the Mann-Whitney test (D), or the chi-square test (E). *, P < 0.05; **, P < 0.01; NS, not significant.