Differences in innate immune responses correlate with differences in murine susceptibility to Chlamydia muridarum pulmonary infection

Immunology. 2010 Apr;129(4):556-66. doi: 10.1111/j.1365-2567.2009.03157.x. Epub 2009 Sep 11.


We investigated the phenotypic basis for genetically determined differences in susceptibility and resistance to Chlamydia muridarum pulmonary infection using BALB/c and C57BL/6 mice. Following C. muridarum intranasal inoculation, the intensity of infection was very different between BALB/c and C57BL/6 beginning as early as 3 days post-infection. Intrapulmonary cytokine patterns also differed at early time-points (days 2 and 4) between these two strains of mice. The early recruitment of neutrophils to lung tissue was greater in BALB/c than in C57BL/6 mice and correlated with a higher number of inclusion forming units (IFU) of C. muridarum. At day 12 post-infection, BALB/c mice continued to demonstrate a greater burden of infection, significantly higher lung cytokine levels for tumour necrosis factor-alpha and interleukin-17 (IL-17) and a significantly lower level for interferon-gamma than did C57BL/6 mice. In vitro, bone-marrow-derived dendritic cells (BMDCs) from BALB/c mice underwent less functional maturation in response to C. muridarum infection than did BMDCs from C57BL/6 mice. The BMDCs of BALB/c mice expressed lower levels of activation markers (CD80, CD86, CD40 and major histocompatibility complex class II) and secreted less IL-12 and more IL-23 than BMDCs from C57BL/6 mice. Overall, the data demonstrate that the differences exhibited by BALB/c and C57BL/6 mice following C. muridarum pulmonary infection are associated with differences in early innate cytokine and cellular responses that are correlated with late differences in T helper type 17 versus type 1 adaptive immune responses.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Chlamydia Infections / immunology*
  • Chlamydia Infections / microbiology
  • Chlamydia muridarum / genetics
  • Chlamydia muridarum / immunology*
  • Cytokines / biosynthesis
  • Cytokines / immunology
  • Disease Models, Animal
  • Disease Susceptibility / immunology
  • Female
  • HeLa Cells
  • Humans
  • Immunity, Innate / immunology*
  • Interleukin-17 / immunology
  • Mice
  • Mice, Inbred BALB C
  • Mice, Inbred C57BL
  • Phenotype
  • Pneumonia, Bacterial / genetics
  • Pneumonia, Bacterial / immunology*
  • T-Lymphocytes, Helper-Inducer / immunology


  • Cytokines
  • Interleukin-17