Although seldom fatal, persistent infection by chikungunya virus (CHIKV) afflicts patients with joint pain lasting months or even years. This insect-borne virus has received relatively little scientific attention in the 50 years since its initial description in African patients, but researchers in Singapore have now uncovered a host protein that can keep CHIKV in check.
"Globalization and climate warming have lent a helping hand in the resurgence of CHIKV, such that a virus originally from Africa and mosquitoes originally from Asia [could] meet in the Indian Ocean and spread to other parts of the world," explains Preston Teng, a researcher in Lisa F. P. Ng's laboratory, part of the A*STAR Singapore Immunology Network. The expanding reach of the virus motivated Ng and her co-workers to investigate how CHIKV interacts with the immune system.
Ng's team had already established that CHIKV infection triggers cellular signaling pathways mediated by the type I interferon proteins, which activate genes involved in the antiviral 'innate' immune response. As a follow-up, the team searched for specific target genes activated in immune cells collected from 24 CHIKV patients. Their analysis revealed a sharp, viral load-dependent increase in the activity of the gene encoding the protein viperin, which is involved in the defensive response to numerous viruses.