Interleukin 12 (IL-12) is an interleukin that is naturally produced by dendritic cells,macrophages, neutrophils, and human B-lymphoblastoid cells (NC-37) in response to antigenic stimulation. IL-12 belongs to the family of interleukin-12. IL-12 family is unique in comprising the only heterodimeric cytokines, which includes IL-12, IL-23, IL-27 and IL-35. Despite sharing many structural features and molecular partners, they mediate surprisingly diverse functional effects. IL-12 is composed of a bundle of four alpha helices. It is a heterodimeric cytokine encoded by two separate genes, IL-12A(p35) and IL-12B (p40). The active heterodimer (referred to as ‘p70’), and a homodimer of p40 are formed following protein synthesis. IL-12 is involved in the differentiation of naive T cells into Th1 cells. It is known as a T cell-stimulating factor, which can stimulate the growth and function of T cells. It stimulates the production of interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) om T cells and natural killer (NK) cells, and reduces IL-4 mediated suppression of IFN-γ. Because of its ability to induce immune responses and its anti-angiogenic activity, there has been an interest in testing IL-12 as a possible anti-cancer drug. There is a link that may be useful in treatment between IL-12 and the diseases psoriasis & inflammatory bowel disease.
- The exons 1-7 of mouse Il12a gene that encode the full length coding sequence were replaced by human IL12A exons 1-7 in B-hIL12A/hIL12B/hIL12RB1/hIL12RB2 mice.
- The exons 2-8 of mouse Il12b gene that encode the full length coding sequence and 3’UTR were replaced by human IL12B exons 2-8 in B-hIL12A/hIL12B/hIL12RB1/hIL12RB2 mice.
- The extracellular and transmembrane region coding sequences of human IL12RB1 gene plus the mouse Il12rb1 cytoplasmic coding sequences were inserted into the exon1 of B-hIL12A/hIL12B/hIL12RB1/hIL12RB2 mice.
- The extracellular region coding sequences of human IL12RB2 gene plus the mouse Il12rb2 transmembrane and cytoplasmic coding sequences were inserted into the exon2 of B-hIL12A/hIL12B/hIL12RB1/hIL12RB2 mice.
Protein expression analysis
Strain specific IL12p70 (IL-12A (p35) and IL-12B (p40) active heterodimer referred to as ‘p70’) expression analysis in homozygous B-hIL12A/hIL12B/hIL12RB1/hIL12RB2 mice by ELISA.
Serum was collected in wild-type (+/+) and homozygous B-hIL12A/hIL12B/hIL12RB1/hIL12RB2 mice (H/H) stimulated with anti-mCD3ε and anti-mCD28 in vivo (n=3), and analyzed by ELISA with species-specific IL12 ELISA kit. Mouse IL12p70 was detectable in wild-type mice. Human IL12 p70 was exclusively detectable in homozygous B-hIL12A/hIL12B/hIL12RB1/hIL12RB2 mice but not in wild-type mice. ND: Not detectable.