Oral Mucosal Barrier Research Articles

Profilin-mediated food-induced allergic reactions are associated with oral epithelial remodeling

In areas of high exposure to grass pollen, allergic patients are frequently sensitized to profilin, and some experience severe profilin-mediated food-induced reactions. This specific population of patients is ideal to study the relationship between respiratory and food allergies. We sought to determine the role of oral mucosal epithelial barrier integrity in profilin-mediated allergic reactions. Thirty-eight patients with profilin allergy stratified into mild or severe according to their clinical history and response to a profilin challenge test and 6 nonallergic subjects were recruited. Oral mucosal biopsies were used for measurement of CD11c, CD3, CD4, tryptase, claudin-1, occludin, E-cadherin, and vascular endothelial growth factor Alevels; Masson trichrome staining; and POSTN, IL33, TPSAB, TPSB, and CMA gene expression analysis by using quantitative RT-PCR. Blood samples were used for basophil activation tests. Distinct features of the group with severe allergy included the following: (1) impaired epithelial integrity with reduced expression of claudin-1, occludin, and E-cadherin and decreased numbers of epithelial cells, which is indicative of acanthosis, higher collagen deposition, and angiogenesis; (2) inflammatory immune response in the mucosa, with an increased number of CD11c+ and CD4+ infiltrates and increased expression of the cytokine genes POSTN and IL33; and (3) a 10-fold increased sensitivity of basophils to profilin. Patients with profilin allergy present with significant damage to the oral mucosal epithelial barrier, which might allow profilin penetration into the oral mucosa and induction of local inflammation. Additionally, severely allergic patients presented with increased sensitivity of effector cells.

Unique Tailoring of Th17 at the Gingival Oral Mucosal Barrier

Our recent work highlights unique requirements for the induction of Th17 cells at the oral/gingival mucosal barrier. Unlike other barrier sites, such as the skin and gastrointestinal tract, we found that Th17 cells can develop at the gingiva independently of commensal microbiota colonization. Instead, we identified that damage, which occurs physiologically due to mastication, promotes induction of Th17 cells and tones homeostatic immunity at the gingiva.

Spectrum of fungal infection in head and neck cancer patients on chemoradiotherapy

BackgroundRadiotherapy for head and neck cancers (HNC) causes alteration of oral mucosal barrier predisposing it to colonization and infection. Such infections often result in pain and burning sensation thus contributing to major morbidity. Objective1.To identify the fungi isolated from the patients undergoing radiotherapy for HNC.2.To determine their antifungal susceptibility and week of colonization.3.To find out association between oral fungal infection and severity of oral mucositis. Materials and methodsStudy was done on 50 patients of HNC treated with concurrent chemoradiotherapy. Three samples (throat, urine, blood) were collected for fungal culture and sensitivity. These samples were collected before the start of radiotherapy, during radiotherapy (2nd and 6th week) and post radiotherapy (10th week). ResultsOnly 49 patients were available for analysis. Fungal infection was found in 27/49 patients (55.10%) out of which Non-albicans Candida was isolated in 18/49 (36.73%) and Candida albicans in 9/49 (18.36%) cases. About 66.66% (18/27) isolates were sensitive to fluconazole. Maximum isolation of yeast was during 6th week of radiotherapy. All grade 4 and 71.42% of grade 3 oral mucositis were found in patients who were positive for fungal infection. ConclusionThe spectrum of fungal species in throat swab was: Non-albicans Candida and Candida albicans observed in 36.73% and 18.36% of patients respectively. Higher rate of fungal colonization and infection was found in patients with grade 3/4 oral mucositis. Prophylactic fluconazole in HNC patients on concurrent chemoradiotherapy has the potential to reduce emerging invasive fungal infection and its associated morbidity.

Osteonecrosis of the Jaw Developed in Mice: DISEASE VARIANTS REGULATED BY γδ T CELLS IN ORAL MUCOSAL BARRIER IMMUNITY

Osteonecrosis of the jaw (ONJ), an uncommon co-morbidity in patients treated with bisphosphonates (BP), occurs in the segment of jawbone interfacing oral mucosa. This study aimed to investigate a role of oral mucosal barrier γδ T cells in the pathogenesis of ONJ. Female C57Bl/6J (B6) mice received a bolus zoledronate intravenous injection (ZOL, 540 μg/kg), and their maxillary left first molars were extracted 1 week later. ZOL-treated mice (WT ZOL) delayed oral wound healing with patent open wounds 4 weeks after tooth extraction with characteristic oral epithelial hyperplasia. γδ T cells appeared within the tooth extraction site and hyperplastic epithelium in WT ZOL mice. In ZOL-treated γδ T cell null (Tcrd(-/-) ZOL) mice, the tooth extraction open wound progressively closed; however, histological ONJ-like lesions were identified in 75 and 60% of WT ZOL and Tcrd(-/-) ZOL mice, respectively. Although the bone exposure phenotype of ONJ was predominantly observed in WT ZOL mice, Tcrd(-/-) ZOL mice developed the pustule/fistula disease phenotype. We further addressed the role of γδ T cells from human peripheral blood (h-γδ T cells). When co-cultured with ZOL-pretreated human osteoclasts in vitro, h-γδ T cells exhibited rapid expansion and robust IFN-γ secretion. When h-γδ T cells were injected into ZOL-treated immunodeficient (Rag2(-/-) ZOL) mice, the oral epithelial hyperplasia developed. However, Rag2(-/-) ZOL mice did not develop osteonecrosis. The results indicate that γδ T cells are unlikely to influence the core osteonecrosis mechanism; however, they may serve as a critical modifier contributing to the different oral mucosal disease variations of ONJ.

TEM‐producing Capnocytophaga sputigena primary bactaeremia in a breast cancer patient

Introduction: Bacteraemia caused by Capnocytophaga sputigena is rarely reported. Here, we present a case of bacteraemia with C. sputigena in a breast cancer patient. Case presentation: C. sputigena was isolated from blood in a breast cancer patient who suffered from oral mucosal barrier breakage for several years. The bacterium was initially identified in the blood culture of the patient by conventional techniques and confirmed by mass spectrometry and sequencing of the 16S rRNA gene. Antibiotics susceptible testing revealed the bacterium was resistant to penicillins, first‐, second‐ and third‐generation cephalosporins and monobactam. PCR was used to detect common β‐lactamase genes; the TEM gene was detected and confirmed by sequencing. Conclusion: To the best of our knowledge, this is the first report of bacteraemia in a breast cancer patient caused by TEM‐producing C. sputigena.

Effect of low-level laser therapy on inflammatory mediator release during chemotherapy-induced oral mucositis: a randomized preliminary study.

Patients undergoing hematopoietic stem cell transplantation (HSCT) are submitted to a conditioning regimen of high-dose chemotherapy, with or without radiation therapy, which usually results in oral ulcerations and mucosal barrier breakdown. Oral mucositis (OM) is a common and debilitating toxicity side effect of autologous and allogeneic HSCT. The aim of this study was to evaluate the effect of low-level laser therapy (LLLT) on the severity of OM and inflammatory mediator (TNF-α, IL-6, IL-1β, IL-10, TGF-β, metalloproteinases, and growth factors) levels in saliva and blood of HSCT patients. Thirty patients were randomly assigned to two groups: control (n = 15) and laser (n = 15). LLLT was applied from the first day of the conditioning regimen until day 7 post-HSCT (D + 7). Saliva and blood were collected from patients on admission (AD), D-1, D + 3, D + 7, and on marrow engraftment day (ME). Clinical results showed less severe OM in the laser group (p < 0.05). The LLLT group showed increased matrix metalloproteinase 2 (MMP-2) levels in saliva on D + 7 (p = 0.04). Significant differences were also observed for IL-10 on D + 7 and on ME in blood plasma, when compared to the control group (p < 0.05). No significant differences were seen in saliva or blood for the other inflammatory mediators investigated. LLLT was clinically effective in reducing the severity of chemotherapy-induced OM in HSCT patients, and its mechanism of action does not seem to be completely linked to the modulation of pro- or anti-inflammatory cytokines, growth factors or matrix metalloproteinases.

Management of an Unresponsive Periodontal Lesion in an Endodontic Involved Tooth Complicated by Actinomyces Species

ABSTRACTActinomycosis is an infectious disease caused byActinomycesspecies found as a commensal in oral flora. However, it does cause opportunistic infections with localized granulomatous and suppurative lesions intraorally once the integrity of the oral mucosal barrier is compromized and access to the underlying tissues or jaw bones is gained. The present case report highlights an unresponsive periodontal lesion associated with an actinomycotic infection in an endodontically involved tooth. The gingiva in relation to the tooth showed profuse spontaneous bleeding and suppurative discharge after multiple appointments of initial therapy which required histopathologic and microbiological assessment for diagnosis. On establishing the diagnosis of actinomycosis, treatment involved extraction of the tooth. This highlights the importance of microbiological investigations in unresponsive periodontal lesions.How to cite this articleMistry AR, Pereira R, Kini V, Padhye A, Poonja LS, Natrajan S. Management of an Unresponsive Periodontal Lesion in an Endodontic Involved Tooth Complicated byActinomycesSpecies. J Contemp Dent 2014;4(3):167-172.

Anodized-hydrothermally treated titanium with a nanotopographic surface structure regulates integrin-α6β4 and laminin-5 gene expression in adherent murine gingival epithelial cells

PurposePeri-implant epithelium associated with the structure of the internal basal lamina is in contact with a transmucosal portion of the endosseous implant surface. This contact is important to protect the many complex factors required for the long-term stability and maintenance of the implant. This study investigated the effect of initial adhesion of gingival epithelial cells to anodized-hydrothermally treated commercially pure titanium with nanotopographic structure (SA-treated c.p.Ti). Changes in cell morphology and gene expression of integrin-α6β4 and laminin-5 were assessed. MethodsMurine immortalized gingival epithelial (GE1) cells were cultured for 1–3 days on c.p.Ti, anodic oxide (AO) c.p.Ti, and SA-treated c.p.Ti disks. Cell morphology was analyzed using scanning electron microscopy (SEM). Cell proliferation was analyzed using the WST-1 assay. Integrin-α6β4 and laminin-5 (α3, β3, γ2) mRNA levels were measured using real-time quantitative RT-PCR. ResultsThe GE1 cells appeared flattened with extensions on all disks by SEM analysis. Filopodium-like extensions were bound closely to the nanotopographic structure surface of SA-treated c.p.Ti especially at day 3 of culture. GE1 cell proliferation as well as the expression of integrin-α6β4 and laminin-5 (α3, β3, γ2) mRNAs was significantly higher on SA-treated c.p.Ti than on c.p.Ti and AO c.p.Ti disks after 3 days (P<0.05). ConclusionsGingival epithelial cells initially attach to a transmucosal portion of SA-treated c.p.Ti implant material and subsequently express the integrin-α6β4 adhesion molecule and the laminin-5 extracellular matrix molecule. This cell behavior may play a key role in maintaining the peri-implant oral mucosal tissue barrier.

The defence architecture of the superficial cells of the oral mucosa

The oral epithelium together with the saliva and its components forms a complex structure which is the first line of defence in the oral cavity. The surface of superficial cells of the oral epithelium contains ridge-like folds, microplicae (MPL), which are typical of the surfaces of areas covered with protective mucus. The role of MPL seen on the upper surface of the oral epithelial cells is still unknown. The salivary mucus gel performs a protective diffusion membrane against harmful substances and this membrane is built up by epithelial cells covered by a highly hydrated and viscous gel, where mucins constitute the scaffold. The interaction between the MPL-structure and the mucins is shown in cornea, so that mucins are expressed on the tips of the MPL of the epithelial cells. We hypothesized that the MPL architecture of oral superficial epithelial cells provides the underlying basis for mucins’s protective function as well as in ocular surface. The salivary mucous barrier is required to protect the superficial cells and the MPL-structure together with membrane anchored mucin binding protein (MBP) forms the ground to this mucous barrier.So, oral mucosal barrier complex (OMBC) contains both the MBP-mucin – complex and the MPL-structure of the superficial cells.In the future, studies of the alterations of the salivary mucins and that of the MPL-structure may yield therapeutic opportunities for burning mouth syndrome and perhaps for mucositis causing by irradiation. Focus on cell surface microplication and mucins in oral mucosal biology and oral mucosal diseases is a promising avenue for future research in several ways.

Vocal Cord Actinomycosis: A Case Report

Introduction: Actinomycosis is a systemic chronic bacterial infection caused by Actinomyces Israelii, an anaerobic organism normally resident in the human mouth. However, the actinomycosis of the larynx is very rare, and only about 15 cases have been reported in the literature so far. Most of the cases reported occurred in patients who had previously undergone radiotherapy for laryngeal cancer. Case Report: Here we report a case of actinomycosis of the larynx in a 14-year-old shepherd boy who was not immunocompromised but had a history of tooth extraction two months prior to admission to the hospital and severe laryngitis one year prior to admission. Conclusion: Laryngeal actinomycosis might be related to poor oral hygiene and mucosal barrier disruption, as well as to being immunocompromised.

Bisphosphonate effects on the behaviour of oral epithelial cells and oral fibroblasts

ObjectiveBisphosphonates (BPs) like Zometa (ZA) are widely used to treat complications of bony metastases in cancer patients. A serious adverse event occurs in 1–12% of patients on BP therapy, osteonecrosis of the jaw (BPONJ). BPONJ develops after oral trauma and is manifested by poor wound healing and soft-tissue breakdown followed by exposure and necrosis of intra-oral bone. Currently, there is no effective clinical treatment for BPONJ. DesignWe evaluated the effect of ZA on the proliferation, apoptosis and migratory capacity of the cell lines CRL-7408, an oral fibroblast culture and OKF/6, an oral epithelial cell line. ResultsIn both oral epithelium and fibroblasts, ZA exposure inhibited proliferation and elevated apoptosis; however oral fibroblasts were differentially influenced versus oral epithelial cells. In oral fibroblasts, ZA treatment significantly inhibited motility. Further, quantitative real-time PCR demonstrated that ZA treatment of oral fibroblasts inhibits expression of both the COL1A1 and COL1A2 chains of type-I collagen, consistent with a loss of collagen immunofluorescent staining. ConclusionsThese data support a model wherein ZA treatment impedes oral wound healing by blocking the growth and migratory capacity of oral fibroblasts as well as downregulating the transcription of type-I collagen, functions necessary to deposit the granulation tissue needed for re-epithelization. Therefore, BP released from bone following tooth extraction may delay wound healing of the oral mucosal barrier and contribute to BPONJ pathogenesis.

Polyvinylpyrrolidone–sodium hyaluronate gel (Gelclair®): a bioadherent oral gel for the treatment of oral mucositis and other painful oral lesions

Background: Painful oral lesions in patients with cancer, HIV or aphthous ulcers can cause significant pain and discomfort. Those with oral mucositis (OM) resulting from high-dose chemotherapy or irradiation are the most at risk for painful lesions that lead to significant morbidity and mortality, decreased quality of life and increased economic costs. Numerous approaches have been taken to prevent and treat OM in the cancer patient but this condition remains a significant obstacle to cancer therapy. Small studies have been done in healing oral lesions arising from laser surgery and in wound healing but research is needed to support the use of polyvinylpyrrolidone–sodium hyaluronate gel (Gelclair®) in these clinical setting. Objective: The purpose of this paper is to review the benefit of polyvinylpyrrolidone–sodium hyaluronate gel, a topical oral mucosal barrier gel to prevent or diminish the pain of OM and other oral lesions. Methods: Primary resources in peer-reviewed journals, chapters in recognized textbooks and information from international and national oncology and dental medicine scientific meetings. Conclusions: Oncology patients receiving high-dose immunosuppressive therapy are the most at risk with painful OM. Current prevention and treatment options for OM have limited effectiveness. Although opioids are available for pain management, novel agents, to be used alone or in combination with other proven measures to decrease the severity and duration of OM, are emerging. Clinical studies in the use of polyvinylpyrrolidone–sodium hyaluronate to reduce the pain or disruption to the oral mucosa has merit. Few clinical trials or main publications have supported the use of this product. Robust randomized trials are needed to further support the clinical utility of this agent.

Decreased salivary vascular endothelial growth factor in elderly patients with pneumonia during the course of recovery

Background: Elderly individuals are known for their high risk of acquiring pneumonia. Poor oral hygiene and high incidence of gastro-oesophageal reflux continue to cause persistent oropharyngeal mucosal injuries and results in overgrowth of bacterial population and alteration of bacterial flora to respiratory pathogens in the oropharyngeal cavity. Salivary secretion contributes in maintaining homeostasis of the oropharyngeal mucosal barrier. Vascular endothelial growth factor (VEGF) acts as an angiogenic and permeability-enhancing cytokine but is normally secreted in saliva. It has been previously demonstrated that VEGF secreted in the airway functions in the restoration or repair of the injured tissue. We hypothesized that salivary VEGF is a candidate as a marker to evaluate the degree of oropharyngeal mucosal injury. Methods: We compared the volumes, protein contents, and the amount of VEGF secreted in the saliva of patients with pneumonia during the course of recovery (P; n = 7) and those without pneumonia (n = 10). Results: Volumes and protein contents within the secreted saliva were similar between the patients with P and the control subjects (0.60 ± 0.28 mL versus 0.41 ± 0.34 mL, P = 0.126, 7.12 ± 5.57 µg/mL versus 3.92 ± 3.58 µg/mL, P = 0.231, respectively). The concentrations of salivary VEGF were significantly lower in patients with P than those of the controls (0.71 ± 0.37 versus 2.66 ± 3.44 µg/µg protein, P = 0.032). Conclusion: Lower concentrations of salivary VEGF in patients with pneumonia during the course of recovery suggested the presence of persistent oropharyngeal mucosal injury even after normalization of systemic C-reactive protein levels. The concentration of salivary VEGF is capable of being a marker for discriminating impaired oral mucosal barrier that precipitates in development of pneumonia in elderly individuals.

An adult case of oral infection with Kingella kingae

An exceptional case of microbiologically confirmed oral infection with Kingella kingae in an immunocompetent adult (30-year-old woman) is presented and the pathogenesis is discussed and related to known literature data.K. kingae is a rather common but yet relatively unknown commensal corroding bacterium from the oro- and nasopharynx in healthy children, which might turn into a human pathogen causing osteomyelitis, arthritis, spondylitis, endocarditis and intervertebral diskitis in young children and rarely endocarditis, septic arthritis, meningitis, epiglottitis, diskitis and bacteraemia in adults. Sofar K. kingae associated stomatitis was reported in children and a few adults, however, with concomitant herpes simplex virus infections, and without microbiological confirmation. In the described case no viral infection was found. The proven K. kingae stomatitis represents an extension of the pathogenic spectrum and suggests that the breach of the oral mucosal barrier can be caused by the bacterial pathogen itself. Whether a concomitant viral infection is necessary forK. kingae to actually invade the bloodstream remains to be considered.

The biologic role for nuclear factor-kappaB in disease and its potential involvement in mucosal injury associated with anti-neoplastic therapy.

Oral mucosal barrier injury (mucositis) is a frequent, painful, serious, dose-limiting toxicity associated with many anti-neoplastic drugs and radiation to the head and neck. Results of recent studies suggest that mucositis is the result of a complex series of interactive biological events that take place in the submucosa and epithelium. The nuclear transcription factor NF-kappaB has been implicated in the control of a broad range of biological responses, the activation of a large number of specific cellular genes, and the determination of the fate of cells exposed to ionizing radiation and anti-neoplastic drugs. Of particular importance to mucositis is the fact that NF-kappaB regulates key elements in the apparent sequence that leads to normal tissue toxicity. Not the least of these is the effect that NF-kappaB activation has on apoptosis. In particular, a paradox exists between the potential pro-apoptotic effect NF-kappaB exerts on normal cells, and the anti-apoptotic and cytoprotective effect it causes in tumor cells. This paper provides a review of the structure and function of NF-kappaB and speculates how its apparent enigmatic effect on normal and tumor cells may occur.

Epithelial Antimicrobial Peptides: Review and Significance for Oral Applications

Epithelial tissues provide the first line of defense between an organism and the environment. Disruption of this barrier leads to bacterial invasion and subsequent inflammation. This is precisely the situation existing in the human oral cavity, where tissues are constantly exposed to a variety of microbial challenges that can lead to bacterially induced periodontal diseases, and to infections of the oral mucosa by bacteria, fungi, and viruses. With the recent discoveries of host-derived peptide antibiotics in mammalian mucosal epithelium, a new line of investigation is emerging to test the hypothesis that one class of these peptides, called "beta-defensins", functions to protect the host against microbial pathogenesis at these critical, confrontational sites. In that light, impairment of beta-defensin activity has recently been implicated in chronic bacterial infections in cystic fibrosis patients. The first direct evidence of expression of defensin peptides in the oral mucosa was the identification of a novel epithelial beta-defensin in mammalian tongue. It was shown to be upregulated in inflammation, suggesting that it participates in host defense. It is theorized that epithelial cell-derived antimicrobial peptides function to keep the natural flora of micro-organisms in a steady state in different niches such as the skin, the intestines, the airway, the endocervix, and the mouth. There is now evidence indicating that normal gingival epithelial cells and tissues express two beta-defensins, hBD-1 and the newly described hBD-2. In addition, a cathelin-class antimicrobial peptide, designated LL-37 and found in human neutrophils, is also expressed in skin and gingiva. It is highly likely that these and/or other epithelial antimicrobial peptides play an important role in determining the outcome of the host-pathogen interaction at the oral mucosal barrier, and that they may have important future applications in antibiotic treatment.

Comparison of the ex-vivo oral mucosal permeation of tryptophan-leucine (Trp-Leu) and its myristoyl derivative

The ex vivo permeation of a model peptide, tryptophan-leucine (Trp-Leu), was studied using two different regions of pig oral mucosa, the hard palate and the cheek. In order to increase the mucosal absorption of Trp-Leu, a lipophilic derivative was synthesized by acylation of the N-terminal amino group of Trp-Leu with myristic acid. The purified Trp-Leu derivative (Myr-Trp-Leu) was more lipophilic than the parent Trp-Leu as observed by HPTLC ( R f's values of 0.41 and 0.81, respectively). Measurement of partition coefficients in n-octanol/phosphate buffer pH 7.4, gave K p values of −0.68 and 1.04 for Trp-Leu and Myr-Trp-Leu, respectively. The native Trp-Leu was unable to pass through the keratinized layer of palatal mucosa, and after 24 h only 12% had passed through the buccal mucosa to the receptor compartment. The higher lipophilicity of the acylated peptide, meant that it was not easily transported across the oral mucosal barrier but accumulated in the tissue, founding 25 and 70% of the original amount in the palatal and buccal mucosae, respectively. Both, Trp-Leu and Myr-Trp-Leu were found to be stable in palatal and buccal mucosae.

Oral infections in the immunocompromised host

This paper provides a summary of a recent International Association for Dental Research symposium, “Oral infections in the immunocompromised host.” Speakers addressed current science relative to the host defense system (oral mucosal barrier, salivary gland function, use of biologic response modifiers), as well as characteristics of bacterial, fungal and viral pathogens. Avenues for future directions in laboratory and clinical research are proposed.