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O Winqvist

Publications and source records attributed to O Winqvist.

At least 19 recordsLinked to original sources
PubMed2006

Sentinel node lymphocytes: tumour reactive lymphocytes identified intraoperatively for the use in immunotherapy of colon cancer.

The sentinel node is the first lymph node to receive lymphatic drainage from a tumour and is usually the first site of metastases. Today, the sentinel node is used for tumour staging. Here, we focus on its immunological role and investigate lymphocytic function in sentinel nodes, identified intraoperatively by peritumoural dye injection, from 15 patients with colon cancer. Tumour infiltrating lymphocytes, sentinel and nonsentinel lymph node cells and peripheral blood leukocytes were studied by flow cytometry, proliferation assays and interferon-gamma secretion after activation with autologous tumour homogenate. Whereas tumour-infiltrating lymphocytes were nonresponsive in the proliferation assays, lymphocytes from sentinel nodes proliferated dose dependently and secreted interferon-gamma upon stimulation with tumour homogenate. The responses were of varying magnitude and tended to be weaker in metastatic sentinel nodes. Sentinel node lymphocytes represents an enriched source of tumour reactive lymphocytes, and may be useful in future trials of adoptive immunotherapy.

Aged↗
PubMed2005

Eosinophil granulocytes are activated during the remission phase of ulcerative colitis.

AIM: The aim of this study was to establish a method of investigating intestinal eosinophil and neutrophil granulocytes by flow cytometry, and to compare the distribution and activity of these cells in different stages of ulcerative colitis (UC). METHODS: Biopsy samples were taken from six locations of the entire colon and from the terminal ileum in 10 patients with active total UC, 10 patients with inactive total UC, eight patients with active distal UC, and 11 control subjects. Cell suspensions from biopsies and from peripheral blood were incubated with fluorophore conjugated monoclonal antibodies. The use of scatter plot-gating and specific antibodies was established in a flow cytometry assay. RESULTS: Eosinophils were more numerous and more active in patients with active UC than in controls. Interestingly, during inactive UC, the number of activated eosinophils was even larger. Eosinophil activity was high in the rectum of patients with distal colitis but was also slightly elevated in the proximal colon. Neutrophils were increased in number and activity during active but not inactive UC. In patients with distal colitis, activated neutrophils were only found in the sigmoid colon and rectum. CONCLUSION: With this method, we confirm that neutrophils participate in the inflammatory process during active UC, and that they express a resting phenotype during remission. The finding of activated eosinophils in inflamed intestine strengthens the view of these cells as proinflammatory and tissue damaging. Nevertheless, our new finding of high eosinophil activation during inactive UC suggests that eosinophils play a role in repair of injured epithelium.

Adult↗
PubMed2005

Identification of sentinel nodes in patients with colon cancer.

AIMS: Lymphatic mapping and sentinel node biopsy entails better staging in malignant melanoma and breast cancer and we used this technique in patients with colon cancer to possibly improve detection of lymphatic spread. METHODS: Thirty patients with invasive adenocarcinomas were investigated. The tumour status in identified sentinel node(s) was compared with the status in all other harvested regional nodes for each patient. Patients were followed at regular visits for more than 30 months. RESULTS: Sentinel nodes were identified in all cases, either per-operatively (28 cases) or at dissection of the formalin-fixed specimen (2 cases). The sentinel nodes were diagnostic for the entire lymphatic field in 28 patients and the false negative rate was 2/12. In four cases, the sentinel nodes were the only metastatic nodes. After at minimum 30 months, three patients had died of colon cancer metastases. CONCLUSION: This method improved the identification of patients with lymph-node metastases, especially those with only few metastatic nodes. Patients dying from metastatic disease had lymph-node metastases at diagnosis.

Adenocarcinoma↗
PubMed1999

Impaired immunoproteasome assembly and immune responses in PA28-/- mice.

In vitro PA28 binds and activates proteasomes. It is shown here that mice with a disrupted PA28b gene lack PA28a and PA28b polypeptides, demonstrating that PA28 functions as a hetero-oligomer in vivo. Processing of antigenic epitopes derived from exogenous or endogenous antigens is altered in PA28-/- mice. Cytotoxic T lymphocyte responses are impaired, and assembly of immunoproteasomes is greatly inhibited in mice lacking PA28. These results show that PA28 is necessary for immunoproteasome assembly and is required for efficient antigen processing, thus demonstrating the importance of PA28-mediated proteasome function in immune responses.

Animals↗
PubMed1999

Intercellular adhesion molecule-1 inhibits interleukin 4 production by naive T cells.

The type of cytokines produced during T cell responses determines susceptibility or resistance to many pathogens and influences the development of autoimmunity and allergy. To define the role of individual accessory molecules in cytokine production during primary immune responses, Drosophila cell lines expressing murine major histocompatibility complex class II molecules with defined combinations of accessory molecules were used to present peptide antigen to naive T cell receptor transgenic T cells. Significantly, expression of B7.1 or B7.2 without additional accessory molecules led to very high production of interleukin (IL)-4, which contrasted with minimal IL-4 production elicited by conventional antigen presenting cells (APC). However, coexpression of ICAM-1 and B7 on Drosophila APC induced little IL-4, suggesting an inhibitory role for intercellular adhesion molecule-1 (ICAM-1). In support of this idea, stimulation of T cell receptor transgenic T cells with peptide presented by splenic APC devoid of ICAM-1 (from ICAM-1-deficient mice) led to high IL-4 production. Thus, the level of IL-4 production by naive CD4(+) T cells during typical primary responses appears to be controlled, at least in part, by T-APC interactions involving ICAM-1.

Animals↗
PubMed1999

The role of H2-O and HLA-DO in major histocompatibility complex class II-restricted antigen processing and presentation.

The function of major histocompatibility complex (MHC) class II molecules is to sample exogenous antigens for presentation to CD4+ T helper cells. After synthesis in the endoplasmic reticulum, class II molecules are directed into the endosomal system by association with the invariant chain (Ii), which is sequentially cleaved, generating class II dimers loaded with Ii-derived peptides (CLIP). These class II-peptide complexes are physiological substrates for H2-M/HLA-DM, a resident of the endosomal/lysosomal system which facilitates the removal of CLIP from newly synthesised class II alpha beta dimers. Exchange of CLIP for antigenic class II-binding peptides is also promoted by the action of H2-M/HLA-DM, resulting in stable peptide-class II complexes that are transported to the cell surface for presentation to CD4+ T cells. Recent evidence suggests that this H2-M/HLA-DM-mediated 'peptide editing' is influenced by another MHC class II-encoded molecule, H2-O/HLA-DO. This non-polymorphic alpha beta heterodimer is associated with H2-M/HLA-DM during intracellular transport and within the endosomal system of B cells. H2-O/HLA-DO alters the peptide exchange function of H2-M/HLA-DM in a pH-dependent manner, so that H2-M/HLA-DM activity is limited to more acidic conditions, corresponding to lysosomal compartments. Indeed, H2-O/HLA-DO may serve to limit the presentation of antigens after fluid phase uptake by B cells, while augmenting presentation of antigens internalised via membrane Ig receptors. Such a mechanism may maintain the fidelity of the B-cell-CD4+ T-cell interaction, counteracting self reactivity arising from less stringent lymphocyte activation. Here, data evaluating the role of H2-O/HLA-DO shall be reviewed and its putative function discussed.

Animals↗
PubMed1998

Altered antigen presentation in mice lacking H2-O.

HLA-DM catalyzes the release of MHC class II-associated invariant chain-derived peptides (CLIP) from class II molecules. Recent evidence has suggested that HLA-DO is a negative regulator of HLA-DM in B cells, but the physiological function of HLA-DO remains unclear. Analysis of antigen presentation by B cells from mice lacking H2-O (the mouse equivalent of HLA-DO), together with biochemical analysis using purified HLA-DO and HLA-DM molecules, suggests that HLA-DO/H2-O influences the peptide loading of class II molecules by limiting the pH range in which HLA-DM is active. This effect may serve to decrease the presentation of antigens internalized by fluid-phase endocytosis, thus concentrating the B cell-mediated antigen presentation to antigens internalized by membrane immunoglobulin.

Animals↗
PubMed1998

A family with hereditary extra-adrenal paragangliomas without evidence for mutations in the von Hippel-Lindau disease or ret genes.

OBJECTIVES: To characterize a family with hereditary paraganglioma, and to search for germline mutations in the von Hippel-Lindau disease (VHL) tumour suppressor gene and the ret proto-oncogene. DESIGN: Patient records and histopathological reports were reviewed. Available tumour samples were reinvestigated using immunohistochemical techniques. The VHL gene was investigated by single strand conformational polymorphism analysis of PCR products amplified from exons 1, 2 and 3 and the 3' untranslated region. The ret gene was analysed by amplifying and sequencing exons 10, 11 and 16. PATIENTS: A family with paragangliomas in three consecutive generations was investigated. RESULTS: The affected individuals were found to have multiple extra-adrenal paragangliomas. All three affected individuals had retroperitoneal tumours, and two also had paraganglioma in the neck. No mutations of the VHL or ret genes were detected. CONCLUSIONS: The described family may represent a novel dominantly inherited neuroendocrine tumour syndrome.

Adolescent↗
PubMed1997

Cytochrome P450IA2 and aromatic L-amino acid decarboxylase are hepatic autoantigens in autoimmune polyendocrine syndrome type I.

Autoimmune chronic active hepatitis (AI-CAH) is a feared component of autoimmune polyendocrine syndrome type I (APS I). In this study, immunoreactivity was assessed in sera from eight APS I patients, of whom three had AI-CAH, in an attempt to identify hepatic autoantigens. We performed indirect immunofluorescence staining of human and rat liver sections, Western blots on subcellular fractions of human and rat liver, immunoprecipitations of labelled aromatic L-amino acid decarboxylase (AADC) and cytochrome P450IA2 (CYP IA2) expressed by an in vitro transcription and translation system and studies of enzymatic activity. Autoantibodies against AADC were present in sera from all eight APS I patients, while immunoreactivity against CYP IA2 was only found in sera from the three APS I patients with AI-CAH. Enzymatic activity of CYP IA2 was inhibited by sera from APS I patients with AI-CAH but not by control sera. Our results show that CYP IA2 and AADC constitute hepatic autoantigens in patients with APS I and that immunoreactivity against CYP IA2 is associated with the presence of AI-CAH.

Animals↗
PubMed1996

The autoimmune basis of adrenocortical destruction in Addison's disease.

Addison's disease is mainly caused by autoimmune destruction of the steroid-producing cells in the adrenal glands. Key enzymes in steroid biosynthesis have been implicated as the major targets of autoantibodies in this disease. The study of B-cell-dependent autoimmune responses reveals two distinguishable forms of Addison's disease. This should permit very accurate diagnosis of the disease and increase future prospects of disease prevention.

Addison Disease↗
PubMed1996

Adrenal autoantibodies and organ-specific autoimmunity in patients with Addison's disease.

OBJECTIVE: Autoimmune destruction of the adrenal gland is the major cause of Idiopathic Addison's disease, but the significance of 21-hydroxylase autoantibodies and their correlation with the presence of other autoantibodies have not so far been investigated in a larger population of patients with Addison's disease. We have now characterized a cohort of patients with idiopathic Addison's disease (n = 97) regarding the specificity of autoantibodies against the adrenal cortex and, as Addison's disease can be either an isolated condition or part of a polyendocrine disorder, we investigated the presence of organ-specific polyendocrine autoimmunity in this patient population. DESIGN: Cross-sectional study. MEASUREMENTS: Autoantibodies were analysed with indirect immunofluorescence (IF) on tissue preparations, ELISA and in Western blots using bacterially expressed proteins. RESULTS: Eighty-four per cent (81/97) of the patient sera recognized the steroid-producing cells of the adrenal cortex in indirect IF. The antigen was identified as 21-hydroxylase by 72% (70/97) of the patient sera in Western blots. Seven sera that were negative on adrenocortical IF identified 21-hydroxylase on Western blot, while eight IF-positive sera were 21-hydroxylase-negative. Five sera weakly recognized 17 alpha-hydroxylase in Western blots, but all of these were also positive for 21-hydroxylase. In 13 cases (12 women), the sera also reacted with testicular Leydig cells, and nine of these identified the side-chain cleavage (SCC) enzyme. Other clinically evident organ-specific autoimmune disorders were present in 40% of the 97 patients and abnormal titres of organ-specific antibodies were found in 60% of the patients. CONCLUSIONS: In idiopathic Addison's disease, auto-antibodies against 21-hydroxylase are found in a majority of cases and this represents an important diagnostic tool. The enzyme 17 alpha-hydroxylase does not seem to constitute a major autoantigen in Addison's disease. In a subgroup of patients with autoantibodies to gonads, antibodies to SCC are produced, often in parallel with antibodies to 21-hydroxylase. In yet another subgroup the specificity of autoantibodies giving positive immunofluorescence is still unknown. Three patients revealed a polyendocrine syndrome which clinically resembles autoimmune polyendocrine syndrome (APS) type I, but serologically corresponds to APS type II. Polyendocrine disorders are often associated with Addison's disease, and screening, including quantification of autoantibodies, may help to identify those at risk of developing associated autoimmune disorders.

Addison Disease↗
PubMed1996

Autoantibodies against adrenal medulla in type 1 and type 2 diabetes mellitus: no evidence for an association with autonomic neuropathy.

OBJECTIVE: To examine the role of autoimmunity in the development of autonomic neuropathy in diabetes mellitus. DESIGN: Retrospective cross-sectional study. SETTING: The Department of Medicine, University Hospital, Uppsala, and the Department of Endocrinology, University of Lund, Malmö General Hospital, Malmö, Sweden. SUBJECTS AND MAIN OUTCOME MEASURES: We examined 135 patients with type 1 (n = 96) or type 2 (n = 39) diabetes mellitus. Tests for cardiovascular autonomic functions were performed, and patient sera were analysed for the presence of autoantibodies against the adrenal medulla by indirect immunofluorescence, Western blot and immunoprecipitation techniques. RESULTS: Sera from 13% (12/96) of the type 1 and 20% (8/39) of the type 2 patients showed a positive cytoplasmic immunofluorescence (IF) staining of the adrenal medullary cells, as did 20% (30/151) of sera from healthy controls. Fifty-eight and 64% of type 1 and type 2 patients, respectively, had cardiovascular autonomic neuropathy, but no correlation between autonomic neuropathy and positive IF against the adrenal medulla was observed, with the exception of significant drops in diastolic blood pressure 8 min after tilt (P < 0.005) in type 1 patients. The various IF-positive sera reacted with several different proteins when analysed with Western blot technique using a total homogenate of the bovine adrenal medulla. These did not correspond to any of the proteins involved in the synthesis or storage of catecholamines which were considered as putative autoantigens. CONCLUSION: The finding of similar frequencies of immunoglobulins binding to adrenal medulla in both type 1 and 2 diabetic patients as well as in normal controls, argues against a role of anti-adreno-medullary antibodies in the pathogenesis of autonomic diabetic neuropathy.

Adrenal Medulla↗
PubMed1996

Differentiation of Chlamydia spp. by sequence determination and restriction endonuclease cleavage of RNase P RNA genes.

The amplification of DNA from Chlamydia trachomatis by PCR with degenerated primers yielded a 345-bp fragment of the putative RNase P RNA gene. From the deduced DNA sequence of this gene in C. trachomatis, a modified primer pair was designed. The primer pair was subsequently used to obtain the corresponding gene products from Chlamydia pneumoniae and Chlamydia psittaci. Sequence comparisons revealed similarities of 76.6% between C. trachomatis and C. pneumoniae, 79.5% between C. trachomatis and C. psittaci, and 84.7% between C. pneumoniae and C. psittaci. Furthermore, the three species were differentiated by fragment length polymorphism analysis after restriction enzyme cleavage of the PCR products. Sequence variations among 14 serotypes of C. trachomatis were confined to one purine base substitution in the putative RNase P RNA gene of lymphogranuloma venereum strains L1 to L3. Complete sequence similarity was found for nine strains of C. pneumoniae of different geographic origins. Taken together, our results indicate a possibility of the general application of this method in clinical bacteriology. Analysis of the secondary structures of the putative RNase P RNA genes from the different Chlamydia species suggested that a novel structural element in the domain of RNase P RNA is involved in base pairing with the 3'-terminal CCA motif of a tRNA precursor. This structure has not previously been found among RNase P RNAs of members of the division Bacteria.

Base Sequence↗
PubMed1995

Aromatic-L-amino-acid decarboxylase, a pyridoxal phosphate-dependent enzyme, is a beta-cell autoantigen.

Different autoantigens are thought to be involved in the pathogenesis of insulin-dependent diabetes mellitus, and they may account for the variation in the clinical presentation of the disease. Sera from patients with autoimmune polyendocrine syndrome type I contain autoantibodies against the beta-cell proteins glutamate decarboxylase and an unrelated 51-kDa antigen. By screening of an expression library derived from rat insulinoma cells, we have identified the 51-kDa protein as aromatic-L-amino-acid decarboxylase (EC 4.1.1.28). In addition to the previously published full-length cDNA, forms coding for a truncated and an alternatively spliced version were identified. Aromatic L-amino acid decarboxylase catalyzes the decarboxylation of L-5-hydroxytryptophan to serotonin and that of L-3,4-dihydroxyphenylalanine to dopamine. Interestingly, pyridoxal phosphate is the cofactor of both aromatic L-amino acid decarboxylase and glutamate decarboxylase. The biological significance of the neurotransmitters produced by the two enzymes in the beta cells remains largely unknown.

Adolescent↗
PubMed1995

Identification of the main gonadal autoantigens in patients with adrenal insufficiency and associated ovarian failure.

Autoimmune adrenal insufficiency is associated with premature ovarian failure at frequencies of 10-20%. In these patients a reactivity against an unknown steroid cell antigen in both the adrenal glands and gonads has been described. We have recently identified the cytochrome P450 enzyme 21-hydroxylase and the side-chain cleavage enzyme (SCC) as the major adrenal autoantigens in Addison's disease and the rare autoimmune polyendocrine syndrome type I (APS-I), respectively. In an attempt to identify the steroid cell antigen, sera from patients with Addison's disease (n = 13) and APS-I (n = 7) that reacted with Leydig cells were selected. Preparations of isolated human granulosa cells, isolated rat Leydig cells, and fractions of human placenta were used in Western blots. All sera were also tested against bacterially expressed 21-hydroxylase, SCC, and 17 alpha-hydroxylase. The SCC was recognized by sera from patients with Addison's disease and those with APS-I. In addition, a majority of the sera (n = 12) reacted with a novel 51-kilodalton autoantigen present in granulosa cells and placenta. The results show that the steroid cell autoantigen consists mainly of the SCC and a novel protein of unknown function.

Addison Disease↗
PubMed1994

Autoantibodies against a novel 51 kDa islet antigen and glutamate decarboxylase isoforms in autoimmune polyendocrine syndrome type I.

Beta-cell function and islet cell antibodies were studied in six patients with autoimmune polyendocrine syndrome type I. All suffered from mucocutaneous candidiasis, five had adrenocortical insufficiency and three hypoparathyroidism. All sera contained high titres of antibodies staining islets of Langerhans. Reactivity against glutamate decarboxylase, predominantly the 65 kDa isoform, was detected by immunoprecipitations and Western blots in five of the six sera, and all six sera immunoprecipitated a 51 kDa antigen from [35S]-methionine labelled rat islet cell lysates. No reactivity against this latter antigen was found in sera of patients with Type 1 (insulin-dependent) diabetes mellitus (n = 9), Graves' disease (n = 5), autoimmune gastritis (n = 4), idiopathic Addison's disease (n = 7), or stiff-man syndrome (n = 2). The 51 kDa antigen was also detected by Western blots using homogenates of rat islets and autoimmune polyendocrine syndrome type I patient sera, whereas no such reactivity was found with homogenates of testes, adrenals, small intestine, spleen, exocrine pancreas or brain. Moreover, the 51 kDa antigen was present in the rat insulinoma cell line RINm 5F but not in the SV-40 transformed, monkey kidney cell line COS, when examined by immunoprecipitations of [35S]-methionine labelled cell lysates and by Western blots. None of the patients with autoimmune polyendocrine syndrome type I had symptoms of diabetes and their insulin responses to glucose challenge were normal. The data illustrate that patients with autoimmune polyendocrine syndrome type I present an autoimmune response against islets of Langerhans, which is apparently different from that associated with classic Type 1 diabetes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Two different cytochrome P450 enzymes are the adrenal antigens in autoimmune polyendocrine syndrome type I and Addison's disease.

Autoimmune polyendocrine syndrome type I (APS I) and idiopathic Addison's disease are both disorders with adrenal insufficiency but with differences in genetic background, clinical presentation, and extent of extraadrenal manifestations. In this study the major adrenal autoantigen identified with sera from patients with APS I was characterized by analyses using indirect immunofluorescence, Western blots of adrenal subcellular fractions and of recombinant proteins, immunoprecipitations of [35S]methionine-labeled lysates of a human steroid-producing cell line, and studies of enzymatic activity. Sera from patients with APS I, identifying cells in adrenal glands and testes involved in steroid synthesis, reacted in Western blots with a 53-kD antigen, which comigrated with the cytochrome P450 cholesterol side chain cleavage enzyme (SCC). The sera also immunoprecipitated this protein from lysates of radiolabeled adrenal cells. The enzymatic activity of SCC was inhibited by the APS I sera but not by control sera. Sera from patients with idiopathic Addison's disease did not react with the SCC. The results show that the autoimmune responses towards adrenal tissue in patients suffering from APS I and Addison's disease are remarkably selective and suggest that a determination of the antigen involved in a patient with autoimmune adrenal insufficiency will have diagnostic as well as prognostic implications.

Addison Disease↗