Species specific analysis of CRBN gene expression in wild-type C57BL/6 mice and homozygous B-hCRBN mice by RT-PCR. Cortex was collected from wild-type C57BL/6 mice (+/+) and homozygous B-hCRBN mice (H/H). Mouse Crbn mRNA was detectable in wild-type C57BL/6 mice. Human CRBN mRNA was only detectable in homozygous B-hCRBN mice, but not in wild-type mice. 

Strain specific CRBN expression analysis in homozygous B-hCRBN mice by Western blot. The cortex, liver, spleen, lung, kidney were collected from wild-type C57BL/6 mice (+/+) and homozygous B-hCRBN mice (H/H), and then analyzed by western blot with anti-CRBN antibody. Mouse CRBN was detectable in wild-type mice. Human CRBN was exclusively detectable in homozygous B-hCRBN mice. The anti-CRBN antibody was cross-reactive between human and mouse.

Naïve CD4+ T cells from B-hCRBN mice have increased production of IL2 when treated with Lenalidomide, but no change in cells of wild-type mice. 

Naïve CD4+ T cells were collected from wild-type C57BL/6 mice (+/+) and homozygous B-hCRBN mice (H/H), then stimulated with DMSO or Lenalidomide in vitro for 24 hours. The supernatants were collected, and IL2 production was measured by ELISA. The results show that Lenalidomide significantly up-regulates the production of IL2 in B-hCRBN mice, but not in wild-type C57BL/6 mice.