To determine whether heparan sulphate residues on the cellular surface could serve as an attachment receptor for pseudorabies virus (PRV), the effect of heparin on PRV in plaque reduction and adsorption tests was investigated. PRV was significantly less sensitive to heparin than was herpes simplex virus type 1 (HSV-1). At concentrations of 500 lag/ml heparin the number of plaques formed by PRV was reduced to 7 % of the untreated control whereas the number of plaques formed by HSV-1 was reduced to below 0.1%. Adsorption of PRV to host cells was also less sensitive to heparin treatment than was adsorption of HSV-1.

Virus adsorption and uptake of human rhinovirus 14 (HRV14) were studied with HeLa cells and baby hamster kidney (BHK) cells which were transfected with the HRV14 receptor intercellular adhesion molecule-1 (ICAM-1). Transmission electron microscopy of HeLa cells revealed that HRV14 was internalized via clathrin-coated pits and -coated vesicles. A minority of virus particles also used uncoated vesicles for entry. The internalization showed the characteristics of receptor-mediated endocytosis. Presence of the carboxylic ionophore monensin inhibited viral uncoating, indicating a pH-dependent entry mechanism. The expression of ICAM-1 on the surface of the ICAM-1 transfected baby hamster kidney cells (BHK-ICAM cells) allowed extensive virus adsorption and internalization through membrane channels. Virus particles were lined up in these channels like pearls on a string, but did not induce a productive infection. Although ICAM-1 was expressed to the same degree on BHK-ICAM and HeLa cells, HRV14 induced neither viral protein and RNA syntheses nor infectious virus progeny in BHK-ICAM cells. ICAM-1 on the transfected BHK cells was a functional active receptor as it rendered these cells permissive to coxsackievirus A21. These results suggest that HRV14 uptake into BHK-ICAM cells is blocked directly in or shortly after its final step of internalization, the uncoating. Our findings underline that the receptor ICAM-1 determines virus uptake into cells, however, is not sufficient to confer susceptibility of BHK cells to HRV14 infection.

Glycosaminoglycans (GAGs) are linear heteropolysaccharides consisting of repeated disaccharide units that are variably N- and O-sulfated. Due to this heterogeneity, GAGs possess a high amount of structural information. Linked to a protein core to form a proteoglycan, GAGs are present on the surface of probably all mammalian tissues. During the recent years, a number of pathogens ranging from viruses to protozoans were found to interact specifically with cell surface GAGs to recognize and bind to their target cells. This review is intended to give a short overview over protein-GAG interaction under the aspects of infection.

Glycosaminoglycans (GAGs) are linear heteropolysaccharides consisting of repeated disaccharide units that are variably N-and O-sulfated. Due to this heterogeneity, GAGs possess a high amount of structural information. Linked to a protein core to form a proteoglycan, GAGs are present on the surface of probably all mammalian tissues. During the recent years, a number of pathogens ranging from viruses to protozoans were found to interact specifically with cell surface GAGs to recognize and bind to their target cells. This review is intended to give a short overview over protein-GAG interaction under the aspects of infection.