TNF Pathway Antibodies

The tumor necrosis factor (TNF or TNF-alpha) is a cytokine produced upon activation of the immune system and plays a central role as regulator of pro-inflammatory responses. TNF is also involved in other cellular processes, including cell death, differentiation, and communication. TNF is recognized as the prototypic member of a rather large family of cytokines known as the TNF ligand family. TNF derives its name from early observations about 30 years ago of a soluble cytokine produced by activated macrophages and is capable of causing significant cytotoxicity or necrosis on mouse tumor cell lines.

TNF is produced as a 25 kDa polypeptide chain that arranges into a type II transmembrane protein homotrimer. The membrane-bound protein is further processed by the TNF-alpha convertase (TACE) protease into a soluble form or cleaved by other proteases to produce TNF intracellular domains (ICD1 and ICD2) released in the cytosol and TNF C-domain 1 and C-domain 2 secreted into the extracellular space. Both expression and processing of TNF are tightly regulated and occur only upon stimulation. Although TNF is primarily produced by activated macrophages during the acute-phase response of inflammation, where it participates in the regulation of immune cells, it is also produced by lymphocytes, mastocytes, endothelial cells, fibroblasts, and neurons. Extensive research on the biology of TNF has shown its association with autoimmune and inflammatory diseases as well as cancer.

Activation by TNF upon binding of its receptors results in the induction and phosphorylation of a wide range of proteins involved in the NF-kB, MAPK, and cell death signaling pathways. Rockland's antibodies exhibiting high specificity and selectivity for the detection of TNF, TNF receptors, and key proteins of the affected pathways are routinely used for reproducible detection by Western blotting (WB), Immunohistochemistry (IHC), Immunofluorescence (IF), and ELISA.

TNF Signaling Pathway

Soluble TNF binds to at least two well-characterized receptors known as TNFR1 and TNFR2. Upon binding, TNF can induce activation of NF-kB, the MAPK cascades of JNK and p38-MAPK, and cell death signaling.

Activation of the canonical NF-kB by TNF signaling through its receptors involves the recruitment of key proteins like TRADD (in the case of signaling through the TNFR1 receptor) or TRAF1 and TRAF2 in the case of the TNFR2 receptor. This pathway results in the translocation of NF-kB in the nucleus and the subsequent expression of proteins that promote inflammation, cell survival, and proliferation.

TNF stimulation of the MAPK pathway markedly occurs on the stress-activated JNK cascade and is mediated by members of the Rho GTPase and the mixed-lineage protein kinases (MLKs) family of proteins, with the latter shown to be essential for activation of inflammation in vivo upon LPS stimulation. The JNK pathway is involved in a variety of biological processes including cell differentiation and proliferation, inflammation, neurodegeneration, and apoptosis.

Finally, TNF can also induce cell death by apoptosis signaling through the non-ubiquitylated receptor-interacting serine/threonine-protein kinase 1 (RIPK1), pro-caspase 8, and the long isoform of FLICE-like inhibitory protein (FLIPL). A different pathway of cell death initiated by TNF is necroptosis, a newly discovered pathway of regulated necrosis. Necroptosis is an important pro-inflammatory form of cell death mediated by the receptor-interacting protein kinase-3 (RIPK3) and its substrate the mixed lineage kinase-like (MLKL) protein.

The variety of effects caused by TNF in inflammation, proliferation, and cell death is determined by highly regulated mechanisms and most likely results from intricate cross-talk between the pathways involved and cellular context.

Figure: TNF signaling pathway (Created with BioRender.com)

TNF Signaling Pathway Antibodies

TNF Signaling Kits

With demonstrated experience in the development and validation of multiple assay formats, Rockland scientists continuously deliver optimized immunoassays for the study of TNF. In particular, ELISA kits provide a valuable, efficient solution for the determination of critical targets involved in TNF signaling. Rockland’s AccuSignal ELISA Kits guarantee high precision, accuracy, sensitivity, and specificity. Each TNF ELISA kit is optimized for accurate quantitation of targets in various sample types, including serum, plasma, saliva, cell lysates, and/or cell culture supernatants. Additionally, cell viability assays further complement a broad suite of tools for deep characterization of TNF signaling pathways.

TNF Signaling Pathway Proteins

Rockland offers a wide range of TNF signaling recombinant proteins from human, mouse, and other species that can be used in a variety of assays as controls or for other purposes since they exhibit a ≥90% purity. Alternatively, scientists can also take advantage of Rockland’s protein expression & purification services for the reliable generation of tailored proteins and custom antibody production services among others.