Expression of influenza virus sialic acid receptors in the airway of asthmatic mice / 中华实验和临床病毒学杂志

ABSTRACT

Objective@#To observe the expression of influenza virus sialic acid receptors(SAa2, 3-gal and SAa2, 6-gal)and the influence of dexamethasone intervention to its expression in the airway of asthmatic mice.@*Methods@#Thirty BALB/c mice were randomly divided into normal group (group N, n=10), asthma group (group A, n=10) and dexamethasone intervention group (group D, n=10). Mice of group A were sensitized and challenged by ovalbumin (OVA) to build asthmatic model. Mice in group D were given dexamethasone (2 mg/kg i. p.) 30 minutes before challenging, other procedures were the same as those of group A. The levels of IL-5 in the brochoalveolar lavage fluid (BALF) of mice in each group were determined by ELISA, the pathological changes of lung tissues were observed by HE staining, the degree of mucus secretion in airways were observed by AB-PAS staining, the expression of Mucin5ac (Muc5ac) in lung tissues were observed by immunohistochemical (IHC) staining, the expression of virus sialic acid receptors were observed by immunofluorescence.@*Results@#The counts of eosinophils, the level of IL-5 in BALF, the airway inflammatory pathological scores, the degree of mucus secretion, the expression of Muc5ac protein of group A were higher than those in group N and D (P<0.05). Receptors of SA α 2, 3-gal and SA α 2, 6-gal were expressed in all groups (P<0.05). The average positive rate for SA α 2, 3-gal receptor in group A were higher than that in group N. The average positive rate for SA α 2, 3-gal and SA α 2, 6-gal receptor in group D were higher than those of group N and A (P<0.05).@*Conclusion@#All these results indicate that the high expression of influenza virus sialic acid receptors due to asthma and dexamethasone intervention may be the mechanism of the enhanced susceptibility to influenza virus of asthma patients.