Flotillin-1 (Reggie-2) contributes to Chlamydia pneumoniae growth and is associated with bacterial inclusion.
Chlamydiae are obligate intracellular pathogens replicating only inside the eukaryotic host. Here, we studied the effect of human flotillin-1 protein on Chlamydia pneumoniae growth in human line (HL) and A549 epithelial cell lines. RNA interference was applied to disrupt flotillin-1-mediated endocytosis. Host-associated bacteria were detected by quantitative PCR, and C. pneumoniae growth was evaluated by inclusion counts. C. pneumoniae attachment to host cells was unaffected, but bacterial intracellular growth was attenuated in the flotillin-1-silenced cells. By using confocal microscopy, we detected flotillin-1 colocalized with the inclusion membrane protein A (IncA) in the C. pneumoniae inclusion membranes. In addition, flotillin-1 was associated with IncA in detergent-resistant membrane microdomains (DRMs) in biochemical fractioning. These results suggest that flotillin-1 localizes to the C. pneumoniae inclusion membrane and plays an important role for intracellular growth of C. pneumoniae.
Centre for Biotechnology, and Institute of Biomedicine, Faculty of Medicine, University of Turku, Turku, Finland.
Juha T
JT
Korhonen
Mirja
M
Puolakkainen
Reetta
R
Häivälä
Tuula
T
Penttilä
Anu
A
Haveri
Eveliina
E
Markkula
Riitta
R
Lahesmaa
D058491:Bacterial Load; D001426:Bacterial Proteins / Q000032:analysis; D002460:Cell Line; D016993:Chlamydophila pneumoniae / Q000254:growth & development / Q000472:pathogenicity*; D004705:Endocytosis; D004847:Epithelial Cells / Q000382:microbiology; D020868:Gene Silencing; D054884:Host-Pathogen Interactions; D006801:Humans; D002479:Inclusion Bodies / Q000382:microbiology*; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D018613:Microscopy, Confocal; D010750:Phosphoproteins / Q000032:analysis; D034622:RNA Interference
D001426:Bacterial Proteins; C094163:IncA protein, bacteria; D008565:Membrane Proteins; D010750:Phosphoproteins; C106354:flotillins