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kDa Antigen (kda + antigen)

Distribution by Scientific Domains

Medical Sciences	66%
Life Sciences	33%

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]

Immunodetection and Characterization of Antigens Expressed by Uncinula necator

JOURNAL OF PHYTOPATHOLOGY, Issue 11-12 2002
V. L. Markovic
Abstract Conidia from four genetically distinct isolates of Uncinula necator (Schw.) Burr. were used to raise a polyclonal antiserum. Immunofluorescent detection of the fungus on Vitis vinifera (cv. Chardonnay) indicated that the antiserum bound specifically to fungal antigens present on both conidia and hyphae, with no detection of underlying berry tissues. The antibody reacted with three antigens present on the conidia (Mr 21, 29 and > 250 kDa). Immunoreactivity with the 21 kDa antigen was dependent upon the preservation of at least one disulphide bond linkage. Evidence from immunoblot staining and enzyme immunoassay indicated that only a small proportion of the recognized epitopes contained carbohydrate moieties. The antibody detected homologous U. necator conidial antigens in a plate trapped antigen-enzyme-linked immunoabsorbent assay (PTA-ELISA), with a linear range of detection extending from 1000 to 9000 conidia/ml at a 1/5000 dilution of serum. Under these conditions the immunoassay also detected antigens from pooled heterologous U. necator isolates. The antiserum exhibited cross-reactivity with antigens present on Aspergillus, Pithomyces and Sporobolomyces species co-isolated from powdery mildew-infected grapes, which could not be removed by fractionation of the antiserum on antigen affinity columns. Monoclonal antibodies were subsequently produced to avoid the problems of cross-reactivity associated with the polyclonal antibody. Antibodies produced from two clonal lines exhibited specificity for U. necator and were shown to detect a 21 kDa conidial antigen. Use of either of these antibodies enabled the differentiation of grapes grouped on the basis of powdery mildew disease levels. [source]

Helicobacter pylori and Campylobacter rectus share a common antigen

MOLECULAR ORAL MICROBIOLOGY, Issue 2 2003
S. Tanabe
Aim: ,The aim of this study was to investigate the presence of antigens with immunological cross-reactivity in periodontopathogenic bacteria and Helicobacter pylori, the pathogen associated with gastritis and peptic ulcers in human. Materials and methods/Results: ,Among the putative periodontopathogens tested (Actinobacillus actinomycetemcomitans, Campylobacter rectus, Fusobacterium nucleatum, Porphyromonas gingivalis, Prevotella intermedia and Treponema denticola), cross-reactive bands were only detected in C. rectus by SDS,PAGE/Western immunoblotting analysis using a polyclonal antibody directed to H. pylori cells. One of these cross-reactive antigens, a 64-kDa band antigen, also reacted with a monoclonal antibody directed to the human heat shock protein (HSP) 60. The N -terminal amino acid sequence of this C. rectus protein revealed a high degree of homology with corresponding regions of other HSPs belonging to the HSP60 family, indicating that the 64-kDa antigen was a GroEL protein. The nucleotide sequence of the C. rectus GroEL protein coded for a 547 amino acid protein with a predicted size of 57.8 kDa. Comparison of the alignment of the deduced amino acid sequence of the GroEL protein of C. rectus with that of H. pylori showed a high degree of similarity throughout its length (76.8%). GroEL protein from C. rectus possessed the ability to stimulate production of IL-6 by a confluent monolayer of human gingival epithelial cells and was cytotoxic when used at a high concentration. Conclusions: ,This study reveals an immunological relationship between H. pylori and C. rectus, and clearly indicates that one of the shared antigens is a GroEL protein possessing a biological activity that might play a role in the initiation and progression of periodontal disease. [source]

Diagnosis of pulmonary tuberculosis using MTB12 and 38-kDa antigens

RESPIROLOGY, Issue 3 2008
Ji-Sook LEE
Background and objective: Mycobacterium tuberculosis MTB12 protein plays an essential role in pro-inflammatory responses during the early stages of human pulmonary tuberculosis (TB), even though the T-cell immunoreactivity of MTB12 is weaker than that of the 30-kDa antigen (Ag). The objective of this study was to evaluate the humoral immune responses induced by MTB12 Ag during human TB. Methods: Using an ELISA, anti-MTB12 IgG levels in the sera of TB patients and healthy controls were compared with those induced by the 30-kDa Ag and 38-kDa Ag, or both. Results: In TB patients, the sensitivity and specificity of MTB12 Ag were similar to those of other antigens at 53.0% and 95.4%, respectively. However, the sensitivity increased to 73.0% when the combination of MTB12 and 38-kDa Ag was measured. Specificity remained high when a combination of the individual antigens was used. ELISA results showed that after anti-tuberculosis treatment, the mean IgG levels against MTB12 alone or MTB12 plus 38-kDa Ag were significantly increased in the TB patients, while those against MTB12 plus 30-kDa Ag were not (P < 0.05). Conclusions: Collectively, these data suggest that MTB12, in combination with 38-kDa Ag, can be used to increase the accuracy of pulmonary TB diagnosis. [source]

Narrow-band UVB-induced Externalization of Selected Nuclear Antigens in Keratinocytes: Implications for Lupus Erythematosus Pathogenesis,

PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 1 2009
Adam Reich
The aim of this study was to analyze whether sera obtained from patients with lupus erythematosus (LE) react with membrane structures found on keratinocytes irradiated with narrow-band ultraviolet B (NB-UVB). We applied atomic force microscopy (AFM) to visualize cell surface structures expressing nuclear antigens upon apoptosis following NB-UVB irradiation. Immortalized human keratinocytes (HaCaT) were cultured under standard conditions, irradiated with 800 mJ cm,2 NB-UVB light and imaged by AFM mounted on an inverted optical microscope. It was observed that NB-UVB irradiation provoked significant alterations of the keratinocyte morphology and led to the membrane expression of antigens recognized by anti-La and anti-Ro 60 kDa sera but not by antidouble-strand DNA sera. The presence of La and Ro 60 kDa antigens on keratinocyte surfaces after NB-UVB irradiation was limited mainly to the small bleb-like protrusions found on the keratinocytes by AFM. A closer investigation by AFM also revealed that some structures positively stained with anti-Ro 60 kDa serum were also located submembranously. We hypothesize that the externalization of some nuclear antigens because of NB-UVB exposure might be responsible for exacerbation of skin symptoms in patients suffering from LE. [source]