Disease and Carrier Isolates of Neisseria meningitidis Cause G ₁ Cell Cycle Arrest in Human Epithelial Cells

Abstract

Microbial pathogens have developed several mechanisms to modulate and interfere with host cell cycle progression. In this study, we analyzed the effect of the human pathogen Neisseria meningitidis on the cell cycle of epithelial cells. Two pathogenic isolates, as well as two carrier isolates, were tested for their ability to adhere to and invade into the epithelial cell lines Detroit 562 and NP69 and to modulate the cell cycle. We found that all isolates adhered equally well to both Detroit 562 and NP69 cells, whereas the carrier isolates were significantly less invasive. Using propidium iodide staining and 5-ethynyl-2=-deoxyuridine pulse-labeling, we provide evidence that meningococcal infection arrested cells in the G 1 phase of the cell cycle at 24 h postinfection. In parallel, a significant decrease of cells in the S phase was observed. Interestingly, G 1 -phase arrest was only induced after infection with live bacteria but not with heat-killed bacteria. By Western blotting we demonstrate that bacterial infection resulted in a decreased protein level of the cell cycle regulator cyclin D1, whereas cyclin E expression levels were increased. Furthermore, N. meningitidis infection induced an accumulation of the cyclin-dependent kinase inhibitor (CKI) p21 WAF1/CIP1 that was accompanied by a redistribution of this CKI to the cell nucleus, as shown by immunofluorescence analysis. Moreover, the p27 CIP1 CKI was redistributed and showed punctate foci in infected cells. In summary, we present data that N. meningitidis can interfere with the processes of host cell cycle regulation.

Anticoagulants impact on innate immune responses and bacterial survival in whole blood models of Neisseria meningitidis infection

“…An overview of the characteristics of the chosen strains is shown in Supplementary Table S1 . We matched two pairs of carriage versus invasive strains which share high genomic homology in this study: MC58 (ST-74, cc32, IMD) versus α522 (ST-35, cc35, carriage) 14 , 33 as well as 8013 (ST-177, cc18, IMD) versus α4 (ST-19, cc18, carriage) 34 .…”

Changes in H3K27ac following lipopolysaccharide stimulation of nasopharyngeal epithelial cells

“…The changes in chromatin following microbial stimuli has been mostly studied in immune cells, most often in mouse macrophages [7, 9, 10]. Here, we studied a human nasopharyngeal epithelial cell line, Detroit 562 cells, used extensively in studying airborne infectious diseases such as infection with Neisseria meningitidis [11], Streptococcus pneumoniae [12] and influenza virus [13] among others. We challenged these cells with Lipopolysaccharide (LPS), a potent gram negative bacterial endotoxin that targets TLR4, and described the changes in H3K27ac mark induced by the stimulation.…”

Rck of Salmonella Typhimurium Delays the Host Cell Cycle to Facilitate Bacterial Invasion

“…For example, the type three secreted effector, cycle inhibiting factor (Cif) expressed by enteropathogenic E. coli , stabilizes CKI p21 and p27, leading to the inhibition the CDK-cyclin complexes inducing arrest of the cell cycle in G1 and G2 phases ( Marchès et al., 2003 ; Samba-Louaka et al., 2008 ; Taieb et al., 2011 ). More recently, it has been pointed out that infection of human epithelial cells with N. meningitidis causes an arrest in the G1-phase mediated by the accumulation of p21 and/or p27 ( von Papen et al., 2016 ). Interestingly, brain endothelial cells infected with N. meningitidis accumulated in the S-phase and this cell cycle regulation was triggered by the Opa protein and the Opc protein, the major invasins of N. meningitidis ( Oosthuysen et al., 2016 ).…”