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Biomedical subjects

J Bondeson

Publications and source records attributed to J Bondeson.

At least 19 recordsLinked to original sources
PubMed2007

Interleukin-1beta induced activation of nuclear factor-kappab can be inhibited by novel pharmacological agents in osteoarthritis.

OBJECTIVES: To investigate the importance of activation of the transcription factor, nuclear factor-kappaB (NF-kappaB) by interleukin-1beta (IL-1beta) and tumour necrosis factor-alpha (TNF-alpha) in the pathogenesis of osteoarthritis (OA) and assess its suitability as a target for therapy by determining its role in the induction of the cytokine IL-6 and the degenerative enzymes, matrix metalloproteinase (MMP)-1 and MMP-3 in vitro. METHODS: Three distinct cellular models, derived from primary OA tissue, were employed, namely, fibroblast-like synoviocytes (OA-SF); co-cultures containing phenotypic macrophage-like and fibroblast-like cells (OA-COCUL); and primary OA synovial tissue explants (OA-EXP). These were treated with specific inhibitors of IL-1beta, TNF-alpha and NF-kappaB to assess their differential role in the production of pathologically relevant mediators, specifically IL-6, MMP-1, MMP-3 and the tissue inhibitor of metalloproteinases-1 (TIMP-1), which were quantified by enzyme-linked immunosorbent assay. RESULTS: Inhibition of NF-kappaB by a novel agent, RO100 at a dose of 0.1 microM, exerted significant (P < 0.05) repression of IL-6, MMP-1 and MMP-3 production in OA-SF. Notably, neither TIMP-1 production nor cell viability was significantly affected at the dose tested. These data were reproduced in OA-EXP, which might be considered as having greater physiological relevance. Interestingly, comparable efficacy was noted using IL-1beta and TNF-alpha neutralizing antibodies in OA-COCUL. CONCLUSIONS: We have demonstrated that a novel pharmacological inhibitor of NF-kappaB, RO100 inhibits pathological mediators of OA progression with equivalent efficacy as established IL-1beta and TNF-alpha neutralizing strategies. Our findings highlight a potential for developing NF-kappaB targeted therapeutics for positively regulating disease activity and improving clinical outcome in OA.

Antirheumatic Agents↗
PubMed2006

Adenoviral gene transfer into osteoarthritis synovial cells using the endogenous inhibitor IkappaBalpha reveals that most, but not all, inflammatory and destructive mediators are NFkappaB dependent.

OBJECTIVES: Despite recent major advances in the understanding of the pathogenesis of rheumatoid arthritis, with tumour necrosis factor-alpha (TNFalpha) established as a major therapeutic target, comparatively little is known about the mediators involved in the destructive and inflammatory pathways in osteoarthritis (OA). Recently, it has become appreciated that an inflammatory synovitis contributes not only to the signs and symptoms of osteoarthritis, but also to disease progression. Here, we use high-efficiency adenoviral gene transfer to investigate the role of the transcription factor nuclear factor-kappaB (NFkappaB) in regulating inflammatory and destructive mediators in the late stage OA synovium. METHODS: Infection with reporter adenoviruses transferring the beta-galactosidase or green fluorescent protein genes verified that OA synovial cells could be infected (>95%). Adenovirus transferring the inhibitory subunit IkappaBalpha inhibited NFkappaB. The production of a whole array of pro- and anti-inflammatory cytokines and mediators, and several matrix metalloproteinases and their main inhibitor, was measured by enzyme-linked immunosorbent assay. RESULTS: The spontaneous production of macrophage-produced pro-inflammatory cytokines varied: TNFalpha was modestly inhibited by IkappaBalpha overexpression, but interleukin (IL)-1 was unaffected. Both IL-6 and IL-8 were potently inhibited, as were granulocyte-macrophage colony stimulating factor and oncostatin M. Anti-inflammatory mediators like IL-10, the IL-1 receptor antagonist and the p55 soluble TNF receptor were unaffected. Matrix metalloproteinases 1, 3, 9 and 13 were potently inhibited by IkappaBalpha overexpression, but not their main inhibitor tissue inhibitor of metalloproteinase-1. CONCLUSIONS: The OA synovium is a highly inflammatory environment, with spontaneous production of many cytokines and matrix metalloproteinases. Inhibition of NFkappaB may have a beneficial effect on the balance between pro-inflammatory cytokines and anti-inflammatory mediators, and between destructive metalloproteinases and their main inhibitor.

Adenoviridae↗
PubMed2005

Wegener's granulomatosis mimicking a parotid abscess.

We present the case of a previously healthy 59-year-old man who was under treatment for scleritis and episcleritis when he developed a parotid-gland swelling and pus-producing sinus. On surgical exploration, the features were those of a parotid abscess, but the lesion not only failed to heal post-operatively but increased in size very significantly. There was also severe necrotizing keratitis of the eyes. Due to clinical suspicion and a positive antineutrophil cytoplasmic antibodies test, Wegener's granulomatosis was diagnosed and the patient successfully treated with cyclophosphamide and steroids. Previously, a number of cases of Wegener's granulomatosis causing salivary-gland swelling have been reported in the literature; this is the first case in which the disease has masqueraded as a parotid abscess.

Abscess↗
PubMed2003

Antigen-specific T-cell downregulation by human dendritic cells following blockade of NF-kappaB.

Dendritic cells (DCs) are important for presenting antigen to T cells, especially naïve T cells. It has recently been shown that blocking the transcription factor, nuclear factor kappa B (NF-kappaB) in human DCs inhibited the mixed leukocyte reaction. The aim of this study was to investigate the effect of blocking NF-kappaB in DCs during presentation of antigen to memory T cells in vitro. Peripheral blood monocytes were differentiated into immature DCs with interleukin-4 (IL-4) and granulocyte-macrophage colony-stimulating factor, and pulsed with an immunogenic tetanus toxoid peptide. Upon maturation, the antigen-pulsed DCs were highly effective in presenting antigen to autologous T cells. However, stimulation with antigen-pulsed DCs overexpressing IotakappaBetaalpha, the endogenous inhibitor of NF-kappaB, led to a significant reduction in T-cell proliferation, and decreased production of interferon-gamma, IL-4 and IL-10, whereas transforming growth factor-beta production was low throughout. There was a significant increase in apoptosis of antigen-specific T cells, even in the presence of IL-2, which was not found in resting T cells. Similar findings were observed using a proteasome inhibitor to block NF-kappaB. The effective downregulation of antigen-specific T-cell responses following blockade of NF-kappaB in DCs could be a useful approach for immunomodulating inflammatory T-cell responses.

Antigen Presentation↗
PubMed2003

Antigen presentation by murine dendritic cells is nuclear factor-kappa B dependent both in vitro and in vivo.

Antigen presentation is a key rate-limiting step in the immune response. Dendritic cells (DCs) have been reported to be the most potent antigen-presenting cells for naïve T cells, but little is known about the biochemical pathways that regulate this function. We here demonstrate that mature murine DC can be infected with adenovirus at high efficiency (>95%) and that an adenovirus transferring the endogenous inhibitor IkappaBalpha blocks nuclear factor-kappa B (NF-kappaB) function in murine DC. This result indicates that antigen presentation in the mixed leucocyte reaction is NF-kappaB dependent, confirming data with human DC in vitro. However, the importance of this finding depends on verifying that this is true also in vivo. Using delayed type hypersensitivity with allogeneic cells, we show that NF-kappaB inhibition had a marked immunosuppressive effect in vivo. These results thus establish NF-kappaB as an effective target for blocking DC antigen presentation and hence inhibiting T-cell-dependent immune responses. This finding has potential implications for the development of therapeutic agents for use in various pathological conditions of the immune system, including allergy and autoimmunity, and also in transplantation.

Adenoviridae↗
PubMed2002

Is NF-kappaB a useful therapeutic target in rheumatoid arthritis?

There is increasing evidence that NF-kappaB is a major, if not the major transcription factor regulating inflammation and immunity. While this implies that blocking NF-kappaB might be therapeutically beneficial, it raises clear questions regarding the balance between efficacy and safety. In this brief review we discuss the effects of NF-kappaB blockade in rheumatoid arthritis, inflammation and immunity, and consider possible therapeutic targets within the NF-kappaB family.

Adenoviridae↗
PubMed2001

Role of NFkappaB in antigen presentation and development of regulatory T cells elucidated by treatment of dendritic cells with the proteasome inhibitor PSI.

Dendritic cells (DC) are the most potent antigen-presenting cells for naive T cells, due to their high expression of MHC and costimulatory molecules, but relatively little is known about the biochemical pathways that regulate this function. We used the proteasome inhibitor N-benzyloxycarbonyl-Ile-Glu(O-tert-butyl)-Ala-leucinal (PSI) to demonstrate that DC antigen presentation is NFkappaB dependent. As PSI is not a specific inhibitor of NFkappaB, we reproduced this finding using a very specific approach, namely adenoviral gene transfer of IkappaBalpha, the naturally occurring inhibitor of NFkappaB. The mechanism for this inhibition of DC antigen presentation involves at least three aspects of antigen presenting function: down-regulation of HLA class II, down-regulation of CD86, and inhibition of the immunostimulatory cytokines IL-12 and TNF-alpha. In the light of the marked down-regulation of antigen-presentation cell function, it was of interest to investigate what effects exposure to PSI-treated DC might have on T cell function. It was found that immunological tolerance was induced, as challenge of T cells previously exposed to PSI-treated DC, with normal DC from the same donor did not restore their response, despite the presence of viable T cells. There were also changes in T cell surface markers, with down-regulation of CD3 and CD25 expression, and inhibition of the production of Th1 cytokines like IL-2 and IFN-gamma. These results demonstrates that NFkappaB is an effective target for blocking DC antigen presentation and inhibiting T cell-dependent immune responses, and this has implications for the development of therapeutic agents for use in multiple conditions, including transplantation, allergy and autoimmune diseases.

Antigen Presentation↗
PubMed2001

Cytokine blockade in rheumatoid arthritis.

As we enter the 2000's it is clear that cytokine blockade is an effective therapeutic strategy for rheumatoid arthritis. In this brief review, we will review the rationale for anti TNFalpha therapy, the current status of therapy and focus on the regulation of TNFalpha production in rheumatoid synovium. New approaches to studying TNF regulation in RA and of elucidating the controversial role of T cells in this complex disease will be described.

Adenoviridae↗
PubMed2001

Dicephalus conjoined twins: a historical review with emphasis on viability.

Dicephalus conjoined twins (2 heads on 1 body) form a distinct subgroup. They are often stillborn because of cardiopulmonary malformations. This article describes 17 historical cases with particular emphasis on viability. There are reliable reports of unseparated dicephali reaching maturity; 1 pair (the Tocci brothers) reached at least 34 years of age. In the absence of concomitant cardiac, pulmonary, and intestinal malformations, dicephalus conjoined twins may well attain adulthood. This appears to be unrelated to whether they have 4 (dicephalus tetrabrachius) or 3 (dicephalus tribrachius) arms at birth.

Female↗
PubMed2001

Effective antigen presentation by dendritic cells is NF-kappaB dependent: coordinate regulation of MHC, co-stimulatory molecules and cytokines.

Antigen presentation is a key rate-limiting step in the immune response. Dendritic cells (DC) are the most potent antigen-presenting cells for naive T cells, due to their high expression of MHC and co-stimulatory molecules, but little is known about the biochemical pathways that regulate this function. We here demonstrate that monocyte-derived mature DC can be infected with adenovirus at high efficiency (>95%) and that this procedure can be used to dissect out which pathways are essential for inducing DC antigen presentation to naive T cells. Using adenoviral transfer of the endogenous inhibitor of NF-kappaB, IkappaBalpha, we show that DC antigen presentation is NF-kappaB dependent. The mechanism for this is that NF-kappaB is essential for three aspects of antigen-presenting function: blocking NF-kappaB coordinately down-regulates HLA class II, co-stimulatory molecules like CD80, CD86 and CD40, and immuno-stimulatory cytokines like IL-12 and tumor necrosis factor-alpha. In contrast adhesion molecules are up-regulated after infection with the adenovirus transferring IkappaBalpha, indicating that NF-kappaB also regulates the duration of T cell-DC interaction. These results establish NF-kappaB as an effective target for blocking DC antigen presentation and inhibiting T cell-dependent immune responses, and this finding has potential implications for the development of therapeutic agents for use in allergy, autoimmunity and transplantation.

Adenoviridae↗
PubMed2001

Everard Home, John Hunter, and cutaneous horns: a historical review.

A cutaneous horn is a protrusion from the skin made up of cornified material. These horns can be derived from a variety of epidermal lesions, both benign and malignant. This historical article reviews a number of early instances of cutaneous horns, some reported in the 16th and 17th centuries. The Danish anatomist Thomas Bartholin was the first to have a correct theory of the ethiology of these horny growths, and the English surgeons John Hunter and Everard Home confirmed his findings in the late 18th century.

Dermatology↗
PubMed2001

High efficiency gene transfer is an efficient way of defining therapeutic targets: a functional genomics approach.

BACKGROUND: Dendritic cells are the most potent antigen presenting cells and key to many aspects of the immune function. Studying the intracellular signalling mechanism used by dendritic cells would provide an insight into the functioning of these cells and give clues to strategies for immunomodulation. METHOD: Highly efficient adenoviral infection of dendritic cells for the delivery of transgenes was obtained. These viral vectors were used to introduce IkappaB alpha into dendritic cells for the inhibition of NF-kappaB. This was used to investigate the role of NF-kappaB in dendritic cell function. RESULTS: By blocking the NF-kappaB function a potent inhibition of the expression of costimulating molecules by dendritic cells with the concomitant loss of T cell stimulating function was demonstrated. CONCLUSION: The use of adenoviral vectors may be a useful way of studying the role of genes in dendritic cell function.

Adenoviridae↗
PubMed2001

Alveolar macrophages and T cells from sarcoid, but not normal lung, are permissive to adenovirus infection and allow analysis of NF-kappa b-dependent signaling pathways.

Adenovirus (Adv)-mediated gene transfer requires efficient infection of target cells. The objective of this study was to establish whether alveolar macrophages (AM) and T cells (AT) from sarcoid patients were permissive to infection with Adv vectors and if this property could be used to investigate cytokine gene regulation. Sarcoid and normal bronchoalveolar lavage (BAL) specimens infected with Adv vectors expressing either beta-galactosidase or a green fluorescent protein were analyzed for transgene expression by fluorescence-activated cell sorter (FACS) and direct immunofluorescence, respectively. Expression of surface antigens previously associated with Adv infection, the coxsackie/adenovirus receptor (CAR), alpha v beta 3, and alpha v beta 5 integrins, was also assessed using FACS analysis. Sarcoid AM and AT were found to efficiently express Adv transgenes, unlike AM from normal volunteers, peripheral blood monocytes, and peripheral blood T cells. Cells permissive to Adv infection expressed the CAR and alpha v beta 5 integrin (also alpha v beta 3 integrin for AM). The data indicate that the upregulation of Adv receptors and the ability to infect sarcoid AM and AT are related to the inflammatory environment within the lung. Having demonstrated efficient Adv-mediated transgene delivery to sarcoid AM and AT, a construct encoding porcine I kappa B alpha was then used to investigate the requirement for nuclear factor (NF)-kappa B in the regulation of cytokine gene expression in pulmonary sarcoidosis. Overexpression of I kappa B alpha in sarcoid BAL specimens indicated that tumor necrosis factor-alpha and interleukin (IL)-6 production by AM and interferon (IFN)-gamma production by AT is NF-kappa B dependent, whereas IL-4 production by AT is NF-kappa B independent. This is the first occasion that the requirement for NF-kappa B in IFN-gamma gene expression within primary human T cells has been demonstrated. The results of this study have implications for the future investigation of molecular pathways in inflammatory lung disease.

Adenoviridae↗
PubMed2001

Tumour necrosis factor as a therapeutic target in rheumatoid arthritis and other chronic inflammatory diseases: the clinical experience with infliximab (REMICADE).

Therapeutic strategies that aim to neutralise the important pro-inflammatory cytokine tumour necrosis factor alpha (TNF alpha) have gained considerable prominence in the therapy of chronic inflammatory diseases, notably rheumatoid arthritis and Crohn's disease. This drug focus review will concentrate on the antitumour necrosis factor antibody infliximab (Remicade), which has been approved for the treatment of rheumatoid arthritis and Crohn's disease in both the US and Europe. In addition, infliximab is under investigation for several other indications, mainly inflammatory rheumatic diseases. Clinical trials have been persuasive that infliximab is both safe and effective, and it has been proven to be far superior to the conventional drug therapy in both rheumatoid arthritis and Crohn's disease. Remarkably, infliximab in combination with methotrexate controls both the inflammatory joint symptoms and the progression of joint damage, which renders it a very attractive therapeutic option in moderate to severe, therapy-resistant rheumatoid arthritis.

Antibodies, Monoclonal↗
PubMed2000

Adenoviral transgene delivery provides an approach to identifying important molecular processes in inflammation: evidence for heterogenecity in the requirement for NFkappaB in tumour necrosis factor production.

The success of anti-tumour necrosis factor (TNF) treatment, either using antibodies or soluble receptors, has defined TNF as a major factor of the inflammatory response in rheumatoid arthritis (RA). As a result of this success, much attention has been devoted to understanding the molecular mechanisms by which TNF expression and activity is elicited and controlled. By understanding these pathways, it is hoped that key elements of the molecular pathology associated with RA will be uncovered and, as a result, new targets for therapeutic intervention will be identified. However, studying the cell and molecular biology of model systems for RA, such as primary human macrophages, or tissue from rheumatoid joints may present technical problems. In an attempt to overcome this, we have investigated the use of adenovirus as a means of delivering transgenes by which different intracellular pathways can be modulated and examined. Our data show that adenovirus can be successfully used to efficiently deliver transgenes to primary human macrophages and RA joint tissue. Using a virus encoding IkappaBalpha, the natural inhibitor of NFkappaB, we show that the requirement for the transcription factor is not universal, but is dependent on the nature of the stimulus. Furthermore, while NFkappaB is of importance for the expression of TNF and other pro-inflammatory cytokines (for example, interleukin 6) and the destructive matrix metalloproteinases, this factor is not required for the expression of anti-inflammatory cytokines interleukin 10 and interleukin 1 receptor antagonist.

Adenoviridae↗