The death-inducing activity of RIPK1 is regulated by the pH environment.

Receptor-interacting protein kinase 1 (RIPK1) is a serine/threonine kinase that dictates whether cells survive or die in response to the cytokine tumor necrosis factor (TNF) and other inflammatory stimuli. The activity of RIPK1 is tightly controlled by multiple posttranslational modification mechanisms, including ubiquitination and phosphorylation. Here, we report that sensitivity to TNF-induced, RIPK1-dependent cell death was tunable by the pH environment. We found that an acidic extracellular pH, which led to a concomitant decrease in intracellular pH, impaired the kinase activation of RIPK1 and autophosphorylation at Ser166 Consequently, formation of the cytosolic death-inducing complex II and subsequent RIPK1-dependent necroptosis and apoptosis were inhibited. By contrast, low pH did not affect the formation of membrane-anchored TNFR1-containing signaling complex (complex I), RIPK1 ubiquitination, and NF-κB activation. TNF-induced cell death in Ripk1 -/- cells was not sensitive to pH changes. Furthermore, mutation of the conserved His151 abolished the pH dependence of RIPK1 activation, suggesting that this histidine residue functions as a proton acceptor to modulate RIPK1 activity in response to pH changes. These results revealed an unexpected environmental factor that controls the death-inducing activity of RIPK1.

Bifidobacterium plays a protective role in TNF-α-induced inflammatory response in Caco-2 cell through NF-κB and p38MAPK pathways.

Kawasaki disease is an immune-mediated acute, systemic vasculitis and is the leading cause of acquired heart disease in children in the developed world. Bifidobacterium (BIF) is one of the dominant bacteria in the intestines of humans and many mammals and is able to adjust the intestinal flora disorder. The Caco-2 cell monolayers were treated with tumor necrosis factor-α (TNF-α) at 10 ng/ml for 24 h to induce the destruction of intestinal mucosal barrier system. Cells viability was detected through Cell Counting Kit-8 assay. Cell apoptosis was measured by flow cytometry and the expression of apoptosis related proteins was also detected through Western blot. The level of pro-inflammatory cytokines interleukin-6 (IL-6) and IL-8 was detected through ELISA, Western blot and qRT-PCR, respectively. Transepithelial electrical resistance (TEER) assay was conducted to value the barrier function of intestinal mucosa. Cell autophagy and NF-κB and p38MAPK pathways associated proteins were examined through Western blot. In the absence of TNF-α treatment, cell viability and apoptosis showed no significant change. TNF-α decreased cell viability and increased cell apoptosis and BIF treatment mitigated the TNF-α-induced change. Then, we found that BIF treatment effectively suppressed TNF-α-induced overexpression of IL-6 and IL-8. Besides, the results of TEER assay showed that barrier function of intestinal mucosa which was destroyed by TNF-α was effectively recovered by BIF treatment. In addition, TNF-α induced autophagy was also suppressed by BIF. Moreover, TNF-α activated NF-κB and p38MAPK signal pathways were also blocked by BIF, SN50 and SB203580. Our present study reveals that BIF plays a protective role in TNF-α-induced inflammatory response in Caco-2 cells through NF-κB and p38MAPK pathways.

R-CHOP preceded by blood-brain barrier permeabilization with engineered tumor necrosis factor-α in primary CNS lymphoma.

Patients with primary central nervous system lymphoma (PCNSL) are treated with high-dose methotrexate-based chemotherapy, which requires hospitalization and extensive expertise to manage related toxicity. The use of R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone) could overcome these difficulties, but blood-brain barrier (BBB) penetration of related drugs is poor. Tumor necrosis factor-α coupled with NGR (NGR-hTNF), a peptide targeting CD13+ vessels, induces endothelial permeabilization and improves tumor access of cytostatics. We tested the hypothesis that NGR-hTNF can break the BBB, thereby improving penetration and activity of R-CHOP in patients with relapsed/refractory PCNSL (NCT03536039). Patients received six R-CHOP21 courses, alone at the first course and preceded by NGR-hTNF (0.8 µg/m2) afterward. This trial included 2 phases: an "explorative phase" addressing the effect of NGR-hTNF on drug pharmacokinetic parameters and on vessel permeability, assessed by dynamic contrast-enhanced magnetic resonance imaging and 99mTc-diethylene-triamine-pentacetic acid-single-photon emission computed tomography, and the expression of CD13 on tumor tissue; and an "expansion phase" with overall response rate as the primary end point, in which the 2-stage Simon Minimax design was used. At the first stage, if ≥4 responses were observed among 12 patients, the study accrual would have continued (sample size, 28). Herein, we report results of the explorative phase and the first-stage analysis (n = 12). CD13 was expressed in tumor vessels of all cases. NGR-hTNF selectively increased vascular permeability in tumoral/peritumoral areas, without interfering with drug plasma/cerebrospinal fluid concentrations. The NGR-hTNF/R-CHOP combination was well tolerated: there were only 2 serious adverse events, and grade 4 toxicity was almost exclusively hematological, which were resolved without dose reductions or interruptions. NGR-hTNF/R-CHOP was active, with 9 confirmed responses (75%; 95% confidence interval, 51-99), 8 of which were complete. In conclusion, NGR-hTNF/R-CHOP was safe in these heavily pretreated patients. NGR-hTNF enhanced vascular permeability specifically in tumoral/peritumoral areas, which resulted in fast and sustained responses.

Linear ubiquitination of cFLIP induced by LUBAC contributes to TNFα-induced apoptosis.

The linear ubiquitin chain assembly complex (LUBAC) regulates NF-κB activation by modifying proteins with linear (M1-linked) ubiquitination chains. Although LUBAC also regulates the apoptosis pathway, the precise mechanism by which LUBAC regulates apoptosis remains not fully defined. Here, we report that LUBAC-mediated M1-linked ubiquitination of cellular FLICE-like inhibitory protein (cFLIP), an anti-apoptotic molecule, contributes to tumor necrosis factor (TNF) α-induced apoptosis. We found that deficiency of RNF31, the catalytic subunit of the LUBAC complex, promoted cFLIP degradation in a proteasome-dependent manner. Moreover, we observed RNF31 directly interact with cFLIP, and LUBAC further conjugated M1-linked ubiquitination chains at Lys-351 and Lys-353 of cFLIP to stabilize cFLIP, thereby protecting cells from TNFα-induced apoptosis. Together, our study identifies a new substrate of LUBAC and reveals a new molecular mechanism through which LUBAC regulates TNFα-induced apoptosis via M1-linked ubiquitination.

Dendritic Mesoporous Silica Nanoparticles for pH-Stimuli-Responsive Drug Delivery of TNF-Alpha.

Tumor necrosis factor-alpha (TNF-α) is a pleiotropic immune stimulatory cytokine and natural endotoxin that can induce necrosis and regression in solid tumors. However, systemic administration of TNF-α is not feasible due to its short half-life and acute toxicity, preventing its widespread use in cancer treatment. Dendritic mesoporous silica nanoparticles (DMSN) are used coated with a pH-responsive block copolymer gate system combining charged hyperbranched polyethylenimine and nonionic hydrophilic polyethylenglycol to encapsulate TNF-α and deliver it into various cancer cell lines and dendritic cells. Half-maximal effective concentration (EC50 ) for loaded TNF-α is reduced by more than two orders of magnitude. Particle stability and premature cargo release are assessed with enzyme-linked immunosorbent assay. TNF-α-loaded particles are stable for up to 5 d in medium. Tumor cells are grown in vitro as 3D fluorescent ubiquitination-based cell cycle indicator spheroids that mimic in vivo tumor architecture and microenvironment, allowing real-time cell cycle imaging. DMSN penetrate these spheroids, release TNF-α from its pores, preferentially affect cells in S/G2/M phase, and induce cell death in a time- and dose-dependent manner. In conclusion, DMSN encapsulation is demonstrated, which is a promising approach to enhance delivery and efficacy of antitumor drugs, while minimizing adverse side effects.

Characterization and Interspecies Scaling of rhTNF-α Pharmacokinetics with Minimal Physiologically Based Pharmacokinetic Models.

Tumor necrosis factor-α (TNF-α) is a soluble cytokine and target of specific monoclonal antibodies (mAbs) and other biologic agents used in the treatment of inflammatory diseases. These biologics exert their pharmacological effects through binding and neutralizing TNF-α, and thus they prevent TNF-α from interacting with its cell surface receptors. The magnitude of the pharmacological effects is governed not only by the pharmacokinetics (PK) of mAbs, but also by the kinetic fate of TNF-α We have examined the pharmacokinetics of recombinant human TNF-α (rhTNF-α) in rats at low doses and quantitatively characterized its pharmacokinetic features with a minimal physiologically based pharmacokinetic model. Our experimental and literature-digitalized PK data of rhTNF-α in rats across a wide range of doses were applied to global model fitting. rhTNF-α exhibits permeability rate-limited tissue distribution and its elimination is comprised of a saturable clearance pathway mediated by tumor necrosis factor receptor binding and disposition and renal filtration. The resulting model integrated with classic allometry was further used for interspecies PK scaling and resulted in model predictions that agreed well with experimental measurements in monkeys. In addition, a semimechanistic model was proposed and applied to explore the absorption kinetics of rhTNF-α following s.c. and other routes of administration. The model suggests substantial presystemic degradation of rhTNF-α for s.c. and i.m. routes and considerable lymph uptake contributing to the overall systemic absorption through the stomach wall and gastrointestinal wall routes of dosing. This report provides comprehensive modeling and key insights into the complexities of absorption and disposition of a major cytokine.

The effects of pregnancy on the pharmacokinetics of infliximab and adalimumab in inflammatory bowel disease.

BACKGROUND: Transplacental transfer of infliximab and adalimumab results in detectable drug levels in the cord blood and infant. AIM: To determine if pregnancy influenced the pharmacokinetics of anti-TNF agents in women with inflammatory bowel disease. METHODS: Twenty-five women from the University of Calgary inflammatory bowel disease(IBD) pregnancy clinic on maintenance infliximab or adalimumab were recruited prospectively with serum bio-banking performed each trimester. Infliximab trough and adalimumab steady-state levels were the outcomes of interest and were analysed using the ANSER infliximab and adalimumab assays. Multivariate linear mixed-effects models were constructed to assess infliximab and adalimumab drug levels during pregnancy adjusting for the clinical covariates of albumin, BMI and CRP. RESULTS: Fifteen women (eight Crohn's disease, seven ulcerative colitis) received infliximab and 10 women with 11 pregnancies were treated with adalimumab. Median age was 29.6 years (IQR: 27.6-31.2 years). Median disease duration was 9.2 years (IQR: 3.16-15.0 years). Median trough infliximab concentrations were 8.50 µg/mL (IQR: 7.23-10.07 µg/mL), 10.31 µg/mL (IQR: 7.66-15.63 µg/mL) and 21.02 µg/mL (IQR: 16.01-26.70 µg/mL) at trimesters 1, 2 and 3 respectively. Significant changes in albumin and BMI (P < 0.05) but not CRP (P > 0.05) were documented throughout pregnancy. After adjusting for albumin, BMI and CRP, infliximab trough levels increased during pregnancy, by 4.2 µg/mL per trimester (P = 0.02), while adalimumab drug levels remained stable (P > 0.05). CONCLUSIONS: Infliximab levels rise during pregnancy, whereas adalimumab levels remain stable after accounting for changes in albumin, BMI and CRP. Therapeutic drug monitoring in the second trimester may be useful in guiding dosing in the third trimester.

Relay Drug Delivery for Amplifying Targeting Signal and Enhancing Anticancer Efficacy.

A "relay drug delivery" system based on two distinct modules, which is composed of a signal transmission nanocarrier A (NCA ) that can specifically induce tumor blood vessel inflammation generation and an execution biomimetic nanocarrier B (NCB ) that can accumulate at the tumor site by receiving the broadcasting signals generated by NCA , is developed for amplifying active tumor targeting signal and enhancing antitumor therapy.

Mitochondria-Targeted Antioxidant SkQR1 Reduces TNF-Induced Endothelial Permeability in vitro.

Prolonged or excessive increase in the circulatory level of proinflammatory tumor necrosis factor (TNF) leads to abnormal activation and subsequent damage to endothelium. TNF at high concentrations causes apoptosis of endothelial cells. Previously, using mitochondria-targeted antioxidants of SkQ family, we have shown that apoptosis of endothelial cells is dependent on the production of reactive oxygen species (ROS) in mitochondria (mito-ROS). Now we have found that TNF at low concentrations does not cause cell death but activates caspase-3 and caspase-dependent increase in endothelial permeability in vitro. This effect is probably due to the cleavage of ß-catenin - an adherent junction protein localized in the cytoplasm. We have also shown that extracellular matrix metalloprotease 9 (MMP9) VE-cadherin shedding plays a major role in the TNF-induced endothelial permeability. The mechanisms of the caspase-3 and MMP9 activation are probably not related to each other since caspase inhibition did not affect VE-cadherin cleavage and MMP9 inhibition had no effect on the caspase-3 activation. Mitochondria-targeted antioxidant SkQR1 inhibited TNF-induced increase in endothelial permeability. SkQR1 also inhibited caspase-3 activation, ß-catenin cleavage, and MMP9-dependent VE-cadherin shedding. The data suggest that mito-ROS are involved in the increase in endothelial permeability due to the activation of both caspase-dependent cleavage of intracellular proteins and of MMP9-dependent cleavage of the transmembrane cell-to-cell contact proteins.

Development and characterization of enteric-coated microparticles of biochanin A for their beneficial pharmacological potential in estrogen deficient-hypertension.

Enteric coating of microparticles prevents stomach degradation and enhances oral bioavailability of poorly soluble drugs. Thus, in the present study, enteric-coated microparticle (ECMP) of biochanin A was developed and their pharmacological potential was investigated in hypertensive ovariectomized rats (Ovx-HT). Biochanin A microparticles were prepared by using ionic gelation method and coating was done by ethyl cellulose using coacervation phase separation method. Surface modified microparticles were characterized on the basis of size, entrapment efficiency, polydispersity index, FTIR and zeta potential and percentage of in vitro release. Ovariectomized rats were administered deoxy corticosterone acetate (40 mg/kg, s.c. twice a week for 6 weeks) salt to induce Ovx-HT. Hypertension was assessed in terms of increase in systolic, diastolic, mean arterial blood pressure, lipid peroxidation level, tumor necrosis factor-alpha (TNF-α) level and decrease in serum nitrite and reduced glutathione (GSH) level. The optimized formulation of ECMP has shown significant increase in oral bioavailability assessed by high-performance liquid chromatography. Furthermore, these ECMPs significantly reduced the mean arterial blood pressure, systolic and diastolic blood pressure, reduced lipid peroxidation and TNF-α level and significantly increased the serum nitrite and reduced GSH level in Ovx-HT rats. However, L-NAME significantly prevented the ameliorative effect of ECMP. Thus, it may be concluded that ECMP of biochanin A has shown delayed release capacity, increase in oral bioavailability up to 6 folds than plain biochanin A and exerts antihypertensive effect in ovariectomized rats possibly in an eNOS dependent manner.

PRINT: A Protein Bioconjugation Method with Exquisite N-terminal Specificity.

Chemical conjugation is commonly used to enhance the pharmacokinetics, biodistribution, and potency of protein therapeutics, but often leads to non-specific modification or loss of bioactivity. Here, we present a simple, versatile and widely applicable method that allows exquisite N-terminal specific modification of proteins. Combining reversible side-chain blocking and protease mediated cleavage of a commonly used HIS tag appended to a protein, we generate with high yield and purity exquisitely site specific and selective bio-conjugates of TNF-α by using amine reactive NHS ester chemistry. We confirm the N terminal selectivity and specificity using mass spectral analyses and show near complete retention of the biological activity of our model protein both in vitro and in vivo murine models. We believe that this methodology would be applicable to a variety of potentially therapeutic proteins and the specificity afforded by this technique would allow for rapid generation of novel biologics.

Tumor Necrosis Factor-α Inhibition in Ankylosing Spondylitis and Nonradiographic Axial Spondyloarthritis: Treatment Response, Drug Survival, and Patient Outcome.

OBJECTIVE: The purpose of this study was to (1) evaluate baseline characteristics of nonradiographic axial spondyloarthritis (nr-axSpA) and ankylosing spondylitis (AS) treated with tumor necrosis factor-α inhibitors (TNFi), (2) assess the response to first TNFi treatment, and (3) compare drug-survival duration and rates. METHODS: Inclusion criteria were patients with axSpA who initiated first TNFi treatment between April 2001 and July 2014 and were followed up for at least 3 months. Efficacy criteria were an improvement of at least 2 points (on a 0-10 scale) or a 50% improvement in the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). Baseline characteristics, responses at 12 months, and drug survival were compared between AS and nr-axSpA. RESULTS: A total of 361 patients were included in the study (AS, n = 263 and nr-axSpA, n = 98). Patients with AS were more often men (65.02% vs 45.92%, p = 0.001) and had longer symptom duration (11.71 ± 9.52 vs 7.34 ± 9.30 yrs, p < 0.001). Median levels of acute-phase reactants (C-reactive protein and erythrocyte sedimentation rate) were significantly higher in patients with AS (p < 0.001 for both). Median BASDAI scores at first TNFi initiation were not higher in patients with nr-axSpA than in patients with AS (59, 49-70 vs 60, 50-70, p = 0.73). BASDAI 20 and BASDAI 50 response rates at 12 months were not statistically different between patients with AS and patients with nr-axSpA (74.58% vs 64.58%, p = 0.19 and 61.02% vs 50.00%, p = 0.19, respectively). No statistically significant difference in terms of survival was observed between patients with AS and nr-axSpA (p = 1.00). CONCLUSION: Treatment response and drug survival were similar in patients with AS and nr-axSpA after first TNFi initiation.

Loss of Infliximab Into Feces Is Associated With Lack of Response to Therapy in Patients With Severe Ulcerative Colitis.

BACKGROUND & AIMS: It is not clear why some patients with ulcerative colitis (UC) do not respond to treatment with anti-tumor necrosis factor (TNF) agents, such as infliximab. It could be that some patients have high level of inflammation, with large quantities of TNF to be neutralized by the drug. We investigated whether loss of anti-TNF agents through ulcerated intestinal mucosa reduces the efficacy of these drugs in patients with severe UC. METHODS: We collected fecal samples from 30 consecutive patients with moderate to severely active UC during the first 2 weeks of infliximab therapy at the University of Amsterdam hospital. Infliximab concentrations were measured in serum and supernatants of fecal samples using an enzyme-linked immunosorbent assay (Sanquin Biologicals Laboratory, Amsterdam, The Netherlands). Clinical and endoscopic responses were assessed 2 and 8 weeks and 3 months after treatment began. RESULTS: Infliximab was detected in 129 of 195 fecal samples (66%); the highest concentrations were measured in the first days after the first infusion. Patients that were clinical nonresponders at week 2 had significantly higher fecal concentrations of infliximab after the first day of treatment than patients with clinical responses (median concentration, 5.01 µg/mL in nonresponders vs 0.54 µg/mL in responders; P = .0047). We did not observe a correlation between fecal and serum concentrations of infliximab. CONCLUSIONS: Infliximab is lost into stools of patients with UC. High fecal concentrations of infliximab in the first days after therapy begins are associated with primary nonresponse. Additional studies are needed to determine how therapeutic antibodies are lost through the intestinal mucosa and how this process affects treatment response. Clinical trial ID: NL41310.018.12.

Hyaluronic acid-tumor necrosis factor-related apoptosis-inducing ligand conjugate for targeted treatment of liver fibrosis.

Liver fibrosis is a chronic liver disease caused by viral infection and/or metabolic, genetic and cholestatic disorders. The inhibition of hepatic stellate cell (HSC) activation and the selective apoptosis of activated HSCs can be a good strategy to treat liver fibrosis. The activated HSCs are known to be more susceptible to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induced apoptosis than normal HSCs because death receptor 5 is overexpressed on the cell surface. In this work, a target-specific and long-acting hyaluronic acid (HA)-TRAIL conjugate was successfully developed for the treatment of liver fibrosis. The HA-TRAIL conjugate was synthesized by a coupling reaction between aldehyde-modified HA and the N-terminal amine group of TRAIL. The biological activity of the HA-TRAIL conjugate was confirmed by an in vitro anti-proliferation assay and caspase-3 expression in human colon cancer HCT116 cells. In vivo real-time bioimaging exhibited the target-specific delivery of near-infrared fluorescence dye-labeled HA-TRAIL conjugate to the liver in mice. According to pharmacokinetic analysis, the HA-TRAIL conjugate was detected for more than 4days after single intravenous injection into Sprague-Dawley (SD) rats. Finally, we could confirm the antifibrotic effect of HA-TRAIL conjugate in an N-nitrosodimethylamine-induced liver fibrosis model SD rats.

Antitumor activity of TNF-α after intratumoral injection using an in situ thermosensitive hydrogel.

Local drug delivery strategies based on nanoparticles, gels, polymeric films, rods and wafers are increasingly used in cancer chemotherapy in order to enhance therapeutic effect and reduce systemic toxicity. Herein, a biodegradable and biocompatible in situ thermosensitive hydrogel was designed and employed to deliver tumor necrosis factor-α (TNF-α) locally by intratumoral injection. The triblock copolymer was synthesized by ring-opening polymerization (ROP) of ß-butyrolactone (ß-BL) and lactide (LA) in bulk using polyethylene glycol (PEG) as an initiator and Sn(Oct)2 as the catalyst, the polymer was characterized by NMR, gel permeation chromatography and differential scanning calorimetry. Blood and tumor pharmacokinetics and in vivo antitumor activity of TNF-α after intratumoral administration in hydrogel or solution with the same dose were evaluated on S180 tumor-bearing mice. Compared with TNF-α solution, TNF-α hydrogel exhibited a longer T1/2 (4-fold) and higher AUCtumor (19-fold), but Cmax was lower (0.5-fold), which means that the hydrogel formulation improved the efficacy with a lower systhemic exposure than the solution formation. In addition, TNF-α hydrogel improved the antitumor activity and survival due to lower systemic exposure than the solution. These results demonstrate that the in situ thermosensitive hydrogel-based local delivery system by intratumoral injection is well suited for the administration of TNF-α.

Peripheral administration of the selective inhibitor of soluble tumor necrosis factor (TNF) XPro®1595 attenuates nigral cell loss and glial activation in 6-OHDA hemiparkinsonian rats.

BACKGROUND: Parkinson's disease (PD) is a complex multi-system age-related neurodegenerative disorder. Targeting the ongoing neuroinflammation in PD patients is one strategy postulated to slow down or halt disease progression. Proof-of-concept studies from our group demonstrated that selective inhibition of soluble Tumor Necrosis Factor (solTNF) by intranigral delivery of dominant negative TNF (DN-TNF) inhibitors reduced neuroinflammation and nigral dopamine (DA) neuron loss in endotoxin and neurotoxin rat models of nigral degeneration. OBJECTIVE: As a next step toward human clinical trials, we aimed to determine the extent to which peripherally administered DN-TNF inhibitor XPro®1595 could: i) cross the blood-brain-barrier in therapeutically relevant concentrations, ii) attenuate neuroinflammation (microglia and astrocyte), and iii) mitigate loss of nigral DA neurons in rats receiving a unilateral 6-hydroxydopamine (6-OHDA) striatal lesion. METHODS: Rats received unilateral 6-OHDA (20 µg into the right striatum). Three or 14 days after lesion, rats were dosed with XPro®1595 (10 mg/kg in saline, subcutaneous) every third day for 35 days. Forelimb asymmetry was used to assess motor deficits after the lesion; brains were harvested 35 days after the lesion for analysis of XPro®1595 levels, glial activation and nigral DA neuron number. RESULTS: Peripheral subcutaneous dosing of XPro®1595 achieved plasma levels of 1-8 microgram/mL and CSF levels of 1-6 ng/mL depending on the time the rats were killed after final XPro®1595 injection. Irrespective of start date, XPro®1595 significantly reduced microglia and astrocyte number in SNpc whereas loss of nigral DA neurons was attenuated when drug was started 3, but not 14 days after the 6-OHDA lesion. CONCLUSIONS: Our data suggest that systemically administered XPro®1595 may have disease-modifying potential in PD patients where inflammation is part of their pathology.

A novel bispecific antibody targeting tumor necrosis factor α and ED-B fibronectin effectively inhibits the progression of established collagen-induce arthritis.

Specific delivery of TNF-α antagonist to the inflamed site can increase its efficacy and reduce the side effects. In this study, we constructed a bispecific diabody (BsDb) that targets TNF-α and ED-B-containing fibronectin (B-FN), a fibronectin isoform specifically expressed in the pannus of the inflamed joint in rheumatoid arthritis. BsDb was produced in Escherichia coli as inclusion bodies, purified to homogeneity, and refolded to the functional form. Our data demonstrate that BsDb could simultaneously bind to human TNF-α and B-FN and neutralize TNF-α action. In the collagen-induced arthritis mouse model, we compared the biodistrubtion and therapeutic efficacy of BsDb with those of the anti-TNF-α scFv (TNF-scFv). Similar to TNF-scFv, BsDb penetrated into the synovial tissue quickly, showing a rapid clearance from blood and normal organs. In contrast, BsDb could selectively accumulate and retain in arthritic joints of mice for a long period time, resulting in a much stronger inhibition of arthritis progression in mice than TNF-scFv. The findings described herein indicate that BsDb has a good specificity to the inflamed joint, with low toxicity to normal organs and seems to be an ideal biological agent for the treatment of RA and other chronic inflammatory disease.

GMP production and characterization of leucine zipper-tagged tumor necrosis factor-related apoptosis-inducing ligand (LZ-TRAIL) for phase I clinical trial.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) exhibits potent antitumor activity in a wide range of cancers without deleterious side effects on normal tissues. Several TRAIL derivatives have been developed to improve its pharmacokinetics and therapeutic effects through strategies such as adding a leucine zipper to increase the circulation half-life. To obtain clinical grade LZ-TRAIL for phase I clinical trial, a single batch of 30 L bioreactor culture was performed using the Escherichia coli BL21 (DE3) strain expressing the recombinant LZ-TRAIL. A robust LZ-TRAIL production fermentation process was developed, which could be scaled up from 5L to 50 L, and had a titer of approximately 1.4 g/l. A four-step purification strategy was carried out to obtain a final product with over 95% purity and 45% yield. The final material was filter sterilized, aseptically vialed, and stored at 4°C, and comprehensively characterized using multiple assays (vialed product was sterile, purity was 95%, aggregates were <5%, potency revealed IC50 of 9 nM on MDA-MB-231 cells, and the endotoxin level was <0.25 U/mg). The purity, composition, and functional activities of the molecule were confirmed. in vivo investigations indicated that LZ-TRAIL has better antitumor potency in three Xenograft tumor models compared to TRAIL (95-281). LZ-TRAIL also showed improved pharmacokinetic and safety profiles in cynomolgus monkeys without abnormalities associated with drug exposure. In conclusion, the scalable synthesis of LZ-TRAIL is useful for production of phase I clinical trial material. These preclinical investigations warrant further clinical development of this product for cancer therapy.

GX1 targeting delivery of rmhTNFα evaluated using multimodality imaging.

GX1 is a tumor targeting peptide. In this study, we evaluated the antitumor efficacy of a GX1-derived fusion toxin, GX1-rmhTNFα, and investigated its targeting efficiency and pharmacokinetics in vivo using multimodality imaging. Flow cytometry revealed a greater level of cell apoptosis induced by GX1-rmhTNFα (27.1%) compared with rmhTNFα or a saline control (13.7% and 4.7%, respectively). SPECT (single-photon emission computed tomography) demonstrated high accumulation of GX1-rmhTNFα in tumor site. Biodistribution studies indicated GX1-rmhTNFα was cleared by the liver and kidney, and the drug may not cross the blood-brain barrier. In addition, bioluminescence imaging (BLI) showed that GX1-rmhTNFα caused a satisfactory delay in tumor growth in both subcutaneous and orthotopic cancer models. Contrast-enhanced ultrasound (CEUS) and CD31 staining revealed a loss in blood perfusion and vasculature. TUNEL and Ki67 staining validated the in vivo results. Biochemical analyses revealed limited renal and hepatic toxicity of GX1-rmhTNFα. This study demonstrated that GX1-rmhTNFα is a safe and potent anticancer agent that may have great potential for the targeted therapy of gastric cancer.

Preparation and evaluation of a new releasable PEGylated tumor necrosis factor-α (TNF-α) conjugate for therapeutic application.

To design a releasable PEGylated TNF-α (rPEG-TNF-α), a cathepsin B-sensitive dipeptide (Val-Cit moiety) was inserted into conventional PEG-modified TNF-α (PEG-TNF-α), facilitating its clinical use for anti-tumor therapy. Comparative pharmacokinetic and pharmacodynamic studies showed that the half-lives of both PEGylated forms of TNF-α were ∼60-fold greater than that of unmodified TNF-α. In addition, the in vitro bioactivity of rPEG-TNF-α was greater than that of PEG-TNF-α with the same degree of PEG modification. Release of TNF-α from rPEG-TNF-α in vitro was dependent on the presence of cathepsin B and was inhibited by a cathepsin B inhibitor. Despite the potent cytotoxicity of unmodified TNF-α against normal cells, its PEGylated forms at higher TNF-α concentrations showed low cytotoxic activity against these cells. In contrast, both forms of PEGylated TNF-α showed potent cytotoxic activity against the B16 and L929 cell lines, with rPEG-TNF-α being 5- and 9-fold more potent, respectively, than PEG-TNF-α. Moreover, rPEG-TNF-α was a more potent in vivo antitumor agent than PEG-TNF-α.