Differential clinical efficacy of anti-CD4 monoclonal antibodies in rat adjuvant arthritis is paralleled by differential influence on NF-kappaB binding activity and TNF-alpha secretion of T cells

Prodrug-based nanomedicines for rheumatoid arthritis

Most antirheumatic drugs with high toxicity exhibit a narrow therapeutic window due to their nonspecific distribution in the body, leading to undesirable side effects and reduced patient compliance. To in response to these challenges, prodrug-based nanoparticulate drug delivery systems (PNDDS), which combines prodrug strategy and nanotechnology into a single system, resulting their many advantages, including stability for prodrug structure, the higher drug loading capacity of the system, improving the target activity and bioavailability, and reducing their untoward effects. PNDDS have gained attention as a method for relieving arthralgia syndrome of rheumatoid arthritis in recent years. This article systematically reviews prodrug-based nanocarriers for rheumatism treatment, including Nano systems based on prodrug-encapsulated nanomedicines and conjugate-based nanomedicines. It provides a new direction for the clinical treatment of rheumatoid arthritis.

Identification of New, Functionally Relevant Mutations in the Coding Regions of the Human Fos and Jun Proto-Oncogenes in Rheumatoid Arthritis Synovial Tissue

In rheumatoid arthritis (RA), the expression of many pro-destructive/pro-inflammatory proteins depends on the transcription factor AP-1. Therefore, our aim was to analyze the presence and functional relevance of mutations in the coding regions of the AP-1 subunits of the fos and jun family in peripheral blood (PB) and synovial membranes (SM) of RA and osteoarthritis patients (OA, disease control), as well as normal controls (NC). Using the non-isotopic RNAse cleavage assay, one known polymorphism (T252C: silent; rs1046117; present in RA, OA, and NC) and three novel germline mutations of the cfos gene were detected: (i) C361G/A367G: Gln121Glu/Ile123Val, denoted as “fos121/123”; present only in one OA sample; (ii) G374A: Arg125Lys, “fos125”; and (iii) C217A/G374A: Leu73Met/Arg125Lys, “fos73/125”, the latter two exclusively present in RA. In addition, three novel somatic cjun mutations (604–606ΔCAG: ΔGln202, “jun202”; C706T: Pro236Ser, “jun236”; G750A: silent) were found exclusively in the RA SM. Tansgenic expression of fos125 and fos73/125 mutants in NIH-3T3 cells induced an activation of reporter constructs containing either the MMP-1 (matrix metalloproteinase) promoter (3- and 4-fold, respectively) or a pentameric AP-1 site (approximately 5-fold). Combined expression of these two cfos mutants with cjun wildtype or mutants (jun202, jun236) further enhanced reporter expression of the pentameric AP-1 construct. Finally, genotyping for the novel functionally relevant germline mutations in 298 RA, 288 OA, and 484 NC samples revealed no association with RA. Thus, functional cfos/cjun mutants may contribute to local joint inflammation/destruction in selected patients with RA by altering the transactivation capacity of AP-1 complexes.

Discrepancy between Jun/Fos Proto-Oncogene mRNA and Protein Expression in the Rheumatoid Arthritis Synovial Membrane

Rheumatoid arthritis (RA) is a chronic inflammatory and destructive joint disease characterized by overexpression of pro-inflammatory/pro-destructive mediators, whose regulation has been the focus of our previous studies. Since the expression of these proteins commonly depends on AP-1, the expression of the AP-1-forming subunits cJun, JunB, JunD, and cFos was assessed in synovial membrane (SM) samples of RA, osteoarthritis (OA), joint trauma (JT), and normal controls (NC) using ELISA and qRT-PCR. With respect to an observed discrepancy between mRNA and protein levels, the expression of the mRNA stability-modifying factors AU-rich element RNA-binding protein (AUF)-1, tristetraprolin (TTP), and human antigen R (HuR) was measured. JunB and JunD protein expression was significantly higher in RA-SM compared to OA and/or NC. By contrast, jun/fos mRNA expression was significantly (cjun) or numerically decreased (junB, junD, cfos) in RA and OA compared to JT and/or NC. Remarkably, TTP and HuR were also affected by discrepancies between their mRNA and protein levels, since they were significantly decreased at the mRNA level in RA versus NC, but significantly or numerically increased at the protein level when compared to JT and NC. Discrepancies between the mRNA and protein expression for Jun/Fos and TTP/HuR suggest broad alterations of post-transcriptional processes in the RA-SM. In this context, increased levels of mRNA-destabilizing TTP may contribute to the low levels of jun/fos and ttp/hur mRNA, whereas abundant mRNA-stabilizing HuR may augment translation of the remaining mRNA into protein with potential consequences for the composition of the resulting AP-1 complexes and the expression of AP-1-dependent genes in RA.

Interleukin-35 Inhibits TNF-α-Induced Osteoclastogenesis and Promotes Apoptosis via Shifting the Activation From TNF Receptor-Associated Death Domain (TRADD)-TRAF2 to TRADD-Fas-Associated Death Domain by JAK1/STAT1

Over-activated osteoclasts derived from myeloid or peripheral blood monocytes by inflammatory cytokines results in osteoporosis, osteoarthritis, and other bone erosion-related diseases. Interleukin 35 (IL-35) is a novel anti-inflammatory and immunosuppressive factor. This study investigated the effect of IL-35 on TNF-α-induced osteoclastogenesis. In the presence of IL-35, this process was detected by Tartrate-Resistant Acid Phosphatase (TRAP) staining, F-actin staining, and bone resorption assays. The effects of IL-35 on TNF-α-induced apoptosis were demonstrated by TUNEL staining, cell viability assays, and flow cytometry. Moreover, a microarray was performed to detect the effect of IL-35 on TNF-α-activated phosphatase kinase. The effect of IL-35 on the TNF-α-mediated activation of NF-κB, MAPK, TRAF2, RIP1, Fas-associated death domain (FADD), and caspase3 was further investigated. In addition, a murine calvarial osteolysis model was established via the subcutaneous injection of TNF-α onto the calvaria, and histological analysis was subsequently performed. As a result, IL-35 inhibited TNF-α-induced osteoclast formation and bone resorption in vitro and osteolysis calvaria in vivo. NFATc1, c-fos, and TRAP were downregulated by IL-35 through the inhibition of NF-κB and MAPK, during which JAK1/STAT1 was activated. Moreover, based on TUNEL staining and flow cytometry, IL-35 was shown to enhance TNF-α-induced osteoclast apoptosis. Meanwhile, FADD and cleaved-caspase 3 were increased in cells treated with TNF-α and IL-35, whereas the DNA-binding activity of NF-κB was increased in TNF-α-treated cells, but was decreased in cells treated with both TNF-α and IL-35. In conclusion, IL-35 inhibits TNF-α-induced osteoclastogenesis and promotes apoptosis by activating JAK1/STAT1 and shifting activation from TNF receptor-associated death domain (TRADD)-TRAF2/RIP1-NF-κB to TRADD-FADD-caspase 3 signaling.

Liposomal encapsulation enhances and prolongs the anti-inflammatory effects of water-soluble dexamethasone phosphate in experimental adjuvant arthritis

Introduction

The objective of this study was to evaluate the efficacy of intravenous (i.v.) injection of liposomally encapsulated dexamethasone phosphate (DxM-P) in comparison to free DxM-P in rats with established adjuvant arthritis (AA). This study focused on polyethylene glycol (PEG)-free liposomes, to minimize known allergic reactions caused by neutral PEG-modified (PEG-ylated) liposomes.

Methods

Efficacy was assessed clinically and histologically using standard scores. Non-specific and specific immune parameters were monitored. Activation of peritoneal macrophages was analyzed via cytokine profiling. Pharmacokinetics/biodistribution of DxM in plasma, synovial membrane, spleen and liver were assessed via mass spectrometry.

Results

Liposomal DxM-P (3 × 1 mg/kg body weight; administered intravenously (i.v.) on Days 14, 15 and 16 of AA) suppressed established AA, including histological signs, erythrocyte sedimentation rate, white blood cell count, circulating anti-mycobacterial IgG, and production of interleukin-1beta (IL-1β) and IL-6 by peritoneal macrophages. The suppression was strong and long-lasting. The clinical effects of liposomal DxM-P were dose-dependent for dosages between 0.01 and 1.0 mg/kg. Single administration of 1 mg/kg liposomal DxM-P and 3 × 1 mg/kg of free DxM-P showed comparable effects consisting of a partial and transient suppression. Moreover, the effects of medium-dose liposomal DxM-P (3 × 0.1 mg/kg) were equal (in the short term) or superior (in the long term) to those of high-dose free DxM-P (3 × 1 mg/kg), suggesting a potential dose reduction by a factor between 3 and 10 by liposomal encapsulation. For at least 48 hours after the last injection, the liposomal drug achieved significantly higher levels in plasma, synovial membrane, spleen and liver than the free drug.

Conclusions

This new PEG-free formulation of macrophage-targeting liposomal DxM-P considerably reduces the dose and/or frequency required to treat AA, with a potential to enhance or prolong therapeutic efficacy and limit side-effects also in the therapy of rheumatoid arthritis. Depot and/or recirculation effects in plasma, inflamed joint, liver, and spleen may contribute to this superiority of liposomally encapsulated DxM-P.

Protective versus pathogenic anti-CD4 immunity: insights from the study of natural resistance to HIV infection

HIV-1 exposure causes several dramatic unbalances in the immune system homeostasis. Here, we will focus on the paradox whereby CD4 specific autoimmune responses, which are expected to contribute to the catastrophic loss of most part of the T helper lymphocyte subset in infected patients, may display the characteristics of an unconventional protective immunity in individuals naturally resistant to HIV-1 infection. Reference to differences in fine epitope mapping of these two oppositely polarized outcomes will be presented, with particular reference to partially or totally CD4-gp120 complex-specific antibodies. The fine tuning of the anti-self immune response to the HIV-1 receptor may determine whether viral exposure will result in infection or, alternatively, protective immunity.

Along this line, an efficacious anti-HIV strategy can rely on the active (i.e., through immunization) or passive targeting of cryptic epitopes of the CD4-gp120 complex, including those harboured within the CD4 molecule. Such epitopes are expected to be safe from genetic drift and thus allow for broad spectrum of efficacy. Moreover, since these epitopes are not routinely exposed in uninfected individuals, they are expected to become targets of neutralizing antibodies or other specifically designed molecules only after viral exposure, with a predictable low impact in terms of potentially harmful anti-CD4 self-reactivity.

The experimentum naturae of naturally resistant individuals indicates a strategy to design innovative strategies to neutralize HIV-1 by acting on the sharp edge between harmful and protective self-reactivity.

Molecular imaging of rheumatoid arthritis by radiolabelled monoclonal antibodies: new imaging strategies to guide molecular therapies

The closing of the last century opened a wide variety of approaches for inflammation imaging and treatment of patients with rheumatoid arthritis (RA). The introduction of biological therapies for the management of RA started a revolution in the therapeutic armamentarium with the development of several novel monoclonal antibodies (mAbs), which can be murine, chimeric, humanised and fully human antibodies. Monoclonal antibodies specifically bind to their target, which could be adhesion molecules, activation markers, antigens or receptors, to interfere with specific inflammation pathways at the molecular level, leading to immune-modulation of the underlying pathogenic process. These new generation of mAbs can also be radiolabelled by using direct or indirect method, with a variety of nuclides, depending upon the specific diagnostic application. For studying rheumatoid arthritis patients, several monoclonal antibodies and their fragments, including anti-TNF-alpha, anti-CD20, anti-CD3, anti-CD4 and anti-E-selectin antibody, have been radiolabelled mainly with (99m)Tc or (111)In. Scintigraphy with these radiolabelled antibodies may offer an exciting possibility for the study of RA patients and holds two types of information: (1) it allows better staging of the disease and diagnosis of the state of activity by early detection of inflamed joints that might be difficult to assess; (2) it might provide a possibility to perform 'evidence-based biological therapy' of arthritis with a view to assessing whether an antibody will localise in an inflamed joint before using the same unlabelled antibody therapeutically. This might prove particularly important for the selection of patients to be treated since biological therapies can be associated with severe side-effects and are considerably expensive. This article reviews the use of radiolabelled mAbs in the study of RA with particular emphasis on the use of different radiolabelled monoclonal antibodies for therapy decision-making and follow-up.

Effect of total flavonoids of Chrysanthemum indicum on the apoptosis of synoviocytes in joint of adjuvant arthritis rats

Chrysanthemum is a traditional Chinese medicine used in China to treat inflammatory diseases. The total flavonoids Chrysanthemum indicum (TFC) were extracted from the dried bud of Chrysanthemum indicum. Our previous study had demonstrated that TFC was a new class of effective anti-inflammation, analgesia and immunoloregulation agents. In this study, we established an adjuvant arthritis (AA) model by injection of Freund's Complete Adjuvant (FCA) to investigate the effect of TFC on the apoptosis of synoviocytes in AA Rats. Synoviocytes isolated from knee joint of rats were treated with different doses of TFC in vitro. Synoviocytes proliferation was measured by MTT assay, and DNA fragmentations were evaluated on agarose gel electrophoresis. The levels of caspase-3 cleaved fragments were analyzed by Western blot. The annexin V stain assay was used to explore the inhibition of caspase-3 on the amelioration of synoviocytes apoptosis. The results showed that TFC inhibited the proliferation of synoviocytes. Electrophoresis showed higher ladders of DNA bands in the TFC group. Cleaved fragments of caspase-3 were increased significantly. Furthermore, the apoptotic synoviocytes were markedly decreased by the caspase-3 specific inhibitor. These results suggest that TFC could induce synoviocytes apoptosis and suppress proliferation of synoviocytes in adjuvant-induced arthritis rats.

Reduction of CD4 positive T cells and improvement of pathological changes of collagen-induced arthritis by FTY720

FTY720 belongs to a new class of immunosuppressants. Little is known about its influence on T cell subtypes and pathological changes in arthritis. Here we illustrated the effect of FTY720 on peripheral T cell subsets and joint damage of collagen-induced arthritis rats. Rats were administered FTY720 or prednisone daily from day 0 to day 28. Body weight, hind paw swelling and arthritis index were measured. Bone destruction was determined by micro-computed tomography and histopathology, and T cell subsets were analyzed by flow cytometry and immunohistochemistry. The results showed that FTY720 inhibited the development of arthritis. Radiological analysis revealed that FTY720 treated collagen-induced arthritic rats had much less joint damage in comparison to untreated collagen-induced arthritic rats. Histological study showed that collagen-induced arthritic rats suffered from inflammatory cell infiltration and synovial hyperplasia in their joints, and FTY720 treatment clearly reduced these pathological changes. Immunohistochemical analysis showed that FTY720 treatment significantly decreased the number of CD4(+) T cells in the synovium of collagen-induced arthritic rats. Collagen-induced arthritic rats appeared to have more CD4(+), but not CD8(+) T cells in their peripheral blood than normal control rats. Following FTY720 treatment, peripheral blood CD3(+) and CD4(+) T cells in collagen-induced arthritic rats were significantly decreased. In conclusion, FTY720 is an effective compound in the treatment of collagen-induced arthritic rats and in reducing CD4(+) T cells in collagen-induced arthritic rats.

Biological therapies directed against cells in autoimmune disease

Among the cells of the immune system involved in the pathogenesis of autoimmune disease, T cells have received the most attention. The central role of these cells in several animal models of autoimmune diseases and in human disease counterparts has provided the rationale for specific therapeutic targeting of T cell subsets, especially CD4 T cells. So far, the applicability of this approach has not been clearly evident in clinical trials, which was also the case when nondepleting "coating" anti-CD4 monoclonal antibodies was used. In the past several years, experimental evidence supporting a major role of B cells in systemic autoimmune disease has grown. This includes the pathogenicity of certain autoantibodies, the potential of B cells to present antigen in the context of MHC Class II and to signal via costimulatory molecules, and to secrete proinflammatory cytokines. In some instances, engagement of the B cell receptor and other surface receptors is sufficient to stimulate B cells to produce antibodies. The depletion of B cells by targeting the surface marker CD20 has been shown to be effective in treating rheumatoid arthritis with a good side effect profile. Series of cases with other systemic autoimmune diseases indicate that this strategy may be effective in these conditions too. The clinical data add weight to the importance of B cells in the pathogenesis of autoimmune diseases.

Anti-CD4 monoclonal antibody treatment in acute and early chronic antigen induced arthritis: influence on macrophage activation

OBJECTIVE

To investigate the indirect effects of anti-CD4 treatment on the functions of macrophages (CD4(-) in mice) in the acute and early chronic phase of mouse antigen induced arthritis (AIA).

METHODS

C57BL/6 mice with AIA were treated intraperitoneally with the anti-CD4 mAb GK1.5 or control rat IgG on days -1, 0, 1, 3, 5, and 7. Proinflammatory cytokines (IL1 beta, IL6, and TNF alpha) were quantified by sandwich ELISA in joint extracts, serum, and supernatants of ex vivo stimulated spleen/lymph node cells or peritoneal macrophages (+LPS/IFN gamma). Nitric oxide (NO) levels in supernatants of ex vivo stimulated peritoneal macrophages were measured by the Griess reaction. Proteolytic activity in joint homogenates was analysed by gelatin, casein, and elastin zymography, and substrate assays.

RESULTS

Anti-CD4 treatment significantly reduced joint swelling in acute (days 3, 5) and early chronic AIA (day 7) and diminished inflammation and destruction scores in late chronic AIA (day 21). On day 3, anti-CD4 treatment significantly reduced IL6 levels in all compartments. IL1 beta was reduced in joint extracts, unaffected in serum or cells from lymphoid organs, and increased in stimulated peritoneal macrophages. TNF alpha was significantly increased in the joints, decreased in serum, and otherwise unchanged. NO production by stimulated peritoneal macrophages was significantly reduced by anti-CD4 treatment. Lower activity of matrix metalloproteinases and neutrophil elastase was seen in joint extracts of anti-CD4 treated animals than in IgG treated AIA controls.

CONCLUSION

CD4(+) T cell directed treatment had strong local and systemic effects on macrophages. These indirect effects may contribute to the reduction of destructive mediators/joint destruction in AIA.

A survey of the year 2002 commercial optical biosensor literature

We have compiled 819 articles published in the year 2002 that involved commercial optical biosensor technology. The literature demonstrates that the technology's application continues to increase as biosensors are contributing to diverse scientific fields and are used to examine interactions ranging in size from small molecules to whole cells. Also, the variety of available commercial biosensor platforms is increasing and the expertise of users is improving. In this review, we use the literature to focus on the basic types of biosensor experiments, including kinetics, equilibrium analysis, solution competition, active concentration determination and screening. In addition, using examples of particularly well-performed analyses, we illustrate the high information content available in the primary response data and emphasize the impact of including figures in publications to support the results of biosensor analyses.

Anti-CD4 monoclonal antibody treatment in acute and early chronic antigen-induced arthritis: influence on T helper cell activation

To examine the effects of anti-CD4 mAb treatment in acute and chronic antigen-induced arthritis (AIA), C57BL/6 mice were treated intraperitoneally either with the depleting anti-CD4 mAb GK1.5 or with rat-IgG (control) on Days -1, 0, 1, 3, 5, and 7. Arthritis was monitored by assessment of joint swelling and histological evaluation in the acute (Day 3) and the chronic phase (Day 21) of AIA. To determine the effects on cellular immune responses, in vivo T-cell reactivity (delayed type hypersensitivity; DTH) was measured, as well as protein levels of TH1- (IL-2, IFN-gamma) and TH2-cytokines (IL-4, IL-10) in joint extracts and supernatants of ex vivo stimulated spleen and lymph node cells. The humoral immune response was analysed by measuring serum antibodies against methylated bovine serum albumine (mBSA) and extracellular matrix proteins. Treatment with GK1.5 reduced swelling, inflammation, and destruction of the arthritic joint. Unexpectedly, the effects were even more pronounced in the acute than in the chronic phase. The anti-inflammatory effect was accompanied by a diminished DTH against the arthritogen mBSA and a decrease of TH1-cytokine production in spleen and pooled body lymph nodes, whereas the TH2-cytokine production in these organs was unchanged and the humoral immune response was only moderately reduced. There was a failure of depleting CD4+ T-cells in the joint, reflected also by unchanged local cytokine levels. Therefore, systemic rather than local effects on the TH1/TH2 balance appear to underlie the therapeutic efficacy of anti-CD4 treatment in AIA.