Adhesion - sialic-acid-specific

It has been known for many years that microbial pathogens, i.e., viruses, mycoplasma, bacteria, and protozoa, take advantage of cell surface sialic acids to adhere to their respective host cells (Table V). In Chapter 9 the role of sialic acids in infection by myxoviruses will be discussed. Sialic acid-specific adhesion... 

Adhesion of the fungus to specific nematode species and regions of the nematode body is mediated by a fungal lectin specific for N-acetylneuraminic acid (sialic acid) (22) It has since been suggested that steric configuration of sialic acid residues on the nematode surface serve as stimuli for the processes of adhesion and infection (23). ... 

Among the fungal and protozoal lectins only a few have been studied in detail. One of these is the galactose-specific lectin of the protozoa Entamoeba histolytica. It mediates adhesion of the parasite to human colonic mucin glycoproteins and has a central role in the contact-dependent cytolysis or histolysis for which the parasite is named. A sialic-acid-speeific lectin has been isolated from merozoites of the human malarial parasite, Plasmodium falciparum. An unusual lectin is that of the protozoan Giardia lamblia, specific for mannose-6-phosphate, which is activated by trypsinization. 

Abstract Persistent colonization of the human stomach by Helicobacter pylori is a risk factor for the development of peptic ulcer disease and gastric cancer. Adhesion of microbes to the target tissue is an important determinant for successful initiation, establishment and maintenance of infection, and a variety of different candidate carbohydrate receptors for H. pylori have been identified. Here the different the binding specifities, and their potential role in adhesion to human gastric epithelium are described. Finally, recent findings on the roles of sialic acid binding SabA adhesin in interactions with human neutrophils and erythrocytes are discussed. 

Replacement of A-acyl and 0-acyl by A-thioacyl groups in sialo-sugar chains of cell surface glycoproteins can influence certain biological functions mediated by sialic acids, such as cellular adhesion phenomena or virus specificity for host cells. Interestingly, sialyltransferases specific for different... 

---