The Change P82L in the Rift Valley Fever Virus NSs Protein Confers Attenuation in Mice

Rift Valley fever virus (RVFV) is a mosquito-borne bunyavirus that causes an important disease in ruminants, with great economic losses. The infection can be also transmitted to humans; therefore, it considered major threat both human and animal health. In previous work, we described novel RVFV variant selected cell culture the presence of antiviral agent favipiravir was highly attenuated vivo. This displayed 24 amino acid substitutions different viral proteins when compared its parental strain, two them located NSs protein known virulence factor RVFV. By means reverse genetics system, this work have analyzed effect one these substitutions, P82L, has attenuation Rescued viruses carrying single change were clearly BALB/c mice while their growth interferon (IFN)-competent line as well production beta (IFN-β) did not seem affected. However, pattern nuclear accumulation modified cells infected mutant viruses. These results highlight key role modulation infectivity.