Anti-TNF antibodies: lessons from the past, roadmap for the future

T-cell functionality testing is highly relevant to developing novel immuno-tracers monitoring T cells in the context of immunotherapies and revealed CD7 as an attractive target

Cancer immunotherapy has proven high efficacy in treating diverse cancer entities by immune checkpoint modulation and adoptive T-cell transfer. However, patterns of treatment response differ substantially from conventional therapies, and reliable surrogate markers are missing for early detection of responders versus non-responders. Current imaging techniques using ¹⁸F-fluorodeoxyglucose-positron-emmission-tomograpy (¹⁸F-FDG-PET) cannot discriminate, at early treatment times, between tumor progression and inflammation. Therefore, direct imaging of T cells at the tumor site represents a highly attractive tool to evaluate effective tumor rejection or evasion. Moreover, such markers may be suitable for theranostic imaging.

Methods: We mainly investigated the potential of two novel pan T-cell markers, CD2 and CD7, for T-cell tracking by immuno-PET imaging. Respective antibody- and F(ab´)₂ fragment-based tracers were produced and characterized, focusing on functional in vitro and in vivo T-cell analyses to exclude any impact of T-cell targeting on cell survival and antitumor efficacy.

Results: T cells incubated with anti-CD2 and anti-CD7 F(ab´)₂ showed no major modulation of functionality in vitro, and PET imaging provided a distinct and strong signal at the tumor site using the respective zirconium-89-labeled radiotracers. However, while T-cell tracking by anti-CD7 F(ab´)₂ had no long-term impact on T-cell functionality in vivo, anti-CD2 F(ab´)₂ caused severe T-cell depletion and failure of tumor rejection.

Conclusion: This study stresses the importance of extended functional T-cell assays for T-cell tracer development in cancer immunotherapy imaging and proposes CD7 as a highly suitable target for T-cell immuno-PET imaging.

Nanocapsule-mediated cytosolic siRNA delivery for anti-inflammatory treatment

The use of nanoparticle-stabilized nanocapsules for cytosolic siRNA delivery for immunomodulation in vitro and in vivo is reported. These NPSCs deliver siRNA directly to the cytosol of macrophages in vitro with concomitant knockdown of gene expression. In vivo studies showed directed delivery of NPSCs to the spleen, enabling gene silencing of macrophages, with preliminary studies showing 70% gene knockdown at a siRNA dose of 0.28 mg/kg. Significantly, the delivery of siRNA targeting tumor necrosis factor-α efficiently silenced TNF-α expression in LPS-challenged mice, demonstrating efficacy in modulating immune response in an organ-selective manner. This research highlights the potential of the NPSC platform for targeted immunotherapy and further manipulation of the immune system.

Mechanistical retinal drug targets and challenges

The retina is constantly exposed to light that increases reactive oxygen species in retina. Oxidative stress, inflammation and neurodegeneration are the major contributors in the most common retinal diseases, such as age-related macular degeneration (AMD), glaucoma and diabetic retinopathy (DR). Emerging developments and research for novel therapy targets and drug delivery to the posterior segment offer a promising future for the treatment of retinal diseases including rare hereditary diseases. In this review we discuss about promising mechanistical retinal drug targets. Vascular endothelial growth factor (VEGF) signaling and anti-VEGF treatments are excluded.

A novel engineered interchain disulfide bond in the constant region enhances the thermostability of adalimumab Fab

We constructed a system for expressing the Fab of the therapeutic human monoclonal antibody adalimumab at a yield of 20 mg/L in the methylotrophic yeast Pichia pastoris. To examine the contribution of interchain disulfide bonds to conformational stability, we prepared adalimumab Fab from which the interchain disulfide bond at the C-terminal region at both the CH₁ and CL domains was deleted by substitution of Cys with Ala (Fab_ΔSS). DSC measurements showed that the Tm values of Fab_ΔSS were approximately 5 °C lower than those of wild-type Fab, suggesting that the interchain disulfide bond contributes to conformational thermostability. Using computer simulations, we designed a novel interchain disulfide bond outside the C-terminal region to increase the stability of Fab_ΔSS. The resulting Fab (mutSS Fab_ΔSS) had the mutations H:V177C and L:Q160C in Fab_ΔSS, confirming the formation of the disulfide bond between CH₁ and CL. The thermostability of mutSS Fab_ΔSS was approximately 5 °C higher than that of Fab_ΔSS. Therefore, the introduction of the designed interchain disulfide bond enhanced the thermostability of Fab_ΔSS and mitigated the destabilization caused by partial reduction of the interchain disulfide bond at the C-terminal region, which occurs in site-specific modification such as PEGylation.

Combination of IgG N-glycomics and corresponding transcriptomics data to identify anti-TNF-α treatment responders in inflammatory diseases

Prediction of responsiveness in biological therapies is an important and challenging issue in different diseases. Analyzing glycosylation pattern changes of key serum glycoproteins is one of the possible avenues to follow disease remission. The aim of this study was to investigate the changes of serum IgG glycoforms in Crohn's disease (CD) and rheumatoid arthritis patients in response to antitumor necrosis factor alpha (anti-TNF-α) treatment. IgG was isolated from patient serum samples using Protein A affinity pull-down, followed by the release of N-glycans with peptide-N-glycosidase F. The released glycans were fluorescently tagged with 8-aminopyrene-1,3,6-trisulfonate and analyzed by CGE with laser-induced fluorescent detection. Significant alterations were detected between responders and nonresponders in both disease groups. In CD patients, disease-specific alteration was found in response to anti-TNF-α therapy, which was also confirmed by transcriptomics data analysis of the corresponding glycosyltransferases and glycosidases.

Structure-based development and optimization of therapy antibody drugs against TNFα

Previously, we reported on the crystal structures of the Fab fragments of two food and drug administration approved therapeutic antibodies, Infliximab and Adalimumab, in complex with TNFα. The structurally identified epitopes on TNFα reveal the mechanism of TNFα inhibition by partially overlapping with the TNFα-receptor interface. In this study, we launched a screen of a phage display library to isolate novel anti-TNFα antibodies based on the adalimumab epitope. Structural analysis, the phage display antibody isolation technology, step-by-step antibody optimization, complementarity-determining region residues random mutagenesis, phage ELISA, binding affinity characterization, and cell signaling assays were used for the development and optimization of the novel anti-TNFα antibodies. Moreover, one of the novel antibodies, hAta09, has a superior inhibitory effect on TNFα function and signaling. Taken together, our report established that the novel anti-TNFα antibody hAta09 may achieve clinical efficacy in a TNFα-associated disease.

B-cell receptor signaling inhibitors for treatment of autoimmune inflammatory diseases and B-cell malignancies

B-cell receptor (BCR) signaling is essential for normal B-cell development, selection, survival, proliferation, and differentiation into antibody-secreting cells. Similarly, this pathway plays a key role in the pathogenesis of multiple B-cell malignancies. Genetic and pharmacological approaches have established an important role for the Spleen tyrosine kinase (Syk), Bruton's tyrosine kinase (Btk), and phosphatidylinositol 3-kinase isoform p110delta (PI3Kδ) in coupling the BCR and other BCRs to B-cell survival, migration, and activation. In the past few years, several small-molecule inhibitory drugs that target PI3Kδ, Btk, and Syk have been developed and shown to have efficacy in clinical trials for the treatment of several types of B-cell malignancies. Emerging preclinical data have also shown a critical role of BCR signaling in the activation and function of self-reactive B cells that contribute to autoimmune diseases. Because BCR signaling plays a major role in both B-cell-mediated autoimmune inflammation and B-cell malignancies, inhibition of this pathway may represent a promising new strategy for treating these diseases. This review summarizes recent achievements in the mechanism of action, pharmacological properties, and clinical activity and toxicity of these BCR signaling inhibitors, with a focus on their emerging role in treating lymphoid malignancies and autoimmune disorders.

Comparison of the inhibition mechanisms of adalimumab and infliximab in treating tumor necrosis factor α-associated diseases from a molecular view

TNFα-targeting therapy with the use of the drugs Etanercept, Infliximab, and Adalimumab is used in the clinical treatment of various inflammatory and immune diseases. Although all of these reagents function to disrupt the interaction between TNFα and its receptors, clinical investigations showed the advantages of Adalimumab treatment compared with Etanercept and Infliximab. However, the underlying molecular mechanism of action of Adalimumab remains unclear. In our previous work, we presented structural data on how Infliximab binds with the E-F loop of TNFα and functions as a TNFα receptor-binding blocker. To further elucidate the variations between TNFα inhibitors, we solved the crystal structure of TNFα in complex with Adalimumab Fab. The structural observation and the mutagenesis analysis provided direct evidence for identifying the Adalimumab epitope on TNFα and revealed the mechanism of Adalimumab inhibition of TNFα by occupying the TNFα receptor-binding site. The larger antigen-antibody interface in TNFα Adalimumab also provided information at a molecular level for further understanding the clinical advantages of Adalimumab therapy compared with Infliximab.

Use of the tumor necrosis factor-blockers for Crohn's disease

The use of anti-tumor necrosis factor-α therapy for inflammatory bowel disease represents the most important advance in the care of these patients since the publication of the National Co-operative Crohn's disease study thirty years ago. The recommendations of numerous consensus groups worldwide are now supported by a wealth of clinical trials and several meta-analyses. In general, it is suggested that tumor necrosis factor-α blockers (TNFBs) are indicated (1) for persons with moderately-severe Crohn's disease or ulcerative colitis (UC) who have failed two or more causes of glucocorticosteroids and an acceptably long cause (8 wk to 12 wk) of an immune modulator such as azathioprine or methotrexate; (2) non-responsive perianal disease; and (3) severe UC not responding to a 3-d to 5-d course of steroids. Once TNFBs have been introduced and the patient is responsive, therapy given by the IV and SC rate must be continued. It remains open to definitive evidence if concomitant immune modulators are required with TNFB maintenance therapy, and when or if TNFB may be weaned and discontinued. The supportive evidence from a single study on the role of early versus later introduction of TNFB in the course of a patient's illness needs to be confirmed. The risk/benefit profile of TNFB appears to be acceptable as long as the patient is immunized and tested for tuberculosis and viral hepatitis before the initiation of TNFB, and as long as the long-term adverse effects on the development of lymphoma and other tumors do not prone to be problematic. Because the rates of benefits to TNFB are modest from a population perspective and the cost of therapy is very high, the ultimate application of use of TNFBs will likely be established by cost/benefit studies.

Targeting of the innate immunity/inflammation as complementary anti-tumor therapies

Different types of cancer take advantage of inflammatory components to improve their life-span in the organs. A sustenance of growth factors and cytokines (e.g. interleukin (IL)-1, tumor necrosis factor, IL-6, vascular endothelial growth factor) supports malignant cell progression and contributes to suppress the body immune defense. Strategies to modulate the host micro-environment offer new approaches for anti-cancer therapies. For these reasons new molecules with anti-tumor and anti-inflammatory features (e.g. trabectedin) are looked at with new eyes in the light of the crucial link between inflammation and cancer.

TNFR2 expression on non-bone marrow-derived cells is crucial for lipopolysaccharide-induced septic shock and downregulation of soluble TNFR2 level in serum

Persistently high serum levels of soluble tumor-necrosis factor (TNF) receptor 2 (sTNFR2) have been observed in septic shock and many inflammatory diseases. However, its origin and regulation during these pathological processes are still largely unknown. In this study, murine bone marrow (BM) chimeras selectively expressing TNFR2 on either BM-derived or non-BM-derived cells were generated and challenged with lipopolysaccharide (LPS). The results show that TNFR2 expression on non-BM-derived cells is crucial for both the sensitivity of mice to LPS and the downregulation of sTNFR2 in serum. Most importantly, sTNFR2 was released from both BM- and non-BM-derived cells. Non-BM TNFR1 expression influenced the sensitivity of mice to LPS challenge but not the level of serum sTNFR2. These results provide the first in vivo evidence for the origin and regulation of sTNFR2 in serum and could aid in the development of novel anti-TNF strategies against septic shock.

Cytokines induce small intestine and liver injury after renal ischemia or nephrectomy

Patients with acute kidney injury (AKI) frequently suffer from extra-renal complications including hepatic dysfunction and systemic inflammation. We aimed to determine the mechanisms of AKI-induced hepatic dysfunction and systemic inflammation. Mice subjected to AKI (renal ischemia reperfusion (IR) or nephrectomy) rapidly developed acute hepatic dysfunction and suffered significantly worse hepatic IR injury. After AKI, rapid peri-portal hepatocyte necrosis, vacuolization, neutrophil infiltration and pro-inflammatory mRNA upregulation were observed suggesting an intestinal source of hepatic injury. Small intestine histology after AKI showed profound villous lacteal capillary endothelial apoptosis, disruption of vascular permeability and epithelial necrosis. After ischemic or non-ischemic AKI, plasma TNF-α, IL-17A and IL-6 increased significantly. Small intestine appears to be the source of IL-17A, as IL-17A levels were higher in the portal circulation and small intestine compared with the levels measured from the systemic circulation and liver. Wild-type mice treated with neutralizing antibodies against TNF-α, IL-17A or IL-6 or mice deficient in TNF-α, IL-17A, IL-17A receptor or IL-6 were protected against hepatic and small intestine injury because of ischemic or non-ischemic AKI. For the first time, we implicate the increased release of IL-17A from small intestine together with induction of TNF-α and IL-6 as a cause of small intestine and liver injury after ischemic or non-ischemic AKI. Modulation of the inflammatory response and cytokine release in the small intestine after AKI may have important therapeutic implications in reducing complications arising from AKI.

Evaluation of an anti-tumor necrosis factor therapeutic in a mouse model of Niemann-Pick C liver disease

Background

Niemann-Pick type C (NPC) disease is a lysosomal storage disease characterized by the accumulation of cholesterol and glycosphingolipids. The majority of NPC patients die in their teen years due to progressive neurodegeneration; however, half of NPC patients also suffer from cholestasis, prolonged jaundice, and hepatosplenomegaly. We previously showed that a key mediator of NPC liver disease is tumor necrosis factor (TNF) α, which is involved in both proinflammatory and apoptotic signaling cascades. In this study, we tested the hypothesis that blocking TNF action with an anti-TNF monoclonal antibody (CNTO5048) will slow the progression of NPC liver disease.

Methodology/Principal Findings

Treatment of wild-type C57BL/6 mice with NPC1-specific antisense oligonucleotides led to knockdown of NPC1 protein expression in the liver. This caused classical symptoms of NPC liver disease, including hepatic cholesterol accumulation, hepatomegaly, elevated serum liver enzymes, and lipid laden macrophage accumulation. In addition, there was a significant increase in the number of apoptotic cells and a proliferation of stellate cells. Concurrent treatment of NPC1 knockdown mice with anti-TNF had no effect on the primary lipid storage or accumulation of lipid-laden macrophages. However, anti-TNF treatment slightly blunted the increase in hepatic apoptosis and stellate cell activation that was seen with NPC1 knockdown.

Conclusions/Significance

Current therapeutic options for NPC disease are limited. Our results provide proof of principle that pharmacologically blocking the TNF-α inflammatory cascade can slightly reduce certain markers of NPC disease. Small molecule inhibitors of TNF that penetrate tissues and cross the blood-brain barrier may prove even more beneficial.

Characterization of golimumab, a human monoclonal antibody specific for human tumor necrosis factor α

We prepared and characterized golimumab (CNTO148), a human IgG1 tumor necrosis factor alpha (TNFα) antagonist monoclonal antibody chosen for clinical development based on its molecular properties. Golimumab was compared with infliximab, adalimumab and etanercept for affinity and in vitro TNFα neutralization. The affinity of golimumab for soluble human TNFα, as determined by surface plasmon resonance, was similar to that of etanercept (18 pM versus 11 pM), greater than that of infliximab (44 pM) and significantly greater than that of adalimumab (127 pM, p=0.018).  The concentration of golimumab necessary to neutralize TNFα-induced E-selectin expression on human endothelial cells by 50% was significantly less than those for infliximab (3.2 fold; p=0.017) and adalimumab (3.3-fold; p=0.008) and comparable to that for etanercept. The conformational stability of golimumab was greater than that of infliximab (primary melting temperature [Tm] 74.8 °C vs. 69.5 °C) as assessed by differential scanning calorimetry.  In addition, golimumab showed minimal aggregation over the intended shelf life when formulated as a high concentration liquid product (100 mg/mL) for subcutaneous administration.  In vivo, golimumab at doses of 1 and 10 mg/kg significantly delayed disease progression in a mouse model of human TNFα-induced arthritis when compared with untreated mice, while infliximab was effective only at 10 mg/kg. Golimumab also significantly reduced histological scores for arthritis severity and cartilage damage, as well as serum levels of pro-inflammatory cytokines and chemokines associated with arthritis. Thus, we have demonstrated that golimumab is a highly stable human monoclonal antibody with high affinity and capacity to neutralize human TNFα in vitro and in vivo.

Overview of TNF superfamily: a chest full of potential therapeutic targets

Since the discovery of tumor necrosis factor TNFalpha about 25 years ago, TNF superfamily has grown to a large family of related proteins consisting of over 20 members that signal through over 30 receptors. Members of this superfamily have wide tissue distribution and play important roles ranging from regulation of the normal biological processes such as immune responses, hematopoiesis and morphogenesis to their role in tumorigenesis, transplant rejection, septic shock, viral replication, bone resorption and autoimmunity. Thus, many approaches to harness the potency of TNF superfamily members to treat human diseases have been developed. Indeed, TNF and TNF agonistic molecules have been approved for human use in the United States and other countries. Many other TNF family members show promise for several therapeutic applications, including cancer, infectious disease, transplantation and autoimmunity. This chapter will give overview of TNF superfamily for exploitation for therapeutic use in humans.

Golimumab: A novel human anti-TNF-alpha monoclonal antibody for the treatment of rheumatoid arthritis, ankylosing spondylitis, and psoriatic arthritis

Introduction:

The introduction of tumor necrosis factor-α (TNF-α) inhibitors represented a significant advance in the management of rheumatoid arthritis (RA) and other chronic inflammatory diseases. Although three TNF-α inhibitors have been approved for the treatment of RA by the US Food and Drug Administration (FDA) and the European Medicinal Products Evaluation Agency (EMEA), not all patients achieve a satisfactory clinical improvement with these therapeutic agents. The mode of administration of these medications is inconvenient for some patients.

Aims:

Golimumab is a novel anti-TNF-α monoclonal antibody that is in clinical development for the treatment of RA, psoriatic arthritis (PsA), and ankylosing spondylitis (AS), either as a first-line biologic therapy or an alternative after other TNF-α inhibitors have been discontinued. This review summarizes the development of, and clinical evidence achieved with, golimumab.

Evidence review:

Golimumab has demonstrated significant efficacy in randomized, double-blind, placebo-controlled trials when administered subcutaneously once every four weeks. It has been generally well tolerated in clinical trials and demonstrates a safety profile comparable with currently available TNF-α inhibitors.

Outcomes summary:

Golimumab has been confirmed to be an effective treatment for patients with RA, PsA, and AS in phase III clinical trials as evaluated by traditional measures of disease activity, such as signs and symptoms, as well as measures of physical function, patient reported outcomes, and health economic measures. The efficacy and safety profile of golimumab in RA, PsA, and AS appears to be similar to other anti-TNF agents. However, golimumab has the potential advantage of once monthly subcutaneous administration and the possibility of both subcutaneous and intravenous administration.

Antibody complementarity-determining regions (CDRs): a bridge between adaptive and innate immunity

BACKGROUND

It has been documented that, independently from the specificity of the native antibody (Ab) for a given antigen (Ag), complementarity determining regions (CDR)-related peptides may display differential antimicrobial, antiviral and antitumor activities.

METHODOLOGY/PRINCIPAL FINDINGS

In this study we demonstrate that a synthetic peptide with sequence identical to V(H)CDR3 of a mouse monoclonal Ab (mAb) specific for difucosyl human blood group A is easily taken up by macrophages with subsequent stimulation of: i) proinflammatory cytokine production; ii) PI3K-Akt pathway and iii) TLR-4 expression. Significantly, V(H)CDR3 exerts therapeutic effect against systemic candidiasis without possessing direct candidacidal properties.

CONCLUSIONS/SIGNIFICANCE

These results open a new scenario about the possibility that, beyond the half life of immunoglobulins, Ab fragments may effectively influence the antiinfective cellular immune response in a way reminiscent of regulatory peptides of innate immunity.

Golimumab, a human anti-tumor necrosis factor alpha monoclonal antibody, injected subcutaneously every four weeks in methotrexate-naive patients with active rheumatoid arthritis: twenty-four-week results of a phase III, multicenter, randomized, double-blind, placebo-controlled study of golimumab before methotrexate as first-line therapy for early-onset rheumatoid arthritis

OBJECTIVE

To assess the safety and efficacy of golimumab in methotrexate (MTX)-naive patients with active rheumatoid arthritis (RA).

METHODS

MTX-naive patients with RA (n = 637) were randomized to receive placebo plus MTX (group 1), golimumab 100 mg plus placebo (group 2), golimumab 50 mg plus MTX (group 3), or golimumab 100 mg plus MTX (group 4). Subcutaneous injections of golimumab or placebo were administered every 4 weeks. The dosage of MTX/placebo capsules started at 10 mg/week and escalated to 20 mg/week. The primary end point, the proportion of patients meeting the American College of Rheumatology 50% improvement criteria (achieving an ACR50 response) at week 24, required significant differences between groups 3 and 4 combined (combined group) versus group 1 and significant differences in a pairwise comparison (group 3 or group 4 versus group 1).

RESULTS

An intent-to-treat (ITT) analysis of the ACR50 response at week 24 did not show a significant difference between the combined group and group 1 (38.4% and 29.4%, respectively; P=0.053), while a post hoc modified ITT analysis (excluding 3 untreated patients) of the ACR50 response showed statistically significant differences between the combined group and group 1 (38.5% versus 29.4%; P=0.049) and between group 3 (40.5%; P=0.038) but not group 4 (36.5%; P=0.177) and group 1. Group 2 was noninferior to group 1 for the ACR50 response at week 24 (33.1%; 95% confidence interval lower bound -5.2%; predefined delta value for noninferiority -10%). The combination of golimumab plus MTX demonstrated a significantly better response compared with placebo plus MTX in most other efficacy parameters, including response/remission according to the Disease Activity Score in 28 joints. Serious adverse events occurred in 7%, 3%, 6%, and 6% of patients in groups 1, 2, 3, and 4, respectively.

CONCLUSION

Although the primary end point was not met, the modified ITT analysis of the primary end point and other prespecified efficacy measures demonstrated that the efficacy of golimumab plus MTX is better than, and the efficacy of golimumab alone is similar to, the efficacy of MTX alone in reducing RA signs and symptoms in MTX-naive patients, with no unexpected safety concerns.

NF-kappaB p100 limits TNF-induced bone resorption in mice by a TRAF3-dependent mechanism

TNF and RANKL mediate bone destruction in common bone diseases, including osteoarthritis and RA. They activate NF-kappaB canonical signaling directly in osteoclast precursors (OCPs) to induce osteoclast formation in vitro. However, unlike RANKL, TNF does not activate the alternative NF-kappaB pathway efficiently to process the IkappaB protein NF-kappaB p100 to NF-kappaB p52, nor does it appear to induce osteoclast formation in vivo in the absence of RANKL. Here, we show that TNF limits RANKL- and TNF-induced osteoclast formation in vitro and in vivo by increasing NF-kappaB p100 protein accumulation in OCPs. In contrast, TNF induced robust osteoclast formation in vivo in mice lacking RANKL or RANK when the mice also lacked NF-kappaB p100, and TNF-Tg mice lacking NF-kappaB p100 had more severe joint erosion and inflammation than did TNF-Tg littermates. TNF, but not RANKL, increased OCP expression of TNF receptor-associated factor 3 (TRAF3), an adapter protein that regulates NF-kappaB p100 levels in B cells. TRAF3 siRNA prevented TNF-induced NF-kappaB p100 accumulation and inhibition of osteoclastogenesis. These findings suggest that upregulation of TRAF3 or NF-kappaB p100 expression or inhibition of NF-kappaB p100 degradation in OCPs could limit bone destruction and inflammation-induced bone loss in common bone diseases.

TNF-alpha drives remodeling of blood vessels and lymphatics in sustained airway inflammation in mice

Inflammation is associated with blood vessel and lymphatic vessel proliferation and remodeling. The microvasculature of the mouse trachea provides an ideal opportunity to study this process, as Mycoplasma pulmonis infection of mouse airways induces widespread and sustained vessel remodeling, including enlargement of capillaries into venules and lymphangiogenesis. Although the mediators responsible for these vascular changes in mice have not been identified, VEGF-A is known not to be involved. Here, we sought to determine whether TNF-alpha drives the changes in blood vessels and lymphatics in M. pulmonis-infected mice. The endothelial cells, but not pericytes, of blood vessels, but not lymphatics, were immunoreactive for TNF receptor 1 (TNF-R1) and lymphotoxin B receptors. Most TNF-R2 immunoreactivity was on leukocytes. Infection resulted in a large and sustained increase in TNF-alpha expression, as measured by real-time quantitative RT-PCR, and smaller increases in lymphotoxins and TNF receptors that preceded vessel remodeling. Substantially less vessel remodeling and lymphangiogenesis occurred when TNF-alpha signaling was inhibited by a blocking antibody or was silenced in Tnfr1-/- mice. When administered after infection was established, the TNF-alpha-specific antibody slowed but did not reverse blood vessel remodeling and lymphangiogenesis. The action of TNF-alpha on blood vessels is probably mediated through direct effects on endothelial cells, but its effects on lymphangiogenesis may require inflammatory mediators from recruited leukocytes. We conclude that TNF-alpha is a strong candidate for a mediator that drives blood vessel remodeling and lymphangiogenesis in inflammation.

Orally delivered siRNA targeting macrophage Map4k4 suppresses systemic inflammation

Gene silencing by double-stranded RNA, denoted RNA interference, represents a new paradigm for rational drug design. However, the transformative therapeutic potential of short interfering RNA (siRNA) has been stymied by a key obstacle-safe delivery to specified target cells in vivo. Macrophages are particularly attractive targets for RNA interference therapy because they promote pathogenic inflammatory responses in diseases such as rheumatoid arthritis, atherosclerosis, inflammatory bowel disease and diabetes. Here we report the engineering of beta1,3-D-glucan-encapsulated siRNA particles (GeRPs) as efficient oral delivery vehicles that potently silence genes in mouse macrophages in vitro and in vivo. Oral gavage of mice with GeRPs containing as little as 20 microg kg(-1) siRNA directed against tumour necrosis factor alpha (Tnf-alpha) depleted its messenger RNA in macrophages recovered from the peritoneum, spleen, liver and lung, and lowered serum Tnf-alpha levels. Screening with GeRPs for inflammation genes revealed that the mitogen-activated protein kinase kinase kinase kinase 4 (Map4k4) is a previously unknown mediator of cytokine expression. Importantly, silencing Map4k4 in macrophages in vivo protected mice from lipopolysaccharide-induced lethality by inhibiting Tnf-alpha and interleukin-1beta production. This technology defines a new strategy for oral delivery of siRNA to attenuate inflammatory responses in human disease.

Effect of the oral application of a highly selective MMP-13 inhibitor in three different animal models of rheumatoid arthritis

Objective

To evaluate the decrease of cartilage destruction by a novel orally active and specific matrix metalloproteinase 13 (MMP-13) inhibitor in three different animal models of rheumatoid arthritis (RA).

Materials and methods

The SCID mouse co-implantation model of RA, the collagen-induced arthritis (CIA) model in mice and the antigen-induced arthritis model (AIA) in rabbits were used.

Results

In the SCID mouse co-implantation model, the MMP-13 inhibitor reduced cartilage destruction by 75%. In the CIA model of RA, the MMP-13 inhibitor resulted in a significant and dose-dependent decrease in clinical symptoms as well as of cartilage erosion by 38% (30 mg/kg), 28% (10 mg/kg) and 21% (3 mg/kg). No significant effects were seen in the AIA model. No toxic effects were seen in all three animal models.

Conclusion

Although several MMPs in concert with other proteinases have a role in the process of cartilage destruction, there is a need for highly selective MMP inhibitors to reduce severe side effects that occur with non-specific inhibitors. Significant inhibition of MMP-13 reduced cartilage erosions in two of three tested animal models of RA. These results strongly support the development of this class of drugs to reduce or halt joint destruction in patients with RA.

Orally delivered siRNA targeting macrophage Map4k4 suppresses systemic inflammation

Gene silencing by double-stranded RNA, denoted RNA interference, represents a new paradigm for rational drug design. However, the transformative therapeutic potential of short interfering RNA (siRNA) has been stymied by a key obstacle-safe delivery to specified target cells in vivo. Macrophages are particularly attractive targets for RNA interference therapy because they promote pathogenic inflammatory responses in diseases such as rheumatoid arthritis, atherosclerosis, inflammatory bowel disease and diabetes. Here we report the engineering of beta1,3-D-glucan-encapsulated siRNA particles (GeRPs) as efficient oral delivery vehicles that potently silence genes in mouse macrophages in vitro and in vivo. Oral gavage of mice with GeRPs containing as little as 20 microg kg(-1) siRNA directed against tumour necrosis factor alpha (Tnf-alpha) depleted its messenger RNA in macrophages recovered from the peritoneum, spleen, liver and lung, and lowered serum Tnf-alpha levels. Screening with GeRPs for inflammation genes revealed that the mitogen-activated protein kinase kinase kinase kinase 4 (Map4k4) is a previously unknown mediator of cytokine expression. Importantly, silencing Map4k4 in macrophages in vivo protected mice from lipopolysaccharide-induced lethality by inhibiting Tnf-alpha and interleukin-1beta production. This technology defines a new strategy for oral delivery of siRNA to attenuate inflammatory responses in human disease.

TNF-alpha and its inhibitors in cancer

Tumor necrosis factor (TNF)-alpha is implicated in the same time in apoptosis and in cell proliferation. TNF-alpha not only acts as pro-inflammatory cytokine conducing to wide spectrum of human diseases including inflammatory diseases, but can also induce tumor development. The molecular mechanisms of TNF-alpha functions have been intensively investigated. In this review we covered TNF-alpha, the molecule, its signaling pathway, and its therapeutic functions. We provide a particular insight in its paradoxical role in tumor promotion and in its use as anti-tumor agent. This review considers also the recent findings regarding TNF-alpha inhibitors, their pharmacokinetics, and their pharmacodynamics. Six TNF-alpha inhibitors have been considered here: Infliximab, Adalimumab, Golimumab, CDP870, CDP571, Etanercept, and Thalidomide. We discussed the clinical relevance of their functions in treatment of several diseases such as advanced inflammatory rheumatic and bowel disease, with a focus in cancer treatment. Targeting TNF-alpha by these drugs has many side effects like malignancies development, and the long-term sequels are not very well explored. Their efficacy and their safety were discussed, underscoring the necessity of close patients monitoring and of their caution use.

Neuroprotective and antiinflammatory properties of a novel demethylated curcuminoid

A demethylated derivative of curcumin (DC; 67.8% bisdemethylcurcumin, 20.7% demethylmonodemethoxycurcumin, 5.86% bisdemethoxycurcumin, 2.58% demethylcurcumin) was prepared by using a 95% extract of curcumin (C(95); 72.2% curcumin, 18.8% monodemethoxycurcumin, 4.5% bisdemethoxycurcumin). DC increased glutathione and reduced reactive oxygen species (ROS) in HT4 neuronal cells. In a model of glutamate-induced death of HT4, DC was more effective than C(95) in neuroprotection. The protective effects of DC were retained even when DC was withdrawn from culture media after pretreatment. DC treatment, unlike an equal dose of C(95), completely spared glutamate-induced loss of cellular GSH. Both DC and C(95) prevented glutamate-induced elevation of cellular ROS but failed to attenuate glutamate-induced elevation of intracellular calcium. In human microvascular endothelial cells (HMECs) challenged with TNF-alpha, GeneChip analysis revealed that only a subcluster of 23 TNF-alpha-inducible genes were uniquely sensitive to C(95). In sharp contrast, 1,065 TNF-alpha-inducible genes were sensitive to DC but not to C(95), suggesting that DC was more effective in antagonizing the effects of TNF-alpha on HMECs. Functional analysis identified that the genes uniquely sensitive to DC belonged in four functional categories: cytokine-receptor interaction, focal adhesion, cell adhesion, and apoptosis. Real-time PCR as well as ELISA studies demonstrated that TNF-alpha-inducible CXCL10 and CXCL11 expression was sensitive to DC but not to C(95). Flow-cytometry studies recognized ICAM-1 and VCAM-1 as TNF-alpha-inducible adhesion molecules that were uniquely sensitive to DC. Taken together, DC exhibited promising neuroprotective and antiinflammatory properties that must be characterized in vivo.

Defining the role of pharmacology in the emerging world of translational research

Pharmacology is focused on studying the effects of endogenous agents and xenobiotics on tissue and organ function. Analysis of the concentration/response relationship is the foundation for these assessments as it provides quantifiable information on compound efficacy, potency, and, ultimately, side-effect liability and therapeutic index. Historically, pharmacology has been viewed as a unifying, hierarchically integrated, and technologically agnostic discipline. Besides being important in the development of new medications, pharmacological research has led to a better understanding of disease pathogenesis and progression. By defining the effects of compounds in vitro and in vivo, pharmacology has provided the means to validate, optimize, and advance new chemical entities (NCEs) to human testing. With the advent of molecular biology-based assay systems and a technology-driven (high-throughput screening, combinatorial chemistry, SNP mapping, systems biology) reductionistic focus, the integrated, hypothesis-driven pharmacological approach to drug discovery has been de-emphasized in recent years. This shift in research emphasis is now viewed by many as a major factor in the decline of new drug approvals and has led to various initiatives, the most notable being the Critical Path and Phase 0 clinical trial initiatives launched by the US Food and Drug Administration (FDA). These programs underscore the growing need for individuals trained in integrative pharmacology and having a background in molecular pharmacology to drive the drug discovery process and to fostering the translational research that is now considered vital for more rapidly identifying novel, more effective, and safer medications.

Transcriptome analyses in normal prostate epithelial cells exposed to low-dose cadmium: oncogenic and immunomodulations involving the action of tumor necrosis factor

BACKGROUND

Cadmium is implicated in prostate carcinogenesis, but its oncogenic action remains unclear.

OBJECTIVES

In this study we aimed to decipher changes in cell growth and the transcriptome in an immortalized human normal prostate epithelial cell line (NPrEC) following exposure to low-dose Cd.

METHODS

Synchronized NPrEC cells were exposed to different doses of Cd and assayed for cell viability and cell-cycle progression. We investigated changes in transcriptome by global profiling and used Ingenuity Pathways Analysis software to develop propositions about functional connections among differentially expressed genes. A neutralizing antibody was used to negate the effect of Cd-induced up-regulation of tumor necrosis factor (TNF) in NPrEC cells.

RESULTS

Exposure of NPrEC to 2.5 microM Cd enhanced cell viability and accelerated cell-cycle progression. Global expression profiling identified 48 genes that exhibited >or= 1.5-fold changes in expression after 4, 8, 16, and 32 hr of Cd treatment. Pathway analyses inferred a functional connection among 35 of these genes in one major network, with TNF as the most prominent node. Fourteen of the 35 genes are related to TNF, and 11 exhibited an average of >2-fold changes in gene expression. Real-time reverse transcriptase-polymerase chain reaction confirmed the up-regulation of 7 of the 11 genes (ADAM8, EDN1, IL8, IL24, IL13RA2, COX2/PTGS2, and SERPINB2) and uncovered a 28-fold transient increase in TNF expression in Cd-treated NPrEC cells. A TNF-neutralizing antibody effectively blocked Cd-induced elevations in the expression of these genes.

CONCLUSIONS

Noncytotoxic, low-dose Cd has growth-promoting effects on NPrEC cells and induces transient overexpression of TNF, leading to up-regulation of genes with oncogenic and immunomodulation functions.