Dexamethasone solution and dexamethasone in Mucolox™ for the treatment of oral inflammatory ulcerative diseases: A phase II randomized clinical trial.

BACKGROUND: Mucolox™ is a mucosal drug delivery system that prolongs the contact time between the oral mucosa and topical corticosteroids, potentially reducing the need for multiple applications daily. This study aimed to assess the clinical efficacy and tolerability of dexamethasone 0.5 mg/5 mL solution in Mucolox™ for the management of oral inflammatory ulcerative diseases. METHODS: Participants were randomly assigned to receive dexamethasone 0.5 mg/5 mL in Mucolox™ (Mucolox™ arm) or dexamethasone 0.5 mg/5 mL solution (standard arm) and instructed to swish/gargle for 5 min three times daily. Changes from pre- to posttreatment patient's sensitivity score (0-10 on a visual analog scale), reticulation/erythema/ulceration score, and oral health-related quality of life were evaluated at baseline and at the end of the study period. RESULTS: Twenty nine patients (75% females) with a median age of 58 years (range 18-79) were enrolled and randomly allocated to the Mucolox™ or standard arm. One subject was excluded. Although statistically significant in both arms, the pre- to posttreatment sensitivity score reduction was higher in the Mucolox™ arm (6.3 vs. 4.4-point reduction). Both arms showed a decrease in the reticulation/erythema/ulceration score between the two visits (7.2 vs. 4.7 [Mucolox™ arm]; 8.0 vs. 4.8 [standard arm]; p > 0.05). Mucolox™ in dexamethasone 0.5 mg/5 mL solution was better tolerated when taste and level of comfort were considered. CONCLUSIONS: Both treatments were effective in the management of oral inflammatory ulcerative diseases. Dexamethasone 0.5 mg/5 mL in Mucolox™ was better tolerated and was slightly better in controlling patients' oral sensitivity. Larger studies are needed to confirm these findings in oral inflammatory ulcerative diseases patients. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04540133.

Differential transmission of HIV traversing fetal oral/intestinal epithelia and adult oral epithelia.

While human immunodeficiency virus (HIV) transmission through the adult oral route is rare, mother-to-child transmission (MTCT) through the neonatal/infant oral and/or gastrointestinal route is common. To study the mechanisms of cell-free and cell-associated HIV transmission across adult oral and neonatal/infant oral/intestinal epithelia, we established ex vivo organ tissue model systems of adult and fetal origin. Given the similarity of neonatal and fetal oral epithelia with respect to epithelial stratification and density of HIV-susceptible immune cells, we used fetal oral the epithelium as a model for neonatal/infant oral epithelium. We found that cell-free HIV traversed fetal oral and intestinal epithelia and infected HIV-susceptible CD4(+) T lymphocytes, Langerhans/dendritic cells, and macrophages. To study the penetration of cell-associated virus into fetal oral and intestinal epithelia, HIV-infected macrophages and lymphocytes were added to the surfaces of fetal oral and intestinal epithelia. HIV-infected macrophages, but not lymphocytes, transmigrated across fetal oral epithelia. HIV-infected macrophages and, to a lesser extent, lymphocytes transmigrated across fetal intestinal epithelia. In contrast to the fetal oral/intestinal epithelia, cell-free HIV transmigration through adult oral epithelia was inefficient and virions did not infect intraepithelial and subepithelial HIV-susceptible cells. In addition, HIV-infected macrophages and lymphocytes did not transmigrate through intact adult oral epithelia. Transmigration of cell-free and cell-associated HIV across the fetal oral/intestinal mucosal epithelium may serve as an initial mechanism for HIV MTCT.

HIV-associated disruption of mucosal epithelium facilitates paracellular penetration by human papillomavirus.

The incidence of human papillomavirus (HPV)-associated epithelial lesions is substantially higher in human immunodeficiency virus (HIV)-infected individuals than in HIV-uninfected individuals. The molecular mechanisms underlying the increased risk of HPV infection in HIV-infected individuals are poorly understood. We found that HIV proteins tat and gp120 were expressed within the oral and anal mucosal epithelial microenvironment of HIV-infected individuals. Expression of HIV proteins in the mucosal epithelium was correlated with the disruption of epithelial tight junctions (TJ). Treatment of polarized oral, cervical and anal epithelial cells, and oral tissue explants with tat and gp120 led to disruption of epithelial TJ and increased HPV pseudovirion (PsV) paracellular penetration in to the epithelium. PsV entry was observed in the basal/parabasal cells, the cells in which the HPV life cycle is initiated. Our data suggest that HIV-associated TJ disruption of mucosal epithelia may potentiate HPV infection and subsequent development of HPV-associated neoplasia.

HIV is inactivated after transepithelial migration via adult oral epithelial cells but not fetal epithelial cells.

Oral transmission of human immunodeficiency virus (HIV) in adult populations is rare. However, HIV spread across fetal/neonatal oropharyngeal epithelia could be important in mother-to-child transmission. Analysis of HIV transmission across polarized adult and fetal oral epithelial cells revealed that HIV transmigrates through both adult and fetal cells. However, only virions that passed through the fetal cells - and not those that passed through the adult cells - remained infectious. Analysis of expression of anti-HIV innate proteins beta-defensins 2 and 3, and secretory leukocyte protease inhibitor in adult, fetal, and infant oral epithelia showed that their expression is predominantly in the adult oral epithelium. Retention of HIV infectivity after transmigration correlated inversely with the expression of these innate proteins. Inactivation of innate proteins in adult oral keratinocytes restored HIV infectivity. These data suggest that high-level innate protein expression may contribute to the resistance of the adult oral epithelium to HIV transmission.

Epstein-Barr virus (EBV)-infected monocytes facilitate dissemination of EBV within the oral mucosal epithelium.

Epstein-Barr virus (EBV) causes hairy leukoplakia (HL), a benign lesion of oral epithelium that occurs primarily in the setting of human immunodeficiency virus (HIV)-associated immunodeficiency. However, the mechanisms of EBV infection of oral epithelium are poorly understood. Analysis of HL tissues shows a small number of EBV-positive intraepithelial macrophages and dendritic/Langerhans cells. To investigate a role for these cells in spreading EBV to epithelial cells, we used tongue and buccal explants infected ex vivo with EBV. We showed that EBV first infects submucosal CD14(+) monocytes, which then migrate into the epithelium and spread virus to oral epithelial cells, initiating productive viral infection within the terminally differentiated spinosum and granulosum layers. Incubation of EBV-infected monocytes and oral explants with antibodies to CCR2 receptor and monocyte chemotactic protein 1 prevented entry of monocytes into the epithelium and inhibited EBV infection of keratinocytes. B lymphocytes played little part in the spread of EBV to keratinocytes in our explant model. However, cocultivation of EBV-infected B lymphocytes with uninfected monocytes in vitro showed that EBV may spread from B lymphocytes to monocytes. Circulating EBV-positive monocytes were detected in most HIV-infected individuals, consistent with a model in which EBV may be spread from B lymphocytes to monocytes, which then enter the epithelium and initiate productive viral infection of keratinocytes.