Localization of influenza virus sialoreceptors in equine respiratory tract

This study was performed to identify the equine respiratory tract areas which express the specific receptor for equine influenza virus; findings may be useful to provide new ways to treat the infectious disease. The present work aims to visualize in situ the presence of sialoderivatives in the horse respiratory tract in order to localize sialoderivatives acting as influenza virus receptors. To this purpose, nasal mucosae, trachea, bronchus and lung parenchyma were removed from 8 mature horses of both sexes. We performed sialic acid characterization by means of mild and strong periodate oxidation and saponification, combined with lectin histochemistry and sialidase digestion, in addition to the direct evidentiation of sialic acid residues. No differences were shown between sexes. Sialic acid residues are present in the nasal mucous cell secretion, where they are linked to galactose by means of a2-3 linkage and are mainly C9 acetylated, and in the nasal and tracheal epithelial lining, where they are represented by periodate labile residues (a2-3)- and/or (a2-6)- linked to galactose. Specific receptors for equine influenza viruses are present at the nasal and tracheal epithelial lining cell coat levels, and in some trachea epithelial cells, but the horse possesses a preventive defence, which consists of the secretion of a mucous layer at nasal level, which could specifically inactivate the hemagglutinins of equine influenza virus; in addition, it expresses other sialoreceptors which can mask the influenza specific ones

Ultrastructural morphology of equine adipose-derived mesenchymal stem cells

Mesenchymal stem cells are a virtually ubiquitous population of adult stem cells, able to differentiate into various tissue lineages. As they are multipotent and easy to grow in culture, they are at present considered very attractive candidates for tissue repair and gene therapy. With the exception of a few reports, mesenchymal stem cell morphology has been widely disregarded in the past years. In this paper we discuss the establishment of mesenchymal stem cell cultures from equine adipose tissue and describe their fine structure by transmission electron microscopy. The cultured cells revealed a fibroblastoid appearance and were characterized by an eccentric nucleus with multiple nucleoli, dense cytoplasm rich in ribosomes, a rough endoplasmic reticulum with dilated cisternae, elongated mitochondria and heterogeneous vacuolar inclusions. In addition, they were often interconnected by adhesion structures located on the cell body and on cytoplasmic processes contacting other cells. The features observed are evocative of an undifferentiated cellular phenotype and of an intense synthetic and metabolic activity