High-mobility group protein N2 (HMGN2) inhibited the internalization of <italic>Klebsiella pneumoniae</italic> into cultured bladder epithelial cells

Abstract

Since bacterial invasion into host cells is an important step in the infection process, using the agents to interfere with bacterial internalization is an attractive approach to block the infection process. In this work, we describe a new, previously unrecognized role of the human cationic host defense peptide HMGN2 during Klebsiella pneumoniae infections. Our results revealed that the internalization of K. pneumoniae strain 03183 into cultured bladder epithelial cells (T24) was significantly reduced at HMGN2 concentrations that were unable to produce any bacteriostatic or bactericidal effect. Using microarrays and followup studies, we demonstrated that HMGN2 affected the internalization of K. pneumoniae strain 03183 by inhibiting the attachment of bacteria, and then decreasing bacteriainduced ERK1/2 activation and actin polymerization, which might contribute to bacterial internalization into T24 cells. This disruption of bacterial internalization implied that HMGN2 could provide protection against K. pneumoniae infections.

High-mobility group nucleosome-binding domain 2 protein inhibits the invasion of Klebsiella pneumoniae into mouse lungs in vivo

“…In the K. pneumoniae and BSA groups, F-actin expression and stress fibers were increased and the average fluorescence intensity of F-actin was significantly increased as compared with that in the PBS group, which indicated that following infection, polymerized F-actin was enhanced. Of note, in the HMGN2 group, F-actin expression and average fluorescence intensity of F-actin were decreased, which indicated that HMGN2 inhibited K. pneumoniae 03183 invasion of lung cells directly through reducing the polymerization of F-actin, which is consistent with previous studies by our group (24,25).…”

“…Is was able to inhibit the gene expression and replication of hepatic B virus in vitro (22) and also exhibited anti-cancer potency in HeLa cells (23). Further studies by our group demonstrated that pre-treatment of K. pneumoniae 03183 with 128 µg/ml HMGN2 significantly inhibited the internalization of K. pneumoniae 03183 into human bladder carcinoma T24 cells by decreasing K. pneumoniae-induced actin polymerization (24,25).…”

“…indicated that it inhibited the invasion of K. pneumoniae 03183 neither by inhibiting the growth of bacteria nor by inhibiting the physical progress of pre-treatment with protein (24,25).…”

“…Recombinant human HMGN2 was prepared as previously described (24). 1% bovine serum albumin (BSA) was obtained from Thermo Fisher Scientific (Waltham, MA, USA).…”

Subinhibitory Concentrations of Allicin Decrease Uropathogenic Escherichia coli (UPEC) Biofilm Formation, Adhesion Ability, and Swimming Motility

“…Human uroepithelial cells, T24 (ATCC HTB-4), were purchased from the Cell Bank of the Chinese Academic of Science (Shanghai, China) and cultured in RPMI 1640 medium (Hyclone Thermo Scientific, Beijing, China) with 10% fetal bovine serum (FuMeng Gene Co., Ltd., Shanghai, China), 100 U/mL penicillin, and 100 µg/mL streptomycin (Beijing Solarbio Science and Technology Co., Ltd., Beijing, China) at 37 °C in humidified air with 5% CO 2 . Adherence assay was performed according to a previous method [ 37 ]. Briefly, an appropriate number of T24 cells were seeded into a 24-well plate and allowed to grow overnight to 2 × 10 5 cells each well.…”