Chikungunya virus (CHIKV) has caused recent outbreaks associated with severe morbidity. Currently no vaccine or treatment exists to protect humans from CHIKV infection. Treatment is therefore purely symptomatic and is based on non-steroidal anti-inflammatory drugs. Accordingly, there is a high medical need exists to have new methods of screening of compounds which could inhibit chikungunya virus. Further to a CRISPR-Cas9 genetic screen the inventors now identify the four and a half LIM domains protein 1 (FHL1) has an essential host factor for CHIKV infection. In particular, they show that primary myoblast and fibroblast from FHL1 deficient patient are resistant to CHIKV infection. They also demonstrate that depletion of FHL1 prevents CHIKV replication. Finally, they show that CHIKV non-structural protein 3 interacts specifically with FHL1A through its hypervariable domain. Thus compounds that are capable of inhibiting the interaction between the non-structural protein 3 and FHL1 would be suitable for inhibiting the replication capacity of the virus. Determining the expression level of FHL1 and/or identifying some genetic variant would also be suitable for determining whether some subjects are predisposed to CHIKV infection.Le virus chikungunya (CHIKV) a provoqué des épidémies récentes associées à une morbidité grave. Actuellement, aucun vaccin ou traitement n'existe pour protéger les êtres humains contre une infection par CHIKV. Le traitement est donc purement symptomatique et est basé sur des médicaments anti-inflammatoires non stéroïdiens. En conséquence, il existe un besoin médical élevé de disposer de nouveaux procédés de criblage de composés qui pourraient inhiber le virus chikungunya. Outre un criblage génétique CRISPR-Cas9, les inventeurs identifient aujourd'hui le rôle essentiel de la protéine 1 à quatre domaines LIM et demi (FHL1) en tant que facteur hôte pour une infection par CHIKV. En particulier, ils montrent que le myoblaste primaire et le fibroblaste
