CXCL11 expressing C57BL/6 mice have intact adaptive immune responses to viral infection

The chemokine receptor CXCR3 is expressed on immune cells to co-ordinate lymphocyte activation and migration. CXCR3 binds three chemokine ligands, CXCL9, CXCL10 and CXCL11. These ligands display distinct expression patterns and ligand signaling biases; however, how each ligand functions individually and collaboratively is incompletely understood. CXCL9 and CXCL10 are considered pro-inflammatory chemokines during viral infection, while CXCL11 may induce a tolerizing state. The investigation of the individual role of CXCL11 in vivo has been hampered as C57BL/6 mice carry several mutations that result in a null allele. Here, CRISPR/Cas9 was used to correct these mutations on a C57BL/6 background. It was validated that CXCL11(KI) mice expressed CXCL11 protein in dendritic cells, spleen and lung. CXCL11(KI) mice were largely phenotypically indistinguishable from C57BL/6 mice, both at steady-state and during two models of viral infection. While CXCL11 expression did not modify acute antiviral responses, this study provides a new tool to understand the role of CXCL11 in other experimental settings.