Electron Microscopic Demonstration of Sialoglycoconjugates in the Sinus Mucosa of Rabbits after Inoculation of the Influenza A Virus

ABSTRACT

This study was conducted in order to observe ultrastructural changes in the expression of sialoglycoconjugates in maxillary sinus mucosa after inoculation of influenza A virus utilizing four different gold-labeled lectins ckia amurensis (MAA), wheat germ agglutinin (WGA), sambucus nigra (SNA), and peanut agglutinin (PNA). A comparison of the affinities of these gold-labeled lectins demonstrated the varying distributions of sialoglycoconjugates in the ciliary layer and the granules in goblet cells. Examination of normal sinus mucosa labeled with four gold-labeled lectins showed the distribution of sialoglycoconjugates to be mainly in the ciliary layer and the granules in goblet cells and restricted to the surface of the cilia, microvilli and the secretory light granules. The application of an influenza A virus infection decreased the labeling intensity of gold-labeled MAA in the cilia and the secretory granules but not of WGA. SNA gold did not label the surface of the cilia and granules in either case. PNA gold particles, however, labeled the cilia and the secretory granules very weakly in normal sinus mucosa, but labeled moderately in cases of influenza A virus infection. These results suggest that the sugar residues of sialoglycoconjugates consist of Neu5Ac(alpha2, 3)Gal, GlcNAc, Neu5Ac. They also suggest that the sugar residues serve as a protecting factor or modulator against influenza A virus infection.