Latent cytokines for targeted therapy of inflammatory disorders.

Introduction: The use of cytokines as therapeutic agents is important, given their potent biological effects. However, this very potency, coupled with the pleiotropic nature and short half-life of these molecules, has limited their therapeutic use. Strategies to increase the half-life and to decrease toxicity are necessary to allow effective treatment with these molecules.

Latency can be conferred to a variety of cytokines by fusion with latency-associated peptide from TGF-β.

Objectives: Targeting cytokines to sites of disease has clear advantages because it increases their therapeutic index. We designed fusion proteins of the latent-associated peptide (LAP) derived from TGF-β with various cytokines via a matrix metalloproteinase (MMP) cleavage site. This design confers latency, increased half-life and targeting to sites of inflammation.

A comparative study of matrix metalloproteinase and aggrecanase mediated release of latent cytokines at arthritic joints.

Background: Latent cytokines are engineered by fusing the latency associated peptide (LAP) derived from transforming growth factor-β (TGF-β) with the therapeutic cytokine, in this case interferon-β (IFN-β), via an inflammation-specific matrix metalloproteinase (MMP) cleavage site.

Objectives: To demonstrate latency and specific delivery in vivo and to compare therapeutic efficacy of aggrecanase-mediated release of latent IFN-β in arthritic joints to the original MMP-specific release.

Methods: Recombinant fusion proteins with MMP, aggrecanase or devoid of cleavage site were expressed in CHO cells, purified and characterised in vitro by Western blotting and anti-viral protection assays.

Research to combat urinary incontinence.

In this article, brought to you in association with Help the Aged, the authors discuss current research into the causes and management of urinary incontinence.

Fighting cancer with oncolytic viruses.

Although gene therapy has huge potential for modern medicine, our enthusiasm for its powerful potential must not cloud our judgment about the dangers of using increasingly diverse, yet relatively untested, replicating viruses

Endocannabinoids control spasticity in a multiple sclerosis model.

Spasticity is a complicating sign in multiple sclerosis that also develops in a model of chronic relapsing experimental autoimmune encephalomyelitis (CREAE) in mice. In areas associated with nerve damage, increased levels of the endocannabinoids, anandamide (arachidonoylethanolamide, AEA) and 2-arachidonoyl glycerol (2-AG), and of the AEA congener, palmitoylethanolamide (PEA), were detected here, whereas comparable levels of these compounds were found in normal and non-spastic CREAE mice. While exogenously administered endocannabinoids and PEA ameliorate spasticity, selective inhibitors of endocannabinoid re-uptake and hydrolysis-probably through the enhancement of endogenous levels of AEA, and, possibly, 2-arachidonoyl glycerol-significantly ameliorated spasticity to an extent comparable with that observed previously with potent cannabinoid receptor agonists.

The protective effects of omega-6 fatty acids in experimental autoimmune encephalomyelitis (EAE) in relation to transforming growth factor-beta 1 (TGF-beta1) up-regulation and increased prostaglandin E2 (PGE2) production.

Polyunsaturated fatty acids are known to affect the immune response and administration of the omega-6 fatty acid linoleic acid has been reported to be beneficial in multiple sclerosis (MS) and EAE. In this study we have investigated the effects of oral feeding of plant lipid rich in the omega-6 fatty acid gamma-linolenic acid from Borago officinalis on acute and relapse disease and the immune response in EAE using SJL mice. EAE was induced by an encephalitogenic peptide (92-106) of myelin oligodendrocyte glycoprotein (MOG), and mice were fed the plant lipid daily from 7 days after EAE induction to assess the effects on acute disease and from day 25 to assess the effects on disease relapse.

Cannabinoids control spasticity and tremor in a multiple sclerosis model.

Chronic relapsing experimental allergic encephalomyelitis (CREAE) is an autoimmune model of multiple sclerosis. Although both these diseases are typified by relapsing-remitting paralytic episodes, after CREAE induction by sensitization to myelin antigens Biozzi ABH mice also develop spasticity and tremor. These symptoms also occur during multiple sclerosis and are difficult to control.

Response to mucosal antigen challenge in IgA nephropathy.

While IgA nephropathy (IgAN) is characterized by the deposition of glomerular IgA, the source of the deposited IgA is not known, with both the mucosal and systemic IgA systems being implicated. In order to investigate mucosal and systemic antibody production to mucosal antigen challenge in IgAN, 9 patients and 11 controls were immunized intranasally with tetanus toxoid (TT). There was no significant difference in the serum or saliva IgG, IgA, IgA1, or IgA2 antibody production to TT.

Increased immunoglobulin A and immunoglobulin A1 cells in bone marrow trephine biopsy specimens in immunoglobulin A nephropathy.

The origin of mesangial immunoglobulin A (IgA) in IgA nephropathy remains unknown. To investigate potential abnormalities within the bone marrow in this condition, bone marrow trephine biopsy specimens from seven patients and matched controls were studied using two-color immunofluorescence. In addition, serum levels of IgA and IgA1 were determined by radial immunodiffusion.

In vitro immunoglobulin isotype suppression in immunoglobulin A nephropathy.

IgA nephropathy (IgAN) is characterized by mesangial IgA deposition, and up-regulation of the IgA system is frequently described. This study investigated in vitro immunoglobulin isotype production by peripheral blood mononuclear cells from patients with IgAN and controls, without mitogenic stimulation and under the influence of cell cycle inhibitors and cyclosporin A (CyA). In controls, only IgM production was suppressed by cell cycle inhibitors, and no isotype was affected by CyA.

Expression of J chain mRNA in duodenal IgA plasma cells in IgA nephropathy.

Glomerular IgA in IgA nephropathy (IgAN) is at least in part polymeric, and is thought to derive from the mucosal IgA system in view of the association between mucosal infection and haematuria in this condition. To investigate this hypothesis, an in situ hybridization (ISH) technique was developed for the detection of J chain mRNA, the expression of which has been correlated with the secretion of high level polymeric immunoglobulin (pIg). Endoscopic duodenal biopsies from ten patients and matched controls were examined by: (i) two color immunofluorescence (IF); (ii) ISH; and (iii) combined ISH and IF, to permit simultaneous identification of plasma cell type.

Antineutrophil cytoplasm antibodies (ANCA) of IgA isotype in adult Henoch-Schönlein purpura.

ANCA are associated with certain forms of systemic vasculitis, and have been reported previously to be of the IgG and IgM isotype. We examined the possible association between IgA ANCA and the IgA-related diseases Henoch-Schönlein purpura (HSP) and IgA nephropathy (IgAN). IgA and IgG ANCA were detected by isotype-specific solid-phase assays with a crude neutrophil extract, and their presence was confirmed by antigen-specific fluid-phase competitive inhibition tests and by indirect immunofluorescence.

Low antibody affinity restricted to the IgA isotype in IgA nephropathy.

Antibody affinity affects the handling and behaviour of immune complexes, and experimental studies have shown that animals which produce predominantly low-affinity antibody are prone to immune complex deposition resulting in glomerulonephritis. In order to investigate the potential role of antibody affinity in the pathogenesis of IgA nephropathy, affinity of both IgA and IgG antibody isotypes during secondary response to systemic immunization with tetanus toxoid was studied in 20 patients with IgA nephropathy. Patients with IgA nephropathy produced IgA antibodies of significantly lower affinity than controls (P < 0.

Increased IgA and decreased IgG production by Epstein-Barr virus transformed B cells in culture in IgA nephropathy.

Despite many studies describing IgA upregulation both in vivo and in vitro in IgA nephropathy (IgAN), the underlying mechanism of increased IgA production is not known. In this study, Epstein-Barr virus was used to transform B cells in vitro in a T-cell-independent manner in order to investigate immunoglobulin production by B cells in IgAN. B cells from patients with IgAN produced more IgA and less IgG in culture than controls.

Systemic and mucosal IgA responses to systemic antigen challenge in IgA nephropathy.

IgA nephropathy (IgAN) is characterized by the deposition of glomerular IgA. The source of the deposited IgA is not known, but both the mucosal and systemic IgA systems have been implicated. In order to investigate mucosal and systemic antibody production to systemic antigen challenge in IgAN, 20 patients and 20 controls where immunized with tetanus toxoid (TT).

Deficiency of IgG subclass antibody response to tetanus toxoid associated with high serum IgA levels in IgA nephropathy.

In order to investigate IgG subclass response in IgA nephropathy (IgAN), 20 patients and 20 age and sex matched controls were systemically immunized with tetanus toxoid (TT). Nineteen/20 controls and 19/20 IgAN made a serum IgG anti-TT response of similar magnitude. However, significantly more patients with IgAN had undetectable amounts of at least one IgG subclass antibody to this antigen than controls (7/19 IgAN, 1/19 controls, p < 0.

Elevation of IgA in IgA nephropathy is localized in the serum and not saliva and is restricted to the IgA1 subclass.

Glomerular deposits in IgA nephropathy (IgAN) are predominantly IgA1 but their origin is not known. Previous studies have analysed serum or saliva IgA, but not in the same patients. To investigate whether IgA and IgA subclass anomalies occur in IgAN at both mucosal and systemic sites, blood and saliva from 20 patients and 20 age- and sex-matched controls were studied.

Increased and prolonged production of specific polymeric IgA after systemic immunization with tetanus toxoid in IgA nephropathy.

IgA nephropathy (IgAN) is a chronic form of glomerulonephritis which is characterized by the deposition in the glomerular mesangium of polymeric IgA (pIgA), the source of which is unknown. In order to investigate the production of pIgA in IgAN, patients were immunized systemically with tetanus toxoid (TT). Two weeks after immunization patients and controls responded to TT with an IgA response of similar magnitude.