Tnf Conditional Knockout mouse models

Encoded as a type II transmembrane trimer and shed by ADAM17, the product of Tnf (mouse ortholog of human TNF) engages TNFRSF1A and TNFRSF1B to nucleate complex I, in which TRADD, TRAF2, cIAP1/2, LUBAC, and RIPK1 ubiquitin chains recruit TAK1 and IKK for canonical NF-kB and JNK output, while RIPK1 deubiquitination diverts signaling into caspase-8 apoptosis or, when FADD or caspase-8 activity is limiting, RIPK3 and MLKL necroptosis. Allele choice tracks the question precisely: conditional null alleles test cell-intrinsic cytokine sources, the AU-rich element deletion knockin stabilizes transcript and reproduces Crohn-like ileitis and erosive arthritis, uncleavable membrane-only knockins separate juxtacrine from systemic activity, and full humanization is mandatory because infliximab and adalimumab do not recognize mouse TNF. Targeting must avoid disrupting the tightly linked Lta and Ltb loci, whose lymphotoxin products independently sustain lymphoid architecture and can confound readouts of germinal center or Peyer patch phenotypes.

Tnf conditional knockout mice carry a floxed allele so you delete function only where Cre is active. The germline allele stays intact until you cross to a tissue specific Cre. Labs reach for this design when a global knockout is lethal, when they need adult onset loss, or when regional redundancy hides a whole body phenotype.