Collagen II antibody-induced arthritis in Tg1278TNFko mice: optimization of a novel model to assess treatments targeting human TNFα in rheumatoid arthritis

Active immunotherapy for C5a-mediated inflammation using adjuvant-free self-assembled peptide nanofibers

The terminal protein in the complement cascade C5a is a potent inflammatory molecule and chemoattractant that is involved in the pathology of multiple inflammatory diseases including sepsis and arthritis, making it a promising protein to target with immunotherapies. Active immunotherapies, in which patients are immunized against problematic self-molecules and generate therapeutic antibodies as a result, have received increasing interest as an alternative to traditional monoclonal antibody treatments. In previous work, we have designed supramolecular self-assembling peptide nanofibers as active immunotherapies with defined combinations of B- and T-cell epitopes. Herein, the self-assembling peptide Q11 platform was employed to generate a C5a-targeting active immunotherapy. Two of three predicted B-cell epitope peptides from C5a were found to be immunogenic when displayed within Q11 nanofibers, and the nanofibers were capable of reducing C5a serum concentrations following immunization. Contrastingly, C5a's precursor protein C5 maintained its original concentration, promising to minimize side effects heretofore associated with C5-targeted therapies. Immunization protected mice against an LPS-challenge model of sepsis, and it reduced clinical severity in a model of collagen-antibody induced arthritis. Together, this work indicates the potential for targeting terminal complement proteins with active immunotherapies by leveraging the immunogenicity of self-assembled peptide nanomaterials. STATEMENT OF SIGNIFICANCE: Chronic inflammatory diseases such as rheumatoid arthritis, psoriasis, and inflammatory bowel disease are currently treated primarily with monoclonal antibodies against key inflammatory mediators. While helpful for many patients, they have high non-response rates, are costly, and commonly fail as anti-drug antibodies are raised by the patient. The approach we describe here explores a fundamentally different treatment paradigm: raising therapeutic antibody responses with an active immunotherapy. We employ innovative supramolecular peptide nanomaterials to elicit neutralizing antibody responses against complement component C5a and demonstrate therapeutic efficacy in preclinical mouse models of sepsis and rheumatoid arthritis. The strategy reported may represent a potential alternative to monoclonal antibody therapies.

Tramadol/paracetamol treatment attenuates the development of collagen antibody-induced arthritis and interferes with prednisolone treatment in mice

The collagen antibody-induced arthritis (CAIA) model is highly effective in inducing arthritis, making it an attractive model for screening therapeutic compounds such as glucocorticoids (GCs). The severity of discomfort in this model makes it desirable to administer analgesics, but it is a prerequisite that these do not interfere with the model or tested therapeutics. In the present study, we studied the effect of 1 mg/mL tramadol and 3.5 mg/mL paracetamol (TP) on CAIA in male BALB/cAnNCrl mice and the possible interference of TP analgesia with the activity of the GC drug prednisolone (Pred). Our results showed that TP abolished the Pred-induced amelioration of CAIA, as well as several other Pred-induced effects, such as the reduction in thymus weight and the increase in insulin level. This most likely results from the effects of TP on the hepatic metabolism of this drug, since it strongly increased the Cyp3a11 expression in the liver. Altogether, we conclude that TP analgesia is not suitable for the CAIA model in male BALB/cAnNCrl mice, in particular when evaluating the effects of GCs such as Pred.

Small heterodimer partner interacting leucine zipper protein (SMILE) ameliorates autoimmune arthritis via AMPK signaling pathway and the regulation of B cell activation

Rheumatoid arthritis (RA) is an autoimmune disease that causes joint swelling and inflammation and can involve the entire body. RA is characterized by the increase of pro-inflammatory cytokines such as interleukin (IL) and tumor necrosis factor, and the over-activation of T lymphocytes and B lymphocytes, which may lead to severe chronic inflammation of joints. However, despite numerous studies the pathogenesis and treatment of RA remain unresolved. This study investigated the use of small heterodimer partner-interacting leucine zipper protein (SMILE) overexpression to treat a mouse model of RA. SMILE is an insulin-inducible corepressor through adenosine monophosphate-activated kinase (AMPK) signaling pathway. The injection of a SMILE overexpression vector to mice with collagen induced-arthritis resulted in a milder clinical pathology and a reduced incidence of arthritis, less joint tissue damage, and lower levels of Th17 cells and plasma B cells in the spleen. Immunohistochemistry of the joint tissue showed that SMILE decreased B-cell activating factor (BAFF) receptor (BAFF-R), mTOR, and STAT3 expression but increased AMPK expression. In SMILE-overexpressing transgenic mice with collagen antibody-induced arthritis (CAIA), a decrease in the arthritis score and reductions in tissue damage, the number of B cells, and antibody production were observed. The treatment of immune cells in vitro with curcumin, a known SMILE-inducing agent, led to decreases in plasma B cells, germinal center B cells, IL-17-producing B cells, and BAFF-R-positive B cells. Taken together, our findings demonstrate the therapeutic potential of SMILE in RA, based on its inhibition of B cell activation mediated by the AMPK/mTOR and STAT3 signaling pathway and BAFF-R expression. Video abstract.

Apoptotic cell death in disease-Current understanding of the NCCD 2023

Apoptosis is a form of regulated cell death (RCD) that involves proteases of the caspase family. Pharmacological and genetic strategies that experimentally inhibit or delay apoptosis in mammalian systems have elucidated the key contribution of this process not only to (post-)embryonic development and adult tissue homeostasis, but also to the etiology of multiple human disorders. Consistent with this notion, while defects in the molecular machinery for apoptotic cell death impair organismal development and promote oncogenesis, the unwarranted activation of apoptosis promotes cell loss and tissue damage in the context of various neurological, cardiovascular, renal, hepatic, infectious, neoplastic and inflammatory conditions. Here, the Nomenclature Committee on Cell Death (NCCD) gathered to critically summarize an abundant pre-clinical literature mechanistically linking the core apoptotic apparatus to organismal homeostasis in the context of disease.

The use of animal models in rheumatoid arthritis research

The pathological hallmark of rheumatoid arthritis (RA) is a synovial pannus that comprises proliferating and invasive fibroblast-like synoviocytes, infiltrating inflammatory cells, and an associated neoangiogenic response. Animal models have been established to study these pathological features of human RA. Spontaneous and induced animal models of RA primarily reflect inflammatory aspects of the disease. Among various induced animal models, collagen-induced arthritis (CIA) and collagen antibody-induced arthritis (CAIA) models are widely used to study the pathogenesis of RA. Improved transplantation techniques for severe combined immunodeficiency (SCID) mouse models of RA can be used to evaluate the effectiveness of potential therapeutics in human tissues and cells. This review provides basic information on various animal models of RA, including CIA and CAIA. In addition, we describe a SCID mouse coimplantation model that can measure the long-distance migration of human RA synoviocytes and cartilage destruction induced by these cells.

High humidity aggravates the severity of arthritis in collagen-induced arthritis mice by upregulating xylitol and L-pyroglutamic acid

Background

Humidity was an unfavorable factor for patients with rheumatoid arthritis (RA). RA disease activity was severe in high humidity conditions. However, there is no evidence to demonstrate the effects of humidity on arthritis in the animal experiments and explore its relevant mechanism.

Methods

Using the DBA/1 mice, this study addressed the effects of a high humidity (80 ± 5%) on arthritis in collagen-induced arthritis (CIA) mice. Then, this study used the gas chromatography-mass spectrometer (GC-MS) to explore alterations in serum metabolome caused by the high humidity. Furthermore, xylitol and L-pyroglutamic acid, which were both significantly upregulated by the high humidity, were selected to further study their effects on arthritis in the CIA mice.

Results

The high humidity (80 ± 5%) could aggravate arthritis variables including increasing arthritis score and swelling, serum autoantibodies (anti-COII and anti-CCP), and proinflammatory cytokines (IL-6, IL-17A, and G-CSF). In addition, the high humidity could cause significant alterations in serum metabolome in the CIA mice. Xylitol and L-pyroglutamic acid were the representative serum metabolites that were significantly upregulated by the high humidity. Further experiments demonstrated that the supplementation of 0.4 mg/mL xylitol in drinking water after inducing the CIA model and 2.0 mg/mL in drinking water before inducing the CIA model could both aggravate arthritis in the CIA mice.

Conclusions

These data demonstrated that high humidity was not beneficial for arthritis development and its mechanism might be associated with xylitol and L-pyroglutamic acid.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-021-02681-x.

Disruption of hepatocyte Sialylation drives a T cell-dependent pro-inflammatory immune tone

Through the catalysis of α2,6-linked sialylation, the enzyme ST6Gal1 is thought to play key roles in immune cell communication and homeostasis. Of particular importance, glycans with terminal α2,6-sialic acids are known to negatively regulate B cell receptor signaling and are associated with an immunosuppressive tumor microenvironment that promotes T cell anergy, suggesting that α2,6-sialic acids are a key immune inhibitory signal. Consistent with this model, mice harboring a hepatocyte-specific ablation of ST6Gal1 (H-cKO) develop a progressive and severe non-alcoholic fatty liver disease characterized by steatohepatitis. Using this H-cKO mouse, we have further discovered that loss of hepatocyte α2,6-sialylation not only increases the inflammatory state of the local tissue microenvironment, but also systemic T cell-dependent immune responses. H-cKO mice responded normally to innate and passively induced inflammation, but showed significantly increased morbidity in T cell-dependent house dust mite-antigen (HDM)-induced asthma and myelin oligodendrocyte glycoprotein (MOG) peptide-induced experimental autoimmune encephalomyelitis (EAE). We further discovered that H-cKO mice have a profound shift toward effector/memory T cells even among unchallenged mice, and that macrophages from both the liver and spleen expressed the inhibitory and α2,6-sialic acid-specific glycan binding molecule CD22. These findings align with previously reported pro-inflammatory changes in liver macrophages, and support a model in which the liver microenvironment sets a systemic immune tone that is regulated by tissue α2,6-sialylation and mediated by liver macrophages and systemic T cells.

Anti-Inflammatory and Anti-Arthritic Efficacies of an Indian Traditional Herbo-Mineral Medicine "Divya Amvatari Ras" in Collagen Antibody-Induced Arthritis (CAIA) Mouse Model Through Modulation of IL-6/IL-1β/TNF-α/NFκB Signaling

Rheumatoid arthritis (RA) is defined as a chronic autoimmune inflammatory disorder that causes damage to limb joints and progressive injuries to secondary organs. Medical practitioners prescribe Methotrexate (MTX) as standard care medicine for treating RA. However, the long-term application of MTX has shown to have adverse health-related effects. Divya Amvatari Ras (DAR), an Indian Ayurvedic herbo-mineral formulation, has been described in ancient texts to provide relief from RA inflammation associated distress. Therefore, in the present study, we explored the biocompatibility, anti-inflammatory, and anti-arthritic efficacy of DAR using in vivo and in vitro disease models. Using carrageenan (CA)-stimulated Wistar rat paw edema model, we showed a reduction in inflammation-induced paw edema at human equivalent dose of DAR. Anti-rheumatic efficacy of DAR was studied using collagen-antibody cocktail (C-Ab) Induced Arthritis (CAIA) mouse model. The onset of RA in the CAIA mice was determined using parameters such as the increase in arthritis score, and induction of disease associated lesions in the ankle and knee joints, and increase in mechanical and thermal hyperalgesia. Treatment of CAIA animals with a human equivalent dose of DAR significantly reversed the RA-associated pathogenesis. These effects were comparable with the standard of care RA drug, MTX. DAR acted at multiple levels of inflammation associated with RA to reduce progressive pathogenesis. Animal serum biochemistry showed DAR was capable of ameliorating RA induced increase in liver enzyme Alanine Aminotransferase (ALT) and pro-inflammatory cytokine interleukin 6 (IL-6). In the lipopolysaccharide stimulated THP-1 cells, DAR was found to inhibit the release of IL-6, IL-1β, TNF-α, and upstream inflammatory gene regulatory protein, NFκB. The study endorsed the anti-arthritic and anti-inflammatory activity of the Indian Traditional herbo-mineral medicine, DAR. These results also confirm that DAR was highly biocompatible and would show minimal health-related side effects than those associated with standard of care MTX. Taken together, we show that the DAR could be utilized as a promising alternative or complementary therapy for treating rheumatoid arthritis.

Herbo-mineral formulation 'Ashwashila' attenuates rheumatoid arthritis symptoms in collagen-antibody-induced arthritis (CAIA) mice model

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disorder that affects joints of hands and feet and introduces injury in secondary organs such as cardiac tissue. In the present study, we induced RA in male Balb/c mice (CAIA) using collagen-antibody cocktail (C-Ab) and lipopolysaccharide intraperitoneal injections. Induction of RA in the animals was detected through the loss of body weight, food, and water consumption, pedal edema, increased arthritis score of the paw and ankle, increase in radiological and histological lesion score of ankle and knee joints and enhanced pain perception in the C-Ab induced RA animals. Ashwashila is a herbo-mineral medicine from Indian Ayurvedic system. Human equivalent doses of Ashwashila (ASHW) and standard of care, Methotrexate were given to the CAIA animals for two weeks. ASHW treatment significantly reversed the effect of C-Ab with reduced pedal edema, arthritis score, radiological and histological lesion scores in ankle-joint, knee-joint and articular cartilage, reduced pain perception. These effects were comparable with the Methotrexate treatment. In human monocytic (THP-1) cells, ASHW was found to be biocompatible at in-vitro test doses. The anti-arthritis mechanism of action for ASHW was established through the suppression of pro-inflammatory cytokines such as IL-1β, IL-6, TNF-α; and upstream regulator, NF-κB. Taken together, we show the pre-clinical efficacy of ASHW in reducing RA associated symptoms by controlling inflammation and suggest it as a potential therapeutic candidate for rheumatoid arthritis.

Characteristics of A20 gene polymorphisms and clinical significance in patients with rheumatoid arthritis

Background

There are a number of studies regarding to the susceptibility of A20 SNPs in rheumatoid arthritis (RA); however, a few of these studies have shown an association between polymorphisms in the A20 gene and RA risk in the Chinese population. The aim of this study was to investigate the characteristics of A20 gene polymorphisms, the association between polymorphisms and clinical significance in Chinese RA patients.

Methods

PCR and sequencing were used to identify A20 gene polymorphisms in peripheral blood mononuclear cells (PBMCs) (50 cases), synovial fluid (11 cases) from RA patients and PBMCs from 30 healthy individuals. Quantitative Real-time PCR (qRT-PCR) was used to analyze the A20 mRNA expression in 38 RA patients and 40 healthy individuals. Pearson’s Chi square test and two independent-samples Wilcoxon tests were used for statistical analysis.

Results

Eight single nucleotide polymorphisms (SNPs) (rs5029937, rs3799491, rs598493, rs2307859, rs146534657, rs2230926, rs661561, and rs582757) were identified in PBMCs of RA patients. One new mutation (14284 T > A) was identified in synovial fluid mononuclear cells from one RA case. rs146534657 was identified for the first time in two RA cases. Patients with rs146534657 (12411 A > G, Asn102Ser) AG genotype or rs2230926 (12486 T > G, Phe127Cys) TG genotype had poor outcome. Significantly lower A20 mRNA expression was found in PBMCs from RA patients compared with healthy individuals (p < 0.001). There was a higher A20 mRNA expression in RA patients with rs2230926 TG genotype and rs146534657 AG genotype (11.56 ± 7.39) than patients with rs2230926 TT genotype and rs146534657 AA genotype (5.63 ± 4.37) (p = 0.031).

Conclusion

Significantly lower A20 expression was found in RA patients. The polymorphisms of A20 were characterized in RA patients. We detected rs146534657 for the first time and identified a new A20 mutation (14284 T > A). A20 rs2230926 TG genotype and rs146534657 AG genotype may be related to poor outcome in RA patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-015-0566-1) contains supplementary material, which is available to authorized users.

A New Approach for the Treatment of Arthritis in Mice with a Novel Conjugate of an Anti-C5aR1 Antibody and C5 Small Interfering RNA

Rheumatoid arthritis (RA) is an inflammatory autoimmune joint disease in which the complement system plays an important role. Of the several components of complement, current evidence points to C5 as the most important inducer of inflammation. Several groups generated Abs or small interfering RNAs (siRNAs) or small molecule inhibitors against C5 and C5aR1 (CD88) that have showed some efficacy in RA in animal models. However, none of these candidate therapeutics has moved from bench to bedside. In this study, we test in collagen Ab-induced arthritis (CAIA) a new therapeutic strategy using a novel anti-C5ab-C5 siRNA conjugate. We first demonstrate that although C5aR2 or C5L2 (GPR77) plays no role in CAIA, C5aR1 contributes to pathogenesis. We demonstrate that injection of siRNAs blocking C5, C5aR1, or the combination decreased clinical disease activity in mice with CAIA by 45%, 51%, and 58%, respectively. Anti-C5 Ab (BB5.1) has only limited efficacy, but significantly reduced arthritis up to 66%. We then generated a novel anti-C5aR1 Ab-protamine-C5 siRNA conjugate. To our knowledge, we show for the first time that whereas unconjugated Ab plus siRNAs reduce arthritis by 19%, our anti-C5aR1 Ab-protamine-C5 siRNA conjugate was effective in reducing arthritis by 83% along with a parallel decrease in histopathology, C3 deposition, neutrophils, and macrophages in the joints of mice with CAIA. These data suggest that by targeting anti-C5 siRNAs to the receptor for its C5a activation fragment (C5aR1), a striking clinical effect can be realized.