DBA/1-hTNF Mice

Catalog Number: C001587

Strain Name: DBA/1-Tnfem1(hTNF)/Cya

Genetic Background: DBA/1

One of Cyagen’s HUGO-GTTM (Humanized Genomic Ortholog for Gene Therapy) Strains

 

Strain Description

The tumor necrosis factor-alpha (TNF/TNF-α) gene encodes a pro-inflammatory cytokine belonging to the TNF superfamily. It is primarily produced by macrophages/monocytes during acute inflammation. TNF-α regulates immune cell function by binding to its receptors TNFRSF1A/TNFR1 and TNFRSF1B/TNFBR, participating in normal inflammatory and immune responses. TNF-α is involved in various biological processes, including cell proliferation, differentiation, apoptosis, lipid metabolism, and coagulation. This factor is associated with several diseases, such as autoimmune conditions, insulin resistance, psoriasis, rheumatoid arthritis, ankylosing spondylitis, tuberculosis, autosomal dominant polycystic kidney disease, and cancer. Mutations in the TNF-α gene impact susceptibility to cerebral malaria, septic shock, and Alzheimer’s disease [1-2]. In mice, defects in this gene are associated with impaired responses to bacterial infections, defects in the organization of follicular dendritic cell networks and germinal centers, and a lack of primary B cell follicles.

The DBA/1-hTNF mice is a mouse Tnf gene humanized model. The mouse Tnf gene in the DBA/1 strain is replaced with the human TNF gene, including the 5’UTR and 3’UTR. This model is useful for diseases researches such as rheumatoid arthritis (RA). Since immunization of DBA/1 mice with type II collagen leads to severe polyarthritis mediated by the autoimmune response, DBA/1 mice are widely used for RA model construction. Therefore, DBA/1-hTNF mice constructed on a DBA/1 strain background can be used to research immune-related diseases such as RA. In addition, based on the independently developed TurboKnockout fusion BAC recombination technology, Cyagen can also generate mutation models based on this strain and provide customized services.

Strain Strategy



Figure 1. Gene editing strategy of DBA/1-hTNF mice. The mouse Tnf genome plus flanking sequence was replaced with the human TNF genome plus flanking sequence.

Application

  • Research on Rheumatoid Arthritis (RA);
  • Research on TNF-α signaling pathway;
  • Research on the pathogenesis and treatment of other TNF-α related diseases.

 

Validation Data

1. Expression of human TNF gene


Figure 2. Human TNF gene expression in the thymus and spleen of 10-week-old female DBA/1 wild-type mice and DBA/1-hTNF mice. RT-qPCR results demonstrate significant expression of the human TNF gene in both the thymus and spleen of DBA/1-hTNF mice, while no expression is detected in DBA/1 mice. (ND: Not detected)

2. Expression of mouse Tnf gene


Figure 3. Mouse Tnf gene expression in the thymus and spleen of 10-week-old female DBA/1 wild-type mice and DBA/1-hTNF mice. RT-qPCR results demonstrate that mouse Tnf gene expression is present in both the thymus and spleen of DBA/1 mice, while DBA/1-hTNF mice do not express the mouse Tnf gene.

3. Expression of TNF protein after LPS induction


Figure 4. ELISA detection of TNF protein expression in the serum of 10-week-old female DBA/1 wild-type mice and DBA/1-hTNF mice (hTNF)*. High-level expression of TNF protein was induced by intraperitoneal injection of 1.5 mg/kg lipopolysaccharide (LPS), and serum samples were collected 6 hours later for ELISA testing**. The results show significant expression of human TNF protein in the serum of LPS-induced DBA/1-hTNF mice, with minimal expression of mouse TNF protein. In contrast, DBA/1 wild-type mice exhibit considerable expression of mouse TNF protein in their serum after LPS induction, while human TNF protein levels remain extremely low.

*The human TNFα protein ELISA kit used for detection is from Thermo Fisher: Human TNF alpha ELISA Kit, Ultrasensitive (Catalog No.: KHC3014));

The mouse TNFα protein ELISA kit used for detection is from MULTI SCIENCES: Mouse TNF-a ELISA Kit (Catalog No.: EK282/4).

**LPS (lipopolysaccharide) is an endotoxin that can stimulate immune responses in mice. Immune activation through LPS can exacerbate the severity of arthritis [3].

4. Pharmacodynamic validation of Adalimumab



Figure 5. Construction of Collagen-Induced Arthritis (CIA) Model with Type II Collagen for Pharmacodynamic Validation of Adalimumab.

a: Experimental Arrangement for CIA Model Construction and Adalimumab Treatment.

b: Images of Mouse Joints.

c: Growth Curves and Clinical Scores. The results show no significant difference in body weight between the model and control groups of DBA/1-hTNF mice and DBA/1 mice. Clinical scores in the model groups of DBA/1-hTNF and DBA/1 mice significantly increased, indicating successful CIA model construction. The disease progressed more rapidly and severely in the DBA/1-hTNF model group compared to the DBA/1 model group. After Adalimumab treatment, the average clinical score of the hTNF-CIA+Adalimumab efficacy group was significantly lower than that of the model group, indicating effective disease control in mice (Note: Efficacy is related to treatment duration and dose).

d: Histopathology.

① No significant abnormalities were observed in the joint cavities of the control groups of DBA/1-hTNF and DBA/1 mice, with no significant synovial hyperplasia and intact cartilage structure. (Blue: No significant synovial hyperplasia; Red: Normal joint cavity without deformation or fusion; Green: Intact cartilage surface without erosion or damage).

② The model group of DBA/1 mice showed significant synovial hyperplasia and thickening, with inflammatory cells invading the joint cavity. The synovium formed pannus and bone erosion, with excessive proliferation of synovial cells eroding cartilage and bone, resulting in the disappearance of the joint space. Pannus formation or extensive pannus was observed in multiple areas.

③ The model group of DBA/1-hTNF mice showed synovial cell hyperplasia, proliferation of fibroblast-like cells and synovial phagocytes, accompanied by infiltration of inflammatory cells such as lymphocytes and plasma cells. The cartilage was affected by synovium, pannus, and inflammatory cells, with cartilage ulcer surfaces covered by connective tissue or fibrocartilage and invaded by new blood vessels. Bone tissue damage and joint cavity deformation were observed.

④ In the DBA/1-hTNF-CIA+Adalimumab efficacy group, Adalimumab treatment significantly improved synovial hyperplasia and inflammatory infiltration; cartilage showed slight erosion (slightly uneven); joints were normal, with mild local cartilage defects and no pannus formation.

e: Pathological Score. The results show that pathological scores in the model groups (G2, G4) of DBA/1-hTNF and DBA/1 mice were significantly higher than those in the control groups, with the disease severity being greater in the DBA/1-hTNF model group. After Adalimumab treatment, synovial hyperplasia and inflammatory infiltration in arthritic mice were significantly improved, with slight cartilage erosion and mild local cartilage defects, resulting in significantly lower pathological scores.

5. Pharmacodynamic validation of TNF inhibitor


Figure 6. Arthritis scores of DBA/1-hTNF mice in the control group (blank) and the efficacy group (TNFi) (n=4, male)*. Collagen-induced arthritis (CIA) model was established by subcutaneous injection of bovine type II collagen at the base of the tail to verify the efficacy of the TNF inhibitor. The results showed that the control group and the efficacy group successfully established the CIA model after bovine type II collagen immunization, and the TNF inhibitor effectively alleviated arthritis in male DBA/1-hTNF mice.

*Data provided by the client.

 

References

[1] Liu ZG. Molecular mechanism of TNF signaling and beyond. Cell Res. 2005 Jan;15(1):24-7.
[2] Kalliolias GD, Ivashkiv LB. TNF biology, pathogenic mechanisms and emerging therapeutic strategies. Nat Rev Rheumatol. 2016 Jan;12(1):49-62.
[3] Hou Y, Lin H, Zhu L, Liu Z, Hu F, Shi J, Yang T, Shi X, Zhu M, Godley BF, Wang Q, Li Z, Zhao Y. Lipopolysaccharide increases the incidence of collagen-induced arthritis in mice through induction of protease HTRA-1 expression. Arthritis Rheum. 2013 Nov;65(11):2835-46.