Beyond Members of the Flaviviridae Family, Sofosbuvir Also Inhibits Chikungunya Virus Replication.

Chikungunya virus (CHIKV) causes a febrile disease associated with chronic arthralgia, which may progress to neurological impairment. Chikungunya fever (CF) is an ongoing public health problem in tropical and subtropical regions of the world, where control of the CHIKV vector, Aedes mosquitos, has failed. As there is no vaccine or specific treatment for CHIKV, patients receive only palliative care to alleviate pain and arthralgia. Thus, drug repurposing is necessary to identify antivirals against CHIKV. CHIKV RNA polymerase is similar to the orthologue enzyme of other positive-sense RNA viruses, such as members of the Flaviviridae family. Among the Flaviviridae, not only is hepatitis C virus RNA polymerase susceptible to sofosbuvir, a clinically approved nucleotide analogue, but so is dengue, Zika, and yellow fever virus replication. Here, we found that sofosbuvir was three times more selective in inhibiting CHIKV production in human hepatoma cells than ribavirin, a pan-antiviral drug. Although CHIKV replication in human induced pluripotent stem cell-derived astrocytes was less susceptible to sofosbuvir than were hepatoma cells, sofosbuvir nevertheless impaired virus production and cell death in a multiplicity of infection-dependent manner. Sofosbuvir also exhibited antiviral activity in vivo by preventing CHIKV-induced paw edema in adult mice at a dose of 20 mg/kg of body weight/day and prevented mortality in a neonate mouse model at 40- and 80-mg/kg/day doses. Our data demonstrate that a prototypic alphavirus, CHIKV, is also susceptible to sofosbuvir. As sofosbuvir is a clinically approved drug, our findings could pave the way to it becoming a therapeutic option against CF.

An observational clinical case of Zika virus-associated neurological disease is associated with primary IgG response and enhanced TNF levels.

Descriptive clinical data help to reveal factors that may provoke Zika virus (ZIKV) neuropathology. The case of a 24-year-old female with a ZIKV-associated severe acute neurological disorder was studied. The levels of ZIKV in the cerebrospinal fluid (CSF) were 50 times higher than the levels in other compartments. An acute anti-flavivirus IgG, together with enhanced TNF-alpha levels, may have contributed to ZIKV invasion in the CSF, whereas the unbiased genome sequencing [obtained by next-generation sequencing (NGS)] of the CSF revealed that no virus mutations were associated with the anatomic compartments (CSF, serum, saliva and urine).