• TNF encodes a multifunctional proinflammatory cytokine that belongs to the tumor necrosis factor (TNF) superfamily. This cytokine is mainly secreted by macrophages. It can bind to its receptors TNFRSF1A and TNFRSF1B and exert its effects through these receptors.
• L6 is a cytokine that functions in inflammation and the maturation of B cells. IL6 is primarily produced at sites of acute and chronic inflammation, where it is secreted into the serum and induces a transcriptional inflammatory response through interleukin 6 receptor, alpha. The functioning of IL6 is implicated in a wide variety of inflammation-associated disease states, such as rheumatoid arthritis.
• The genome of the mouse Tnf gene encoding the full-length protein was replaced with human TNF counterpart in B-hTNFA/hTNFR2/hTNFR1/hIL6/hIL6R mice. The genome of the mouse Tnfr1 gene encoding the extracellular domain was replaced with its human TNFR1 counterpart in in B-hTNFA/hTNFR2/hTNFR1/hIL6/hIL6R mice. The genome of the mouse Tnfr2 gene encoding the extracellular domain was replaced with its human TNFR2 counterpart in B-hTNFA/hTNFR2/hTNFR1/hIL6/hIL6R mice. The exons 1~5 of mouse Il6 gene that encode the whole molecule (ATG to STOP codon) were replaced by human counterparts in B-hTNFA/hTNFR2/hTNFR1/hIL6/hIL6R mice. The CDS of human IL6R gene was inserted after the start codon ATG of mouse Il6ra gene in B-hTNFA/hTNFR2/hTNFR1/hIL6/hIL6R mice.
• Human TNFA, IL6, IL6R was exclusively detectable in the homozygous B-hTNFA/hTNFR2/hTNFR1/hIL6/hIL6R mice.
• This product is used for the evaluation of the pharmacodynamics and safety of anti-human IL6 and/or anti-human TNFA antibodies in autoimmune diseases.

Gene targeting strategy for B-hTNFA/hTNFR2/hTNFR1/hIL6/hIL6R mice. 

• The genome of the mouse Tnf gene encoding the full-length protein was replaced with human TNF counterpart in B-hTNFA/hTNFR2/hTNFR1/hIL6/hIL6R mice. 
• The genome of the mouse Tnfr1 gene encoding the extracellular domain was replaced with its human TNFR1 counterpart in in B-hTNFA/hTNFR2/hTNFR1/hIL6/hIL6R mice. 
• The genome of the mouse Tnfr2 gene encoding the extracellular domain was replaced with its human TNFR2 counterpart in B-hTNFA/hTNFR2/hTNFR1/hIL6/hIL6R mice. 
• The exons 1~5 of mouse Il6 gene that encode the whole molecule (ATG to STOP codon) were replaced by human counterparts in B-hTNFA/hTNFR2/hTNFR1/hIL6/hIL6R mice. 
• The CDS of human IL6R gene was inserted after the start codon ATG of mouse Il6ra gene in B-hTNFA/hTNFR2/hTNFR1/hIL6/hIL6R mice.

Human TNFA, human IL6, and mouse IFNγ expression analysis in homozygous humanized B-hTNFA/hTNFR2/hTNFR1/hIL6/hIL6R mice by ELISA. Mice received LPS injection (i.p.) two hours following PBS or adalimumab analog (i.v., in house) treatment. Serum was collected from homozygous B-hTNFA/hTNFR2/hTNFR1/hIL6/hIL6R mice one hour and four hours after LPS injection. Expression level of human TNFA, human IL6, and mouse IFNγ, were analyzed by ELISA (ELISA MAX™ Deluxe Set Human TNF-α, Biolegend, 430204; ELISA MAX™ Deluxe Set Human IL-6, Biolegend, 430508; ELISA MAX™ Deluxe Set Mouse IFN-γ, Biolegend, 430804). Human TNFA level was significantly increased one hour and four hours after LPS injection. Human IL6 level was significantly increased one and four hours after LPS injection. Mouse IFNγ level was significantly increased four hours after LPS injection. Pre-treatment of adalimumab analog (in house) significantly decreased human TNFA expression at one hour after LPS injection, human IL6 one and four hours after LPS stimulation, and mouse IFNγ expression at four hours after LPS injection, indicating a successful inhibition of the downstream activation caused by hTNFA. Values are expressed as mean ± SEM. Significance was determined by one-way ANOVA test . * p < 0.5, **p < 0.01, ***p < 0.001.