Table 2.: Development on the Role of Heparan Sulfate (HS) and Modified HS in HSV-1 Entry

Year	Chronological Development on the Role of HSPGs (Heparan Sulfate Proteoglycans) in HSV-1 Entry and Spread
1992	HSV-1 uses cell surface HS for cell binding/attachment  [23]
1999	3-OST-3 modifications of HS generates HSV-1 gD receptor [3]
2002	3-OST-5 modified HS allows HSV-1 entry and spread [40]
2004	3-OST-6  modified HS is a receptor for HSV-1 entry and spread [43]
2005	3-OST-4 modified HS is a receptor for HSV-1 entry and spread [42]
2005	3-OST-2 modified HS is a receptor for HSV-1 entry and spread [42]
2006	Clinical significance of 3-OST-3 in HSV-1 infection to human corneal fibroblasts [70]
2006	Role of  HS in HSV-1 surfing on filopodia [71]
2010	Role of  syndecans in HSV-1 infection  [72]
2011	Zebrafish encoded 3-OST-3 also function as HSV-1 entry receptor [69]
2011	In vivo significance of 3-OST-3 receptor during corneal HSV-1 infection [73]
2012	Role of anti-3-OS HS peptides  targeting HSV-2 entry [74]