title: Temperature and host cell-dependent changes in virulence of Chlamydia pneumoniae CWL029 in an optimized mouse infection model.
abstract: The obligate intracellular bacterium Chlamydia (C.) pneumoniae causes respiratory infections and is associated with vascular diseases. To elucidate how temperature and host cells used for propagation alter chlamydial virulence, C. pneumoniae CWL0129 (Cpn) was cultured at 35 or 37°C in two different cell lines and then applied to mice. These mice infected with differentially propagated chlamydiae showed differences in clinical score, body weight and inflammatory cytokines in the lung. Our study demonstrates that Cpn cultured at 37°C in hamster fibroblast BHK-21 are able to colonize the mouse lung faster and better, and induce stronger symptoms and cytokine induction than bacteria cultured at 35°C. The temperature-triggered virulence alteration could not be observed for Cpn propagated in HeLa cells and was independent of host cell protein synthesis. Transcriptome analysis did not reveal temperature-induced effects on chlamydial gene expression, suggesting that the observed virulence changes are regulated on a different, so far unknown level. Preculture close to the central body temperature of its warm-blooded human or murine host might 'prepare' Cpn for subsequent in vivo infection. Our identification of culture-dependent virulence alteration helps to establish an optimized mouse lung infection model for Cpn and provides the basis to further unravel the molecular mechanisms underlying chlamydial pathogenicity.
authors: Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School (MHH), Carl-Neuberg-Str. 1, D-30625 Hannover, Germany.
authors: Katrin
authors: K
authors: Janik
authors: Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School (MHH), Carl-Neuberg-Str. 1, D-30625 Hannover, Germany.
authors: Jenny
authors: J
authors: Bode
authors: Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School (MHH), Carl-Neuberg-Str. 1, D-30625 Hannover, Germany.
authors: Pavel
authors: P
authors: Dutow
authors: Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School (MHH), Carl-Neuberg-Str. 1, D-30625 Hannover, Germany.
authors: Robert
authors: R
authors: Laudeley
authors: Genome Analytics, Helmholtz Centre for Infection Research, Inhoffenstraße 7, D-38124 Braunschweig, Germany.
authors: Robert
authors: R
authors: Geffers
authors: Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School (MHH), Carl-Neuberg-Str. 1, D-30625 Hannover, Germany.
authors: Kirsten
authors: K
authors: Sommer
authors: Institute for Laboratory Animal Science, MHH, Carl-Neuberg-Str. 1, D-30625 Hannover, Germany.
authors: Silke
authors: S
authors: Glage
authors: Institute of Medical Microbiology and Hospital Epidemiology, Hannover Medical School (MHH), Carl-Neuberg-Str. 1, D-30625 Hannover, Germany klos.andreas@mh-hannover.de.
authors: Andreas
authors: A
authors: Klos
mesh_terms: D000818:Animals; D001835:Body Weight; D002460:Cell Line; D023521:Chlamydophila Infections / Q000382:microbiology / Q000473:pathology*; D016993:Chlamydophila pneumoniae / Q000254:growth & development*; D006224:Cricetinae; D016207:Cytokines / Q000032:analysis; D004195:Disease Models, Animal; D004847:Epithelial Cells / Q000382:microbiology*; D005347:Fibroblasts / Q000382:microbiology*; D020869:Gene Expression Profiling; D006801:Humans; D008168:Lung / Q000473:pathology; D008297:Male; D008810:Mice, Inbred C57BL; D018410:Pneumonia, Bacterial / Q000382:microbiology / Q000473:pathology*; D012720:Severity of Illness Index; D013696:Temperature; D014774:Virulence
chemical_list: D016207:Cytokines
keywords: animal model; animal study; pathogenicity