			Home About us Contact

Major Autoantigen (major + autoantigen)

Distribution by Scientific Domains

Medical Sciences	85%

Selected Abstracts

Desmoglein-3 is a target autoantigen in spontaneous canine pemphigus vulgaris

EXPERIMENTAL DERMATOLOGY, Issue 2 2003
Thierry Olivry
Abstract: Pemphigus vulgaris (PV) is an autoimmune blistering skin disease of humans and companion animals. In human patients, PV is associated with the production of IgG autoantibodies specific for keratinocyte desmosomal glycoproteins of the cadherin family. The purpose of this study was to determine whether antikeratinocyte IgG autoantibodies were present in the skin and serum of dogs with PV, and also to identify the canine PV autoantigen(s) targeted by circulating autoantibodies. Eleven dogs were selected because of the microscopic demonstration of suprabasal epithelial acantholysis. Direct immunofluorescence revealed the presence of IgG autoantibodies bound to the membrane of keratinocytes in skin biopsy specimens of 8/9 dogs (89%). Using indirect immunofluorescence, serum-circulating IgG autoantibodies were found in 10/11 (91%) and 5/11 (45%) dogs, using normal canine gingiva and cultured canine oral keratinocytes, respectively. By immunoblotting using cultured canine oral keratinocyte protein lysates, IgG autoantibodies from 7/9 (78%) tested dogs recognized a 130-kDa antigen that comigrated with that identified by rabbit polyclonal antibodies raised against desmoglein-3. This 130 kDa antigen was confirmed to represent the canine equivalent of human desmoglein-3 by immunoprecipitation-immunoblotting. The results of these studies provide evidence that the canine desmoglein-3 homologue is a major autoantigen in dogs with PV. These observations further establish spontaneous canine PV as a natural model for research on pathogenesis, etiology and novel therapeutic approaches for this disease of humans. [source]

Recombinant human GAD65 accumulates to high levels in transgenic tobacco plants when expressed as an enzymatically inactive mutant

PLANT BIOTECHNOLOGY JOURNAL, Issue 8 2010
Linda Avesani
Summary The 65-kDa isoform of glutamic acid decarboxylase (GAD65) is the major autoantigen implicated in the development of type 1 diabetes mellitus (T1DM). The bulk manufacture of GAD65 is a potential issue in the fight against T1DM but current production platforms are expensive. We show that a catalytically inactive form of GAD65 (GAD65mut) accumulates at up to 2.2% total soluble protein in transgenic tobacco leaves, which is more than 10-fold the levels achieved with active GAD65, yet the protein retains the immunogenic properties required to treat T1DM. This higher yield was found to be a result of a higher rate of protein synthesis and not transcript availability or protein stability. We found that targeting GAD65 to the endoplasmic reticulum, a strategy that increases the accumulation of many recombinant proteins expressed in plants, did not improve production of GAD65mut. The production of a catalytically inactive autoantigen that retains its immunogenic properties could be a useful strategy to provide high-quality therapeutic protein for treatment of autoimmune T1DM. [source]

RNA helicase encoded by melanoma differentiation,associated gene 5 is a major autoantigen in patients with clinically amyopathic dermatomyositis: Association with rapidly progressive interstitial lung disease,

ARTHRITIS & RHEUMATISM, Issue 7 2009
Shinji Sato
Objective To identify the autoantigen recognized by the autoantibody that is associated with clinically amyopathic dermatomyositis (C-ADM) and rapidly progressive interstitial lung disease (ILD). Methods An anti,CADM-140 antibody,positive prototype serum sample was used to screen a HeLa cell,derived complementary DNA (cDNA) library. Selected cDNA clones were further evaluated by immunoprecipitation of their in vitro,transcribed and in vitro,translated products using anti,CADM-140 antibody,positive and anti-CADM-140 antibody,negative sera. The lysates of COS-7 cells transfected with the putative antigen were similarly tested. An enzyme-linked immunosorbent assay (ELISA) to detect the anti,CADM-140 antibody was established using a recombinant CADM-140 antigen, and its specificity and sensitivity for C-ADM and rapidly progressive ILD were assessed in 294 patients with various connective tissue diseases. Results By cDNA library screening and immunoprecipitation of in vitro,transcribed and in vitro,translated products, we obtained a cDNA clone encoding melanoma differentiation,associated gene 5 (MDA-5). The anti,CADM-140 antibodies in patients' sera specifically reacted with MDA-5 protein expressed in cells transfected with full-length MDA-5 cDNA, confirming the identity of MDA-5 as the CADM-140 autoantigen. The ELISA, using recombinant MDA-5 protein as the antigen, showed an analytical sensitivity of 85% and analytical specificity of 100%, in comparison with the "gold standard" immunoprecipitation assay, and was useful for identifying patients with C-ADM and/or rapidly progressive ILD. Conclusion Given that RNA helicase encoded by MDA-5 is a critical molecule involved in the innate immune defense against viruses, viral infection may play an important role in the pathogenesis of C-ADM and rapidly progressive ILD. Moreover, our ELISA using recombinant MDA-5 protein makes detection of the anti,CADM-140 antibody routinely available. [source]

Bullous pemphigoid antigen II (BP180) and its soluble extracellular domains are major autoantigens in mucous membrane pemphigoid: the pathogenic relevance to HLA class II alleles and disease severity

BRITISH JOURNAL OF DERMATOLOGY, Issue 1 2006
N. Oyama
Summary Background, Mucous membrane pemphigoid (MMP), a chronic autoimmune subepithelial blistering disease, is associated with circulating IgG and/or IgA autoantibodies against several basement membrane zone antigens. The heterogeneity of clinical presentation and diversity of target autoantigens have contributed to difficulties in characterizing this condition immunologically. Objectives, To analyse serum autoantibody profile and HLA class II alleles in MMP patients and to correlate this with the clinical presentation of disease. Methods, Well-defined subgroups consisting of 124 patients with MMP were examined for IgG and IgA reactivity with immunoblotting using human epidermal, dermal and placental amnion proteins. The results were further analysed on the basis of detailed clinical (sites of involvement and disease severity) and immunopathological criteria (immunofluorescence study and HLA class II alleles). Results, Immunoblot assay revealed that the majority of MMP patients had IgG (93 of 124, 75%) and/or IgA autoantibodies (63 of 124, 51%) to BP180 (including its soluble ectodomains, 120-kDa LAD-1 and 97-kDa LABD97 antigens). Other antigens targeted predominantly by IgG autoantibodies included: BP230 in 34 (27%), ,4 integrin in 26 (21%), and laminin 5 in three (2%). All the BP230+ sera and 23 (88%) ,4 integrin+ sera also reacted with at least one of the BP180 antigens. Over 85% of patients with reactivity to ,4 integrin had ocular involvement. In most cases of MMP, more severe clinical features were associated with antibody reactivity to multiple basement membrane zone antigens, as well as reactivity to multiple BP180 component antigens. Dual BP180/LAD-1 reactivity with IgG and IgA was associated with a more severe phenotype. In addition, the subset-dependent autoantibody reactivity correlated well with specific HLA class II alleles, DQB1*0301, DRB1*04 and DRB1*11. Conclusions, Our results confirmed that BP180 is a major autoantigen targeted by the sera of patients with MMP. The disease-prevalent HLA class II alleles and humoral autoimmune response against the particular subsets of antigenic epitope(s) within BP180 ectodomain may contribute to the clinicopathological significance and disease severity of MMP. [source]

Elevated neutrophil membrane expression of proteinase 3 is dependent upon CD177 expression

CLINICAL & EXPERIMENTAL IMMUNOLOGY, Issue 1 2010
M. Abdgawad
Summary Proteinase 3 (PR3) is a major autoantigen in anti-neutrophil cytoplasmic antibodies (ANCA)-associated systemic vasculitis (AASV), and the proportion of neutrophils expressing PR3 on their membrane (mPR3+) is increased in AASV. We have shown recently that mPR3 and CD177 are expressed on the same cells in healthy individuals. In this study we try to elucidate mechanisms behind the increased mPR3 expression in AASV and its relationship to CD177. All neutrophils in all individuals were either double-positive or double-negative for mPR3 and CD177. The proportion of double-positive neutrophils was increased significantly in AASV and systemic lupus erythematosus patients. The proportion of mPR3+/CD177+ cells was not correlated to general inflammation, renal function, age, sex, drug treatment and levels of circulating PR3. AASV patients had normal levels of granulocyte colony-stimulating factor and granulocyte,macrophage colony-stimulating factor. Pro-PR3 was found to constitute 10% of circulating PR3 but none of the mPR3. We found increased mRNA levels of both PR3 and CD177 in AASV, but they did not correlate with the proportion of double-positive cells. In cells sorted based on membrane expression, CD177,mRNA was several-fold higher in mPR3+ cells. When exogenous PR3 was added to CD177-transfected U937 cells, only CD177+ cells bound PR3 to their membrane. In conclusion, the increased membrane expression of PR3 found in AASV is not linked directly to circulating PR3 or PR3 gene transcription, but is dependent upon CD177 expression and correlated with the transcription of the CD177 gene. [source]

Anti-p200 pemphigoid: A novel autoimmune subepidermal blistering disease

THE JOURNAL OF DERMATOLOGY, Issue 1 2007
Amrei DILLING
ABSTRACT Anti-p200 pemphigoid is a recently defined autoimmune subepidermal blistering disease characterized by circulating and tissue-bound autoantibodies to a 200-kDa protein (p200) of the dermal,epidermal junction (DEJ). This DEJ constituent is thought to be important for adhesion of basal keratinocytes to the underlying dermis. While the exact identity of p200 remains unknown, it has been demonstrated to be immunologically and biochemically distinct from all major autoantigens of the DEJ, including bullous pemphigoid antigens 180 and 230, laminin 1, 5 and 6, ,6,4 integrin, and type VII collagen. Clinically, most reported cases present with tense blisters as well as urticarial papules and plaques, closely resembling bullous pemphigoid. Histopathological examination of lesional skin biopsies shows subepidermal split formation and superficial inflammatory infiltrate typically dominated by neutrophils. Immunopathologically, linear deposits of immunoglobulin (Ig)G and C3 are detected along the DEJ by direct immunofluorescence microscopy of perilesional skin. Indirect immunofluorescence microscopy of patients' sera on NaCl-split human skin demonstrates circulating IgG autoantibodies labeling the dermal side of the split. By immunoblotting, these autoantibodies recognize a 200-kDa protein of human dermis. Biochemical characterization of the p200 molecule revealed a noncollagenous N-glycosylated acidic protein with an isoelectric point of approximately 5.5. We present an overview of the pathogenesis, clinical features, diagnosis and treatment of this new disease entity. [source]

Bullous pemphigoid antigen II (BP180) and its soluble extracellular domains are major autoantigens in mucous membrane pemphigoid: the pathogenic relevance to HLA class II alleles and disease severity