Axl is not an indispensable factor for Zika virus infection in mice

Recently, Zika virus (ZIKV) outbreak has been associated with a sharp increase in cases of Guillain-Barre syndrome and severe fetal abnormalities. However, the mechanism underlying the interaction of ZIKV with host cells is not yet clear. Axl, a receptor tyrosine kinase, is postulated as a receptor for ZIKV entry; however, its in vivo role during ZIKV infection and its impact on the outcome of the disease have not been fully characterized and evaluated. Moreover, there are contradictory results on its involvement in ZIKV infection. Here we utilized Axl-deficient mice (Axl(-/-)) and their littermates (Axl(+/-)) to study the in vivo role of Axl in ZIKV infection. Our results showed that both Axl(+/-) and Axl(-/-) suckling mice supported the replication of ZIKV and presented clinical manifestations. No significant difference has been found between Axl-deficient mice and their littermates in terms of the survival rate, clinical manifestations, viral load, ZIKV distribution and histopathological changes in major organs. These results therefore indicate that Axl is not an indispensable factor for ZIKV infection in mice.