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Biomedical subjects

G Messer

Publications and source records attributed to G Messer.

At least 55 records · Page 3Linked to original sources
PubMed1996

Polymorphism within the second intron of the IL-1 receptor antagonist gene in patients with hematopoietic malignancies.

Alleles of the IL-1 genes are associated with several autoimmune and inflammatory diseases, where they tend to have a role in the severity of the disease rather than in susceptibility to the disease itself. Allele 2 of the variable number tandem repeat (VNTR) polymorphism in the IL-1 receptor antagonist (IL-1ra) gene was the first marker of the IL-1 cluster to be associated in this way with severity of chronic, systemic and local inflammatory diseases. Because of the role that IL-1 also plays in the pathobiology of certain hematopoietic disorders, we aimed at examining the allelic distribution of the IL-1ra VNTR in leukemias, lymphomas and related malignancies. While in patients with chronic lymphocytic leukemia (CLL), hairy cell leukemia (HCL), multiple myeloma (MM) and related disorders, primary acute myeloid leukemia (AML), chronic myeloid leukemia (CML), and Hodgkin's disease (HD), the allelic distribution of IL-1RN was comparable to that seen in healthy control subjects, in a small group of patients with secondary AML the frequency of the IL-1RN*4 allele appeared to be significantly increased.

Alleles↗
PubMed1995

Photodynamic therapy induces expression of interleukin 6 by activation of AP-1 but not NF-kappa B DNA binding.

Inducibility and regulation of the pleiotropic cytokine interleukin 6 (IL-6) upon photodynamic therapy (PDT) was studied in the epithelial cell line HeLa. Photofrin-mediated photosensitization resulted in a rapid and dose-dependent induction of IL-6 mRNA production. Maximal levels were reached after 4 h and had decreased to baseline levels after 24 h. This photochemical induction of IL-6 transcription was followed by a strong secretion of IL-6 protein. In comparison to stimulation by 12-O-tetradecanoylphorbol-13-acetate, the kinetics of IL-6 mRNA and protein synthesis after PDT were delayed, although the maximal amounts of secreted IL-6 protein were comparable. As compared to UV irradiation, on the other hand, PDT-induced IL-6 protein levels were 2- to 10-fold higher and were detectable 4 h earlier. Several potentially relevant regulatory DNA elements of the IL-6 promoter were analyzed by gel retardation assays for PDT-induced protein binding. Interestingly, increased AP-1 DNA binding was detected only at the distal AP-1-specific motif and not at the proximal site, differing in 1 bp. Binding of c-Fos-containing AP-1 heterodimers to the specific motif was up-regulated 30 min after PDT, reaching maximal activity at 4 h. This PDT-induced AP-1 activation was independent from protein kinase C activity. Photosensitization did not induce increased binding at the well-characterized NF-kappa B element, nor at the multiple cytokine- and second messenger-responsive element of the IL-6 promoter. By analyzing the molecular mechanisms of IL-6 up-regulation upon PDT, we provide evidence for regulatory differences compared to UV light, ionizing irradiation, or stimulation by phorbol ester. Furthermore, this study suggests that the "proinflammatory" cytokine IL-6 might be involved in the inflammatory reaction and subsequent immunological antitumor responses.

Base Sequence↗
PubMed1995

Cloning and genomic characterization of LST1: a new gene in the human TNF region.

The leucocyte specific transcript - 1 (LST1) represents the human homolog of the mouse B144 transcript, encoded within the tumor necrosis factor (TNF) region of the human major histocompatibility complex class III interval. The gene is localized about 4 kilobases upstream of the lymphotoxin beta gene. It spans a polymorphic genomic region encompassing the microsatellites TNFd and TNFe in intron 3 and a polymorphic Pvu II restriction site 260 base pairs downstream of the polyadenylation signal. Isolation of a full-length cDNA clone revealed that LST1 codes for IFN-gamma-inducible 800 nt transcripts, which are present in lymphoid tissues, T cells, macrophages, and histiocyte cell lines. The cDNA contains three long open reading frames (ORF) with the most likely ORF encoding a transmembrane protein. Its close linkage to the TNF genes and pattern of expression point toward a possible role for LST1 in the immune response.

Amino Acid Sequence↗
PubMed1995

[Skin ulcers in rheumatoid arthritis].

The appearance of severe ulceration of the skin in patients with rheumatoid arthritis is often associated with a tendency to progression of the underlying disease, involvement of internal organs and increased mortality. In the pathogenesis of such ulceration there are multiple causes for their development, persistence and tendency to poor healing. They include localized or generalized immune complex vasculitis, treatment with anti-inflammatory drugs and their side effects following the treatment, arterial and venous insufficiency, and mechanical factors. The management of severe ulceration requires stabilization of the underlying autoimmune disease, e.g. with high doses of glucocorticosteroids or other immunosuppressive drugs or plasmapheresis. Adjuvant treatment of pain with analgesics, improvement of blood perfusion and anti-inflammatory drugs should accompany the topical therapy of ulcers. After suppression of the local inflammatory reaction surgical intervention becomes necessary in most of the patients, and vascularized muscle flaps should be used in preference to meshgrafts or split skin grafts for extensive ulceration in rheumatoid arthritis. A hopeful perspective in the treatment of severe rheumatoid arthritis might be opened up with immunotherapy using monoclonal antibodies.

Aged↗
PubMed1994

HLA-G: expression in human keratinocytes in vitro and in human skin in vivo.

Classical, polymorphic major histocompatibility complex class I molecules are expressed on most nucleated cells. They present peptides at the cell surface and, thus, enable the immune system to scan peptides for their antigenicity. The function of the other, nonclassical class I molecules in man is controversial. HLA-G which has been shown by transfection experiments to be expressed at the cell surface, is only transcribed in placental tissue and in the fetal eye. Therefore, a role of HLA-G in the control of rejection of the allogeneic fetus has been discussed. We found that HLA-G expression is induced in keratinocytes by culture in vitro. Three different alternative splicing products of HLA-G can be detected: a full length transcript, an mRNA lacking exon 3 and a transcript devoid of exon 3 and 4. Reverse transcription followed by polymerase chain reaction also revealed the presence of HLA-G mRNA in vivo in biopsies of either diseased or healthy skin.

Alternative Splicing↗
PubMed1994

Polymorphism of the tumor necrosis factor genes in patients with dermatitis herpetiformis.

In 18 patients with dermatitis herpetiformis (DH) of whom 16 were HLA-DR3 positive and 14 had the HLA-B8, -DR3 haplotype, the frequencies of known mutations of the tumor necrosis factor alpha (TNF-alpha) and TNF-beta genes were investigated using restriction fragment length polymorphism analysis and the single-strand conformational polymorphism technique. In DH, the phenotype frequency (28%) and allele frequency (0.58) of the rare TNF-beta allele TNFB*1 were significantly increased (normal control 12.4% and 0.37). For the TNF-alpha promoter/enhancer polymorphism, the rare allele TNF2 was more frequent in DH patients (11%, 0.47) compared to controls (2%, 0.16). Since functional studies have associated the rare TNFB*1 and TNF2 alleles with a higher secretion of TNF upon activation in vitro, the predominance of these two 'high-response' TNF alleles in DH patients may represent a genetic basis for the chronic inflammatory response in the skin and mucosal tissues of patients with DH.

Alleles↗
PubMed1993

Polymorphism of the tumor necrosis factor beta gene in systemic lupus erythematosus: TNFB-MHC haplotypes.

We investigated the Nco I restriction fragment length polymorphism (RFLP) of the tumor necrosis factor beta (TNFB) gene in 173 patients with systemic lupus erythematosus (SLE), 192 unrelated healthy controls, and eleven panel families, all of German origin. The phenotype frequency of the TNFB*1 allele was significantly increased in patients compared to controls (63.6% vs 47.1%, RR = 1.96, p < 0.002). The results of a two-point haplotype statistical analysis between TNFB and HLA alleles show that there is linkage disequilibrium between TNFB*1 and HLA-A1, Cw7, B8, DR3, DQ2, and C4A DE. The frequency of TNFB*1 was compared in SLE patients and controls in the presence or absence of each of these alleles. TNFB*1 is increased in patients over controls only in the presence of the mentioned alleles. Therefore, the whole haplotype A1, Cw7, B8, TNFB*1, C4A DE, DR3, DQ2 is increased in patients and it cannot be determined which of the genes carried by this haplotype is responsible for the susceptibility to SLE. In addition, two-locus associations were analyzed in 192 unrelated healthy controls for TNFB and class I alleles typed by serology, and for TNFB and class II alleles typed by polymerase chain reaction/oligonucleotide probes. We found positive linkage disequilibrium between TNFB*1 and the following alleles: HLA-A24, HLA-B8, DRB1*0301, DRB1*1104, DRB1*1302, DQA1*0501, DQB1*0201, DQB1*0604, and DPB1*0101. TNFB*2 is associated with HLA-B7, DRB1*1501, and DQB1*0602.

Base Sequence↗
PubMed1993

[Herpes gestationis: immunologic and immunogenetic aspects].

Herpes gestationis or pemphigoid gestationis (PG) is a bullous disease developing in association with pregnancy. It is believed to be an immunologically mediated disorder. Antibody binding by specific autoantibodies was detected in placental tissue and in the area of the hemidesmosomes and the basal membrane zone of the skin. These autoantibodies react with antigens of 180 kDa and 230 kDa relative molecular mass, which are presumably identical to the bullous pemphigoid antigen BPAG1 and BPAG2. The herpes gestationis factor (HG factor) preferentially binds to the 180-kDa antigen (BPAG2). The involvement of specific autoantibodies against adhesion molecules suggests the involvement of an aberrant immune response. Several groups have reported an association of pemphigoid gestationis to alleles of the human leukocyte antigens; HLA-B8 (class I) and HLA-DR3 and HLA-DR4 (class II), encoded on the short arm of chromosome 6. The unique feature of pemphigoid gestations is compared with other bullous dermatoses the association with the hormonal regulation during pregnancy and the presence of allogenic tissue. The hormonal regulation at the level of gene expression, possibly including gene expression of non-classic HLA class I molecules such as HLA-G, may be a cofactor in the pathogenesis of pemphigoid gestationis. This account, together with a case report, discusses the association of pemphigoid gestationis with HLA and a putative pathophysiological role of the newly described non-classical HLA molecules encoded in the MHC.

Autoantibodies↗
PubMed1993

[Immunogenetic findings in herpes gestationis].

A 27-year-old woman suffered from herpes gestationis in her second pregnancy. The pruricy urticarial and bullous skin lesions were exacerbated immediately after birth, and premenstrually after the onset of menstruation. The diagnosis was confirmed by the determination of anti-basement membrane antibodies of the IgG class both in the serum (herpes gestationis factor) and in lesional skin by immunofluorescence techniques. The newborn had no skin lesions and no basement membrane zone antibodies were detected. The HLA (human leucocyte antigen) typing revealed the HLA-A11/1, B18/w63, C-/-, DR4/w13, DQw3/w1 haplotype in the mother and the HLA-A3/31, B7/35, Cw7/w4, DR2/3, DQw1/w2 haplotype in the father. Comparison with the first child (HLA-A11/31, B18/35, -/Cw4, DR4/3, DQw3/w2) showed that the second child (HLA-A11/3, B18/7, -/Cw7, DR4/2, DQw3/w1) had a different HLA haplotype. The pattern of the HLA haplotype of the mother and the father seems to be important in the immunopathogenesis of herpes gestationis.

Adult↗
PubMed1992

Leishmania infections damage the feeding mechanism of the sandfly vector and implement parasite transmission by bite.

Leishmania parasites are transmitted by the bites of infected female sandflies by a mechanism that has not been clarified. Leishmania infections in the vector develop only in the gut, and the parasites' exit is through the food channel in the proboscis. The problem is how during the bite, when blood flows in, parasites are emitted through the same channel in the opposite direction. It is well documented that infected sandflies maintained on sugar diets are potent vectors, whereas transmission fails after constant feeding on blood. Hence to study the mechanism of transmission, we fed these diets to Phlebotomus papatasi infected with L. major. Histological examination demonstrated that only in the sugar-fed flies did the cuticle lining of the cardiac valve detach and other valve tissues degenerate gradually. The injury of the main valve of the food pumps hindered gorging of most flies when force-fed from capillaries, and they regurgitated the gut contents with fluids from the capillaries. We suggest that infections are caused by parasites regurgitated from the stomach that are deposited in the host tissue. We found that secretion of chitinolytic enzymes by cultured L. major parasites is inhibited by blood or hemoglobin, and hence these enzymes are apparently absent from the blood-fed infected flies, where the cardiac valve appears undamaged. We therefore presume that lysis of the chitin in the cuticle lining of the valve leads to exposure and degeneration of the underlying tissues.

Animals↗
PubMed1992

HLA-J, a second inactivated class I HLA gene related to HLA-G and HLA-A. Implications for the evolution of the HLA-A-related genes.

Ragoussis and co-workers (Genomics 4:301) previously described a class I HLA gene (now designated HLA-J) that maps to within 50 kb of HLA-A. The nucleotide sequences of three HLA-J alleles are reported here. Comparison of the nucleotide sequences of HLA-J alleles shows this gene is more related to HLA-G, A, and H than to HLA-B, C, E, and F. All four alleles of HLA-J are pseudogenes because of deleterious mutations that produce translation termination either in exon 2 or exon 4. Apart from these mutations, the predicted proteins have structures similar to those of HLA-A, B, and C molecules. There is, however, little polymorphism at HLA-J and none at functional positions of the Ag-recognition site. The polymorphism is less than found for HLA-H another HLA-A-related pseudogene. HLA-J appears, like HLA-H, to be an inactivated gene that result from duplication of an Ag-presenting locus related to HLA-A. Nucleotide sequence comparisons show that the HLA-A, H, J, and G genes form a well defined group of "HLA-A-related" loci. Evolutionary relationships as assessed by construction of trees suggest the four modern loci: HLA-A, G, H, and J were formed by successive duplications from a common ancestral gene. In this scheme one intermediate locus gave rise to HLA-A and H, the other to HLA-G and J.

Alleles↗
PubMed1992

T lymphocytes from patients with primary biliary cirrhosis produce reduced amounts of lymphotoxin, tumor necrosis factor and interferon-gamma upon mitogen stimulation.

Primary biliary cirrhosis (PBC) is considered an autoimmune disease characterized by destruction of small intrahepatic bile ducts by lymphocytes. Altered functions of these lymphocytes might reflect an abnormal immune response leading to tissue damage. We investigated lymphokine secretion by mitogen-stimulated T lymphocytes from the liver biopsies of patients with PBC and for comparison also peripheral blood. In PBC, diminished synthesis of lymphotoxin (TNF beta), tumor necrosis factor (TNF alpha) and interferon-gamma (IFN gamma) was found both in T-cell lines from liver tissue and in peripheral blood. The reduction was most prominent for TNF beta in early histological stages of PBC, and appeared to be a stable phenomenon when T cells were tested after long-term tissue culture. Analysis of mRNA levels indicates a possible link between reduced TNF beta production and a defect in interleukin-2 transcription. The data suggest that diminished lymphokine production in patients with PBC may play an important role in the immunopathogenesis of this disease.

Adult↗
PubMed1992

Polymorphism of the tumor necrosis factor region in relation to disease: an overview.

HLA antigens have been shown to be associated with several immunoinflammatory diseases. The mechanisms by which these antigens confer susceptibility to disease continue to be of major interest. Rapid progress has been made in the elucidation of the structure and function of class I and II MHC molecules, and several genes located within the HLA complex have been identified which are potentially involved in immunologic processes. Because of the HLA localization of the TNF-alpha and -beta genes and the biologic activities of the gene products, recent investigation has focused on a possible role of polymorphic TNF genes in the pathogenesis of HLA-associated diseases. Allelic variations have only been detected in the TNF-beta gene. No evidence has been found so far that a particular TNF-beta allele contributes significantly in the susceptibility to the diseases studied. Although it has been postulated that the TNF beta*2 allele contributes to susceptibility to IDDM in HLA-DR3, 4 heterozygous individuals, a larger group of HLA-typed patients and controls is needed to provide more conclusive evidence for this hypothesis. The increasing number of genes of unknown function encoded by the class III region leaves the possibility that the observed HLA associations in some diseases may be related to the presence of these genes. In AS, the lack of association with the TNF-beta alleles furthermore supports the function of the HLA-B27 molecule in the disease and underlines the improbability that HLA-B27 is merely a marker for a closely linked susceptibility gene.

Cytokines↗
PubMed1991

Polymorphic structure of the tumor necrosis factor (TNF) locus: an NcoI polymorphism in the first intron of the human TNF-beta gene correlates with a variant amino acid in position 26 and a reduced level of TNF-beta production.

Since a dysregulated synthesis of tumor necrosis factor alpha (TNF-alpha) may be involved in the pathogenesis of autoimmune diseases, it was of interest to precisely locate the recently reported NcoI restriction fragment length polymorphism (RFLP) of the TNF-alpha region. However, by mapping of 56.8 kb of overlapping cosmid clones and direct sequencing, we could localize the polymorphic NcoI restriction site within the first intron of the TNF-beta gene and not in the TNF-alpha gene. To study whether regulatory mechanisms are affected by this polymorphism, we analyzed the TNF-alpha/TNF-beta production of phytohemagglutinin-stimulated peripheral blood mononuclear cells of individuals homozygous for the TNF-beta NcoI RFLP by ELISA and concomitant Northern blot analysis. On days 2-4 after stimulation with mitogen, the TNFB*1 allele corresponding to a 5.3-kb NcoI fragment presented with a significantly higher TNF-beta response. A mRNA analysis demonstrated that higher protein levels of TNF-beta correlate also with increased amounts of TNF-beta transcripts. No allelic association was found in respect to TNF-alpha production. To further investigate a possible allelic influence on transcription, we determined the DNA sequence of 2 kb of the 5' portion of our cloned TNFB*2 allele and compared it with the available TNF-beta sequences. By computer-aided recognition motif search of DNA binding factors, we report putative binding sites conserved between mouse and man in the 5' flanking region as well as in intron 1 of the TNF-beta gene, found also in other cytokine promoter sequences. In addition, by polymerase chain reaction amplification and sequencing of 740 bp of the 5' part of TNF-beta of individuals typed homozygously for the NcoI RFLP, we could show that amino acid position 26 is conserved as asparagine in the TNFB*1 and as threonine in the TNFB*2 sequence. A previously reported, EcoRI RFLP in the 3' untranslated region of TNF-beta does not segregate with either of the two alleles. Thus, four TNFB alleles can be defined at the DNA level.

Alleles↗
PubMed1991

Cell-free supernatants of sarcoid alveolar macrophages suppress proliferation of sarcoid alveolar fibroblasts.

We have reported that alveolar macrophages (AM) isolated from sarcoidosis (SA) patients, as well as cell-free supernatants of these macrophages, markedly suppressed mitogenic stimulation of peripheral blood lymphocyte (PBL). We now show that cell-free supernatants of AM originating from sarcoidosis patients also suppress [3H]thymidine incorporation by fibroblast (Fb) cultures resulting from bronchoalveolar lavages (BAL) of SA: 40.6% inhibition compared with only 8.2% by supernatants of AM obtained from nonsarcoid controls. The clones of proliferating Fb appeared in cultures of BAL cells after most of the macrophages were detached from the tissue culture surface and actively synthesized collagen, as demonstrated by ultrastructural studies. In confirmation with previously reported results, the same supernatants from AM of SA patients also suppressed mitogenic stimulation of PBL (35.7% inhibition of [3H]thymidine incorporation compared with only 16.3% inhibition by control supernatants). They also contained high amounts of IL-1 (178 compared to 9.2 U/ml of control supernatants), whereas the PGE2 content was within normal levels (0.28 compared to 0.19 ng/ml/10(5) cells in control supernatants). It is concluded that AM from SA patients release a factor(s) which suppresses the proliferation of alveolar fibroblasts.

Adult↗