Antibody-mediated enhancement aggravates chikungunya virus infection and disease severity

Lum, Fok-Moon; Couderc, Thérèse; Chia, Bing-Shao; Ong, Ruo-Yan; Her, Zhisheng; Chow, Angela; Leo, Yee-Sin; Kam, Yiu-Wing; Rénia, Laurent; Lecuit, Marc; Ng, Lisa F. P.

To elucidate which class of FcγRs enhances CHIKV infection, four different FcγR-expressing stable human B lymphocyte cell line, ST486, that have been modified to stably express a single class of FcγR driven by the same promoter 36 were used (Fig. 2a) . Parental ST486 cells naturally deficient in FcγRs expression were used as controls and were not susceptible to CHIKV infection (Fig. 2b) . A significant increase in CHIKV antigen was detected in ST486 cells over-expressing FcγRI or FcγRII when infection was performed in the presence of low levels of CHIKV-specific antibodies (Fig. 2c,d) . ST486 cells over-expressing FcγRIII neither supported nor enhanced CHIKV infection (Fig. 2e ).