Chikungunya Virus Infection Model

Three-week-old WT or CD4 KO C57/BL6J female mice were inoculated subcutaneously in the ventral side of the right hind footpad with 10⁶ pfu CHIKV diluted in 30 μl PBS. Following CHIKV infection, PBS, 1.5 μg murine IL-2 (Peprotech), 50 μg of rat anti-mouse IL-2 (JES6-1) monoclonal antibody (eBioscience) or 1.5 μg murine IL-2 in complex with 50 μg anti-mouse IL-2 mAb were injected i.p daily on 3, 4 and 5 dpi. IL-2 Ab Cx pre-treatment was carried out as described21 (link). Joint footpad swelling was determined daily by the measurement of the height and the breadth of the footpad using a caliper and quantified as (height x breadth). The degree of inflammation was expressed as relative increase compared to pre-infection (d 0) with the following formula: [(x –d 0)/d 0] where x is footpad size measurements for respective dpi4 (link)25 (link)27 (link)66 (link).