A cell-surface receptor used by the chikungunya virus to infect cells is identified in a study published in Nature this week.
Arthritogenic alphaviruses, such as the chikungunya virus (CHIKV), are a group of enveloped RNA viruses, which are transmitted to humans by mosquitoes and can cause acute and chronic musculoskeletal disease. However, the factors required for alphavirus entry into cells remain poorly understood.
Michael Diamond and colleagues performed a genome-wide screen to find host-cell factors that might be required by CHIKV for infection. The authors identified the cell adhesion molecule Mxra8 - found in mammals, birds, and amphibians - as an entry mediator. In laboratory experiments, the authors found that editing the mouse and human forms of the gene responsible for this protein reduced the ability of CHIKV to infect cells. Mxra8 was also found to be required for infection by some other alphaviruses, including Mayaro, Ross River and O’nyong nyong viruses. In a mouse model, administration of anti-Mxra8 blocking antibodies reduced CHIKV or O’nyong nyong virus infection and associated foot swelling.
Further research is required to identify the exact binding mechanism between Mxra8 and CHIKV but the authors suggest that such studies could form the basis of therapeutic agents to treat diseases caused by multiple emerging alphaviruses.