"Central for portal function is the bridging glycoprotein MFG-E8. Using a phosphatidylserine binding domain and an RGD motif MFG-E8 helps target HIV-1 VLPs to alpha V integrin bearing sinus lining macrophage. Lack of MFG-E8 or integrin blockade severely limits HIV-1 VLP spread onto FDC networks."xsd:string