40 research outputs found

    Inactivation of HIV-1 in Polarized Infant Tonsil Epithelial Cells by Human Beta-Defensins 2 and 3 Tagged with the Protein Transduction Domain of HIV-1 Tat

    No full text
    Mother-to-child transmission (MTCT) of HIV-1 may occur during pregnancy, labor, and breastfeeding; however, the molecular mechanism of MTCT of virus remains poorly understood. Infant tonsil mucosal epithelium may sequester HIV-1, serving as a transient reservoir, and may play a critical role in MTCT. Innate immune proteins human beta-defensins 2 (hBD-2) and -3 may inactivate intravesicular virions. To establish delivery of hBD-2 and -3 into vesicles containing HIV-1, we tagged hBDs with the protein transduction domain (PTD) of HIV-1 Tat, which facilitates an efficient translocation of proteins across cell membranes. Our new findings showed that hBD-2 and -3 proteins tagged with PTD efficiently penetrated polarized tonsil epithelial cells by endocytosis and direct penetration. PTD-initiated internalization of hBD-2 and -3 proteins into epithelial cells led to their subsequent penetration of multivesicular bodies (MVB) and vacuoles containing HIV-1. Furthermore, PTD played a role in the fusion of vesicles containing HIV-1 with lysosomes, where virus was inactivated. PTD-initiated internalization of hBD-2 and -3 proteins into ex vivo tonsil tissue explants reduced the spread of virus from epithelial cells to CD4+ T lymphocytes, CD68+ macrophages, and CD1c+ dendritic cells, suggesting that this approach may serve as an antiviral strategy for inactivating intraepithelial HIV-1 and reducing viral MTCT

    Effectiveness and costs of sialendoscopy in pediatric patients with salivary gland disorders.

    No full text
    Objectives/hypothesisThis study aimed to characterize the common salivary gland disorders presenting in the pediatric population and to describe the diagnostic and therapeutic outcomes of sialendoscopy in this population.Study designRetrospective observational study in a tertiary care pediatric medical center.MethodsMedical records review of patients under 18 years of age who presented to pediatric otolaryngology with symptoms related to a salivary gland disorder from 2002 to 2014.ResultsFifty patients were identified with an average age of 7.5 years at presentation. Eighty percent (40/50) of cases were diagnosed with juvenile recurrent parotitis (JRP), and 15 underwent sialendoscopy. The other 10 (20%) patients presented with sialolithiasis. These patients had a higher average age at presentation (12.4 vs. 6.3 years), and the majority were successfully removed with sialendoscopic techniques. Juvenile recurrent parotitis patients who underwent sialendoscopy had significantly higher costs of care during the period of observation compared to those who did not have a procedure, without a statistically significant difference in outcomes.ConclusionsSialendoscopy is an effective tool for stone retrieval in pediatric sialolithiasis. Juvenile recurrent parotitis patients who underwent sialendoscopy had outcomes similar to those selected for conservative therapy, calling into question whether the substantially higher care costs can be justified. Further prospective studies addressing cost-effectiveness will help define the role of sialendoscopy in JRP.Level of evidence4

    Pediatric sialendoscopy indications and outcomes.

    No full text
    Purpose of reviewChronic sialadenitis can affect patients of all age ranges and typically presents as recurrent or chronic painful swelling of the salivary glands. In children, the most common cause of sialadenitis is juvenile recurrent parotitis. Salivary stones, or sialolithiasis, are a much less common cause. Historically, for patients with chronic sialadenitis who failed conservative management, salivary gland removal was the standard treatment option. Recently, however, sialendoscopy has emerged as an effective gland-preserving procedure for sialadenitis evaluation and treatment in adults and children. The aim of this review is to discuss pediatric sialadenitis evaluation and treatment, including sialendoscopy indications, technique, and outcomes.Recent findingsSialendoscopy is a well tolerated and effective treatment for sialadenitis Sialendoscopy and salivary duct irrigation have been shown to improve frequency and severity of sialadenitis episodes in patients with juvenile recurrent parotitis. Salivary stones are managed successfully with endoscopic and combined endoscopic-assisted open approaches. Minimally invasive approaches with sialendoscopy have improved the ability to preserve salivary glands in patients with recurrent sialadenitis.SummarySialendoscopy is a well tolerated and effective procedure for recurrent sialadenitis in children

    HIV internalization into oral and genital epithelial cells by endocytosis and macropinocytosis leads to viral sequestration in the vesicles.

    No full text
    Recently, we showed that HIV-1 is sequestered, i.e., trapped, in the intracellular vesicles of oral and genital epithelial cells. Here, we investigated the mechanisms of HIV-1 sequestration in vesicles of polarized tonsil, foreskin and cervical epithelial cells. HIV-1 internalization into epithelial cells is initiated by multiple entry pathways, including clathrin-, caveolin/lipid raft-associated endocytosis and macropinocytosis. Inhibition of HIV-1 attachment to galactosylceramide and heparan sulfate proteoglycans, and virus endocytosis and macropinocytosis reduced HIV-1 sequestration by 30-40%. T-cell immunoglobulin and mucin domain 1 (TIM-1) were expressed on the apical surface of polarized tonsil, cervical and foreskin epithelial cells. However, TIM-1-associated HIV-1 macropinocytosis and sequestration were detected mostly in tonsil epithelial cells. Sequestered HIV-1 was resistant to trypsin, pronase, and soluble CD4, indicating that the sequestered virus was intracellular. Inhibition of HIV-1 intraepithelial sequestration and elimination of vesicles containing virus in the mucosal epithelium may help in the prevention of HIV-1 mucosal transmission

    HIV-1 proteins gp120 and tat induce the epithelial-mesenchymal transition in oral and genital mucosal epithelial cells.

    No full text
    The oral, cervical, and genital mucosa, covered by stratified squamous epithelia with polarized organization and strong tight and adherens junctions, play a critical role in preventing transmission of viral pathogens, including human immunodeficiency virus (HIV). HIV-1 interaction with mucosal epithelial cells may depolarize epithelia and disrupt their tight and adherens junctions; however, the molecular mechanism of HIV-induced epithelial disruption has not been completely understood. We showed that prolonged interaction of cell-free HIV-1 virions, and viral envelope and transactivator proteins gp120 and tat, respectively, with tonsil, cervical, and foreskin epithelial cells induces an epithelial-mesenchymal transition (EMT). EMT is an epigenetic process leading to the disruption of mucosal epithelia and allowing the paracellular spread of viral and other pathogens. Interaction of cell-free virions and gp120 and tat proteins with epithelial cells substantially reduced E-cadherin expression and activated vimentin and N-cadherin expression, which are well-known mesenchymal markers. HIV gp120- and tat-induced EMT was mediated by SMAD2 phosphorylation and activation of transcription factors Slug, Snail, Twist1 and ZEB1. Activation of TGF-β and MAPK signaling by gp120, tat, and cell-free HIV virions revealed the critical roles of these signaling pathways in EMT induction. gp120- and tat-induced EMT cells were highly migratory via collagen-coated membranes, which is one of the main features of mesenchymal cells. Inhibitors of TGF-β1 and MAPK signaling reduced HIV-induced EMT, suggesting that inactivation of these signaling pathways may restore the normal barrier function of mucosal epithelia
    corecore