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Synthesis and characterization of a thermally-responsive tumor necrosis factor antagonist.

ABSTRACT: Numerous antagonists of tumor necrosis factor alpha (TNFalpha) have been developed to attenuate inflammation and accompanying pain in many disease processes. Soluble TNF receptor type II (sTNFRII) is one such antagonist that sequesters TNFalpha away from target receptors and attenuates its activity. Systemic delivery of soluble TNF receptors or other antagonists may have deleterious side effects associated with immune suppression, so that strategies for locally targeted drug delivery are of interest. Elastin-like polypeptides (ELPs) are biopolymers capable of in situ drug depot formation through thermally-driven supramolecular complexes at physiological temperatures. A recombinant fusion protein between ELP and sTNFRII was designed and evaluated for retention of bivalent functionality. Thermal sensitivity was observed by formation of supramolecular submicron-sized particles at 32 degrees C, with gradual resolubilization from the depot observed at physiological temperatures. In vitro refolding of the sTNFRII domain was required and the purified product exhibited an equilibrium dissociation constant for interacting with TNFalpha that was seven-fold higher than free sTNFRII. Furthermore, anti-TNF activity was observed in inhibiting TNFalpha-mediated cytotoxicity in the murine L929 fibrosarcoma assay. Potential advantages of this ELP-sTNFRII fusion protein as an anti-TNFa drug depot include facility of injection, in situ depot formation, low endotoxin content, and functionality against TNFalpha.

SUBMITTER: Shamji MF

PROVIDER: S-EPMC2637771 | biostudies-other | 2008 Aug

REPOSITORIES: biostudies-other

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Synthesis and characterization of a thermally-responsive tumor necrosis factor antagonist.

Shamji Mohammed F MF Chen Jun J Friedman Allan H AH Richardson William J WJ Chilkoti Ashutosh A Setton Lori A LA

Journal of controlled release : official journal of the Controlled Release Society 20080501 3

Numerous antagonists of tumor necrosis factor alpha (TNFalpha) have been developed to attenuate inflammation and accompanying pain in many disease processes. Soluble TNF receptor type II (sTNFRII) is one such antagonist that sequesters TNFalpha away from target receptors and attenuates its activity. Systemic delivery of soluble TNF receptors or other antagonists may have deleterious side effects associated with immune suppression, so that strategies for locally targeted drug delivery are of inte ...[more]

PMID: 18547669

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Project description:Biochemical irritation of the dorsal root ganglion (DRG) after intervertebral disc herniation contributes to radiculopathy through tumor necrosis factor-alpha (TNFalpha)-mediated inflammation. Soluble TNF receptor Type II (sTNFRII) sequesters this cytokine, providing clinical benefit. Previous work involving conjugation of sTNFRII with thermally responsive elastin-like polypeptide (ELP) yielded a chimeric protein (ELP-sTNFRII) with in vitro anti-TNFalpha bioactivity. Furthermore, temperature-triggered ELP aggregation into a "depot" prolongs protein residence time following perineural injection. In this study the authors evaluated the inflammatory phenotype of DRG explants after TNFalpha stimulation, and assessed the abilities of sTNFRII or ELP-sTNFRII to attenuate these neuro-inflammatory changes.Rat lumbar DRGs (35 animals) were treated in 6 groups, as follows: control; TNFalpha (25 ng/ml); TNFalpha with low-(0.2 microg/ml) or high-dose (1 microg/ml) sTNFRII; and TNFalpha with low-(52.5 microg/ml) or high-dose (262.5 microg/ml) ELP-sTNFRII. After 24 hours, supernatant was evaluated for inflammatory cytokines (interleukin [IL]-1, IL-6, and IL-10); prostaglandin E2; and metabolites (glutamate, lactate, and pyruvate). Single-factor analysis of variance with post hoc Dunn analysis (alpha = 0.05) was used to assess treatment differences.Incubation of explants with TNFalpha caused metabolic stress reflected by an increased lactate/pyruvate ratio (1.8 +/- 0.5-fold) and extracellular glutamate (79 +/- 8% increase). Inflammatory activation was observed with heightened IL-6 release (5.2 +/- 1.4-fold) and prostaglandin E2 production (14 +/- 3-fold). An autoregulatory response occurred with an 11.8 +/- 0.6-fold increase in sTNFRI shedding. Treatment with high doses of sTNFRII or ELP-sTNFRII reversed all changes. Values are expressed as the mean +/- standard deviation.These results demonstrate that TNFalpha stimulation of DRG explants yields a phenotype of neurotoxic metabolite release and inflammatory mediator expression. Coincubation with either sTNFRII or ELP-sTNFRII antagonizes TNFalpha activity to abrogate these changes, suggesting potential for therapeutic intervention to treat peripheral nerve inflammatory disease.

Project description:Although tumor necrosis factor (TNF) initially came to prominence because of its anti-tumor activity, most attention is now focused on its proinflammatory actions. TNF appears to play a critical role in both early and late events involved in inflammation, from localizing the noxious agent and amplifying the cellular and mediator responses at the local site and systemically, to editing (e.g., apoptosis) injured cells or effete immune cells and repairing inflammatory damage. We have generated mice deficient in TNF (TNF-/- mice) and have begun to examine the multiple functions attributed to TNF. TNF-/- mice develop normally and have no gross structural or morphological abnormalities. As predicted, they are highly susceptible to challenge with an infectious agent (Candida albicans), are resistant to the lethality of minute doses of lipopolysaccharide (LPS) following D-galactosamine treatment, have a deficiency in granuloma development, and do not form germinal centers after immunization. Phagocytic activity of macrophages appears relatively normal, as do T cell functions, as measured by proliferation, cytokine release, and cytotoxicity. B cell response to thymus-independent antigens is normal, but the Ig response to thymus-dependent antigen is reduced. Surprisingly, cytokine production induced by LPS appears essentially intact, with the exception of reduced colony-stimulating factor activity. Other unexpected findings coming from our initial analysis are as follows. (i) TNF has low toxicity in TNF-/- mice. (ii) TNF-/- mice show an anomalous late response to heat-killed Corynebacterium parvum. In contrast to the prompt response (granuloma formation, hepatosplenomegaly) and subsequent resolution phase in C. parvum-injected TNF+/+ mice, similarly treated TNF-/- mice show little or no initial response, but then develop a vigorous, disorganized inflammatory response leading to death. These results suggest that TNF has an essential homeostatic role in limiting the extent and duration of an inflammatory process-i.e., an anti-inflammatory function. (iii) In contrast to the expectation that TNF+/+ mice and TNF+/- mice would have identical phenotypes, TNF+/- mice showed increased susceptibility to high-dose LPS lethality, increased susceptibility to Candida challenge, and delayed resolution of the C. parvum-induced inflammatory process, indicating a strong gene dose requirement for different actions of TNF.

Project description:Introduction: Tumor necrosis factor antagonists (anti-TNF) therapies are used for the management of moderate to severe inflammatory bowel disease (IBD). Anti-TNF combination therapy, with immunomodulators, has been shown to reduce immunogenicity, especially for infliximab, improve treatment success rate and patient outcomes. We evaluated factors associated with gastroenterologists adherence to anti-TNF combination therapy. Methods: A retrospective cohort study was performed to evaluate the adherence of gastroenterologists (n = 14), at an inflammatory bowel disease center, to anti-TNF combination therapy. Records of patients who received Infliximab (n = 137) or adalimumab (n = 152) were obtained and their ordering physicians' data was analyzed. Gastroenterologists were divided into six groups according to their age and interest in IBD. The baseline characteristics of their patients were also obtained. Results: The proportion of patients on combination therapy in the young gastroenterologists group was higher than those in the senior gastroenterologists group for both infliximab (83.2 vs. 55.6%, respectively, P < 0.001) and adalimumab (59 vs. 30.8%, respectively, P < 0.001). Gastroenterologists with interest in inflammatory bowel disease (IBD interest group) had also more proportion of patients on adalimumab combination therapy compared to gastroenterologists with no interest in IBD (non-IBD interest group) (61.7 vs. 35.2%, respectively, P < 0.001). Gastroenterologists who were both young and have interest in IBD had more proportion of patients on combination therapy than those who were senior or had no interest in IBD for both infliximab (89.4 vs. 63.4%, respectively, P < 0.001) and adalimumab (75.9 vs. 33%, P < 0.001). The IBD interest group was also requesting more antidrug antibody level tests than those in the non-IBD interest group (41.4 vs. 12.3 tests, respectively, P < 0.001). Conclusion: Young gastroenterologists are more likely to prescribe anti-TNF infliximab and adalimumab combination therapy than senior gastroenterologists. In addition, gastroenterologists with IBD interest are more likely to prescribe adalimumab combination therapy than gastroenterologists with no IBD interest. Moreover, young gastroenterologists who have interest in IBD are more likely to prescribe both infliximab and adalimumab combination therapy than senior gastroenterologists or those with no IBD interest. In addition, gastroenterologists with IBD interest requested more anti-TNF serum drug concentrations and antidrug antibody level tests than those with no IBD interest.

Project description:Type 1 diabetes with periodontitis shows elevated TNF-α expression. Tumor necrosis factor (TNF)-α stimulates the expression of receptor activator of nuclear factor-κB ligand (RANKL) and sclerostin. The objective of this study was to determine the effect of TNF-α expression of osteocytic RANKL and sclerostin in type 1 diabetes rats with periodontitis using infliximab (IFX), a TNF-α antagonist. Rats were divided into two timepoint groups: day 3 and day 20. Each timepoint group was then divided into four subgroups: 1) control (C, n = 6 for each time point); 2) periodontitis (P, n = 6 for each time point); 3) diabetes with periodontitis (DP, n = 8 for each time point); and 4) diabetes with periodontitis treated with IFX (DP+IFX, n = 8 for each time point). To induce type 1 diabetes, rats were injected with streptozotocin (50 mg/kg dissolved in 0.1 M citrate buffer). Periodontitis was then induced by ligature of the mandibular first molars at day 7 after STZ injection (day 0). IFX was administered once for the 3 day group (on day 0) and twice for the 20 day group (on days 7 and 14). The DP group showed greater alveolar bone loss than the P group on day 20 (P = 0.020). On day 3, higher osteoclast formation and RANKL-positive osteocytes in P group (P = 0.000 and P = 0.011, respectively) and DP group (P = 0.006 and P = 0.017, respectively) than those in C group were observed. However, there was no significant difference in osteoclast formation or RANKL-positive osteocytes between P and DP groups. The DP+IFX group exhibited lower alveolar bone loss (P = 0.041), osteoclast formation (P = 0.019), and RANKL-positive osteocytes (P = 0.009) than that of the DP group. On day 20, DP group showed a lower osteoid area (P = 0.001) and more sclerostin-positive osteocytes (P = 0.000) than P group. On days 3 and 20, the DP+IFX group showed more osteoid area (P = 0.048 and 0.040, respectively) but lower sclerostin-positive osteocytes (both P = 0.000) than DP group. Taken together, these results suggest that TNF-α antagonist can diminish osteocytic RANKL/sclerostin expression and osteoclast formation, eventually recovering osteoid formation. Therefore, TNF-α might mediate alveolar bone loss via inducing expression of osteocytic RANKL and sclerostin in type 1 diabetes rats with periodontitis.

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Synthesis and characterization of a thermally-responsive tumor necrosis factor antagonist.

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Synthesis and characterization of a thermally-responsive tumor necrosis factor antagonist.

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