Infectious clones of novel lineage 1 and lineage 2 West Nile virus strains WNV-TX02 and WNV-Madagascar.

We report the generation of West Nile virus (WNV) infectious clones for the pathogenic lineage 1 Texas-HC2002 and nonpathogenic lineage 2 Madagascar-AnMg798 strains. The infectious clones exhibited biological properties similar to those of the parental virus isolates. We generated chimeric viruses and found that viral factors within the structural and nonstructural regions of WNV-TX contribute to the control of type I interferon defenses. These infectious clones provide new reagents to study flavivirus immune regulation and pathogenesis.