PMID: 28329704

Authors:

Mendoza JL, Schneider WM, Hoffmann HH, Vercauteren K, Jude KM, Xiong A, Moraga I, Horton TM, Glenn JS, de Jong YP, Rice CM, Garcia KC

Title:

The IFN-lambda-IFN-lambdaR1-IL-10Rbeta Complex Reveals Structural Features Underlying Type III IFN Functional Plasticity.

Journal:

Immunity. 2017 Mar 21;46(3):379-392. doi: 10.1016/j.immuni.2017.02.017.

Abstract:

Type III interferons (IFN-lambdas) signal through a heterodimeric receptor complex composed of the IFN-lambdaR1 subunit, specific for IFN-lambdas, and interleukin-10Rbeta (IL-10Rbeta), which is shared by multiple cytokines in the IL-10 superfamily. Low affinity of IL-10Rbeta for cytokines has impeded efforts aimed at crystallizing cytokine-receptor complexes. We used yeast surface display to engineer a higher-affinity IFN-lambda variant, H11, which enabled crystallization of the ternary complex. The structure revealed that IL-10Rbeta uses a network of tyrosine residues as hydrophobic anchor points to engage IL-10 family cytokines that present complementary hydrophobic binding patches, explaining its role as both a cross-reactive but cytokine-specific receptor. H11 elicited increased anti-proliferative and antiviral activities in vitro and in vivo. In contrast, engineered higher-affinity type I IFNs did not increase antiviral potency over wild-type type I IFNs. Our findings provide insight into cytokine recognition by the IL-10R family and highlight the plasticity of type III interferon signaling and its therapeutic potential.