Basic Information

Strain name
C57BL/6-Il4tm2(IL4)Il4ratm1(IL4RA) Il13tm1(IL13)//Bcgen
Common name
B-hIL4/hIL4RA/hIL13 mice
Catalog number
131037
Background
C57BL/6
Aliases
IL4: interleukin 4; IL4RA: interleukin 4 receptor, IL4R; Il13:interleukin 13

Description

IL4 (interleukin 4) encodes a pleiotropic cytokin produced by activated T cells. IL4 is capable of binding to its receptor IL4R, while IL13 is also capable of binding to IL4R, which may result in a functional overlap of IL4 and IL13. IL-4 has immunomodulatory effects on B cells, T cells, mast cells, and macrophages. It can promote the proliferation of antigen or mitogen-activated B cells; promote T cell activity, single IL-4 can not stimulate macrophage proliferation, but can enhance macrophage function.IL4RA (interleukin 4 receptor) encodes the alpha chain of the IL4 receptor and belongs to the type I transmembrane protein, which plays a huge role in the immune response. IL4R can bind to IL4 and IL13 to regulate the production of IgE, and binding to IL4 can promote the differentiation of Th2 cells, thereby inducing the occurrence of asthma.Therefore, antagonists of IL4 and IL4R can reduce the level of IL4 in the body, and can exert anti-inflammatory and anti-immune effects on asthma patients. IL4 and IL4R are considered to be star targets for the treatment of allergies and asthma. Interleukin 13 (IL-13) is a protein that in humans is encoded by the IL13 gene. IL-13 was first cloned in 1993 and is located on chromosome 5q31 with a length of 1.4kb. It has a mass of 13 kDa and folds into 4 alpha helical bundles. The secondary structural features of IL-13 are similar to that of Interleukin 4 (IL-4); however it only has 25% sequence homology to IL-4 and is capable of IL-4 independent signaling. IL-13 is a cytokine secreted by T helper type 2 (Th2) cells, CD4 cells, Natural killer T cell, Mast cell, Basophil cells, Eosinophil cells and Nuocyte cells. Interleukin-13 is a central regulator in IgE synthesis, goblet cell hyperplasia, mucus hypersecretion, airway hyperresponsiveness, fibrosis and chitinase up-regulation. It is a mediator of allergic inflammation and different diseases including asthma.

Targeting strategy

The exons 1-4 of mouse Il4 gene that encode the full length coding sequence were replaced by human IL4 exons 1-4 in B-hIL4/hIL4RA/hIL13 mice. The exons 4-7 of mouse Il4ra gene that encode the extracellular region coding sequences were replaced by human IL4RA exons 4-7 in B-hIL4/hIL4RA/hIL13 mice. The exons 1-4 of mouse Il13 gene that encode the full length coding sequence were replaced by human IL13 exons 1-4 in B-hIL4/hIL4RA/hIL13 mice.

mRNA expression analysis

Strain specific analysis of IL4, IL4RA and IL13 gene expression in wild-type and B-hIL4/hIL4RA/hIL13 mice by RT-PCR. Mouse Il4, Il4ra and Il13 mRNA was detectable in thymocytes of wild-type mice (+/+) but not in homozygous B-hIL4/hIL4RA/hIL13 mice (H/H). Human IL4, IL4RA and IL13 mRNA was detectable only in homozygous B-hIL4/hIL4RA/hIL13 mice (H/H) but not in wild-type mice.

Protein expression analysis

Strain specific IL4 expression analysis in homozygous B-hIL4/hIL4RA/hIL13 mice by ELISA.

Serum were collected from wild-type mice (+/+) and homozygous B-hIL4/hIL4RA/hIL13 mice (H/H) stimulated with anti-CD3ε in vivo, and analyzed by ELISA with species-specific IL4 ELISA kit. Mouse IL4 was detectable in wild-type mice. Human IL4 was exclusively detectable in homozygous B-hIL4/hIL4RA/hIL13  mice but not in wild-type mice.

Strain specific IL13 expression analysis in homozygous B-hIL4/hIL4RA/hIL13 mice by ELISA.

CD4+ T cells were collected from wild-type mice (+/+) and homozygous B-hIL4/hIL4RA/hIL13 mice (H/H), and then induction of CD4 + T cells differentiation into Th2 cells, supernatants from Th2 cells culture was analyzed by ELISA with species-specific IL13 ELISA kit. Mouse IL13 was detectable in wild-type mice. Human IL13 was exclusively detectable in homozygous B-hIL4/hIL4RA/hIL13  mice but not in wild-type mice.

Strain specific IL4RA expression analysis in homozygous B-hIL4/hIL4RA/hIL13 mice by flow cytometry. Splenocytes were collected from wild-type mice and homozygous B-hIL4/hIL4RA/hIL13 mice (H/H), and analyzed by flow cytometry with species-specific anti-IL4RA antibody. Mouse IL4RA was detectable in wild-type mice. Human IL4RA was exclusively detectable in homozygous B-hIL4/hIL4RA/hIL13 mice but not in wild-type mice.