Development of a Novel Nasal Epithelial Cell Model Supporting Colonization With Human Nasal Microbiota.

The nasal mucosa provides first line defense against inhaled pathogens while creating a unique microenvironment for bacterial communities. Studying the impact of microbiota in the nasal cavity has been difficult due to limitations with current models including explant cultures, primary cells, or neoplastic cell lines. Most notably, none have been shown to support reproducible colonization by bacterial communities from human donors.

Combination of Cystatins 9 and C Modulates Serum Biomarkers Associated with Inflammation and Provides Prophylactic as Well as Long-Term Protection against Multidrug-Resistant .

We have identified recombinant human cystatins 9 (rCST9) and C (rCSTC) as a combination immunotherapeutic treatment against multidrug-resistant (MDR) New Delhi metallo-β-lactamase-1 (NDM-1)-producing We evaluated the lasting protection of rCST9/rCSTC treatment against MDR NDM-1 pneumonia. Results showed that rCST9/rCSTC treatment modulated endogenous serum biomarkers, cystatins 9 and C and amyloid A, associated with poor patient outcomes and provided prophylactic and long-term protection in a murine model of pneumonia.

GPR43 mediates microbiota metabolite SCFA regulation of antimicrobial peptide expression in intestinal epithelial cells via activation of mTOR and STAT3.

The antimicrobial peptides (AMP) produced by intestinal epithelial cells (IEC) play crucial roles in the regulation of intestinal homeostasis by controlling microbiota. Gut microbiota has been shown to promote IEC expression of RegIIIγ and certain defensins. However, the mechanisms involved are still not completely understood.

Cystatins 9 and C as a Novel Immunotherapy Treatment That Protects against Multidrug-Resistant New Delhi Metallo-Beta-Lactamase-1-Producing Klebsiella pneumoniae.

Multidrug-resistant (MDR) bacterial pneumonia can induce dysregulated pulmonary and systemic inflammation leading to morbidity and mortality. Antibiotics to treat MDR pathogens do not function to modulate the extent and intensity of inflammation and can have serious side effects. Here we evaluate the efficacy of two human cysteine proteinase inhibitors, cystatin 9 (CST9) and cystatin C (CSTC), as a novel immunotherapeutic treatment to combat MDR New Delhi metallo-beta-lactamase-1 (NDM-1)-producing Our results showed that mice infected intranasally (i.

Correction: Intraluminal Flagellin Differentially Contributes to Gut Dysbiosis and Systemic Inflammation following Burn Injury.

[This corrects the article DOI: 10.1371/journal.pone.

Intraluminal Flagellin Differentially Contributes to Gut Dysbiosis and Systemic Inflammation following Burn Injury.

Burn injury is associated with a loss of gut barrier function, resulting in systemic dissemination of gut-derived bacteria and their products. The bacterial protein and TLR5 agonist, flagellin, induces non-specific innate immune responses. Because we detected flagellin in the serum of burn patients, we investigated whether gut-derived flagellin was a primary or secondary contributor to intestinal dysfunction and systemic inflammation following burn injury.

M-Cells Contribute to the Entry of an Oral Vaccine but Are Not Essential for the Subsequent Induction of Protective Immunity against Francisella tularensis.

M-cells (microfold cells) are thought to be a primary conduit of intestinal antigen trafficking. Using an established neutralizing anti-RANKL (Receptor Activator of NF-κB Ligand) antibody treatment to transiently deplete M-cells in vivo, we sought to determine whether intestinal M-cells were required for the effective induction of protective immunity following oral vaccination with ΔiglB (a defined live attenuated Francisella novicida mutant). M-cell depleted, ΔiglB-vaccinated mice exhibited increased (but not significant) morbidity and mortality following a subsequent homotypic or heterotypic pulmonary F.

Cultivated vaginal microbiomes alter HIV-1 infection and antiretroviral efficacy in colonized epithelial multilayer cultures.

There is a pressing need for modeling of the symbiotic and at times dysbiotic relationship established between bacterial microbiomes and human mucosal surfaces. In particular clinical studies have indicated that the complex vaginal microbiome (VMB) contributes to the protection against sexually-transmitted pathogens including the life-threatening human immunodeficiency virus (HIV-1). The human microbiome project has substantially increased our understanding of the complex bacterial communities in the vagina however, as is the case for most microbiomes, very few of the community member species have been successfully cultivated in the laboratory limiting the types of studies that can be completed.

Immunomodulatory and antibacterial effects of cystatin 9 against Francisella tularensis.

Cystatin 9 (CST9) is a member of the type 2 cysteine protease inhibitor family, which has been shown to have immunomodulatory effects that restrain inflammation, but its functions against bacterial infections are unknown. Here, we report that purified human recombinant (r)CST9 protects against the deadly bacterium Francisella tularensis (Ft) in vitro and in vivo. Macrophages infected with the Ft human pathogen Schu 4 (S4), then given 50 pg of rCST9 exhibited significantly decreased intracellular bacterial replication and increased killing via preventing the escape of S4 from the phagosome.

Burkholderia mallei and Burkholderia pseudomallei stimulate differential inflammatory responses from human alveolar type II cells (ATII) and macrophages.

Alveolar type II pneumocytes (ATII) and alveolar macrophages (AM) play a crucial role in the lung's innate immune response. Burkholderia pseudomallei (BP) and Burkholderia mallei (BM) are facultative Gram-negative bacilli that cause melioidosis and glanders, respectively. The inhalation of these pathogens can cause lethal disease and death in humans.

Commensal bacteria modulate innate immune responses of vaginal epithelial cell multilayer cultures.

The human vaginal microbiome plays a critical but poorly defined role in reproductive health. Vaginal microbiome alterations are associated with increased susceptibility to sexually-transmitted infections (STI) possibly due to related changes in innate defense responses from epithelial cells. Study of the impact of commensal bacteria on the vaginal mucosal surface has been hindered by current vaginal epithelial cell (VEC) culture systems that lack an appropriate interface between the apical surface of stratified squamous epithelium and the air-filled vaginal lumen.

Luminal-applied flagellin is internalized by polarized intestinal epithelial cells and elicits immune responses via the TLR5 dependent mechanism.

Bacteria release flagellin that elicits innate responses via Toll-like receptor 5 (TLR5). Here, we investigated the fate of apically administrated full length flagellin from virulent and avirulent bacteria, along with truncated recombinant flagellin proteins in intestinal epithelial cells and cellular responses. Flagellin was internalized by intestinal epithelial cell (IEC) monolayers of IEC-18.

Protection Afforded by Fluoroquinolones in Animal Models of Respiratory Infections with Bacillus anthracis, Yersinia pestis, and Francisella tularensis.

Successful treatment of inhalation anthrax, pneumonic plague and tularemia can be achieved with fluoroquinolone antibiotics, such as ciprofloxacin and levofloxacin, and initiation of treatment is most effective when administered as soon as possible following exposure. Bacillus anthracis Ames, Yersinia pestis CO92, and Francisella tularensis SCHU S4 have equivalent susceptibility in vitro to ciprofloxacin and levofloxacin (minimal inhibitory concentration is 0.03 μg/ml); however, limited information is available regarding in vivo susceptibility of these infectious agents to the fluoroquinolone antibiotics in small animal models.

Toll-like receptor 3 agonist protection against experimental Francisella tularensis respiratory tract infection.

We investigated whether Toll-like receptor 3 (TLR3) stimulation would protect the host from inhaled Francisella tularensis. TLR3 is expressed by respiratory epithelial cells and macrophages and can be activated by a synthetic double-stranded RNA ligand called polyinosine-polycytosine [poly(I:C)]. Thus, we evaluated poly(I:C) as a novel treatment against inhaled F.

Levofloxacin rescues mice from lethal intra-nasal infections with virulent Francisella tularensis and induces immunity and production of protective antibody.

The ability to protect mice against respiratory infections with virulent Francisella tularensis has been problematic and the role of antibody-versus-cell-mediated immunity controversial. In this study, we tested the hypothesis that protective immunity can develop in mice that were given antibiotic therapy following infection via the respiratory tract with F. tularensis SCHU S4.

Effects of flagellin on the functions of follicle-associated epithelium.

Bacterial flagellin activates innate immune responses by signaling through Toll-like receptor 5 and is a potential vaccine adjuvant. Mucosal lymphoid follicles, inductive sites for adaptive mucosal immune responses, are covered by a follicle-associated epithelium (FAE) specialized for the uptake of antigens. This study demonstrates that mucosal application of Salmonella dublin flagellin enhanced transepithelial transport of microparticles by the FAE of mouse Peyer's patches in vivo.

Escherichia coli isolated from a Crohn's disease patient adheres, invades, and induces inflammatory responses in polarized intestinal epithelial cells.

Inflammatory diseases of the intestinal tract are a major health concern both in the United States and around the world. Evidence now suggests that a new category of Escherichia coli, designated Adherent Invasive E. coli (AIEC) is highly prevalent in Crohn's Disease (CD) patients.

Role of primary human alveolar epithelial cells in host defense against Francisella tularensis infection.

Francisella tularensis, an intracellular pathogen, is highly virulent when inhaled. Alveolar epithelial type I (ATI) and type II (ATII) cells line the majority of the alveolar surface and respond to inhaled pathogenic bacteria via cytokine secretion. We hypothesized that these cells contribute to the lung innate immune response to F.

Critical role for serum opsonins and complement receptors CR3 (CD11b/CD18) and CR4 (CD11c/CD18) in phagocytosis of Francisella tularensis by human dendritic cells (DC): uptake of Francisella leads to activation of immature DC and intracellular survival of the bacteria.

Francisella tularensis is one of the most infectious human pathogens known. Although much has been learned about the immune response of mice using an attenuated live vaccine strain (LVS) derived from F. tularensis subspecies holarctica (Type B), little is known about the responses of human monocyte-derived immature dendritic cells (DC).

Outer membrane protein A of Escherichia coli O157:H7 stimulates dendritic cell activation.

Outer membrane protein A (OmpA) is located in the membrane of Escherichia coli and other gram-negative bacteria and plays a multifunctional role in bacterial physiology and pathogenesis. In enterohemorrhagic E. coli (EHEC), especially serotype O157:H7, OmpA interacts with cultured human intestinal cells and likely acts as an important component to stimulate the immune response during infection.

Heat shock inhibits activation of NF-kappaB in the absence of heat shock factor-1.

The heat shock response is known to inhibit NF-kappaB activation and NF-kappaB-dependent gene expression. Herein we determined if cells lacking heat shock factor-1 (HSF-1), the major transcription factor regulating heat shock protein gene expression, have an altered ability to modulate NF-kappaB activation. Embryonic fibroblasts from HSF-1-null mutant mice (HSF-1-/- cells) had a drastically reduced ability to express heat shock protein-70 in response to heat shock, compared to embryonic fibroblasts from wild-type mice (HSF+/+ cells).