Can the tonsils influence oral HIV transmission?July 26, 2007Bethesda, MD - Current research demonstrates that the tonsils may possess the necessary factors to act as a transmission site for the spread of HIV. The related report by Moutsopoulos et al, "Tonsil Epithelial Factors May Influence Oropharyngeal Human Immunodeficiency Virus Transmission," appears in the August issue of The American Journal of Pathology. Human immunodeficiency virus (HIV) spreads mainly through sexual contact of mucosal surfaces, which the virus must cross to come in contact with underlying immune cells for infection to occur. While the oral mucosal surfaces are largely protected by their thickened exterior and the defensive proteins present in saliva, it is speculated that a low number of infections may occur via oral sexual contact. Researchers have questioned whether such transmission is facilitated by the tonsils, which contain high numbers of immune cells that may be easily accessible to HIV. Researchers led by Dr. Sharon M. Wahl, of the National Institute of Dental and Craniofacial Research, NIH, examined this question by comparing the gene expression profiles of tonsils and oral gingiva. Although many of the genes examined showed similar expression patterns between the two oral sites, differences were observed. Notably, several genes related to immune functions, including HIV co-receptor CXCR4, displayed significantly higher expression in the tonsils while gingiva more strongly expressed keratin genes, which "thicken" the tissue and provide barrier protection. Further, Dr. Wahl's group found that CXCR4 protein was expressed on gingiva, oral mucosa and tonsils, but the expression was strongest in tonsils, particularly in regions where immune surveillance is known to occur. Levels of additional molecules that may bind and entrap HIV, such as complement receptors and FcR, were also higher in the tonsils. However, when antiviral proteins were examined, lower levels of SLPI (secretory leukocyte protease inhibitor), defensins, and thrombospondin were found in the tonsils. Altogether, Moutsopoulos et al's data "suggest that increased expression of molecules associated with HIV binding and entry coupled with decreased innate antiviral factors may render the tonsil a potential site for oral transmission." The decreased amount of keratin and antiviral proteins in the tonsils renders this tissue more permeable to foreign invaders, thus allowing tonsils to function in immune surveillance. However, it also renders the site more accessible to pathogens that infect immune cells. Future studies will elucidate how host vulnerability is influenced by tonsils during exposure to HIV. American Journal of Pathology |
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| Related Tonsils Current Events and Tonsils News Articles Tobacco use linked to worse outcomes in HPV-positive head and neck cancer, U-M study finds Patients with head and neck cancer linked to high risk human papillomavirus, or HPV, have worse outcomes if they are current or former tobacco users, according to a new study from researchers at the University of Michigan Comprehensive Cancer Center. Possible pharmacological target(s) identified in pediatric OSA Children with obstructive sleep apnea (OSA) may one day be able to have an injection or use a throat spray instead of getting their tonsils removed to cure their snoring, according to a new study from the University of Chicago, which found that a specific gene product may be responsible for the proliferation of adenotonsillar tissue that can cause pediatric OSA. Urine test for pediatric obstructive sleep apnea possible Researchers at the University of Chicago have discovered a technique that is able to determine whether a child has obstructive sleep apnea (OSA) or habitual snoring by screening their urine. Cell study explains why younger people more at risk of vCJD Specific cells within the immune system could help explain why younger people are more susceptible to variant CJD, scientists believe. Rare head and neck cancer linked to HPV, study finds An increase in cases of a rare type of head and neck cancer appears to be linked to HPV, or human papillomavirus, according to a new study from researchers at the University of Michigan Comprehensive Cancer Center. Radiofrequency energy technique as effective as tonsillectomy surgery Radiofrequncy-tonsillotomy, which enables surgeons to reduce the size of the tonsillar tissue instead of removing the tonsils entirely, seems to be an effective and safe method of treating children with symptoms of enlarged tonsils. Study finds increased 'sibling risk' of obstructive sleep apnea in children A study in the Aug. 1 issue of the journal SLEEP indicates that children have an increased risk of developing obstructive sleep apnea (OSA) if they have at least one sibling who has been diagnosed with the sleep disorder. Sleeping with the enemy It has been linked to learning impairment, stroke and premature death. Now UNSW research has found that snoring associated with sleep apnoea may impair brain function more than previously thought. Waist size and body mass index are risk factors for sleep disordered breathing in children A study in the June 1 issue of the journal SLEEP found that waist circumference and body mass index (BMI) are consistent, independent risk factors for all severity levels of sleep disordered breathing (SDB) in children, suggesting that as with adult SDB, metabolic factors are important risk factors for childhood SDB. Surgery proves effective in treating pediatric obstructive sleep apnea Infants and young toddlers with obstructive sleep apnea and sleep disordered breathing experience significant improvement following surgical treatment of the ailment, according to an invited article in the June 2009 issue of Otolaryngology-Head and Neck Surgery. More Tonsils Current Events and Tonsils News Articles |
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