Bacillus megaterium SF185 induces stress pathways and affects the cell cycle distribution of human intestinal epithelial cells.
The interaction between the enteric microbiota and intestinal cells often involves signal molecules that affect both microbial behaviour and host responses. Examples of such signal molecules are the molecules secreted by bacteria that induce quorum sensing mechanisms in the producing microorganism and signal transduction pathways in the host cells. The pentapeptide competence and sporulation factor (CSF) of Bacillus subtilis is a well characterized quorum sensing factor that controls competence and spore formation in the producing bacterium and induces cytoprotective heat shock proteins in intestinal epithelial cells. We analysed several Bacillus strains isolated from human ileal biopsies of healthy volunteers and observed that some of them were unable to produce CSF but still able to act in a CSF-like fashion on model intestinal epithelial cells. One of those strains belonging to the Bacillus megaterium species secreted at least two factors with effects on intestinal HT29 cells: a peptide smaller than 3 kDa able to induce heat shock protein 27 (hsp27) and p38-MAPK, and a larger molecule able to induce protein kinase B (PKB/Akt) with a pro-proliferative effect.
1 Department of Biology, Complesso Universitario di Monte Sant'Angelo Federico II University, via Cinthia, 80126 Napoli, Italy;
B
B
Di Luccia
1 Department of Biology, Complesso Universitario di Monte Sant'Angelo Federico II University, via Cinthia, 80126 Napoli, Italy;
E
E
D'Apuzzo
1 Department of Biology, Complesso Universitario di Monte Sant'Angelo Federico II University, via Cinthia, 80126 Napoli, Italy;
F
F
Varriale
1 Department of Biology, Complesso Universitario di Monte Sant'Angelo Federico II University, via Cinthia, 80126 Napoli, Italy;
L
L
Baccigalupi
1 Department of Biology, Complesso Universitario di Monte Sant'Angelo Federico II University, via Cinthia, 80126 Napoli, Italy;
E
E
Ricca
1 Department of Biology, Complesso Universitario di Monte Sant'Angelo Federico II University, via Cinthia, 80126 Napoli, Italy;
A
A
Pollice
D001410:Bacillus megaterium / Q000145:classification / Q000302:isolation & purification / Q000502:physiology*; D001426:Bacterial Proteins / Q000378:metabolism / Q000627:therapeutic use; D018938:Caco-2 Cells; D002453:Cell Cycle; D045744:Cell Line, Tumor; D003470:Culture Media; D004847:Epithelial Cells / Q000166:cytology / Q000382:microbiology*; D055551:HSP27 Heat-Shock Proteins / Q000378:metabolism; D019073:HT29 Cells; D006801:Humans; D053038:Quorum Sensing; D012097:Repressor Proteins / Q000378:metabolism / Q000627:therapeutic use; D015398:Signal Transduction; D013312:Stress, Physiological
D001426:Bacterial Proteins; D003470:Culture Media; D055551:HSP27 Heat-Shock Proteins; C101115:PhrC protein, Bacillus subtilis; D012097:Repressor Proteins
Bacillus; CSF; HT29 cells; quorum sensing; signal molecules