1A)

1A). Open in a separate window Open in a separate window FIG. C8 to TNF was found to be comparable with that of infliximab, which is a commercially available anti-TNF mAb. Keywords: monoclonal antibodies, TNF, inflammation Introduction Tumor necrosis factor (TNF) is a proinflammatory cytokine having pleiotropic effects on immune cells and plays an indispensable role in inflammation, cell differentiation, cell proliferation, apoptosis, and cell metabolism.(1,2) There are two types of TNF, tumor necrosis factor- (TNF) and tumor necrosis factor- (TNF), both of which are cytotoxic.(3,4) They are sequentially and structurally related and compete with each other for binding to their receptors.(5) Soluble TNF exerts a broad range of biological activities on interaction with two specific receptors, TNF receptor-type 1 (TNFR1 or p55) and TNF receptor-type 2 (TNFR2 or p75). TNFR1, expressed on almost all cell types, plays a major role in triggering the TNF signaling pathways. TNFR2 expression on the other hand is mostly limited to the cells of the immune system, nerve cells, and endothelial Kv3 modulator 3 cells under normal physiological conditions.(6C8) Upon binding to receptors, TNF promotes a series of intracellular signaling cascades, such as, activation of transcription factor NFB, Kv3 modulator 3 p38 mitogen-activated protein kinase (p38MAPK), and c-Jun N-terminal kinase (JNK) extracellular signal-regulated kinase.(8,9) Although TNF plays an essential role in an effective immune response, its unrestricted production may lead to several inflammatory disorders. Inhibition of TNF by pharmacological agents has FLJ11071 proven to be effective in palliative treatment.(10,11) In the study described in this article, we developed an anti-human TNF (hTNF) monoclonal antibody (mAb), namely C8, which can neutralize human-TNF activity. Furthermore, Kv3 modulator 3 using truncation and mutation analysis, we mapped the TNF-binding sites of the mAb, which was supported by docking studies using sequenced variable regions of heavy and light chain of the antibody. A study of mAb C8 and infliximab (a commercialized anti-TNF antibody), demonstrated that both antibodies have comparable affinities as well as TNF-neutralizing efficiency. Methods Animal and cell lines All the animal experiments were reviewed and approved by the Institutional Animal Ethics Committee (IAEC) of the Indian Institute of Science, CAF/Ethics/184/2010 dated June 16, 2010. L929 mouse fibroblast cells were maintained as monolayer cultures in Dulbecco’s modified Eagle’s medium (DMEM) and passaged every 2C3 days using 0.25% trypsin-EDTA. Hybridoma cells were cultured in Iscove’s modified Dulbecco’s medium (IMDM). Both media were supplemented with 10% fetal bovine serum (FBS), 1?mM GlutaMAX (Gibco), and antibiotics. IMDM was supplemented also with 50?M -mercaptoethanol. All cultures were maintained at 37C in a humidified incubator with 5% CO2. Expression and purification of His-tagged human-TNF and mouse-TNF strain cells were transformed with the pET15b vector containing the human-gene and pET28a vector containing the mouse-gene. Then, cells Kv3 modulator 3 were induced with 1?mM IPTG and were incubated at 30C for 8 hours in an incubator shaker at 200?rpm for the expression of each respective protein; the cells were harvested by centrifugation at 6000?rpm for 20 minutes at 4C. The cell pellet obtained was resuspended with 50?mM Tris-HCl, pH 8.0 containing 150?mM NaCl (TBS), sonicated (sonication conditions: 4C, ampt 30%, 30 minutes), and the soluble proteins were separated by centrifugation at 13,000?rpm for 30 minutes at 4C. The supernatant (soluble protein) was loaded on the Ni-NTA column. Unbound proteins were Kv3 modulator 3 washed away with TBS containing 30?mM imidazole and the bound protein was eluted with 300?mM imidazole in TBS. After elution, the protein was dialyzed against phosphate-buffered saline (PBS; 50?mM phosphate buffer pH, 7.4, containing 150?mM NaCl)..