Rhian Mair Goodfellow

Soluble complement receptor one (sCR1) inhibits the development and progression of rat collagen-induced arthritis

We set out to determine whether inhibition of complement using sCR1 could influence the development and progression of collagen arthritis in the Lewis rat. Collagen arthritis was successfully established in the Lewis rat, using a novel immunization schedule. In separate experiments, cobra venom factor (CVF) and sCR1 were used to achieve systemic complement inhibition. Their respective effects on disease onset and on the progression of established disease compared with saline‐treated control animals was explored. Arthritis was assessed by measurement of clinical score, paw diameter and paw volume. Complement inhibition using either CVF or sCR1, prior to the onset of clinical signs of inflammation, delayed the development of disease. CVF was ineffective in the treatment of established disease, whereas sCR1 delayed the progression of disease in affected joints and prevented the recruitment of further joints while the animals were complement‐depleted. In the control saline‐treated groups the disease continued to progress relentlessly. We conclude that complement activation is important in the initiation and maintenance of inflammation in collagen arthritis. The potent disease‐modulating effect of sCR1 provides persuasive evidence that specific complement inhibiting agents may be an effective approach to the treatment of inflammatory joint diseases

Interferon-γ inhibits interleukin-1β-induced matrix metalloproteinase production by synovial fibroblasts and protects articular cartilage in early arthritis

IntroductionThe first few months after symptom onset represents a pathologically distinct phase in rheumatoid arthritis (RA). We used relevant experimental models to define the pathological role of interferon-γ (IFN-γ) during early inflammatory arthritis.MethodsWe studied IFN-γs capacity to modulate interleukin-1β (IL-1β) induced degenerative responses using RA fibroblast-like synoviocytes (FLS), a bovine articular cartilage explant (BACE)/RA-FLS co-culture model and an experimental inflammatory arthritis model (murine antigen-induced arthritis (AIA)).ResultsIFN-γ modulated IL-1β driven matrix metalloproteinases (MMP) synthesis resulting in the down-regulation of MMP-1 and MMP-3 production in vitro. IFN-γ did not affect IL-1β induced tissue inhibitor of metalloproteinase-1 (TIMP-1) production by RA FLS but skewed the MMP/TIMP-1 balance sufficiently to attenuate glycosaminoglycan-depletion in our BACE model. IFN-γ reduced IL-1β expression in the arthritic joint and prevented cartilage degeneration on Day 3 of AIA.ConclusionsEarly therapeutic intervention with IFN-γ may be critical to orchestrate tissue-protective responses during inflammatory arthritis.

The suppression of rat collagen-induced arthritis and inhibition of macrophage derived mediator release by liposomal methotrexate formulations

Abstract.Objective and Design: This study was designed to determine whether liposomes are suitable vehicles for the delivery of methotrexate (MTX-γ-DMPE) for arthritis therapy.¶Material or Subjects: Liposomal formulations containing either egg lecithin (EPC), cholesterol (CHOL) and phosphatidic acid (PA) (MTX-EPC) or distearoylphosphatidylcholine (DSPC), CHOL and distearoylphosphatidylethanolamine conjugated to polyethyleneglycol (PEG) (MTX-PEG) were employed. Rat peritoneal macrophages (rPMφ) were used to test the mechanism of action of these liposomes in vitro, whilst, the rat collagen-induced arthritis (CIA) model was used to evaluate the in vivo efficacy of MTX-EPC and MTX-PEG.¶Treatment: In vitro, rPMφ were incubated with liposomal MTX concentrations ranging from 0 to 15 μg/well. In vivo, rats were given 4 daily intravenous injections of liposomal MTX (2.5 mg/Kg).¶Methods: IL-1β and prostaglandin-E2 (PGE2) release from rPMφ were quantified by immunoradiometric assay. Arthritis progression, in vivo, was measured by serial clinical score and hind paw diameter measurements.¶Results: MTX-EPC and MTX-PEG respectively (15 μg of MTX and 0.15 mg of lipid) were powerful inhibitors of both IL-1β (77 ± 2.3%; 79 ± 4.0%) and PGE2 (75.5 ± 4.9%; 68.5 ± 2.3%) release (mean ± SEM % inhibition) from lipopolysaccaride stimulated rPMφ. In vivo, only MTX-EPC exerted an anti-inflammatory effect, clinical score (p < 0.001) and paw diameter (p < 0.001) measurements being significantly lower than in control rats, after 2 days treatment.¶Conclusions: MTX-EPC and MTX-PEG are potent inhibitors of pro-inflammatory mediators in vitro, but liposomes with long circulation times do not appear to have therapeutic potential for treating arthritis in vivo.

Is knee osteoarthritis a symmetrical disease? Analysis of a 12 year prospective cohort study

BackgroundThe aim of this study was to document the development of bilateral knee osteoarthritis over a 12 year period using a middle-aged population-based cohort with knee pain at inclusion.MethodsOne hundred and forty three patients aged 35 to 54 were recruited from a population based cohort of 279 subjects who had knee pain at baseline and assessed with clinical and radiographic data, with 5 and 12 year follow up. The data was analysed with regard to the development and progression of uni- and bilateral knee osteoarthritis over 12 years. A definition of KL = 1 was used to define radiographic disease.Results24 of the 30 (80%) patients with unilateral disease at baseline developed bilateral disease after 12 years. At baseline 37 patients (26%) had bilateral disease, whereas that number increased to 65 (52%) at 5 years and 100 (70%) at the 12 year follow up. The most common pattern was medial compartment involvement in both knees. Six patients had lateral compartment disease in one knee and medial in the other whereas only two had lateral compartment disease bilaterally.ConclusionsBilateral knee osteoarthritis is very common with time, as the majority of sufferers will eventually develop radiographic disease in both knees. Clinicians need to be aware of the ‘joint at risk’ and researchers need to remember to account for both knees when assessing the relationship between physical function, pain and structural disease. The other knee should not be used for comparison, even if it appears to be normal at baseline.

Interleukin‐1β (IL‐1β) inhibition: a possible mechanism for the anti‐inflammatory potency of liposomally conjugated methotrexate formulations in arthritis

Liposomes with conventional and long‐circulation times were employed as carriers for the methotrexate derivative MTX‐γ‐DMPE (MTX‐EPC and MTX‐PEG respectively), their mechanism of action was investigated in vitro and in vivo and their therapeutic efficacy assessed using the rat collagen‐induced arthritis (CIA) model. At non‐toxic dose, both MTX‐EPC and MTX‐PEG inhibited the lipopolysaccharide (LPS) induced release of IL‐1β from activated rat peritoneal macrophages (rPMΦ) in a dose and time dependent manner. Free methotrexate (MTX) was not active in this respect. After a single intravenous injection (i.v.), and at equivalent doses, both free MTX (500 μg) and MTX‐EPC inhibited the LPS induced rise in plasma IL‐1β levels observed in MTX‐PEG and saline treated rats. When used to treat established CIA, MTX‐EPC resulted in significantly lower clinical score (CS) (1.0±0.42 (P<0.001)) and hind paw diameter (HPD) (6.5±0.34 mm (P<0.001)) measurements than controls (3.0±0.26; 7.33±0.41 mm), after only two i.v. doses, and remained significantly lower for the entire experimental period. By day 24 both CS (2±0.61 (P<0.001)) and HPD (6.97±0.25 mm (P<0.002)) measurements had also become significantly lower in MTX‐PEG treated rats than in saline treated controls (3.62±0.17, 7.92±0.38 mm) and remained lower until day 30. Joint inflammation in MTX treated rats was completely ameliorated by day 20 but the health and well being of the animals was compromised and the experiment terminated at this time‐point. Our results clearly demonstrate that both MTX‐EPC and MTX‐PEG liposomes have potential for development into therapeutic modalities for the treatment of inflammatory joint disease in man.

Death Receptor 3 orchestrates erosive pathology in inflammatory arthritis [Poster Abstract]

Recognition of invading bacterial pathogens by human peripheral blood cd T-cells is attributed to their unique TCR-mediated detection of the microbial metabolite, HMB-PP, although the exact mechanism behind cd T-cell access to this activating ligand is largely unclear. The response of cd T-cells to HMB-PP is likely to occur at early stages of infection and collectively with cells of the innate immune system. Here we assessed the crosstalk of autologous Vc9/Vd2 T-cells, neutrophils and monocytes in response to HMB-PP producing (e.g. Klebsiella pneumoniae, Enterobacter cloacae, Pseudomonas aeruginosa, Mycobacterium smegmatis) and HMB-PP deficient live bacteria (e.g. Staphylococcus aureus, Enterococcus faecalis, Chryseobacterium indologenes, Listeria innocua). Neutrophils harbouring HMB-PP producing but not HMB-PP deficient bacteria induced CD69 on Vc9/Vd2 T-cells and secretion of IFN-c and TNF-a. In addition, activation of Vc9/Vd2 Tcells only occurred with Listeria innocua transfected with HMB-PP synthase but not with HMB-PP deficient L. innocua wild-type, demonstrating that the response of Vc9/Vd2 T-cells to neutrophils harbouring phagocytosed bacteria depended on the ability of these bacteria to produce HMB-PP. Transwell experiments showed that Vc9/ Vd2 T-cells responded directly to soluble HMB-PP released from infected neutrophils and that cell-cell contact with monocytes was required for optimum activation. HMB-PP responsive Vc9/Vd2 T-cells also rescued neutrophils from spontaneous apoptosis and stimulated them to upregulate CD11b, shed CD62L, and release IL-8. Our findings link the essential innate function of pathogen clearance by neutrophils to the activation of cd T-cells, implicating an unconventional mechanism of pathogen recognition with the ability to potentiate innate and adaptive immunity. BSI 2010 Abstracts Selected for Poster Presentations