Cytokine mRNA expression in pneumococcal carriage, pneumonia, and sepsis in young mice.
We studied cytokine mRNA expression in Streptococcus pneumoniae carriage, pneumonia, and sepsis in 3-week-old, inbred C57BL/6 and BALB/c mice. Mice were inoculated intranasally with S. pneumoniae serotype 6B, 14, or 3. Survival, bacterial load in the nasopharynx (NP) and lungs, and mRNA levels of tumor necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta, interleukin (IL)-10, and IL-12 in the spleen were analyzed. No baseline mRNA expression levels were found, except for TNF-alpha in C57BL/6 mice. Serotype 6B caused NP colonization only, a significant (P<.05) increase in the levels of TNF-alpha, and induction of TGF-beta and IL-12 mRNA. Serotype 14 caused NP and nonlethal lung colonization and induction of TGF-beta, IL-10, and IL-12. Serotype 3 caused NP colonization, pneumonia, 35% mortality, and no alteration in the mRNA expression of tested cytokines. Although activation of the immune system culminated in nonlethal disease, evasion of the immune system was associated with detrimental disease.
Ling
Eduard
E
Department of Microbiology and Immunology and Pediatric Infectious Disease Unit, Soroka Medical Center, Faculty of Health Sciences, Ben Gurion University of the Negev, Beer Sheva, Israel.
Feldman
Galia
G
Dagan
Ron
R
Mizrachi-Nebenzahl
Yaffa
Y
D000818:Animals; D016470:Bacteremia / Q000276:immunology*; D002353:Carrier State / Q000276:immunology*; D016207:Cytokines / Q000235:genetics*; D018664:Interleukin-12 / Q000235:genetics; D008168:Lung / Q000382:microbiology; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D009305:Nasopharynx / Q000382:microbiology; D011018:Pneumonia, Pneumococcal / Q000276:immunology*; D012333:RNA, Messenger / Q000032:analysis*; D016212:Transforming Growth Factor beta / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics
D016207:Cytokines; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D014409:Tumor Necrosis Factor-alpha; D018664:Interleukin-12