Increased Concentration of Iodide in Airway Secretions Is Associated with Reduced Respiratory Syncytial Virus Disease Severity

摘要: Recent studies have revealed that the human and nonrodent mammalian airway mucosa contains an oxidative host defense system. This three-component system consists of hydrogen peroxide (H2O2)-producing enzymes dual oxidase (Duox)1 Duox2, thiocyanate (SCN−), secreted lactoperoxidase (LPO). The LPO-catalyzed reaction between H2O2 SCN− yields bactericidal hypothiocyanite (OSCN−) in surface liquid (ASL). Although is physiological substrate LPO, Duox/LPO/halide can generate hypoiodous acid when iodide (I−) concentration elevated ASL. Because acid, but not OSCN−, inactivates respiratory syncytial virus (RSV) cell culture, we used a lamb model RSV to test whether potassium (KI) could enhance this vivo. Newborn lambs received KI by intragastric gavage or were left untreated before intratracheal inoculation RSV. treatment led 10-fold increase ASL I− concentration, was approximately 30-fold higher than measured serum. Also, expiratory effort, gross lung lesions, pulmonary expression antigen IL-8 reduced KI-treated as compared with nontreated control lambs. Inhibition LPO activity significantly increased mRNA, antigen. Similar experiments 3-week-old demonstrated administration associated decreased titers bronchoalveolar lavage fluid, expression. Overall, these data indicate high-dose supplementation be vivo lessen severity infections, potentially through augmentation mucosal defenses.