Figure 3.

Direct Binding of FcRn to Echo 6 Virus

(A and B) BIAcore diagram of soluble FcRn protein (A) or CD55 protein (B) bound to Echo 6 virus. The K_D values were calculated by the BIAcore 3000 analysis software (BIAevaluation version 4.1).

(C and D) The binding affinity of CV-B4 virus with FcRn (C) or CD55 protein (D) was measured by SPR, which served as a control.

(E–G) Binding of FcRn (E), CD55 (F), or CD26 (G, control) in 2-fold serial dilutions with Echo 6 virus was assayed using ELISAs.

(H) Dose dependence of soluble FcRn or CD55 protein to block Echo 6 virus infection. CD26 was used as a control protein.

(I and J) Echo 6 was incubated with FCGRT^KO, B2M^KO, CD55^KO, or WT HEK293T cells at 4°C for 1 h (I) or plus 37°C for 30 min (J). Cells were collected, and RNA was extracted for qPCR analysis.

The data depict means with SEM. ^∗∗p < 0.01; ^∗∗∗p < 0.001; ^∗∗∗∗p < 0.0001; ns, not significant.

See also Figures S3 and S4.