Protein expression analysis
Strain specific ALB expression analysis in homozygous B-hALB/hFcRn mice by ELISA. Serum was collected from wild-type mice (+/+) and homozygous B-hALB/hFcRn mice (H/H;H/H), and analyzed by ELISA with species-specific ALB ELISA kit. Mouse ALB was detectable in wild-type mice . Human ALB was exclusively detectable in homozygous B-hALB/hFcRn mice but not in wild-type mice. ND: not detected.
Strain specific FcRn expression analysis in homozygous B-hALB/hFcRn mice by western blot. Liver tissue was collected from wild-type C57BL/6 mice (+/+) and homozygous B-hALB/hFcRn mice (H/H;H/H), and analyzed by western blot with anti-FcRn antibody. Mouse FcRn was detectable in wild type mice. Human FcRn was exclusively detectable in homozygous B-hALB/hFcRn mice but not in wild-type C57BL/6 mice.
Serum half-life of drug in B-hALB/hFcRn mice
PK study of hIL21-anti-HSA in homozygous B-hALB/hFcRn mice. C57BL/6 mice and homozygous B-hALB/hFcRn mice were injected intraperitoneally with hIL21-anti-HSA at time 0. Blood was collected at specified timepoints and serum was analyzed for IL21 concentrations using an ELISA kit. The G3 and G4 groups exhibited slower clearance of IL21 compared to the G1 and G2 groups, indicating C57BL/6 mice and homozygous B-hALB/hFcRn mice can bind anti-HSA to extend the half-life of hIL21. The anti-HSA antibody can react with both human and mouse albumin.