Anti-IL6 monoclonal antibody [PE]

Background Interleukin-6 (IL-6) is a pleiotropic cytokine that controls numerous physiological processes both in basal and neuroinflammatory conditions, including the inflammatory response to experimental autoimmune encephalomyelitis (EAE). IL-6 is produced by multiple peripheral and central cells, and until now, the putative roles of IL-6 from different cell types have been evaluated through conditional cell-specific IL-6 knockout mice. Nevertheless, these mice probably undergo compensatory responses of IL-6 from other cells, which makes it difficult to assess the role of each source of IL-6. Methods To give some insight into this problem, we have produced a novel mouse model: a conditional reversible IL-6 KO mouse (IL6-DIO-KO). By using double-inverted, open-reading-frame (DIO) technology, we created a mouse line with the loss ofIl6expression in all cells that can be restored by the action of Cre recombinase. Since microglia are one of the most important sources and targets of IL-6 into the central nervous system, we have recovered microglialIl6expression in IL6-DIO-KO mice through breeding toCx3cr1-CreER mice and subsequent injection of tamoxifen (TAM) when mice were 10-16 weeks old. Then, they were immunized with myelin oligodendrocyte glycoprotein 35-55 peptide (MOG(35-55)) 7 weeks after TAM treatment to induce EAE. Clinical symptoms and demyelination, CD3 infiltration, and gliosis in the spinal cord were evaluated. Results IL6-DIO-KO mice were resistant to EAE, validating the new model. Restoration of microglialIl6was sufficient to develop a mild version of EAE-related clinical symptoms and neuropathology. Conclusions IL6-DIO-KO mouse is an excellent model to understand in detail the role of specific cellular sources of IL-6 within a recovery-of-function paradigm in EAE.

Multiple human and animal studies suggest that the upregulation of inflammatory cytokines and other pain-related molecules in degenerated or injured intervertebral discs (IVDs) may cause discogenic low back pain (LBP). We previously reported that macrophages in injured IVD in mice produced inflammatory cytokines, but not other pain-related molecules. CD14 is a monocyte marker expressed mainly by macrophages. The aim of the current study was to evaluate the role of CD14-positive cells in inflammatory cytokine and pain-related molecule expression in human degenerated IVD. IVD samples were harvested from 14 patients, including 10 with lumbar spinal stenosis, four with adult spinal deformity, and one with lumbar disc herniation during spinal interbody fusion surgery. Harvested IVD-derived mononuclear cells were obtained and CD14-positive (+) and CD14-negative (-) cells were separated using CD14 antibody and streptavidin-labeled magnetic beads. Inflammatory cytokines messenger RNA (mRNA) in the CD14(+) and CD14(-) cells, including tumor necrosis factor x251; (TNFA), in, terleukin-1 beta (IL1B) andIL6, were determined using quantitative polymerase chain reaction (qPCR) and their expression levels were compared. To evaluate factors controlling the regulation of pain-related molecules mRNA expression, cultured CD14(-) and CD14(+) cells from IVDs were stimulated with recombinant human TNF-x251; and IL-1 beta and levels of pain-related molecules, including calcitonin gene-related peptide (CGRP) and nerve growth factor (NGF) were determined using qPCR. Levels ofTNFA, IL1B, IL6, andNGFin CD14(+) cells were significantly increased compared with those in CD14(-) cells (TNFA, p = 0.006;IL1B, p = .017;IL6, p = .010;NGF, p = .027). FollowingTNFAstimulation,NGFlevels were significantly increased in CD14(-) and CD14(+) cells (CD14(-),p = .003; CD14(+),p < .001) and CGRP was significantly increased in CD14(-) IVD cells (p = .040). FollowingIL1Bstimulation,NGFlevels were significantly increased in CD14(-) cells (p = .004). CD14(+) cells had higherTNFA, IL1B, IL6, andNGFexpressions than CD14(-) cells in human degenerated IVDs. Additionally,TNFAstimulation promoted the upregulation ofNGFandCGRPin CD14(-) cells. These findings suggested that CD14(+) cells directly and indirectly contributed to inflammatory cytokine and pain-related molecule expression in human degenerated IVD. CD14(+) cells might be important in the pathological mechanism of chronic discogenic LBP in humans.