摘要:

Murine monoclonal antibodies (mAb) produced against native human thyroid peroxidase (TPO) are powerful tools for analyzing the autoantibody (Aab) epitopes on TPO. Binding sites of thirteen mAbs cover all or most antigenic regions on TPO. We determined the competition between Aabs from 75 AITD patients and 13 mAbs in binding to TPO.Autoantibodies recognize predominantly the TPO area close or identical to mAb#9 epitope. All sera tested inhibited this mAb binding by 92.9±14.8 (mean f SD), range from 69-100%. AITD patients' sera with low Aabs titer up to 1/2,000 inhibited mAb#9 binding to TPO by 85±11.5% (mean f SD) and did not influence remaining mAbs binding to TPO. With elevated Aab levels the inhibition of other mAbs binding was higher, but never exceeded 35%. The amount of Aabs yielding 50% inhibition of mAbs binding was lowest for mAb#9. In order to obtain this degree of inhibition for other mAbs 5 to 25 times more Aabs were needed.Our results demonstrate that the majority of autoantibodies in sera of patients with AITD recognize a single immunodominant region on the TPO mapped by mAb#9. They account for about 80-90% of serum TPO autoantibodies. The autoimmune response to other regions on TPO molecule is directed to several other epitopes, but represents quantitatively a minority of autoantibodies. This response intensifies with increasing Aabs level in the serum.

ISSN:0891-6934    

DOI:10.3109/08916939608995338

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

Keratinocytes synthesize urokinase-type plasminogen activator (uPA) and a specific cell surface receptor for uPA (uPA-R, CD 87). Plasminogen is present in plasma and interstitial fluids from where it is bound to cell surfaces via plasmin(ogen) binding sites. uPA binds to the uPA-R in an autocrine manner and activates cell-bound plasminogen: a mechanism, which provides plasmin for pericellular proteolysis. Cell-bound uPA is regulated by plasminogen activator inhibitor type-1 (PAI-1) or type-2 (PAI-2). Bullous pemphigoid is an autoimmune inflammatory skin disease characterized by subepidermal blisters. Although circumstantial evidence suggested plasminogen activation in lesional epidermis of bullous pemphigoid, immunohisto-logical data on the type of plasminogen activators, on the uPA-receptor or the type of plasminogen activator inhibitors in the lesions of bullous pemphigoid are lacking so far. To obtain this information we have performed the present immunohistological study. The presence of uPA and its receptor as well as PAI-2 was disclosed in epidermal keratinocytes in the roof of the subepidermal blisters. Moreover, keratinocytes at the bottom of the blister, which most likely represent keratinocytes during reepithelialization were stained. Co-localization was found for uPA and its receptor, uPA and plasmin(ogen) as well as for uPA and PAI-2. In non-lesional epidermis of bullous pemphigoid only PAI-2 was found. We propose that the expression of uPA and uPA-R, as well as the upregulation of PAI-2 in keratinocytes of lesional epidermis is part of the repair and reepithelialization process following lesion formation, i.e. epidermodermal dyshesion, in bullous pemphigoid.

ISSN:0891-6934    

DOI:10.3109/08916939608995339

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

The relation between islet cell specific antibodies, other autoantibodies and antibodies to cow's milk proteins was studied in IDDM and pre-IDDM by analysing islet cell antibodies (ICA), insulin autoantibodies (IAA), anti-nuclear (ANA), anti-reticulin class IgA [ARA(IgA)], smooth muscle, anti-mitochondria, parietal cell (PCA), adrenal and thyroid antibodies and antibodies to cow's milk formula (CMF),β-lactoglobulin (BLG) and bovine serum albumin (BSA) in a population based study with more than 650 children with newly diagnosed IDDM and more than 550 initially non-diabetic siblings. After adjustment for age a weak association was seen in the diabetic children between IAA and ANA but none between ICA and autoantibodies directed against the other organ-specific or non-organ-specific antigens. There was no significant difference in cow's milk antibodies between diabetic children with and without ICA or IAA. The siblings with ICA had higher CMF (IgA and IgM) antibody levels and BLG (IgA) antibody levels than the remaining siblings, but no such differences were found when comparing IAA-positive and negative siblings. Siblings positive for ICA had PCA more often than did the ICA-negative siblings, whereas siblings positive for both ICA and PCA had increased levels of antibodies against CMF, BLG and BSA. These findings indicate that the humoral islet cell-associated autoimmunity characteristic of recent-onset childhood IDDM is clearly restricted to the islet cells and not directly related to signs of other organ-specific or non-organ-specific autoimmunity. The observation of increased levels of antibodies to cow's milk proteins in siblings positive for ICA suggests that the immune response to cow's milk proteins may be related to the progressive autoimmune process resulting in p-cell destruction and ultimately in the clinical manifestation of IDDM. Gastrointestinal autoimmune mechanisms may play a role in the pathogenesis of IDDM, and the association observed between combined ICA and PCA positivity and increased levels of antibodies to cow's milk proteins in the siblings implies that there may be an enhanced transfer of nutritional antigens across the gut barrier in these subjects.

ISSN:0891-6934    

DOI:10.3109/08916939608995340

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

cDNA encoding 287 amino acids of the C-terminus of mouse thyroglobulin was cloned and sequenced. The amino acid homology between mouse and rat thyroglobulin was 96%, and was 78% between mouse and human. It was found that mouse thyroglobulin completely shared homology with two thyroiditogenic peptides described by other investigators. These findings are consistent with our hypothesis that in murine experimental thyroiditis, the primary thyroiditogenic epitopes are encoded by mouse-specific regions of thyroglobulin.

ISSN:0891-6934    

DOI:10.3109/08916939608995341

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

To ascertain whether membrane signal transduction is induced by bullous pemphigoid (BP) antibody and whether cell lysis is induced by its complement activation, we assessed the intracellular Ca2+concentration ([Ca2+]i), intracellular pH, membrane potential and morphology of living cells by following the time course of fluorescence intensity of Fluo-3/AM, Snaff-1/AM, Dioc-5 and Luciffer yellow, respectively. A transient increase of Fluo-3 fluorescence intensity in DJM-1 cells (a squamous cell carcinoma line) was revealed when the cells were incubated with 2 of five IgG, BP antibodies. However, no transient increase of Hue-3 fluorescence intensity was revealed when the cells were incubated with IgG2and IgG4BP antibodies. A transient increase of Fluo-3 fluorescence intensity was revealed in DJM-I cells incubated with 3 of seven IgG1and 1 of four IgG2BP antibodies in an EGTA-containing low-Ca2+medium.On the other hand, the Dioc-5 fluorescence intensity did not change significantly, though the increase of Fluo-3 fluorescence intensity was observed. The increase of Snarf-1 fluorescence intensity was revealed in DJM-1 cells incubated with 2 of five IgG1BP antibodies, but was not revealed in the cells incubated with IgG2or IgG4of BP antibodies.Study of complement activation by BP IgG1showed a transient increase of Hue-3 fluorescence intensity of with 3 of five IgG1BP antibodies when DJM-1 cells were incubated with complement-supplemented normal-Ca2+medium. At the same time, however, endocytosis and cell lysis were not observed with 2 IgG1BP antibodies which did induce an increase of Fluo-3 fluorescence intensity when Lucifer-yellow-loaded DJM-1 cells were incubated with complement-supplemented normal-Ca2+medium.We examined next whether anti-180 kD BP antigen monoclonal antibodies (mAbs R-223 and 233) induce an increase of nuo-3 fluorescence intensity. MAb R-223 did not induce any increase of Fluo-3 fluorescence intensity in DJM-1 cells, when incubated with normal- and low-Ca2+media However, mAb R-223 induced a transient increase of Fluo-3 fluorescence intensity in DJM-1 cells when incubated with complement-supplemented normal-Ca2+medium. MAb 233 did not induced

ISSN:0891-6934    

DOI:10.3109/08916939608995342

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

摘要:

The causes of the aberrant constitutive expression of cytokines in SLE have not been elucidated yet, but alterations in cytokine gene structure could be a contributing factor. By RFLP (Restriction Fragment Length Polymorphism) analysis of genomic DNA, we found a higher incidence of allelic, higher MW XbaI bands in the IL-6 genes of 9/57 SLE patients vs 1/36 unrelated controls (p = 0.05) HLA DWDQ typing of the polymorphic patients revealed they were all DQβ6. The study of one family indicated that the XbaI polymorphic patient and her polymorphic unaffected offspring had higher than normal levels of constitutive IL-6 mRNA. The SLE-associated IL-6 XbaI restriction alleles had duplications of AT-repeat sequences, approximately 500 bp downstream of the 2ndpolyadenylation site, in an AT-rich mini-satellite with similarities to Matrix Associated Regions (MARS), that may be important in DNA replication and in gene expression. These are novel observations that suggest that, in SLE, there is increased variability in the 3′flanking region of the IL-6 gene. This variability may be related to the aberrant IL6 expression that was reported by US and others in this disease.

ISSN:0891-6934    

DOI:10.3109/08916939608995343

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor

ISSN:0891-6934    

DOI:10.3109/08916939608995344

出版商:Taylor&Francis    

年代:1996

数据来源: Taylor