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IgG Deposition (igg + deposition)

Distribution by Scientific Domains

Medical Sciences	100%

Selected Abstracts

Generalized multi-organ autoimmunity in CCR7-deficient mice

EUROPEAN JOURNAL OF IMMUNOLOGY, Issue 3 2007

Abstract Development of autoimmunity is a multi-factorial process involving genetic predisposition as well as environmental and stochastic factors. Although the mechanisms responsible for the initiation of autoimmunity remain only partially understood, several studies have demonstrated that genetic predisposition plays a major role in this process. In the present study, we analyzed the influence of CCR7 signaling in the development of autoimmunity, because this chemokine receptor is essentially involved in the functional organization of thymus architecture. We demonstrate that CCR7-deficient mice are prone to develop generalized multi-organ autoimmunity. The autoimmune phenotype of CCR7,/, mice encompasses the presence of lymphocyte infiltrates in several peripheral organs, circulating autoantibodies against a multitude of tissue-specific antigens and IgG deposition on renal glomeruli. Additionally, CCR7-deficient mice show increased susceptibility to streptozotocin-induced diabetes and spontaneously display signs of chronic autoimmune renal disease. Thus, this study identifies CCR7 as a genetic factor involved in the regulation of autoimmunity. [source]

Targeted tumor necrosis factor receptor I preligand assembly domain improves skin lesions in MRL/lpr mice

ARTHRITIS & RHEUMATISM, Issue 8 2010
Guo-Min Deng
Objective Skin disease is the second most common manifestation in patients with systemic lupus erythematosus (SLE). Tumor necrosis factor receptor (TNFR) preligand assembly domain (PLAD) has been found to block the effect of TNF,, and TNFRI PLAD (p60 PLAD) inhibits inflammatory arthritis. This study was undertaken to investigate whether TNFR PLAD limits inflammatory skin injury in a mouse model of SLE. Methods Female MRL/lpr mice received p60 PLAD (100 ,g/mouse intraperitoneally), p80 PLAD (100 ,g/mouse intraperitoneally), or phosphate buffered saline (100 ,l/mouse intraperitoneally) 3 times a week for 26 weeks, starting at age 6 weeks. Results Immunohistochemistry studies demonstrated that TNFRI but not TNFRII was dominantly expressed in skin lesions in MRL/lpr mice. We found that TNFRI PLAD (p60 PLAD) but not TNFRII PLAD (p80 PLAD) protein significantly inhibited skin injury in the MRL/lpr mouse model of lupus. NF-,B, monocyte chemotactic protein 1, and inducible nitric oxide synthase expression in skin lesions were significantly inhibited by p60 PLAD. Lupus serum,induced monocyte differentiation into dendritic cells was reduced by p60 PLAD, but p60 PLAD did not reduce IgG deposition in the skin or improve the progression of kidney damage in MRL/lpr mice. Conclusion Our results indicate that TNFRI is involved in the expression of skin injury in MRL/lpr mice with lupus and that p60 PLAD or similar biologics may be of clinical value if applied locally. [source]

Anti-DNA antibody induction of protein kinase C phosphorylation and fibronectin synthesis in human and murine lupus and the effect of mycophenolic acid

ARTHRITIS & RHEUMATISM, Issue 7 2009
Susan Yung
Objective To examine fibronectin (FN) expression in human lupus nephritis and the effect of anti-DNA antibodies on transforming growth factor ,1 (TGF,1) and FN synthesis in cultured human mesangial cells. The effects of mycophenolic acid (MPA) on this pathway, and the effects of mycophenolate mofetil (MMF) treatment in (NZB × NZW)F1/J mice were also studied. Methods Immunohistochemical analyses of renal biopsy samples from patients with active diffuse proliferative lupus nephritis were performed. Cultured human mesangial cells were incubated with human polyclonal anti-DNA antibodies, with or without MPA. (NZB × NZW)F1/J mice with active nephritis were randomized to receive either MMF (100 mg/kg/day) or vehicle treatment for 12 weeks. Results Glomerular FN expression was increased in patients with lupus nephritis, and it colocalized with IgG deposition. Anti-DNA antibodies induced protein kinase C, (PKC,), PKC,I, and PKC,II activation, increased levels of bioactive TGF,1, and increased FN synthesis in human mesangial cells (P < 0.001 for each comparison versus control conditions). Pretreatment of anti-DNA antibodies with exogenous DNA reduced their cellular binding and abrogated their induction of TGF,1 and FN synthesis. Inhibition of PKC activation in human mesangial cells prior to anti-DNA antibody stimulation had no effect on cell proliferation, but resulted in significantly reduced antibody-mediated TGF,1 secretion and FN synthesis. MPA treatment down-regulated PKC,, PKC,I, and PKC,II phosphorylation, reduced levels of TGF,1 bioactivation, and decreased FN synthesis and deposition into the extracellular matrix. MMF treatment in (NZB × NZW)F1/J mice resulted in a reduction in glomerular IgG deposition, PKC activation, and FN expression, as well as an amelioration of proteinuria. Conclusion Human polyclonal anti-DNA antibodies induce TGF,1 and FN synthesis in human mesangial cells through PKC activation, which is inhibited by MPA. [source]