• IL-12 is primarily produced by antigen-stimulated dendritic cells, macrophages, and other cells, and it binds to receptors on the surface of T cells or NK cells to participate in cell-mediated immunity, activating Th1 cells to produce a large amount of IFN-γ. IL-23 mainly acts on Th17 cells, playing an important role in their proliferation and stability, and it promotes the production of cytokines such as IL-17A, IL-17F, and IL-22 by Th17 cells, contributing to the development and progression of various diseases. The core therapeutic mechanism of IL-12/IL-23 inhibitors is to modulate the immune response and reduce the production of pro-inflammatory cytokines by inhibiting the IL-12 and IL-23 signaling pathways, thereby alleviating disease symptoms.
• The chimeric IL23R CDS and  chimeric IL12RB2 CDS were inserted into B-hIL23R/hIL12RB1/hIL12RB2 ad mice. The genome of mouse Il12rb1 gene encode signal peptide and extracellular domain was replaced by human IL12RB1 genome in B-hIL23R/hIL12RB1/hIL12RB2 ad mice.
• Mouse IFN-γ were successfully induced with mIL12 or hIL-12 in homozygous B-hIL23R/hIL12RB1/hIL12RB2 ad mice. Both mIL23 and hIL23 successfully induced mouse IL17A production in homozygous B-hIL23R/hIL12RB1/hIL12RB2 ad mice.
• This product is used for pharmacodynamics and safety evaluation of autoimmune diseases such as psoriasis, arthritis, and inflammatory bowel disease.

Gene targeting strategy for B-hIL23R/hIL12RB1/hIL12RB2 ad mice. A chimeric CDS that encodes mouse IL23R signal peptide, human IL23R extracellular domain, mouse IL23R transmembrane and cytoplasmic domain, followed by mouse 3’UTR-STOP was inserted after exon 3 of mouse Il23r. The chimeric IL23R protein expression will be driven by endogenous mouse Il23r promoter, while mouse IL23r gene transcription and translation will be disrupted. The exons 1-14 of mouse Il12rb1 gene that encode signal peptide and extracellular domain were replaced by human counterparts. The genomic region of mouse Il12rb2 gene that encodes transmembrane domain and cytoplasmic portion was retained. The promoter, 5’UTR and 3’UTR region of the mouse gene were also retained. The chimeric IL12RB1 expression was driven by endogenous mouse Il12rb1 promoter, while mouse Il12rb1 gene transcription and translation will be disrupted. A chimeric CDS that encodes mouse IL12RB2 signal peptide, human IL12RB2 extracellular domain, mouse IL12RB2 transmembrane and cytoplasmic domain, followed by mouse 3’UTR-STOP was inserted after exon 2 of mouse Il12rb2. The chimeric IL12RB2 protein expression will be driven by endogenous mouse Il12rb2 promoter.

IL12 induced CD4+ T cells from splenocytes of wild-type C57BL/6 mice and homozygous B-hIL23R/hIL12RB1/hIL12RB2 ad mice to produce mouse IFNγ. CD4+ T cells were sorted from splenocytes of wild-type C57BL/6 mice and homozygous B-hIL23R/hIL12RB1/hIL12RB2 ad mice (male, n=3, 10-week-old). CD4+ T cells were cultured on anti-mCD3 antibody and anti-mCD28 antibody pre-coated plates, and stimulated with 10 ng/mL mouse IL12 (mIL12) or human IL12 (hIL12) at 37℃ for 48 h. The production of mouse IFNγ in the supernatant was detected by ELISA (Biolegend, 430804). Mouse IFN-γ were successfully induced with mIL12 in wild-type C57BL/6 mice and homozygous B-hIL23R/hIL12RB1/hIL12RB2 ad mice. Mouse IFN-γ were successfully induced with hIL-12 in homozygous B-hIL23R/hIL12RB1/hIL12RB2 ad mice, but not in wild-type C57BL/6 mice. These results indicate that the IL12 pathway is functional in B-hIL23R/hIL12RB1/hIL12RB2 ad mice. Values are expressed as mean ± SEM. Significance was determined by two-way ANOVA test.  *P < 0.05, **P < 0.01, ***P < 0.001.

IL12 induced CD4+ T cells from splenocytes of wild-type C57BL/6 mice and homozygous B-hIL23R/hIL12RB1/hIL12RB2 ad mice to produce mouse IL17A. CD4+ T cells were sorted from splenocytes of wild-type C57BL/6 mice and homozygous B-hIL23R/hIL12RB1/hIL12RB2 ad mice (female, n=3, 8-week-old). CD4+ T cells were cultured on anti-mCD3 antibody and anti-mCD28 antibody pre-coated plates, and stimulated with 10 ng/mL mouse IL23 (mIL23), human IL23 (hIL23) or anti-human IL23R antibody Ab1 (provided by the client) at 37℃ for 48 h. The production of mouse IL17A in the supernatant was detected by ELISA (Biolegend, 432504). Both mIL23 and hIL23 successfully induced mouse IL17A production in wild-type C57BL/6 mice and homozygous B-hIL23R/hIL12RB1/hIL12RB2 ad mice. Anti-human IL23R antibody Ab1 (provided by the client) significantly reduced the expression of mouse IL17A in homozygous B-hIL23R/hIL12RB1/hIL12RB2 ad mice hIL23A stimulated with hIL-23. These results indicate that the IL23 pathway is functional in B-hIL23R/hIL12RB1/hIL12RB2 ad mice. Values are expressed as mean ± SEM. Significance was determined by two-way ANOVA test.  *P < 0.05, **P < 0.01, ***P < 0.001.