The role of scavenger receptor BI in hepatitis - eTheses Repository ...

1.4.2 Attachment factors
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The true definition of a virus receptor is somewhat debatable. There are some
types of molecules used by viruses to aid tethering to the cell surface that are
not thought to initiate specific entry. These so called attachment factors are
important for infection as they bring a virus into proximity with the cell surface
and its entry receptors. However virus interaction with them may be of low
specificity and have little role in viral entry (102, 194). The following section
discusses molecules employed by HCV that, as current understanding allows,
fall into this category.
Heparan sulphate
Glycosaminoglycans (GAGs) are polysaccharide moieties that are post-
translationally added to certain types of protein know as proteoglycans (30).
Heparan sulphate (HS) is a long chain, highly sulphated GAG, that is
commonly found on proteoglycans in the extracellular matrix and at the
plasma membrane and offers a ubiquitous target for viral attachment (30,
102).
HCV E2 association with HS (20, 22), is believed to occur via electrostatic
interactions involving basic residues possibly including the HVR (20, 22),
although some evidence disputes this (57). Soluble highly sulphated HS
inhibits the binding of E2 to cells and reduces HCVpp entry, as does removal
of cellular HS by heparinase (20, 22). However, to date there is little evidence