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Publication
Journal: Molecular and Cellular Proteomics
February/2/2012
Abstract
Pancreatic cancer is one of the leading causes of cancer-related deaths, for which serological biomarkers are urgently needed. Most discovery-phase studies focus on the use of one biological source for analysis. The present study details the combined mining of pancreatic cancer-related cell line conditioned media and pancreatic juice for identification of putative diagnostic leads. Using strong cation exchange chromatography, followed by LC-MS/MS on an LTQ-Orbitrap mass spectrometer, we extensively characterized the proteomes of conditioned media from six pancreatic cancer cell lines (BxPc3, MIA-PaCa2, PANC1, CAPAN1, CFPAC1, and SU.86.86), the normal human pancreatic ductal epithelial cell line HPDE, and two pools of six pancreatic juice samples from ductal adenocarcinoma patients. All samples were analyzed in triplicate. Between 1261 and 2171 proteins were identified with two or more peptides in each of the cell lines, and an average of 521 proteins were identified in the pancreatic juice pools. In total, 3479 nonredundant proteins were identified with high confidence, of which ∼ 40% were extracellular or cell membrane-bound based on Genome Ontology classifications. Three strategies were employed for identification of candidate biomarkers: (1) examination of differential protein expression between the cancer and normal cell lines using label-free protein quantification, (2) integrative analysis, focusing on the overlap of proteins among the multiple biological fluids, and (3) tissue specificity analysis through mining of publically available databases. Preliminary verification of anterior gradient homolog 2, syncollin, olfactomedin-4, polymeric immunoglobulin receptor, and collagen alpha-1(VI) chain in plasma samples from pancreatic cancer patients and healthy controls using ELISA, showed a significant increase (p < 0.01) of these proteins in plasma from pancreatic cancer patients. The combination of these five proteins showed an improved area under the receiver operating characteristic curve to CA19.9 alone. Further validation of these proteins is warranted, as is the investigation of the remaining group of candidates.
Publication
Journal: Infection and Immunity
August/23/2006
Abstract
In previous studies we characterized the Burkholderia cenocepacia ZmpA zinc metalloprotease. In this study, we determined that B. cenocepacia has an additional metalloprotease, which we designated ZmpB. The zmpB gene is present in the same species as zmpA and was detected in B. cepacia, B. cenocepacia, B. stabilis, B. ambifaria, and B. pyrrocinia but was absent from B. multivorans, B. vietnamiensis, B. dolosa, and B. anthina. The zmpB gene was expressed, and ZmpB was purified from Escherichia coli by using the pPROEXHTa His(6) Tag expression system. ZmpB has a predicted preproenzyme structure typical of thermolysin-like proteases and is distantly related to Bacillus cereus bacillolysin. ZmpB was expressed as a 63-kDa preproenzyme precursor that was autocatalytically cleaved into mature ZmpB (35 kDa) and a 27-kDa prepropeptide. EDTA, 1,10-phenanthroline, and Zn(2+) cations inhibited ZmpB enzyme activity, indicating that it is a metalloprotease. ZmpB had proteolytic activity against alpha-1 proteinase inhibitor, alpha(2)-macrogobulin, type IV collagen, fibronectin, lactoferrin, transferrin, and immunoglobulins. B. cenocepacia zmpB and zmpA zmpB mutants had no proteolytic activity against casein and were less virulent in a rat agar bead chronic infection model, indicating that zmpB is involved in B. cenocepacia virulence. Expression of zmpB was regulated by both the CepIR and CciIR quorum-sensing systems.
Publication
Journal: Current Biology
June/19/2006
Abstract
Macrophages, dendritic cells, and neutrophils use phagocytosis to capture and clear off invading pathogens. The process is triggered by the interaction of ligands on the pathogens' surface with specific phagocytic receptors, including immunoglobulin (FcR) and complement C3bi (CR3) receptors (integrin alpha(M)beta2, Mac1) . Localized actin-filament assembly that acts as the driving force for particle engulfment is controlled by Rho-family small GTPases . RhoA regulates CR3-mediated phagocytosis through a mechanism that is still unclear . Mammalian Diaphanous-related (mDia) formins participate in the generation of a diverse set of actin-remodeling events downstream of RhoA , and mDia1 is recruited around fibronectin-coated beads in a RhoA-dependent manner in fibroblasts . Here, we set out to examine whether mDia proteins are involved in CR3-mediated phagocytosis in macrophages. We show that the RhoA effector mDia1 is recruited early during CR3-mediated phagocytosis and colocalizes with polymerized actin in the phagocytic cup. Interfering with mDia activity inhibits CR3-mediated phagocytosis while having no effect on FcR-mediated phagocytosis. These results indicate a new function for mDia proteins in the regulation of actin polymerization during CR3-mediated phagocytosis.
Publication
Journal: Journal of Experimental Medicine
July/31/1986
Abstract
24 human T cell receptor alpha chain messages have been examined by cDNA sequence analysis and Southern blot. The data indicate that there are approximately 40 alpha chain T cell receptor variable gene segments, which can be divided into 12 families. Comparison of the J gene segments from the cDNAs to previously determined germline J alpha sequences places the number of J alpha gene segments over 21, and indicates their number to be approximately 55. Identical nucleotide sequences in independent isolates of V alpha and J alpha gene segments indicate that hypermutation may not be a common mechanism for the expansion of diversity in these genes, and suggest that the major source of diversity within the alpha chain repertoire is a result of recombinational joinings between germline V alpha and J alpha sequences, combined with imprecise junctional joining. Analysis of the V regions of these alpha chain messages reveals the presence of three domains of hypervariability roughly analogous to the CDR1, CDR2, and CDR3 regions of immunoglobulin.
Publication
Journal: Nature
November/28/1991
Abstract
The CD2 antigen is largely restricted to cells of the T-lymphocyte lineage and has been established as an important adhesion molecule in interactions between human T lymphocytes and accessory cells. In the adhesion reaction, CD2 on T cells binds to LFA-3 on other cells, with binding through domain 1 of CD2. CD2 can also be a target for the delivery of mitogenic signals to T lymphocytes cultured with combinations of anti-CD2 antibodies. Two predictions that are contradictory have been made for the structure of CD2 domain 1. One suggests an immunoglobulin (Ig) fold, on the basis of sequence patterns conserved in the Ig-superfamily (IgSF), whilst the other proposes a pattern of alternating alpha-helices and beta-strands, on the basis of secondary structure predictions. Thus CD2 domain 1 is an important test case for the validity of IgSF assignments based on sequence patterns. We report here the expression of domain 1 of rat CD2 in an Escherichia coli expression system and have determined a low-resolution solution structure by NMR spectroscopy.
Publication
Journal: EMBO Journal
March/21/1990
Abstract
Two classes of immunoglobulin, IgM and IgD, are present as antigen receptors on the surface of mature B lymphocytes. We show here that IgD molecules are noncovalently associated in the B cell membrane with a heterodimer consisting of two proteins of 35 kd (IgD-alpha) and 39 kd (Ig-beta), respectively. The two novel proteins are not found in the IgD-expressing myeloma J558L delta m, which fails to bring IgD antigen receptor onto the cell surface. In a surface IgD positive variant line of this myeloma, however, membrane-bound IgD molecules are associated with the heterodimer, suggesting that the formation of an antigen receptor complex is required for surface IgD expression. We further demonstrate that the IgD-associated heterodimer differs partly from that of the IgM antigen receptor and that its binding to the heavy chain only requires the presence of the last constant domain and the transmembrane part of the delta m chain.
Publication
Journal: Journal of Experimental Medicine
January/30/2002
Abstract
Immature bone marrow-derived myeloid dendritic cells (BMDCs) are induced to undergo phenotypic maturation and secretion of tumor necrosis factor (TNF)-alpha, interleukin (IL)-6, IL-12, and IL-10 when pulsed in vitro with intact Streptococcus pneumoniae. After transfer to naive mice, pulsed BMDCs induce immunoglobulin (Ig) isotype responses specific for both protein and polysaccharide pneumococcal antigens, having in common the requirement for viable BMDCs, T cells, and B7-dependent costimulation in the recipient mice. Whereas primary Ig isotype responses to bacterial proteins uniformly require BMDC expression of major histocompatibility complex class II, CD40, and B7, and the secretion of IL-6, but not IL-12, similar requirements for antipolysaccharide Ig responses were only observed for the IgG1 isotype.
Publication
Journal: American Journal of Kidney Diseases
June/24/1996
Abstract
We retrospectively evaluated the prevalence of primary glomerular lesions in adults who had a renal biopsy for nephrotic proteinuria. From July 1975 to May 1994, 340 patients undergoing renal biopsies evaluated at Rush-Presbyterian-St Lukes Medical Center had the primary glomerular lesions of minimal-change disease, focal segmental glomerular sclerosis (FSGS), membranous glomerulonephritis (MGN), membranoproliferative glomerulonephropathy, immunoglobulin A nephropathy, and immunotactoid glomerulopathy. The patients had a mean age of 43 +/- 17 years, 57% were male, and 50% were white, 36% were black, 7% were of other race, and 7% were of unknown race. The distribution of lesions for black patients was minimal-change disease 14%, FSGS 57%, MGN 24%, membranoproliferative glomerulonephritis 2%, immunoglobulin A 2%, and immunotactoid glomerulopathy 1%; for white patients, the distribution of lesions was minimal-change disease 20%, FSGS 23%, MGN 36%, membranoproliferative glomerulonephropathy 6%, immunoglobulin A 8%, and immunotactoid glomerulopathy 6%. The prevalence of FSGS was significantly greater (P < 0.0001) and that for MGN, immunoglobulin A, and immunotactoid glomerulopathy was significantly less (P < 0.05) for black patients compared with white patients. In a logistic regression analysis, race remained the only significant predictor of FSGS (P = 0.0001), with black patients four times as likely to have FSGS as white patients. The distribution of lesions among white patients was similar based on gender, age, and biopsy period. For black patients the distribution was also similar based on gender and age, but over 20 years the incidence of FSGS increased from 39% (1975 to 1984) to 64% (1985 to 1994) (P < 0.01). Thus, significant racial differences in the distribution of primary glomerular lesions exists. This has important prognostic and therapeutic implications for nephrotic adults.
Publication
Journal: Molecular Biology of the Cell
August/24/2000
Abstract
When fluid-phase markers are internalized from opposite poles of polarized Madin-Darby canine kidney cells, they accumulate in distinct apical and basolateral early endosomes before meeting in late endosomes. Recent evidence suggests that significant mixing of apically and basolaterally internalized membrane proteins occurs in specialized apical endosomal compartments, including the common recycling endosome and the apical recycling endosome (<em>A</em>RE). The relationship between these latter compartments and the fluid-labeled apical early endosome is unknown at present. We report that when the apical recycling marker, membrane-bound <em>immunoglobulin</em> <em>A</em> (a ligand for the polymeric <em>immunoglobulin</em> receptor), and fluid-phase dextran are cointernalized from the apical poles of Madin-Darby canine kidney cells, they enter a shared apical early endosome (</=2.5 min at 37 degrees C) and are then rapidly segregated from one another. The dextran remains in the large supranuclear EE<em>A</em>1-positive early endosomes while recycling polymeric <em>immunoglobulin</em> receptor-bound <em>immunoglobulin</em> <em>A</em> is delivered to a Rab11-positive subapical recycling compartment. This latter step requires an intact microtubule cytoskeleton. Receptor-bound transferrin, a marker of the basolateral recycling pathway, has limited access to the fluid-rich apical early endosome but is excluded from the subapical elements of the Rab11-positive recycling compartment. We propose that the term <em>A</em>RE be used to describe the subapical Rab11-positive compartment and that the <em>A</em>RE is distinct from both the transferrin-rich common recycling endosome and the fluid-rich apical early endosome.
Publication
Journal: Molecular Medicine
April/7/1998
Abstract
BACKGROUND
A common genetic basis for IgA deficiency (IgAD) and common variable immunodeficiency (CVID) is suggested by their occurrence in members of the same family and the similarity of the underlying B cell differentiation defects. An association between IgAD/CVID and HLA alleles DR3, B8, and A1 has also been documented. In a search for the gene(s) in the major histocompatibility complex (MHC) that predispose to IgAD/CVID, we analyzed the extended MHC haplotypes present in a large family with 8 affected members.
METHODS
We examined the CVID proband, 72 immediate relatives, and 21 spouses, and determined their serum immunoglobulin concentrations. The MHC haplotype analysis of individual family members employed 21 allelic DNA and protein markers, including seven newly available microsatellite markers.
RESULTS
Forty-one (56%) of the 73 relatives by common descent were heterozygous and nine (12%) were homozygous for a fragment or the entire extended MHC haplotype designated haplotype 1 that included HLA- DR3, -C4A-0, -B8, and -A1. The remarkable prevalence of haplotype 1 was due in part to marital introduction into the family of 11 different copies of the haplotype, eight sharing 20 identical genotype markers between HLA-DR3 and HLA-B8, and three that contained fragments of haplotype 1.
CONCLUSIONS
Crossover events within the MHC indicated a susceptibility locus for IgAD/CVID between the class III markers D821/D823 and HLA-B8, a region populated by 21 genes that include tumor necrosis factor alpha and lymphotoxins alpha and beta. Inheritance of at least this fragment of haplotype 1 appears to be necessary for the development of IgAD/CVID in this family.
Publication
Journal: Journal of Experimental Medicine
January/31/1993
Abstract
We examined the effect of mutations in the V beta portion of a pigeon cytochrome c (cyto c)-specific V beta 3+/V alpha 11+ T cell receptor on its ability to recognize cyto c/IEk and various superantigens. The results were consistent with an immunoglobulin-like structure for the receptor V beta domain and with separate interaction sites on V beta for conventional antigen and superantigens. An amino acid predicted to lie in CDR1 was critical for cyto c/IEk but not superantigen recognition, while several amino acids predicted to lie in the hypervariable region 4 loop were critical for superantigen but not cyto c/IEk recognition.
Publication
Journal: Infection and Immunity
August/6/2008
Abstract
Francisella tularensis is a gram-negative intracellular bacterium and the causative agent of the zoonotic disease tularemia. F. tularensis is a category A select agent and thus a potential agent of bioterrorism. Whereas an F. tularensis live, attenuated vaccine strain (LVS) is the basis of an investigational vaccine, this vaccine is not licensed for human use because of efficacy and safety concerns. In the present study, we immunized mice with isolated native outer membrane proteins (OMPs), ethanol-inactivated LVS (iLVS), or purified LVS lipopolysaccharide (LPS) and assessed the ability of each vaccine preparation to protect mice against pulmonary challenge with the virulent type A F. tularensis strain SchuS4. Antibody isotyping indicated that both Th1 and Th2 antibody responses were generated in mice after immunization with OMPs or iLVS, whereas LPS immunization resulted in only immunoglobulin A production. In survival studies, OMP immunization provided the greatest level of protection (50% survival at 20 days after infection with SchuS4), and there were associated 3-log reductions in the spleen and liver bacterial burdens (compared to nonvaccinated mice). Cytokine quantitation for the sera of SchuS4-challenged mice indicated that OMP and iLVS immunizations induced high levels of tumor necrosis factor alpha and interleukin-2 (IL-2) production, whereas only OMP immunization induced high levels of IL-10 production. By comparison, high levels of proinflammatory cytokines, including RANTES, granulocyte colony-stimulating factor, IL-6, IL-1alpha, IL-12p40, and KC, in nonvaccinated mice indicated that these cytokines may facilitate disease progression. Taken together, the results of this study demonstrate the potential utility of an OMP subunit (acellular) vaccine for protecting mammals against type A F. tularensis.
Publication
Journal: Journal of Bacteriology
September/12/1968
Abstract
Oral bacteria become coated with immunoglobulin A in human saliva in vivo. This may indicate that the salivary immunoglobulin A possesses antibacterial activity. Some of the immunoglobulin-coated cocci grow in extremely long chains and exhibit synchronous cell division. The long chain phenomenon may result from growth in the presence of salivary antibody specific to antigenic determinants of the bacterial cell walls.
Publication
Journal: Molecular and Cellular Biology
April/19/1993
Abstract
alpha-Agglutinin is a cell adhesion glycoprotein expressed on the cell wall of Saccharomyces cerevisiae alpha cells. Binding of alpha-agglutinin to its ligand a-agglutinin, expressed by a cells, mediates cell-cell contact during mating. Analysis of truncations of the 650-amino-acid alpha-agglutinin structural gene AG alpha 1 delineated functional domains of alpha-agglutinin. Removal of the C-terminal hydrophobic sequence allowed efficient secretion of the protein and loss of cell surface attachment. This cell surface anchorage domain was necessary for linkage to a glycosyl phosphatidylinositol anchor. A construct expressing the N-terminal 350 amino acid residues retained full a-agglutinin-binding activity, localizing the binding domain to the N-terminal portion of alpha-agglutinin. A 278-residue N-terminal peptide was inactive; therefore, the binding domain includes residues between 278 and 350. The segment of alpha-agglutinin between amino acid residues 217 and 308 showed significant structural and sequence similarity to a consensus sequence for immunoglobulin superfamily variable-type domains. The similarity of the alpha-agglutinin-binding domain to mammalian cell adhesion proteins suggests that this structure is a highly conserved feature of adhesion proteins in diverse eukaryotes.
Publication
Journal: Nature
May/21/1986
Abstract
Specific chromosomal aberrations are associated with specific types of cancer (for review see ref. 1). The distinctiveness of each association has led to the belief that these chromosomal aberrations are clues to oncogenic events or to the state of differentiation in the malignant cell type. Malignancies of T lymphocytes demonstrate such an association characterized most frequently by structural translocations or inversions of chromosomes 7 and 14 (refs 7-9). Analyses of these chromosomally marked tumours at the molecular level may therefore provide insight into the aetiology of the cancers as well as the mechanisms by which chromosomes break and rejoin. Here we report such an analysis of the tumour cell line SUP-T1 derived from a patient with childhood T-cell lymphoma carrying an inversion of one chromosome 14 between bands q11.2 and q32.3, that is, inv(14) (q11.2; q32.2). These are the same chromosomal bands to which the T-cell receptor alpha-chain (14q11.2) and the immunoglobulin heavy-chain locus (14q32.3) have been assigned. Our analysis reveals that this morphological inversion of chromosome 14 was mediated by a site-specific recombination event between an immunoglobulin heavy-chain variable region (Ig VH) and a T-cell receptor (TCR) alpha-chain joining segment (TCR J alpha). S1 nuclease analysis shows that this hybrid gene is transcribed into poly(A)+ RNA.
Publication
Journal: Infection and Immunity
April/14/2004
Abstract
Adenylate cyclase toxin (CyaA) from Bordetella pertussis can subvert host immune responses allowing bacterial colonization. Here we have examined its adjuvant and immunomodulatory properties and the possible contribution of lipopolysaccharide (LPS), known to be present in purified CyaA preparations. CyaA enhanced antigen-specific interleukin-5 (IL-5) and IL-10 production and immunoglobulin G1 antibodies to coadministered antigen in vivo. Antigen-specific CD4(+)-T-cell clones generated from mice immunized with antigen and CyaA had cytokine profiles characteristic of Th2 or type 1 regulatory T (Tr1) cells. Since innate immune cells direct the induction of T-cell subtypes, we examined the influence of CyaA on activation of dendritic cells (DC) and macrophages. CyaA significantly augmented LPS-induced IL-6 and IL-10 and inhibited LPS-driven tumor necrosis factor alpha and IL-12p70 production from bone marrow-derived DC and macrophages. CyaA also enhanced cell surface expression of CD80, CD86, and major histocompatibility class II on immature DC. The stimulatory activity of our CyaA preparation for IL-10 production and CD80, CD86, and major histocompatibility complex class II expression was attenuated following the addition of polymyxin B or with the use of DC from Toll-like receptor (TLR) 4-defective mice. However, treatment of DC with LPS alone at the concentration present in the CyaA preparation (0.2 ng/ml) failed to activate DC in vitro. Our findings demonstrate that activation of innate cells in vitro by CyaA is dependent on a second signal through a TLR and that CyaA can promote Th2/Tr1-cell responses by inhibiting IL-12 and promoting IL-10 production by DC and macrophages.
Publication
Journal: Journal of Clinical Oncology
April/8/1991
Abstract
Ten patients with myeloid leukemias were treated in a phase I trial with escalating doses of mouse monoclonal antibody (mAb) M195, reactive with CD33, a glycoprotein found on myeloid leukemia blasts and early hematopoietic progenitor cells but not on normal stem cells. M195 was trace-labeled with iodine-131 (131I) to allow detailed pharmacokinetic and dosimetric studies by serial sampling of blood and bone marrow and whole-body gamma-camera imaging. Total doses up to 76 mg were administered safely without immediate adverse effects. Absorption of M195 onto targets in vivo was demonstrated by biopsy, pharmacology, flow cytometry, and imaging; saturation of available sites occurred at doses greater than or equal to 5 mg/m2. The entire bone marrow was specifically and clearly imaged beginning within hours after injection; optimal imaging occurred at the lowest dose. Bone marrow biopsies demonstrated significant dose-related uptake of M195 as early as 1 hour after infusion in all patients, with the majority of the dose found in the marrow. Tumor regressions were not observed. An estimated 0.33 to 1.0 rad/mCi 131I was delivered to the whole body, 1.1 to 6.1 rad/mCi was delivered to the plasma, and up to 34 rad/mCi was delivered to the red marrow compartment. 131I-M195 was rapidly modulated, with a majority of the bound immunoglobulin G (IgG) being internalized into target cells in vivo. These data indicate that whole bone marrow ablative doses of 131I-M195 can be expected. The rapid, specific, and quantitative delivery to the bone marrow and the efficient internalization of M195 into target cells in vivo also suggest that the delivery of other isotopes such as auger or alpha emitters, toxins, or other biologically important molecules into either leukemia cells or normal hematopoietic progenitor cells may be feasible.
Publication
Journal: Journal of Clinical Microbiology
October/21/1985
Abstract
Serum and nasal wash specimens from 13 human volunteers undergoing experimental secondary infection with influenza <em>A</em>/Peking/2/79 (H3N2) wild-type virus were examined for the molecular form and subclass distribution of <em>immunoglobulin</em> <em>A</em> (Ig<em>A</em>) antibodies to the viral hemagglutinin (H<em>A</em>). Nasal Ig<em>A</em> antibodies were polymeric and did not bind radiolabeled secretory component, indicating that they were secretory Ig<em>A</em> antibodies. Both Ig<em>A</em>1 and Ig<em>A</em>2 antibodies were detected; however, Ig<em>A</em>1 accounted for most of the rise in Ig<em>A</em> anti-H<em>A</em> levels seen after infection. In serum virtually all of the Ig<em>A</em> H<em>A</em> antibodies were of the Ig<em>A</em>1 subclass. Furthermore, the serum antibodies were predominantly polymeric and were capable of binding radiolabeled secretory component. These results suggested that the serum Ig<em>A</em> antibodies to H<em>A</em> were of mucosal origin and that influenza <em>A</em> virus H<em>A</em> preferentially stimulates an Ig<em>A</em>1 response.
Publication
Journal: Methods in enzymology
April/16/1991
Abstract
The techniques described allow controlled permeabilization of plasma membranes from different types of cells for gaining access to the cell interior and enables one to control intracellular events. Most common techniques are electropermeabilization, permeabilization with mild non-ionic detergents such as saponin and digitonin and by pore-forming toxins, such as alpha-toxin and streptolysin O. Whereas electropermeabilization and alpha-toxin create small pores of approximately 2 nm, digitonin, saponin, and streptolysin O form bigger holes and therefore also allow the introduction of large molecules, such as enzymes and immunoglobulins. A disadvantage of the latter methods is the loss of cytosolic constituents which might be necessary for signal-transduction pathways in the cell. In secretory cells the main requirement for exocytosis appears to be Ca2+, which brings about the full response comparable to hormone effects in some cells (platelets), adrenal medullary cells, but not in all cells (pancreatic acinar cells). The nucleotide, anion, and cation requirements are different for different cell types and are probably intimately related to the cell-specific mechanisms involved in exocytosis such as regulation of ion channels and ion carriers, or the involvement of nucleotide-binding proteins. Since permeabilized cells are preparations intermediate between intact cells and isolated organelles, they offer great opportunities for the advancement of our understanding of the mechanisms involved in stimulus-response coupling.
Authors
Publication
Journal: Cell
November/6/1991
Abstract
We describe the direct detection of radiolabeled antigen fragments bound to class II MHC molecules following immunoglobulin-mediated endocytosis and processing of native antigen in B lymphoblastoid cells. Tris-Tricine SDS gels revealed six distinct iodinated processing products that could be detected on class II MHC 1 hr after antigen endocytosis and persisted for at least 20 hr. These physiological processed antigen-class II complexes were remarkably stable, as judged by the fact that class II alpha beta dimers, which remain associated in SDS, became labeled with the same set of processed peptides. Using a lectin-binding assay, we show that these physiological processing products bind to the newly maturing population of MHC molecules rather than binding to the preexisting cell surface population; in contrast, an exogenous peptide binds predominantly to the latter population. A direct T cell-independent assay for processed peptide-MHC complex formation should facilitate additional studies on the exogenous antigen processing pathway.
Publication
Journal: Digestive Diseases and Sciences
August/8/2001
Abstract
The worldwide increase of celiac disease prompted us to assess its prevalence in the Italian general population. The 3483 inhabitants of Campogalliano were tested for <em>immunoglobulin</em> <em>A</em> anti-endomysial antibodies. Twenty subjects showed antibody positivity and duodenal biopsy detected typical mucosal lesions of celiac disease in 17 of them; the remaining three cases had a normal villous architecture, but the finding of increased gamma/delta intraepithelial lymphocytes in all and the heterodimer DQ<em>A</em>1*0501, DQB1*0201 in two of them was consistent with potential celiac disease. Only one patient had an overt malabsorption syndrome, characterized by diarrhea, weight loss, and severe weakness. In eight subjects atypical symptoms of celiac disease, such as dyspepsia and depression, were present, whereas the remaining subjects were silent. Celiac disease was more frequent in younger age groups. Our cross-sectional design study demonstrates that celiac disease prevalence in the Italian general population is 4.9 per 1000 (95% CI 2.8-7.8), increasing up to 5.7 per 1000 (95% CI 3.5-8.8) with the inclusion of potential cases.
Publication
Journal: Gastroenterology
March/20/2002
Abstract
Celiac disease is a T cell-mediated enteropathy induced by gluten in genetically predisposed individuals. The majority of patients responds to a gluten-free diet but a small number do not. After the exclusion of gluten in the diet, ulcerative jejunititis, and an enteropathy-associated T-cell lymphoma, another treatment modalities, such as systemic steroids and immunosuppressives, may be necessary. This article reports the case of a 47-year-old white woman with immunoglobulin A deficiency. She was diagnosed with celiac disease with subtotal villous atrophy on jejunal biopsy together with positive antiendomysium and antigliadin immunoglobulin G antibodies. Despite close adherence to a gluten-free diet, her weight continued to decrease, she had diarrhea, and her distal duodenal histology showed no improvement. Some improvement in her symptoms was observed with cyclosporine and systemic steroids, but this was not sustained. Recent evidence has suggested that anti-tumor necrosis factor alpha antibodies have a role in the amelioration of an animal model of villous atrophy, and after careful consideration, she was treated with infliximab. There was a dramatic improvement in her weight, symptoms, and distal duodenal histology. The response has been maintained for 18 months while on azathioprine therapy. It is concluded that infliximab is an effective treatment that may be considered in a small number of patients with refractory celiac disease, resistant to other therapy.
Publication
Journal: Journal of Virology
May/23/2001
Abstract
We recently found a novel cell-cell adhesion system at cadherin-based adherens junctions (AJs), consisting at least of nectin, a Ca(2+)-independent homophilic immunoglobulin-like adhesion molecule, and afadin, an actin filament-binding protein that connects nectin to the actin cytoskeleton. Nectin is associated with cadherin through afadin and alpha-catenin. The cadherin-catenin system increases the concentration of nectin at AJs in an afadin-dependent manner. Nectin constitutes a family consisting of three members: nectin-1, -2, and -3. Nectin-1 serves as an entry and cell-cell spread mediator of herpes simplex virus type 1 (HSV-1). We studied here a role of the interaction of nectin-1alpha with afadin in entry and/or cell-cell spread of HSV-1. By the use of cadherin-deficient L cells overexpressing the full length of nectin-1alpha capable of interacting with afadin and L cells overexpressing a truncated form of nectin-1alpha incapable of interacting with afadin, we found that the interaction of nectin-1alpha with afadin increased the efficiency of cell-cell spread, but not entry, of HSV-1. This interaction did not affect the binding to nectin-1alpha of glycoprotein D, a viral component mediating entry of HSV-1 into host cells. Furthermore, the cadherin-catenin system increased the efficiency of cell-cell spread of HSV-1, although it also increased the efficiency of entry of HSV-1. It is likely that efficient cell-cell spread of HSV-1 is caused by afadin-dependent concentrated localization of nectin-1alpha at cadherin-based AJs.
Publication
Journal: Psychosomatic Medicine
February/14/2001
Abstract
OBJECTIVE
Many patients feel exhausted or depressed before the onset of an acute coronary event, but little is known about the origin of these feelings. We tested the hypothesis that the depressive symptomatology is associated with a reactivation of latent viruses and inflammation of a coronary vessel.
METHODS
A blood sample was drawn and a biopsy sample was obtained from the coronary lesion of 15 exhausted and 15 nonexhausted patients treated with directional coronary angioplasty because of severe angina. Blood samples were analyzed to measure antibody titers against Chlamydia pneumoniae, cytomegalovirus, and the cytokines interleukin (IL)-1beta, IL-6, and tumor necrosis factor (TNF)-alpha. The biopsy sample was analyzed for the presence of IL-1beta and TNF-alpha.
RESULTS
Exhausted/depressed patients had higher antibody titers against cytomegalovirus, higher levels of C. pneumoniae immunoglobulin G, and higher levels of IL-1beta and TNF-alpha. No associations between the mental state of a patient and cytokine mRNA in the biopsy sample were found.
CONCLUSIONS
The findings indicate that the mental state of angioplasty patients is positively associated with serological markers of inflammation. It remains to be seen whether the inflammation causes feelings of exhaustion, whether exhaustion and depression set the stage for inflammation, or whether existing feelings of exhaustion are amplified by the inflammation.
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