FIG. 5.

The selective usage of DC-SIGNR for infection is specific to WNV glycoproteins containing native glycosylation patterns. A Renilla luciferase-expressing WNV replicon was packaged into RVPs by transfection of BHK cells containing this replicon with expression plasmids encoding flavivirus capsid proteins and prM-E polyproteins. Serial fourfold dilutions of RVPs were added to K562 cell lines, and infection was assessed after 48 h by measuring luciferase activity. Open squares, K562-SIGN cells; closed circles, K562-SIGNR cells; closed diamonds, K562 control cells. (A) RVPs were made by use of pWNIIcap, encoding the WNV capsid protein, and pCBWN, encoding the prM-E polyprotein of WNV strain NY99-6480 (NY99). The E protein of NY99-6480 is identical to the E protein of NY2000. (B) RVPs were made using pDEN1cap, encoding the dengue virus capsid protein, and pDV1 prM-E VAX, encoding a serotype 1 dengue virus prM-E polyprotein. (C) RVPs were made as described for panel A, but DMJ was added during production to yield particles containing predominantly high-mannose N-linked glycans. Similar results were seen with more than four separate RVP preparations. Note the difference between the x axis scale in panels A and C and that in panel B.