Oral mucosal immunity

The Effect of Bacterial Composition Shifts in the Oral Microbiota on Alzheimer's Disease

Alzheimer's disease (AD), a neurological disorder, despite significant advances in medical science, has not yet been definitively cured, and the exact causes of the disease remain unclear. Due to the importance of AD in the clinic, large expenses are spent annually to deal with this neurological disorder, and neurologists warn of an increase in this disease in elderly in the near future. It has been believed that microbiota dysbiosis leads to Alzheimer's as a multi-step disease. In this regard, the presence of footprints of perturbations in the oral microbiome and the predominance of pathogenic bacteria and their effect on the nervous system, especially AD, is a very interesting topic that has been considered by researchers in the last decade. Some studies have looked at the mechanisms by which oral microbiota cause AD. However, many aspects of this interaction are still unclear as to how oral microbiota composition can contribute to this disease. Understanding this interaction requires extensive collaboration by interdisciplinary researchers to explore all aspects of the issue. In order to reveal the link between the composition of the oral microbiota and this disease, researchers from various domains have sought to explain the mechanisms of shift in oral microbiota in AD in this review.

Natural History of Nonhuman Primates After Oral Exposure to Ebola Virus Variant Makona

BACKGROUND

The primary route of infection by Ebola virus (EBOV) is through contact of mucosal surfaces. Few studies have explored infection of nonhuman primates (NHPs) via the oral mucosa, which is a probable portal of natural infection in humans.

METHODS

To further characterize the pathogenesis of EBOV infection via the oral exposure route, we challenged cohorts of cynomolgus monkeys with low doses of EBOV variant Makona.

RESULTS

Infection with 100 or 50 PFU of EBOV Makona via the oral route resulted in 50% and 83% lethality, respectively. Animals that progressed to fatal disease exhibited lymphopenia, marked coagulopathy, high viral loads, and increased levels of serum markers of inflammation and hepatic/renal injury. Survival in these cohorts was associated with milder fluctuations in leukocyte populations, lack of coagulopathy, and reduced or absent serum markers of inflammation and/or hepatic/renal function. Surprisingly, 2 surviving animals from the 100- and 50-PFU cohorts developed transient low-level viremia in the absence of other clinical signs of disease. Conversely, all animals in the 10 PFU cohort remained disease free and survived to the study end point.

CONCLUSIONS

Our observations highlight the susceptibility of NHPs, and by extension, likely humans, to relatively low doses of EBOV via the oral route.

Pathophysiology of Medication-Related Osteonecrosis of the Jaw-A Minireview

Medication-related osteonecrosis of the jaw (MRONJ) is a rare but serious adverse effect of antiresorptive medications administered for control of osseous malignancy, osteoporosis, or other bone metabolic diseases. Despite being reported in the literature two decades ago, MRONJ etiology, pathophysiology, and progression remain largely unknown, and current nonoperative or operative treatment strategies are mostly empirical. Several hypotheses that attempt to explain the mechanisms of MRONJ pathogenesis have been proposed. However, none of these hypotheses alone is able to capture the complex mechanistic underpinnings of the disease. In this minireview, we aim to highlight key findings from clinical and translational studies and propose a unifying model for the pathogenesis and progression of MRONJ. We also identify aspects of the disease process that require further investigation and suggest areas for future research efforts toward calibrating methodologic approaches and validating experimental findings. © 2023 The Authors. JBMR Plus published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research.

Comparison of the Effects of Prebiotics and Synbiotics Supplementation on the Immune Function of Male University Football Players

This study was conducted to compare the effects of long-term prebiotic and synbiotic supplementations on the immunosuppression of male football players after daily high-intensity training and a one-time strenuous exercise. A total of 30 male university student-athletes were recruited and randomly assigned to the prebiotic (PG, n = 15) or synbiotic group (SG, n = 15), receiving a prebiotic or synbiotic once per day for six weeks. Physiological assessments were conducted by a maximal oxygen uptake (VO2max) test and an exhaustive constant load exercise (75% VO2max test). Inflammatory cytokine and secretory immunoglobulin A (SIgA) were measured. VO2max, maximal heart rate (HRmax), and lactic acid elimination rate (ER) were used to evaluate aerobic capacity. Upper respiratory tract infection (URTI) complaints were evaluated using a questionnaire. URTI incidence and duration were significantly lower in the SG group than that in the PG group (p < 0.05). At baseline, SIgA and interleukin-1β (IL-1β) levels in the SG group (p < 0.01) as well as IL-1β and IL-6 in the PG group (p < 0.05) were significantly increased, and IL-4 concentration was markedly reduced in the PG group (p < 0.01). The concentrations of IL-4, IL-10 and transforming growth factor-β1 (TGF-β1) were significantly reduced in the PG and SG group immediately after the constant load exercise. Significantly decreased HRmax and enhanced ER (increased by 193.78%) were detected in the SG group, not in the PG group, during the constant load experiment (p < 0.05) and the recovery period (p < 0.01), respectively. However, VO2max value was not changed. These data suggest that synbiotic supplementation for six weeks has a more positive effect than prebiotics on the immune function and athletic performance of male university football players.

Salivary macrophage chemokines as potential biomarkers of gingivitis

OBJECTIVE

The present study aimed to analyze the salivary levels of macrophage-activating factor (MAF), macrophage-chemotactic factor (MCF), and macrophage migration inhibitory factor (MIF) in healthy and gingivitis patients, and to correlate between the concentrations of these chemo attractants with the intensity of gingival inflammation clinically.

METHODS

Sixty saliva specimens were collected from periodontally healthy (n = 30), and gingivitis patients (n = 30). Bleeding on probing (BOP), Visible Plaque Index (VPI), and Simplified Modified Gingival Index (SMGI) were recorded through clinical examination. Salivary MAF, MCF, and MIF concentrations were assayed using enzyme-linked immunosorbent assays (ELISA). Statistical analysis was performed using SPSS (version 28). Total mean score for each biomarker was determined, and descriptive bivariate statistics were conducted to characterize the levels of biomarkers among the study groups. The difference in the biomarker levels among the study groups were analyzed by independent sample t test and one-way ANOVA. The diagnostic ability of the biomarkers was further tested by ROC curve analysis.

RESULTS

Salivary levels of MAF was not significantly different between periodontally healthy individuals and gingivitis patients. The difference in MCF and MIF levels between patients with gingivitis and those with healthy periodontium was statistically significant (p 0.05 and p 0.001, respectively). When examined across the various stages of disease progression, MIF showed statistically significant difference among the three biomarkers (p 0.05). ROC curve analysis further revealed that area under the curve (AUC) for MIF has a better diagnostic capacity than MCF (AUC 0.981 vs. 0.673).

CONCLUSIONS

Our results suggest that MIF could be considered as a potential salivary biomarker for gingivitis.

Understanding the Predictive Potential of the Oral Microbiome in the Development and Progression of Early Childhood Caries

BACKGROUND

Early childhood caries (ECC) is the most common chronic disease in young children and a public health problem worldwide. It is characterized by the presence of atypical and fast progressive caries lesions. The aggressive form of ECC, severe early childhood caries (S-ECC), can lead to the destruction of the whole crown of most of the deciduous teeth and cause pain and sepsis, affecting the child's quality of life. Although the multifactorial etiology of ECC is known, including social, environmental, behavioral, and genetic determinants, there is a consensus that this disease is driven by an imbalance between the oral microbiome and host, or dysbiosis, mediated by high sugar consumption and poor oral hygiene. Knowledge of the microbiome in healthy and caries status is crucial for risk monitoring, prevention, and development of therapies to revert dysbiosis and restore oral health. Molecular biology tools, including next-generation sequencing methods and proteomic approaches, have led to the discovery of new species and microbial biomarkers that could reveal potential risk profiles for the development of ECC and new targets for anti-caries therapies. This narrative review summarized some general aspects of ECC, such as definition, epidemiology, and etiology, the influence of oral microbiota in the development and progression of ECC based on the current evidence from genomics, transcriptomic, proteomic, and metabolomic studies and the effect of antimicrobial intervention on oral microbiota associated with ECC.

CONCLUSION

The evaluation of genetic and proteomic markers represents a promising approach to predict the risk of ECC before its clinical manifestation and plan efficient therapeutic interventions for ECC in its initial stages, avoiding irreversible dental cavitation.

Immunomodulatory role of oral microbiota in inflammatory diseases and allergic conditions

In recent years, the interplay between oral microbiota and systemic disease has gained attention as poor oral health is associated with several pathologies. The oral microbiota plays a role in the maintenance of overall health, and its dysbiosis influences chronic inflammation and the pathogenesis of gum diseases. Periodontitis has also been associated with other diseases and health complications such as cancer, neurogenerative and autoimmune disorders, chronic kidney disease, cardiovascular diseases, rheumatic arthritis, respiratory health, and adverse pregnancy outcomes. The host microbiota can influence immune cell development and immune responses, and recent evidence suggests that changes in oral microbiota composition may also contribute to sensitization and the development of allergic reactions, including asthma and peanut allergies. Conversely, there is also evidence that allergic reactions within the gut may contribute to alterations in oral microbiota composition. Here we review the current evidence of the role of the oral microbiota in inflammatory diseases and health complications, as well as its future relevance in improving health and ameliorating allergic disease.

β-defensinas como posibles indicadores de la actividad inflamatoria en la enfermedad periodontal

Periodontal disease (gingivitis and periodontitis) is an inflam-matory process caused by the activity of pathogenic bacteria and their products on the gingival sulcus, with the consequent activation of the immune response. Saliva and crevicular fluid contain a wide variety of enzymes and antimicrobial factors that are in contact with the supragingival and subgingival region, in-cluding β-defensins (hBDs). hHBDs are non-glycosylated, cysteine-rich cationic peptides produced by epithelial cells with antimicrobial and immunoregulatory effects, thus contributing to maintaining homeostasis in periodontal tissues. The changes in the microbiota and the immune response from a healthy peri-odontium to gingivitis and, finally, to periodontitis are complex. Their sever-ity depends on a dynamic balance between bacteria associated with plaque, genetic and environmental factors. Recent advances have made it possible to understand the implication of hBDs in the detection, diagnosis, and therapy of periodontal disease and the relationship between periodontitis and other inflammatory conditions. This review aims to describe the effect of hBDs on the immune response and its use as a possible marker of the inflammatory activity of the periodontal disease.

Oral dysbiosis and systemic diseases

The aim of this mini review is to investigate the connection between oral microbiome dysbiosis and systemic diseases. Many systemic conditions can have oral manifestations and cause worsening in oral diseases. For example, uncontrolled type 2 diabetes has been associated with worsening of periodontal disease. Other inflammatory diseases or autoimmune diseases may predispose to oral mucositis, mucosal ulcers, xerostomia, and higher susceptibility to oral infections. This review will outline common systemic diseases, such as metabolic, cardiovascular, and immunologic disorders as they relate to oral manifestations and changes in the oral microbiome composition.

Immunoglobulin Disorders and the Oral Cavity: A Narrative Review

The oral mucosa is a mechanical barrier against the penetration and colonization of microorganisms. Oral homeostasis is maintained by congenital and adaptive systems in conjunction with normal oral flora and an intact oral mucosa. Components contributing to the defense of the oral cavity include the salivary glands, innate antimicrobial proteins of saliva, plasma proteins, circulating white blood cells, keratinocyte products of the oral mucosa, and gingival crevicular fluid. General disturbances in the level of immunoglobulins in the human body may be manifested as pathological lesions in the oral mucosa. Symptoms of immunoglobulin-related general diseases such as mucous membrane pemphigoid (MMP), pemphigus vulgaris (PV), linear IgA bullous dermatosis (LABD), Epidermolysis Bullosa Aquisita (EBA), and Hyper-IgE syndrome (HIES) may appear in the oral cavity. In this review, authors present selected diseases associated with immunoglobulins in which the lesions appear in the oral cavity. Early detection and treatment of autoimmune diseases, sometimes showing a severe evolution (e.g., PV), allow the control of their dissemination and involvement of skin or other body organs. Immunoglobulin disorders with oral manifestations are not common, but knowledge, differentiation and diagnosis are essential for proper treatment.

Function of normal oral mucosa revealed by single-cell RNA sequencing

The functions of oral mucosa include barrier, sensation, and secretion. The barrier protection function is particularly important, which includes physical barrier and immunological barrier. Few studies have revealed the function of oral mucosa by displaying the map of normal oral mucosal cells from the perspective of single cells. Here, single-cell transcriptome sequencing was used to bring a relatively comprehensive map of the normal oral mucosal cells. In total, 26,398 cells from three cases of normal oral mucosa were analyzed by single-cell RNA-sequencing and 14 distinct cell groups were defined, 7 of which were immune cells. We performed subgroup classification and heterogeneity analysis of epithelial cells, T cells, and macrophagocytes, which found a subpopulation of epithelial cells with high expression of major histocompatibility complex class II molecules, a subpopulation CD8⁺ GZMK⁺ T cells, and two kinds of active macrophagocytes. Meanwhile, we identified ligand-receptor pairs among the major cell types to explore the interactions and how they maintain the homeostasis of normal oral mucosa. Based on these results, the epithelial barrier function, immunological barrier function, and potential maintenance function of stromal cells in the oral mucosa were described at the single-cell level, which provides basic data resources for further studies of oral mucosal diseases.

Effects of Long-Term Enclosed Environment on Human Health Based on the Analysis of Salivary Microbiota and Cytokines

Long-term exposure to space environments may influence the human microbiome, the human immune system, and the intricate balance between the two, causing impaired immunity and increased disease susceptibility. It was previously believed that the main potential factors of long-term spaceflight on human health were microgravity and radiation.

Oropharyngeal administration of mother's own milk influences levels of salivary sIgA in preterm infants fed by gastric tube

The aim of the present study was to explore the effect of oropharyngeal mother’s milk administration on salivary secretory immunoglobulin A (sIgA) levels in preterm infants fed by gastric tube. Infants (n = 130) with birth weight < 1500 g were randomly allocated into two groups which both received breast milk for enteral nutrition. The experimental group (n = 65) accepted oropharyngeal mother’s milk administration before gastric tube feeding for 14 days after birth. The control group (n = 65) accepted oropharyngeal 0.9% normal saline administration. Saliva concentration of sIgA were assessed at the 2 h, 7th and 14th day after birth. The level of salivary sIgA in experimental group were significantly higher than those in control group on the 7th day after birth (p < 0.05), but there were no differences in salivary sIgA levels on the 14th day between the two groups. The results of quantile regression analysis showed that oropharyngeal mother’s milk administration, delivery mode and gestational age had significant effects on the increase of sIgA. SIgA in experimental group and the total number of intervention had a significant positive correlation (p < 0.05). Oropharyngeal mother’s milk administration can improve salivary sIgA levels of preterm infants.

Differential Signature of the Microbiome and Neutrophils in the Oral Cavity of HIV-Infected Individuals

HIV infection is associated with a wide range of changes in microbial communities and immune cell components of the oral cavity. The purpose of this study was to evaluate the oral microbiome in relationship to oral neutrophils in HIV-infected compared to healthy individuals. We evaluated oral washes and saliva samples from HIV-infected individuals (n=52) and healthy controls (n=43). Using 16S-rRNA gene sequencing, we found differential β-diversity using Principal Coordinate Analysis (PCoA) with Bray-Curtis distances. The α-diversity analysis by Faith’s, Shannon, and observed OTUs indexes indicated that the saliva samples from HIV-infected individuals harbored significantly richer bacterial communities compared to the saliva samples from healthy individuals. Notably, we observed that five species of Spirochaeta including Spirochaetaceae, Spirochaeta, Treponema, Treponema amylovorum, and Treponema azotonutricum were significantly abundant. In contrast, Helicobacter species were significantly reduced in the saliva of HIV-infected individuals. Moreover, we found a significant reduction in the frequency of oral neutrophils in the oral cavity of HIV-infected individuals, which was positively related to their CD4⁺ T cell count. In particular, we noted a significant decline in CD44 expressing neutrophils and the intensity of CD44 expression on oral neutrophils of HIV-infected individuals. This observation was supported by the elevation of soluble CD44 in the saliva of HIV-infected individuals. Overall, the core oral microbiome was distinguishable between HIV-infected individuals on antiretroviral therapy compared to the HIV-negative group. The observed reduction in oral neutrophils might likely be related to the low surface expression of CD44, resulting in a higher bacterial diversity and richness in HIV-infected individuals.

Dynamic Interaction Between Mucosal Immunity and Microbiota Drives Nose and Pharynx Homeostasis of Common Carp (Cyprinus carpio) After SVCV Infection

The crosstalk between the immune system and microbiota drives an amazingly complex mutualistic symbiosis. In mammals, the upper respiratory tract acts as a gateway for pathogen invasion, and the dynamic interaction between microbiota and mucosal immunity on its surface can effectively prevent disease development. However, the relationship between virus-mediated mucosal immune responses and microbes in lower vertebrates remains uncharacterized. In this study, we successfully constructed an infection model by intraperitoneally injecting common carp (Cyprinus carpio) with spring viremia of carp virus (SVCV). In addition to the detection of the SVCV in the nose and pharynx of common carp, we also identified obvious histopathological changes following viral infection. Moreover, numerous immune-related genes were significantly upregulated in the nose and pharynx at the peak of SVCV infection, after which the expression levels decreased to levels similar to those of the control group. Transcriptome sequencing results revealed that pathways associated with bacterial infection in the Toll-like receptor pathway and the Nod-like receptor pathway were activated in addition to the virus-related Rig-I-like receptor pathway after SVCV infection, suggesting that viral infection may be followed by opportunistic bacterial infection in these mucosal tissues. Using 16S rRNA gene sequencing, we further identified an upward trend in pathogenic bacteria on the mucosal surface of the nose and pharynx 4 days after SVCV infection, after which these tissues eventually reached new homeostasis. Taken together, our results suggest that the dynamic interaction between mucosal immunity and microbiota promotes the host to a new ecological state.

Associations of streptococci and fungi amounts in the oral cavity with nutritional and oral health status in institutionalized elders: a cross sectional study

BACKGROUND

Disruption of the indigenous microbiota is likely related to frailty caused by undernutrition. However, the relationship between undernutrition and the oral microbiota, especially normal bacteria, is not obvious. The aim of this study was to elucidate the associations of nutritional and oral health conditions with prevalence of bacteria and fungi in the oral cavity of older individuals.

METHODS

Forty-one institutionalized older individuals with an average age ± standard deviation of 84.6 ± 8.3 years were enrolled as participants. Body mass index (BMI) and oral health assessment tool (OHAT) scores were used to represent nutritional and oral health status. Amounts of total bacteria, streptococci, and fungi in oral specimens collected from the tongue dorsum were determined by quantitative polymerase chain reaction (PCR) assay results. This study followed the STROBE statement for reports of observational studies.

RESULTS

There was a significant correlation between BMI and streptococcal amount (ρ = 0.526, p < 0.001). The undernutrition group (BMI < 20) showed a significantly lower average number of oral streptococci (p = 0.003). In logistic regression models, streptococcal amount was a significant variable accounting for "not undernutrition" [odds ratio 5.68, 95% confidential interval (CI) 1.64-19.7 (p = 0.06)]. On the other hand, participants with a poor oral health condition (OHAT ≥ 5) harbored significantly higher levels of fungi (p = 0.028).

CONCLUSION

Oral streptococci were found to be associated with systemic nutritional condition and oral fungi with oral health condition. Thus, in order to understand the relationship of frailty with the oral microbiota in older individuals, it is necessary to examine oral indigenous bacteria as well as etiological microorganisms.

Beyond the Finish Line: The Impact and Dynamics of Biomarkers in Physical Exercise-A Narrative Review

The research of biomarkers continues to emerge as a developing academic field which is attracting substantial interest. The study of biomarkers proves to be useful in developing and implementing new screening methods for a wide variety of diseases including in the sports area, whether for leisure activities or professional sports. Novel research has brought into question the immune system and the limitations it may impose on sports practicing. As the well-being of athletes is a priority, the state of their immune function offers valuable information regarding their health status and their ability to continue training. The assessment of various biomarkers may contribute to a more accurate risk stratification and subsequent prevention of some invalidating or even fatal pathologies such as the sudden cardiac death. Therefore, we have reviewed several studies that included sports-related pathology or specific morphofunctional alterations for which some immune biomarkers may represent an expression of the underlying mechanism. These include the defensins, immunoglobulin A (IgA), interleukin-6 (IL-6), the tumoral necrosis factor α (TNF-α), and the white blood cells (WBC) count. Similarly, also of significant interest are various endocrine biomarkers, such as cortisol and testosterone, as well as anabolic or catabolic markers, respectively. Literature data highlight that these values are greatly influenced not only by the duration, but also by the intensity of the physical exercise; moderate training sessions actually enhance the immune function of the body, while a significant increase in both duration and intensity of sports activity acts as a deleterious factor. Therefore, in this paper we aim to highlight the importance of biomarkers’ evaluation in connection with sports activities and a subsequent more adequate approach towards personalized training regimens.

Alterations in the oral microbiome in HIV infection: causes, effects and potential interventions

ABSTRACT

A massive depletion of CD4+ T lymphocytes has been described in early and acute human immunodeficiency virus (HIV) infection, leading to an imbalance between the human microbiome and immune responses. In recent years, a growing interest in the alterations in gut microbiota in HIV infection has led to many studies; however, only few studies have been conducted to explore the importance of oral microbiome in HIV-infected individuals. Evidence has indicated the dysbiosis of oral microbiota in people living with HIV (PLWH). Potential mechanisms might be related to the immunodeficiency in the oral cavity of HIV-infected individuals, including changes in secretory components such as reduced levels of enzymes and proteins in saliva and altered cellular components involved in the reduction and dysfunction of innate and adaptive immune cells. As a result, disrupted oral immunity in HIV-infected individuals leads to an imbalance between the oral microbiome and local immune responses, which may contribute to the development of HIV-related diseases and HIV-associated non-acquired immunodeficiency syndrome comorbidities. Although the introduction of antiretroviral therapy (ART) has led to a significant decrease in occurrence of the opportunistic oral infections in HIV-infected individuals, the dysbiosis in oral microbiome persists. Furthermore, several studies with the aim to investigate the ability of probiotics to regulate the dysbiosis of oral microbiota in HIV-infected individuals are ongoing. However, the effects of ART and probiotics on oral microbiome in HIV-infected individuals remain unclear. In this article, we review the composition of the oral microbiome in healthy and HIV-infected individuals and the possible effect of oral microbiome on HIV-associated oral diseases. We also discuss how ART and probiotics influence the oral microbiome in HIV infection. We believe that a deeper understanding of composition and function of the oral microbiome is critical for the development of effective preventive and therapeutic strategies for HIV infection.

Salivary Metabolomics for Diagnosis and Monitoring Diseases: Challenges and Possibilities

Saliva is a useful biological fluid and a valuable source of biological information. Saliva contains many of the same components that can be found in blood or serum, but the components of interest tend to be at a lower concentration in saliva, and their analysis demands more sensitive techniques. Metabolomics is starting to emerge as a viable method for assessing the salivary metabolites which are generated by the biochemical processes in elucidating the pathways underlying different oral and systemic diseases. In oral diseases, salivary metabolomics has concentrated on periodontitis and oral cancer. Salivary metabolites of systemic diseases have been investigated mostly in the early diagnosis of different cancer, but also neurodegenerative diseases. This mini-review article aims to highlight the challenges and possibilities of salivary metabolomics from a clinical viewpoint. Furthermore, applications of the salivary metabolic profile in diagnosis and prognosis, monitoring the treatment success, and planning of personalized treatment of oral and systemic diseases are discussed.

Biological consequences of cancer radiotherapy in the context of oral squamous cell carcinoma

Approximately 50% of subjects with cancer have been treated with ionizing radiation (IR) either as a curative, adjuvant, neoadjuvant or as a palliative agent, at some point during the clinical course of their disease. IR kills cancer cells directly by injuring their DNA, and indirectly by inducing immunogenic cell killing mediated by cytotoxic T cells; but it can also induce harmful biological responses to non-irradiated neighbouring cells (bystander effect) and to more distant cells (abscopal effect) outside the primary tumour field of irradiation.Although IR can upregulate anti-tumour immune reactions, it can also promote an immunosuppressive tumour microenvironment. Consequently, radiotherapy by itself is seldom sufficient to generate an effective long lasting immune response that is capable to control growth of metastasis, recurrence of primary tumours and development of second primary cancers. Therefore, combining radiotherapy with the use of immunoadjuvants such as immune checkpoint inhibitors, can potentiate IR-mediated anti-tumour immune reactions, bringing about a synergic immunogenic cell killing effect.The purpose of this narrative review is to discuss some aspects of IR-induced biological responses, including factors that contributes to tumour radiosensitivity/radioresistance, immunogenic cell killing, and the abscopal effect.

Mechanisms of Immunotoxicity: Stressors and Evaluators

The immune system defends the body against certain tumor cells and against foreign agents such as fungi, parasites, bacteria, and viruses. One of its main roles is to distinguish endogenous components from non-self-components. An unproperly functioning immune system is prone to primary immune deficiencies caused by either primary immune deficiencies such as genetic defects or secondary immune deficiencies such as physical, chemical, and in some instances, psychological stressors. In the manuscript, we will provide a brief overview of the immune system and immunotoxicology. We will also describe the biochemical mechanisms of immunotoxicants and how to evaluate immunotoxicity.

Emerging Advances of Nanotechnology in Drug and Vaccine Delivery against Viral Associated Respiratory Infectious Diseases (VARID)

Viral-associated respiratory infectious diseases are one of the most prominent subsets of respiratory failures, known as viral respiratory infections (VRI). VRIs are proceeded by an infection caused by viruses infecting the respiratory system. For the past 100 years, viral associated respiratory epidemics have been the most common cause of infectious disease worldwide. Due to several drawbacks of the current anti-viral treatments, such as drug resistance generation and non-targeting of viral proteins, the development of novel nanotherapeutic or nano-vaccine strategies can be considered essential. Due to their specific physical and biological properties, nanoparticles hold promising opportunities for both anti-viral treatments and vaccines against viral infections. Besides the specific physiological properties of the respiratory system, there is a significant demand for utilizing nano-designs in the production of vaccines or antiviral agents for airway-localized administration. SARS-CoV-2, as an immediate example of respiratory viruses, is an enveloped, positive-sense, single-stranded RNA virus belonging to the coronaviridae family. COVID-19 can lead to acute respiratory distress syndrome, similarly to other members of the coronaviridae. Hence, reviewing the current and past emerging nanotechnology-based medications on similar respiratory viral diseases can identify pathways towards generating novel SARS-CoV-2 nanotherapeutics and/or nano-vaccines.

Metabolic Disturbance and Th17/Treg Imbalance Are Associated With Progression of Gingivitis

Objective

This study sought to explore the role of metabolic disturbance in immunoregulation of gingivitis targeting T helper 17 cells (Th17)/regulatory T cell (Treg).

Materials and Methods

A total of 20 gingivitis patients and 19 healthy volunteers were recruited. Quantitative real time polymerase chain reaction (qRT-PCR) was used to evaluate expression patterns of Forkhead box protein P3 (Foxp3), transforming growth factor-β (TGF-β), retinoid-related orphan receptor-gammat (RORγt) and interleukin 17A (IL-17A) in the peripheral blood lymphocytes of subjects across the two groups. Moreover, the enzyme-linked immunosorbent assay (ELISA) technique was used to detect levels of TGF-β, IL-4, IL-6,TL-10 and L-17A secreted in the plasma as well as the SIgA secreted in saliva. Flow cytometry was used to detect the percentage of CD4⁺CD25⁺ Foxp3⁺Treg cells and the percentage of CD4⁺IL-17A⁺ Th17 cells in whole blood of subjects in both groups. Gas chromatography-mass spectrometry (GC-MS) was employed to analyze the plasma metabolites in the gingivitis patient group. Statistical analysis was applied to determine whether the plasma metabolites and related metabolic pathways significantly differed between gingivitis patients and healthy controls. Ingenuity pathway analysis (IPA) was employed to identify the potential relation between the metabolites and the Th17 and Treg related pathway.

Results

The percentages of CD4⁺IL17A⁺Th17 cells and IL-17 significantly increased in the peripheral blood in the gingivitis group. Moreover, the upregulation of IL-17A mRNA and RORγt mRNA were also found in the gingivitis group. However, the percentage of CD4⁺CD25⁺ Foxp3⁺Treg cells and Foxp3 mRNA in the whole blood did not significantly change. However, TGF-β mRNA as well as TGF-β, IL-4, IL-6, IL-10 in the periperial blood and SIgA in the saliva were higher in the gingivitis group. Notably, that the ratio of Th17/Treg cells was significantly increased during peripheral circulation. Furthermore, we identified 18 different metabolites which were differentially expressed in plasma between the gingivitis and healthy control groups. Notably, the levels of cholesterol, glycerol 1-octadecanoate, d-glucose, uric acid, cyclohexaneacetic acid, 3-pyridine, tryptophan, and undecane 2,4-dimethyl were significantly up-regulated. whereas the levels of lactic acid, glycine, linoleic acid, monopalmitic acid, glycerol, palmitic acid, pyruvate, 1-(3-methylbutyl)-2,3,4,6-tetramethylbenzene, 1 5-anhydro d-altrol, and boric acid were down-regulated in the gingivitis group, relative to healthy controls. IPA showed that these metabolites are connected to IL17 signaling, TGF-B signaling, and IL10 signaling, which are related closely to Th17 and Treg pathway.

Conclusion

Overall, these results showed that disturbance to glycolysis as well as amino and fatty acid metabolism are associated with Th17/Treg balance in gingivitis. Impaired immunometabolism may influence some periodontally involved systemic diseases, hence it is a promising strategy in targeted development of treatment therapies.

To Trap a Pathogen: Neutrophil Extracellular Traps and Their Role in Mucosal Epithelial and Skin Diseases

Neutrophils are the most abundant circulating innate immune cells and comprise the first immune defense line, as they are the most rapidly recruited cells at sites of infection or inflammation. Their main microbicidal mechanisms are degranulation, phagocytosis, cytokine secretion and the formation of extracellular traps. Neutrophil extracellular traps (NETs) are a microbicidal mechanism that involves neutrophil death. Since their discovery, in vitro and in vivo neutrophils have been challenged with a range of stimuli capable of inducing or inhibiting NET formation, with the objective to understand its function and regulation in health and disease. These networks composed of DNA and granular components are capable of immobilizing and killing pathogens. They comprise enzymes such as myeloperoxidase, elastase, cathepsin G, acid hydrolases and cationic peptides, all with antimicrobial and antifungal activity. Therefore, the excessive formation of NETs can also lead to tissue damage and promote local and systemic inflammation. Based on this concept, in this review, we focus on the role of NETs in different infectious and inflammatory diseases of the mucosal epithelia and skin.

The investigation of bacterial adhesion of palatine tonsils epithelial cells in patient with infectious mononucleosis

Aim. To evaluate the features of pharynx tonsils mucous membrane colonization by pathogenic and opportunistic microorganisms by using the pharynx palatine tonsils epithelium electron microscopic examination of the patients with infectious mononucleosis and acute streptococcal tonsillitis. Materials and methods. Two patients – patient P., 12 years old with a confirmed diagnosis of infectious mononucleosis and patient A., 8 years old with confirmed acute streptococcal tonsillitis. The patients were taken a bacteriological examination of the mucus and epithelium scraping from the surface of the pharyngeal tonsils. Tissue samples were examined in the electron microscopy laboratory of the Lviv National University. Results and discussion. 36 tonsils epithelial tissue micro preparations of patient A. and 41 micro preparations of patient P. were studied. Streptococcus pyogenes, Str. pneumoniae, Str. viridans, Сandida albicans, as well as non-pathogenic bacteria: Diphtheroides sp., Neisseria sp., Corynebacterium spp. were identified as result of the patient P. bacteriological examination of mucus from the surface of the pharyngeal tonsils. Staph. aureus, Str. viridans, Str. pneumoniae were identified during a bacteriological examination of patient A. Eosinophils with a two-segmented nucleus, specific granularity, phagocytosed spherical bacteria in the cytoplasm were detected during the histological examination of the materials taken from the surface of the patient’s tonsils with acute tonsillitis. Research showed that bacteria were accumulated not only in the structure of extracellular detritus. Numerous bacteria accumulations were also found in the cytoplasm of the epithelial cells in the patient with infectious mononucleosis. The cell's shape looked like a bunch of grapes. Conclusions. The electron microscopic examination showed differences in the coccal flora localization: the extracellular localization of bacteria in the patient with acute bacterial tonsillitis and intraepithelial presence of the bacteria in the patient with tonsillitis during infectious mononucleosis were found.

Salivary Osteopontin as a Potential Biomarker for Oral Mucositis

Osteopontin (OPN), a multifunctional phosphoglycoprotein also presents in saliva, plays a crucial role in tumour progression, inflammation and mucosal protection. Mucosal barrier injury due to high-dose conditioning regimen administered during autologous and allogeneic peripheral stem cell transplantation (APSCT) has neither efficient therapy nor established biomarkers. Our aim was to assess the biomarker role of OPN during APSCT, with primary focus on oral mucositis (OM). Serum and salivary OPN levels were determined by ELISA in 10 patients during APSCT at four stages of transplantation (day -3/-7, 0, +7, +14), and in 23 respective healthy controls. Results: There was a negative correlation between both salivary and serum OPN levels and grade of OM severity during APSCT (r = -0.791, p = 0.019; r = -0.973, p = 0.001). Salivary OPN increased at days +7 (p = 0.011) and +14 (p = 0.034) compared to controls. Among patients, it was higher at day +14 compared to the time of admission (day -3/-7) (p = 0.039) and transplantation (day 0) (p = 0.011). Serum OPN remained elevated at all four stages of transplantation compared to controls (p = 0.013, p = 0.02, p = 0.011, p = 0.028). During APSCT elevated salivary OPN is a potential non-invasive biomarker of oral mucositis whereas the importance of high serum OPN warrants further studies.

Oral Microbial Diversity Formed and Maintained through Decomposition Product Feedback Regulation and Delayed Responses

Oral microbial diversity plays an important role on oral health maintenance. However, there are only few kinds of substrates available for the microbial flora in oral cavity, and it still remains unclear why oral microbial diversity can be formed and sustained without obvious competitive exclusion. Based on experimental phenomena and data, a new hypothesis was proposed, namely, the decomposition product negative feedback regulation on microbial population size and microbial delay responses including reproductive, reaction, interspecific competition, and substrate decomposition delay responses induced by oral immunity. According to hypothesis and its cellular automata (CA) model, the CA simulation results sufficiently proved that the decomposition product negative feedback regulation and four microbial delay responses could significantly alleviate the interspecific competitions and inhibit the emergence of dominant species, causing the formation and sustenance of oral microbial diversity. This study could also offer effective guidance of prevention and treatment of oral cavity diseases.

Significant salivary changes in relation to oral mucositis following autologous hematopoietic stem cell transplantation

The aim of this multicentre, longitudinal study was to determine salivary changes in relation to oral mucositis (OM) in multiple myeloma patients following high-dose melphalan and autologous hematopoietic stem cell transplantation (ASCT). Unstimulated and stimulated whole-mouth saliva samples (UWS and SWS) were collected before ASCT, 1×/wk during the hospitalisation phase, and 3 and 12 months post-ASCT. During the hospitalisation period OM was scored 3×/wk (WHO system). Flow rate, pH, total protein concentration (Nanodrop), albumin, lactoferrin, neutrophil defensin-1 (HNP1), total IgA and S100A8/A9 (ELISA) were determined. Mixed models were used to evaluate differences between ulcerative (u)OM (≥2 WHO, n = 20) and non-uOM (n = 31) groups. Until 18 days after ASCT, flow rate, pH, total IgA and HNP1 levels decreased in UWS and/or SWS, while log lactoferrin levels were significantly increased (UWS: p = 0.016 95% CI [0.36, 3.58], SWS: p < 0.001 95% CI [1.14, 3.29]). Twelve months post-ASCT, salivary protein levels were similar to baseline except for log total IgA, which was higher (UWS: p < 0.001 95% CI [0.49, 1.29], SWS: p < 0.001 95% CI [0.72, 1.45]). No differences between uOM and non-uOM groups were observed. Changes in salivary proteins indicated an inflammatory reaction in salivary glands coinciding with mucosal and systemic reactions in response to high-dose melphalan.

Alterations in Oral-Nasal-Pharyngeal Microbiota and Salivary Proteins in Mouth-Breathing Children

Mouth breathing induces a series of diseases, while the influence on microbiota of oral cavity and salivary proteins remains unknown. In this study, for the first time, profiles of oral-nasal-pharyngeal microbiota among mouth-breathing children (MB group, n = 10) were compared with paired nose-breathing children (NB group, n = 10) using 16S ribosomal DNA (rDNA) (V3-V4 region) high-throughput sequencing. The differentially expressed salivary proteins were revealed using label-free quantification (LFQ) method, and their associations with bacterial abundance were measured by canonical correspondence analysis (CCA). The overall bacterial profiles differed between the two groups, and the differences were related to the duration of mouth breathing. The diversity of oral-pharyngeal microbiota was significantly higher, and the nasal-pharyngeal species tended to be consistent (unweighted UniFrac, p = 0.38) in the MB group. Opportunistic pathogens were higher in relative abundance as follows: Acinetobacter in the anterior supragingival plaque, Neisseria in unstimulated saliva, Streptococcus pneumoniae in the pharynx, and Stenotrophomonas in the nostrils. The expression level of oxidative-stress-related salivary proteins (lactoylglutathione lyase and peroxiredoxin-5) were upregulated, while immune-related proteins (integrin alpha-M and proteasome subunit alpha type-1) were downregulated in MB group. The differentially expressed proteins were associated with specific bacteria, indicating their potentials as candidate biomarkers for the diagnosis, putatively early intervention, and therapeutic target of mouth breathing. This study showed that mouth breathing influences the oral-nasal-pharyngeal microbiota and enriches certain pathogens, accompanied with the alterations in the salivary environment. Further research on the pathological mechanisms and dynamic changes in longitudinal studies are warranted.

Mediation of Mucosal Immunoglobulins in Buccal Cavity of Teleost in Antibacterial Immunity

The buccal mucosa (BM) of vertebrates is a critical mucosal barrier constantly exposed to rich and diverse pathogens from air, water, and food. While mammals are known to contain a mucosal associated lymphoid tissue (MALT) in the buccal cavity which induces B-cells and immunoglobulins (Igs) responses against bacterial pathogens, however, very little is known about the evolutionary roles of buccal MALT in immune defense. Here we developed a bath infection model that rainbow trout experimentally exposed to Flavobacterium columnare (F. columnare), which is well known as a mucosal pathogen. Using this model, we provided the first evidence for the process of bacterial invasion in the fish BM. Moreover, strong pathogen-specific IgT responses and accumulation of IgT⁺ B-cells were induced in the buccal mucus and BM of infected trout with F. columnare. In contrast, specific IgM responses were for the most part detected in the fish serum. More specifically, we showed that the local proliferation of IgT⁺ B-cells and production of pathogen-specific IgT within the BM upon bacterial infection. Overall, our findings represent the first demonstration that IgT is the main Ig isotype specialized for buccal immune responses against bacterial infection in a non-tetrapod species.

Syringic acid modulates molecular marker-involved cell proliferation, survival, apoptosis, inflammation, and angiogenesis in DMBA-induced oral squamous cell carcinoma in Syrian hamsters

Despite, different medicinal phyto compounds giving an inexhaustible variety of anticancer drugs, potent signalling mechanism of leads  the key successes of anticancer agent, anti-inflammatory, induction of apoptosis, and antiangiogenic. The current study was conducted to estimate the effect of syringic acid (SA) on tumor necrosis factor-α (TNF-α)-mediated nuclear factor-κB (NF-κB) signaling pathways, inducing apoptosis and angiogenic signaling pathways in a hamster model by preneoplastic stages, histological, immunohistochemistry and immunoblots analysis. Hamsters were given oral cancer by painting 0.5% 7,12-dimethylbenz[a]anthracene (DMBA) for 10 weeks. The DMBA-painted hamsters were treated with an effective dose (50 mg/kg body weight) of SA for 14 weeks. The results revealed that oral preadministration of SA to DMBA-treated hamster oral tumorigenesis significantly increased Bcl-2-associated X protein, caspases-3 and -9, and reduced B-cell lymphoma protein 2 and inflammatory cyclooxygenase-2 (COX-2), inducible nitric oxide synthase, and TNF-α expression through NF-κB, and angiogenic vascular endothelial growth factor markers. Taken together, the current study suggests that SA prevents the DMBA-induced hamster buccal pouch carcinogenesis by triggering intrinsic apoptotic pathway via abrogation of the downstream signaling molecules such as COX-2, NF-κB, and TNF-α. This type of preventive strategy based on animal study will offer a means to design chemoprevention trials for humans.

Innate Antimicrobial Defense of Skin and Oral Mucosa

This special issue intends to review and update our understanding of the antimicrobial defense mechanisms of the skin and oral cavity. These two environments are quite different in terms of water, pH, and nutrient availability, but have some common antimicrobial factors. The skin surface supports the growth of a limited range of microorganisms but provides a hostile environment for others. The growth of most microorganisms is prevented or limited by the low pH, scarcity of some nutrients such as phosphorus and the presence of antimicrobial peptides, including defensins and cathelicidins, and antimicrobial lipids, including certain fatty acids and long-chain bases. On the other hand, the oral cavity is a warm, moist, nutrient rich environment which supports the growth of diverse microflora. Saliva coating the oral soft and hard surfaces determines which microorganisms can adhere to these surfaces. Some salivary proteins bind to bacteria and prevent their attachment to surfaces. Other salivary peptides, including defensins, cathelicidins, and histatins are antimicrobial. Antimicrobial salivary proteins include lysozyme, lactoferrin, and lactoperoxidase. There are also antimicrobial fatty acids derived from salivary triglycerides and long-chain bases derived from oral epithelial sphingolipids. The various antimicrobial factors determine the microbiomes of the skin surface and the oral cavity. Alterations of these factors can result in colonization by opportunistic pathogens, and this may lead to infection. Neutrophils and lymphocytes in the connective tissue of skin and mucosa also contribute to innate immunity.

Exosomes from EV71-infected oral epithelial cells can transfer miR-30a to promote EV71 infection

OBJECTIVE

As an extracellular vesicle, exosomes can release from virus-infected cells containing various viral or host cellular elements and could stimulate recipient's cellular response. Enterovirus 71 (EV71), a single-strand positive-sense RNA virus, is known to cause hand, foot, and mouth disease (HFMD) in children and bring about severe clinical diseases.

METHODS

Separated the human oral epithelial cells (OE cells) from normal buccal mucosa through enzyme digestion. Performed a comprehensive miRNA profiling in exosomes from EV71-infected OE cells through deep small RNA-seq. Using the Human Antiviral Response RT Profiler PCR Array profiles to explore the interactions of innate immune signaling networks with exosomal miR-30a. Knocked out the MyD88 gene in macrophages using CRISPR/Cas9-mediated genome editing method.

RESULTS

Our study demonstrated that the miR-30a was preferentially enriched in exosomes that released from EV71-infected human oral epithelial cells through small RNA-seq. We found that the transfer of exosomal miR-30a to macrophages could suppress type Ⅰ interferon response through targeting myeloid differentiation factor 88 (MyD88) and subsequently facilitate the viral replication.

CONCLUSIONS

Exosomes released from EV71-infected OE cells selectively packaged high level of miR-30a that can be functionally transferred to the recipient macrophages resulted in targeting MyD88 and subsequently inhibited type I interferon production in receipt cells, thus promoting the EV71 replication.

Oral microbiota and Alzheimer's disease: Do all roads lead to Rome?

Alzheimer's disease (AD) is a progressive neurodegenerative pathology affecting milions of people worldwide associated with deposition of senile plaques. While the genetic and environmental risk factors associated with the onset and consolidation of late onset AD are heterogeneous and sporadic, growing evidence also suggests a potential link between some infectious diseases caused by oral microbiota and AD. Oral microbiota dysbiosis is purported to contribute either directly to amyloid protein production, or indirectly to neuroinflammation, occurring as a consequence of bacterial invasion. Over the last decade, the development of Human Oral Microbiome database (HOMD) has deepened our understanding of oral microbes and their different roles during the human lifetime. Oral pathogens mostly cause caries, periodontal disease, and edentulism in aged population, and, in particular, alterations of the oral microbiota causing chronic periodontal disease have been associated with the risk of AD. Here we describe how different alterations of the oral microbiota may be linked to AD, highlighting the importance of a good oral hygiene for the prevention of oral microbiota dysbiosis.

Noma (cancrum oris): An unresolved global challenge

Noma (canrum oris) is a mutilating necrotizing disease of uncertain etiology, but it is accepted that it is caused primarily by a polybacterial infection with secondary ischemia. The consequent necrotizing fasciitis, myonecrosis, and osteonecrosis results in destruction of facial structures with severe functional impairment and disfigurement. It most frequently affects children, particularly in sub‐Saharan Africa, who are malnourished or debilitated by systemic conditions including but not limited to malaria, measles, and tuberculosis; and less frequently debilitated HIV‐seropositive subjects. In the vast majority of cases, in susceptible subjects, noma is preceded by necrotizing stomatitis. However, it has been reported, albeit rarely, that noma can arise without any preceding oral lesions being observed. Noma is not recurrent and is not transmissible.

Immune Response to Mucosal Brucella Infection

Brucellosis is one of the most prevalent bacterial zoonosis of worldwide distribution. The disease is caused by Brucella spp., facultative intracellular pathogens. Brucellosis in animals results in abortion of fetuses, while in humans, it frequently manifests flu-like symptoms and a typical undulant fever, being osteoarthritis a common complication of the chronic infection. The two most common ways to acquire the infection in humans are through the ingestion of contaminated dairy products or by inhalation of contaminated aerosols. Brucella spp. enter the body mainly through the gastrointestinal and respiratory mucosa; however, most studies of immune response to Brucella spp. are performed analyzing models of systemic immunity. It is necessary to better understand the mucosal immune response induced by Brucella infection since this is the main entry site for the bacterium. In this review, some virulence factors and the mechanisms needed for pathogen invasion and persistence are discussed. Furthermore, some aspects of local immune responses induced during Brucella infection will be reviewed. With this knowledge, better vaccines can be designed focused on inducing protective mucosal immune response.

Role of whole saliva in the efficacy of sublingual immunotherapy in seasonal allergic rhinitis

BACKGROUND

The development of methods to predict the clinical effectiveness of sublingual immunotherapy (SLIT) for allergic diseases is a crucial matter. We sought to determine whether whole saliva, which is the first body component that contacts allergen extracts during SLIT, is associated with the clinical effectiveness of SLIT in Japanese cedar pollinosis.

METHODS

Blood monocytes or monocytic THP-1 cells were cultured in the presence or absence of either whole saliva or pure saliva with or without treatments including filtration and blockade of TLR2 and/or TLR4 signaling. IL-10 levels in the supernatants were then measured. Whole saliva-induced IL-10 production by THP-1 cells was compared between asymptomatic and disease-onset patients during peak pollen dispersal after SLIT.

RESULTS

Both monocytes and THP-1 cells produced substantial amounts of IL-10 in response to whole saliva. IL-10 production was significantly reduced in response to pure saliva and 0.2 μm-filtered saliva. Simultaneous treatment with polymyxin B and TL2.1, a neutralizing antibody against TLR2, also reduced IL-10 production. IL-10 levels produced by THP-1 cells in response to whole saliva collected prior to SLIT were significantly higher in asymptomatic patients determined by symptom-medication scores than disease-onset patients following SLIT. Such differences were not seen in saliva collected 3 months after the initiation of SLIT or saliva collected during peak pollen dispersal.

CONCLUSIONS

Our results provide a basis for why the sublingual route is effective and preferable in allergen immunotherapy. Saliva-induced IL-10 levels produced by THP-1 cells may be a predictive marker for clinical remission after SLIT.

Subclinical oral involvement in patients with endemic pemphigus foliaceus

Background

We have described a variant of endemic pemphigus foliaceus (EPF) in El Bagre area known as pemphigus Abreu-Manu. Our previous study suggested that Colombian EPF seemed to react with various plakin family proteins, such as desmoplakins, envoplakin, periplakin BP230, MYZAP, ARVCF, p0071 as well as desmoglein 1.

Objectives

To explore whether patients affected by a new variant of endemic pemphigus foliaceus (El Bagre-EPF) demonstrated oral involvement.

Materials and Methods

A case-control study was done by searching for oral changes in 45 patients affected by El Bagre-EPF, as well as 45 epidemiologically matched controls from the endemic area matched by demographics, oral hygiene habits, comorbidities, smoking habits, place of residence, age, sex, and work activity. Oral biopsies were taken and evaluated via hematoxylin and eosin staining, direct immunofluorescence, indirect immunofluorescence, confocal microscopy, and immunohistochemistry.

Results

Radicular pieces and loss of teeth were seen in in 43 of the 45 El Bagre-EPF patients and 20 of the 45 controls (P < 0.001) (confidence interval [CI] 98%). Hematoxylin and eosin staining showed 23 of 45 El Bagre-EPF patients had corneal/subcorneal blistering and lymphohistiocytic infiltrates under the basement membrane zone and around the salivary glands, the periodontal ligament, and the neurovascular bundles in all cell junction structures in the oral cavity; these findings were not seen in the controls (P < 0.001) (CI 98%). The direct immunofluorescence, indirect immunofluorescence, confocal microscopy, and microarray staining displayed autoantibodies to the salivary glands, including their serous acini and the excretory duct cell junctions, the periodontal ligament, the neurovascular bundles and their cell junctions, striated muscle and their cell junctions, neuroreceptors, and connective tissue cell junctions. The autoantibodies were polyclonal. IgA autoantibodies were found in neuroreceptors in the glands and were positive in 41 of 45 patients and 3 of 45 controls.

Conclusions

Patients affected by El Bagre-EPF have some oral anomalies and an immune response, primarily to cell junctions. The intrinsic oral mucosal immune system, including IgA and secretory IgA, play an important role in this autoimmunity. Our data contradict the hypothesis that pemphigus foliaceus does not affect the oral mucosa due to the desmoglein 1-desmoglein 3 compensation.

Vitamin D Deficiency as It Relates to Oral Immunity and Chronic Periodontitis

The biologically active form of vitamin D, 1,25 dihydroxyvitamin D (1,25(OH)2D) and its receptor, the vitamin D receptor (VDR), play roles in maintaining oral immunity and the integrity of the periodontium. Results of observational cross-sectional clinical studies investigating the association between vitamin D serum level and the incidence and severity of chronic periodontitis indicate that, perhaps owing to the immunomodulatory, anti-inflammatory, and antibacterial properties of 1,25(OH)2 D/VDR signalling, a sufficient serum level of vitamin D is necessary for the maintenance of periodontal health. In cases of established chronic periodontitis, vitamin D supplementation is associated with reduction in the severity of periodontitis. As cross-sectional studies provide only weak evidence for any causal association and therefore are of questionable value, either longitudinal cohort studies, case controlled studies, or randomized control trials are needed to determine whether or not deficiency of vitamin D is a risk factor for chronic periodontitis, and whether or not vitamin D supplementation adjunctive to standard periodontal treatment is in any way beneficial. In this article, we discuss the relationship between vitamin D, oral immunity and periodontal disease and review the rationale for using vitamin D supplementation to help maintain periodontal health and as an adjunct to standard periodontal treatment.

A histomorphometric classification system for normal and inflamed mouse duodenum-Quali-quantitative approach

Gut-associated intestinal lymphoid tissue, the largest secondary lymphoid organ in the human body, constantly samples antigens from the gut lumen, presenting as a default response the activation of TCD4⁺ FOXP3⁺ regulatory T cells that secrete a profile of anti-inflammatory cytokines maintaining gut homeostasis denominated from an immunological perspective as mucosal tolerance. However, when antigens are sampled in an inflammatory setting, the immune response may either be protective, in the case of harmful pathogens, or cause further inflammatory reactions as in food allergy, inflammatory bowel diseases, coeliac disease or food protein-induced enterocolitis syndrome. Therefore, there is a need for accurate and consistent experimental models. However, a drawback in comparing these models is the lack of a classification system similar to that which is already used for humans. Thus, the aim of this work was to propose a classification system of the small intestinal histomorphology in experimental mice. To do this we used a mouse antigen-specific gut inflammation model developed by our research group. Duodenum sections stained with haematoxylin-eosin and Alcian blue were scanned using the APERIO scanning system and analysed with the ImageScope^® software. The evaluated parameters were villus area, villus height and width, enterocyte count, mononuclear intra-epithelial leucocyte and goblet cell counts, and architectural and cellular ratios. Food-sensitized animals challenged with a diet containing the corresponding food allergen presented, as for humans, time-dependent shortened and widened villi accompanied by leucocyte infiltrate and loss of goblet cells. With these data, we were able to establish a classification system for experimental intestinal inflammation in mice thus permitting better comparisons among and between experiments than has been possible previously.

Prevalence of two Entamoeba gingivalis ST1 and ST2-kamaktli subtypes in the human oral cavity under various conditions

Advances in molecular biology have facilitated analyses of the oral microbiome; however, the parasites role is poorly understood. Periodontal disease is a multifactorial process involving complex interactions among microorganisms, the host, and environmental factors. At present, the precise composition of the mouth parasites microbiota is unclear. Two protozoan species have been detected in the oral microbiota: Trichomonas tenax and Entamoeba gingivalis, and a new variant, E. gingivalis-ST2-kamaktli, was recently identified by us. In this study, both E. gingivalis and the new E. gingivalis-ST2-kamaktli variant were detected in the oral cavities of people with healthy periodontium, individuals undergoing orthodontic treatment, and patients with periodontal disease. In the group with healthy periodontium, the prevalence of E. gingivalis-ST1 was 48.6% and that of E. gingivalis-ST2-kamaktli 29.5%, with a combined prevalence of 54.3%. In patients undergoing orthodontics treatment, 81.2% carried both amoebas, with 47.5% having E. gingivalis-ST1 and 73.8% E. gingivalis-ST2-kamaktli. In people with periodontal disease, the prevalence of E. gingivalis-ST1 was 57.8%, and that of E. gingivalis-ST2-kamaktli 50.0%, with a combined prevalence of 73.5%; hence, E. gingivalis-ST1 and E gingivalis-ST2-kamaktli were detected in all three groups. The question arises, what are E. gingivalis-ST1 and E. gingivalis-ST2-kamaktli doing in the oral cavity? Although, the answer remains unclear, our results suggest that each amoeba subtype is genetically distinct, and they exhibit different patterns of infectious behavior. We hypothesize that E. gingivalis-ST1 and E. gingivalis-ST2-kamaktli may represent separate species. Our data contribute to better understanding of the roles of E. gingivalis-ST1 and E. gingivalis-ST2-kamaktli in the oral microbiota.

Innate immunity in HIV-1 infection: epithelial and non-specific host factors of mucosal immunity- a workshop report

The interplay between HIV-1 and epithelial cells represents a critical aspect in mucosal HIV-1 transmission. Epithelial cells lining the oral cavity cover subepithelial tissues, which contain virus-susceptible host cells including CD4(+) T lymphocytes, monocytes/macrophages, and dendritic cells. Oral epithelia are among the sites of first exposure to both cell-free and cell-associated virus HIV-1 through breast-feeding and oral-genital contact. However, oral mucosa is considered to be naturally resistant to HIV-1 transmission. Oral epithelial cells have been shown to play a crucial role in innate host defense. Nevertheless, it is not clear to what degree these local innate immune factors contribute to HIV-1 resistance of the oral mucosa. This review paper addressed the following issues that were discussed at the 7th World Workshop on Oral Health and Disease in AIDS held in Hyderabad, India, during November 6-9, 2014: (i) What is the fate of HIV-1 after interactions with oral epithelial cells?; (ii) What are the keratinocyte and other anti-HIV effector oral factors, and how do they contribute to mucosal protection?; (iii) How can HIV-1 interactions with oral epithelium affect activation and populations of local immune cells?; (iv) How can HIV-1 interactions alter functions of oral epithelial cells?

HIV Infection and Compromised Mucosal Immunity: Oral Manifestations and Systemic Inflammation

Mucosal surfaces account for the vast majority of HIV transmission. In adults, HIV transmission occurs mainly by vaginal and rectal routes but rarely via oral route. By contrast, pediatric HIV infections could be as the result of oral route by breastfeeding. As such mucosal surfaces play a crucial role in HIV acquisition, and spread of the virus depends on its ability to cross a mucosal barrier. HIV selectively infects, depletes, and/or dysregulates multiple arms of the human immune system particularly at the mucosal sites and causes substantial irreversible damage to the mucosal barriers. This leads to microbial products translocation and subsequently hyper-immune activation. Although introduction of antiretroviral therapy (ART) has led to significant reduction in morbidity and mortality of HIV-infected patients, viral replication persists. As a result, antigen presence and immune activation are linked to “inflammaging” that attributes to a pro-inflammatory environment and the accelerated aging process in HIV patients. HIV infection is also associated with the prevalence of oral mucosal infections and dysregulation of oral microbiota, both of which may compromise the oral mucosal immunity of HIV-infected individuals. In addition, impaired oral immunity in HIV infection may predispose the patients to periodontal diseases that are associated with systemic inflammation and increased risk of cardiovascular diseases. The purpose of this review is to examine existing evidence regarding the role of innate and cellular components of the oral cavity in HIV infection and how HIV infection may drive systemic hyper-immune activation in these patients. We will also discuss current knowledge on HIV oral transmission, HIV immunosenescence in relation to the oral mucosal alterations during the course of HIV infection and periodontal disease. Finally, we discuss oral manifestations associated with HIV infection and how HIV infection and ART influence the oral microbiome. Therefore, unraveling how HIV compromises the integrity of the oral mucosal tissues and innate immune components of the oral cavity and its association with induction of chronic inflammation are critical for the development of effective preventive interventions and therapeutic strategies.

HIV Infection and Compromised Mucosal Immunity: Oral Manifestations and Systemic Inflammation

Mucosal surfaces account for the vast majority of HIV transmission. In adults, HIV transmission occurs mainly by vaginal and rectal routes but rarely via oral route. By contrast, pediatric HIV infections could be as the result of oral route by breastfeeding. As such mucosal surfaces play a crucial role in HIV acquisition, and spread of the virus depends on its ability to cross a mucosal barrier. HIV selectively infects, depletes, and/or dysregulates multiple arms of the human immune system particularly at the mucosal sites and causes substantial irreversible damage to the mucosal barriers. This leads to microbial products translocation and subsequently hyper-immune activation. Although introduction of antiretroviral therapy (ART) has led to significant reduction in morbidity and mortality of HIV-infected patients, viral replication persists. As a result, antigen presence and immune activation are linked to "inflammaging" that attributes to a pro-inflammatory environment and the accelerated aging process in HIV patients. HIV infection is also associated with the prevalence of oral mucosal infections and dysregulation of oral microbiota, both of which may compromise the oral mucosal immunity of HIV-infected individuals. In addition, impaired oral immunity in HIV infection may predispose the patients to periodontal diseases that are associated with systemic inflammation and increased risk of cardiovascular diseases. The purpose of this review is to examine existing evidence regarding the role of innate and cellular components of the oral cavity in HIV infection and how HIV infection may drive systemic hyper-immune activation in these patients. We will also discuss current knowledge on HIV oral transmission, HIV immunosenescence in relation to the oral mucosal alterations during the course of HIV infection and periodontal disease. Finally, we discuss oral manifestations associated with HIV infection and how HIV infection and ART influence the oral microbiome. Therefore, unraveling how HIV compromises the integrity of the oral mucosal tissues and innate immune components of the oral cavity and its association with induction of chronic inflammation are critical for the development of effective preventive interventions and therapeutic strategies.

Review: allergic contact stomatitis

Allergic contact stomatitis (ACS) is an oral mucosal immunoinflammatory disorder variably characterized clinically by erythematous plaques, vesiculation, ulceration, and/or hyperkeratosis and by pain, burning sensation, or itchiness. ACS is brought about by a T cell-mediated, delayed hypersensitivity immune reaction generated by a second or subsequent contact exposure of an allergen with the oral mucosa, in a genetically susceptible, sensitized subject. Lichenoid contact reaction is a variant of ACS brought about by direct contact with the oral mucosa of certain metals in dental restorations. The features of ACS are neither clinically nor histopathologically specific, so the diagnosis is usually presumptive and can only be confirmed by resolution of the inflammation after withdrawal or removal of the suspected causative allergen. When ACS is suspected but an allergen cannot be identified, patch testing is necessary. In persistent cases, topical corticosteroids are the treatment of choice, but for severe and extensive lesions, systemic corticosteroid and systemic antihistamines may be indicated. In this short review, we highlight the clinical, immunologic, and histopathological features of ACS, and provide some guidelines for diagnosis and management.

Diversity and function of group 1 innate lymphoid cells

Innate lymphoid cells (ILCs) are a heterogeneous population of cells with diverse roles in immune responses. Three major groups of ILCs have been defined on the basis of similarity in their production of signature cytokines, developmental requirements, and phenotypic markers. Group 1 ILCs produce IFN-γ, express the T-box transcription factors (TF) T-bet and/or Eomesodermin (Eomes), group 2 ILCs secrete IL-5 and IL-13 and express the TF GATA-3, while group 3 ILCs produce IL-22 and IL-17 and express the TF RORgt. In this review, we will briefly overview each group in terms of phenotype, function and development and then focus more extensively on group 1 ILCs, expanding on their emerging diversity, their disparate functions and the differences between NK cells and ILC1.