Resistance to chlamydial lung infection is dependent on major histocompatibility complex as well as non-major histocompatibility complex determinants.
Our previous work has shown that C3H/HeN and C57BL/6 mice have differential susceptibility to Chlamydia trachomatis mouse pneumonitis (C. muridarum) lung infection. C3H/HeN (H-2(k)) mice were found to be highly susceptible to C. muridarum infection with higher mortality and more severe morbidity compared to C57BL/6 (H-2(b)) mice. To examine the role of major histocompatibility complex (MHC) genes on host resistance to chlamydial lung infection, we compared MHC congenic mice, B6.H2k [C57BL/6 background, C3H MHC (H-2(k))] and C3H.H2b [C3H/HeN background, C57BL/6 MHC (H-2(b))] and their corresponding wild type C57BL/6 mice and C3H/HeN mice, respectively, in susceptibility to C. muridarum infection. We found that B6.H2k, C3H.H2b and C3H/HeN mice are more susceptible to chlamydial lung infection compared to the wild type C57BL/6 mice by showing more serious body weight loss, higher in vivo chlamydial growth and more severe pathologic changes. Congenic B6.H2k mice showed significantly lower levels of IL-12 and IFN-gamma production compared to C57BL/6 as well as C3H/HeN and C3H.H2b mice. One the other hand, although congenic C3H.H2b mice displayed similar cytokine response to C57BL/6 mice, they were highly susceptible to C. muridarum infection. Overall, the results suggest that protection against chlamydial lung infection is both MHC and non-MHC gene dependent, and that the interaction between MHC and non-MHC elements may contribute to host resistance to chlamydial infection.
Qiu
Hongyu
H
Department of Medical Microbiology, University of Manitoba, Winnipeg, Canada.
Wang
Shuhe
S
Yang
Jie
J
Fan
Yijun
Y
Joyee
Antony George
AG
Han
Xiaobing
X
Jiao
Lei
L
Yang
Xi
X
D000818:Animals; D002690:Chlamydia Infections / Q000235:genetics* / Q000276:immunology / Q000473:pathology; D023502:Chlamydia muridarum / Q000254:growth & development; D005260:Female; D020022:Genetic Predisposition to Disease; D007371:Interferon-gamma / Q000096:biosynthesis; D016753:Interleukin-10 / Q000096:biosynthesis; D018664:Interleukin-12 / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis; D008285:Major Histocompatibility Complex; D051379:Mice; D008809:Mice, Inbred C3H; D008810:Mice, Inbred C57BL; D018410:Pneumonia, Bacterial / Q000235:genetics* / Q000276:immunology / Q000473:pathology; D013045:Species Specificity; D015431:Weight Loss
D016753:Interleukin-10; D018664:Interleukin-12; D015847:Interleukin-4; D007371:Interferon-gamma