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Biomedical subjects

D Kaiserlian

Publications and source records attributed to D Kaiserlian.

At least 55 records · Page 3Linked to original sources
PubMed1993

Immortalization of mouse intestinal epithelial cells by the SV40-large T gene. Phenotypic and immune characterization of the MODE-K cell line.

Intestinal epithelial cells from the mouse small intestine were immortalized by SV40 large T gene transfer through a murine ecotropic virus. The resulting cell lines expressed the SV40 large T mRNA and exhibited morphological and phenotypic characteristics of normal enterocytes, including intercellular junctions, and expression of cytokeratin, villin, poly-Ig receptor (i.e., secretory component) and vasoactive intestinal peptide receptors. All expressed cell surface major histocompatibility complex class I molecules, but cell surface class II antigens were undetectable. Functional studies on antigen presentation were carried out using the MODE-K cell line established from the mouse duodenum. Interferon-gamma treatment of MODE-K cells resulted in a high level of class II molecule expression, and the ability to process and present native protein antigens to specific CD4+ T-cell hybridomas, via functional class II molecules. These data suggest that the MODE-K cell line is a suitable model for the analysis of intestinal epithelial cell function in mucosal immunity.

Animals↗
PubMed1993

Unexpected lack of reactivity of allogeneic anti-Ia monoclonal antibodies with MHC class II molecules expressed by mouse intestinal epithelial cells.

We have examined MHC class II molecules expression by murine gut epithelial cells using a large panel of anti-Ia antibodies. In contrast to conventional APC (i.e., B cells and macrophages), only two anti-Ia antibodies reacted with enterocytes: a xenogeneic rat anti-Ia mAb (CD311) directed against a monomorphic class II determinant, and a polyclonal antiserum directed against both I-A and I-E heterodimers. In contrast, allogeneic anti-Ia mAb were either unreactive (17 of 20) or reacted weakly (3 of 20) with enterocytes, even after in vivo treatment with IFN-gamma. This pattern of Ia reactivity of epithelial cells was tissue specific (restricted to gut mucosa) and cell specific (restricted to gut epithelial cells). Biochemical and molecular studies confirmed that enterocytes expressed I-A and I-E isotypes on their cell surface and contained mRNA of both subregion loci. Interestingly, enterocytes appeared deficient in expression of the MHC class II-associated invariant chain, and are not able to stimulate allogeneic T cells. These data suggest that gut epithelial cells express a conformation of class II molecules, antigenically distinct from that expressed on conventional APC.

Animals↗
PubMed1993

Mouse intestinal epithelial cells express the self superantigen Mls1a.

In previous studies, we demonstrated that intestinal epithelial cells of the mouse small intestine could present exogenous antigen to specific CD4+ T cell hybridomas. We now report on the ability of normal enterocytes to present the self superantigen Mls1a. Enterocytes from Mls1a but not from Mls1b strains stimulated interleukin-2 production through a V beta 6+ T cell hybridoma specific for Mls1a determinants. Antibody inhibition experiments showed that enterocytes presented Mls determinants via a major histocompatibility complex class II-dependent mechanism. Furthermore, the ability of enterocytes to activate V beta 6+ Mls1a-specific T cells was inhibited by monoclonal antibodies against the Orf protein encoded by an Mtv-7 provirus which is associated with Mls1a expression. These findings provide evidence for the first time that Mls determinants are expressed on normal enterocytes and support the theory of a possible role of these cells in extrathymic selection of T cell receptor V beta repertoire of intraepithelial T lymphocytes.

Animals↗
PubMed1993

Intestinal epithelial cells express the CD23/Fc epsilon RII molecule: enhanced expression in enteropathies.

Immunohistochemical analysis of normal human intestine revealed that two anti-CD23 monoclonal antibodies (mAb), EBVCS 1 and EBVCS 2, reacted with human intestinal epithelial cells. Both mAb exhibited an exclusive reactivity with epithelial cells of the small and large bowels. Staining with both EBVCS 1 and EBVCS 2 was localized on the apical and basal sides of enterocytes. Enhanced expression of CD23 on gut epithelial cells was found in inflammatory bowel diseases, in children with food intolerance to cows' milk proteins and in a young infant with severe autoimmune enteropathy. Western blot analysis of anti-CD23 mAb reactivity with gut epithelial cell extracts showed the presence of a non-reducible 42,000-45,000 M(r) polypeptide compatible with the membrane form of the intact CD23 molecule. These data show that CD23 is constitutively expressed by intestinal epithelial cells and that its expression is enhanced in enteropathies.

Antibodies, Monoclonal↗
PubMed1993

[CD23: structures, functions and practical perspectives in allergy reactions].

CD23, the low-affinity receptor for IgE, is a surface cell marker and surface CD23 is cleaved into soluble fragments by an autocatalytic mechanism. cDNA clone encoding for CD23 has been isolated and structural studies realized. CD23 is expressed by B and T lymphocytes and by other cells including tumor cells. IL4 and IgE are the most potent inducer of CD23 expression. CD23 has multiple functions: B cell growth and differentiation, capacity to present antigen, cellular mobility, inflammation... The serum sCD23 level is often increased in allergic patients.

Cell Membrane↗
PubMed1991

Expression, function and regulation of the intercellular adhesion molecule-1 (ICAM-1) on human intestinal epithelial cell lines.

We have characterized the presence of the intercellular adhesion molecule-1 (ICAM-1) (CD54) on human intestinal adenocarcinoma cell lines as a nonreducible polypeptide of Mr 93 kDa, identified as a rhinovirus receptor. Expression of ICAM-1 was positively correlated with enterocytic maturation, in that the percentage of ICAM-1+ cells was highest in the most differentiated cell line Caco-2. ICAM-1 could be up-regulated only on the less differentiated cell lines HT29 and T84 by phorbol 12-myristate 13-acetate and by the cytokines interferon-gamma (IFN-gamma) and interleukin (IL) 1 beta. Enterocyte ICAM-1 was involved in adhesion to activated T cells through binding to the leukocyte function associated antigen-1 (LFA-1). These data provide evidence that colon adenocarcinoma cell lines express functional ICAM-1 sensitive to cytokine regulation. These findings support the hypothesis that lympho-epithelial interactions involving the ICAM-1/LFA-1 pathway may be implicated in immunosurveillance of colon adenocarcinomas, inflammatory bowel disease and celiac disease, where increased levels of proinflammatory cytokines are locally produced within the gut mucosa.

Antigens, CD↗
PubMed1991

Murine gut epithelial cells express Ia molecules antigenically distinct from those of conventional antigen-presenting cells.

Murine gut epithelial cells, endowed with MHC class II-restricted antigen-presenting function, express membrane Ia molecules, which are not recognized by a panel of allospecific mAbs directed against determinants on the alpha or the beta chain of Ia heterodimers. These data indicate that intestinal epithelium bears surface Ia molecules antigenically distinct from those of conventional APC.

Animals↗
PubMed1991

Characterization of calcitonin gene-related peptide receptors and adenylate cyclase response in the murine macrophage cell line P388 D1.

Specific receptors for calcitonin gene-related peptide (CGRP) were identified and characterized on plasma membranes from the interleukin-1 secreting murine macrophage-like cells line P388 D1. The binding of [125I]-rat CGRP I was time-dependent, reversible and the rate of dissociation of [125I]-rat CGRP I increased in the presence of GTP. Scatchard analysis was consistent with a single class of binding sites, with an apparent dissociation constant of 1.76 nM and a maximal binding capacity of 85.48 fmol/mg protein. In competitive displacement studies, rat CGRP I, human CGRP I and human CGRP II were equipotent to inhibit the binding of [125I]-rat CGRP I (IC50 = 4 nM) while rat CGRP II and the synthetic analogue [tyr(o)]-human CGRP I were ten-fold less potent. Porcine calcitonin and VIP did not inhibit tracer binding. In the presence of GTP, CGRP stimulation of adenylate cyclase was dose-dependent and strongly correlated with receptor occupation. These results indicate that the P388 D1 macrophage-like cell line expresses CGRP specific receptors functionally coupled to adenylate cyclase, which may be involved in CGRP-mediated macrophage immune response.

Adenylyl Cyclases↗
PubMed1990

Expression of the asialo GM1 determinant on murine intestinal epithelia.

Murine intestinal epithelial cells were studied by flow cytometric analyses for the expression of lymphocyte-associated membrane antigens. Three lymphocyte antigens were found to be expressed at high density on most nonhematopoietic intestinal epithelial cells. These included major histocompatibility complex class II antigens, the T cell-associated CT carbohydrate determinant, and the asialo GM1 (aGM1) neutral glycolipid. Examination of aGM1 determinant density on epithelial cells, estimated by fluorescence intensity, indicated that aGM1 was expressed at levels equal to those present on lymphoid cells known to be aGM1+. The potential role for lymphocyte antigenic determinants on nonhematopoietic cells of murine epithelia with respect to local regulation of intestinal lymphocytes is discussed.

Animals↗
PubMed1989

A rapid mechanical vibration procedure for purifying mature (Ia positive) columnar epithelial cells from the mouse small intestine.

A mechanical vibration method previously described for isolating gut epithelium was adapted to purify murine small intestinal epithelial cells in single cell suspension with high viability, good yield, optimal purity (99% epithelial cells with no other contaminating intestinal cells), and with preservation of phenotypical and physiological properties of epithelial cells. This rapid and easy procedure did not involve the use of any chelating agent or proteolytic enzyme. Extracted gut epithelial cells were suitable for in vitro functional assays within 45 min. Cell viability, as assessed by both the trypan blue due exclusion test and by titration of lactate dehydrogenase activity in the supernatant was greater than 75% up to 7 h after epithelial cell extraction. Light microscopy analysis of the duodeno-jejunal segment before and after mechanical vibration indicated that villous but not crypt epithelium was obtained using this method. Furthermore 99% of isolated epithelial cells expressed major histocompatibility class II (Ia) antigens indicating that the method was suitable for studies of the antigen presenting capacity of gut enterocytes.

Animals↗
PubMed1989

Murine enterocytes can present soluble antigen to specific class II-restricted CD4+ T cells.

Highly purified mature epithelial cells (EC) from murine small intestinal villi (excluding Peyer's patch epithelium) were examined for their capacity to present foreign antigen to T cells. Cell suspensions composed of 99% Ia+T200- EC were able to present keyhole limpet hemocyanin to an antigen-specific class II-restricted L3T4+ T cell hybridoma, and stimulate interleukin 2 production. Antigen presentation by EC was inhibited by major histocompatibility complex class II-specific monoclonal antibodies. It is concluded that EC express functional class II molecules and may activate adjacent CD4+ T cells to induce lymphokine synthesis.

Animals↗
PubMed1989

Epithelial cell heterogeneity in mammalian thymus: monoclonal antibody to high molecular weight keratins exclusively binds to Hassall's corpuscles.

Hassall's corpuscles represent a subset of medullary thymic epithelial cells whose origin and function within the thymus still remain largely unknown. The present study shows that Hassall's corpuscles can be defined by their intracellular content in specific keratin subunits. Two monoclonal anti-keratin antibodies were used: KL1, directed to high molecular weight keratins, and KL4, specific for high and medium molecular weight polypeptides. In vivo, KL1 exclusively binds to Hassall's corpuscles of five mammalian species including mouse, rat, guinea-pig, rabbit and pig. Thus KL1 appears as an exclusive marker of Hassall's corpuscles in a large number of mammals. In vitro, thymic epithelial cells gave rise in certain species to Hassall's corpuscles. In contrast to its in vivo reactivity, KL1 never labelled Hassall's corpuscles developed in vitro. These data strongly support the following conclusions: (1) Hassall's corpuscles derive from medullary epithelial cells; (2) they represent advanced stages of thymic epithelial maturation; (3) thymic epithelial cell differentiation is impaired in vitro. Furthermore, this study provides additional evidence that thymic epithelium heterogeneity reflects different stages in epithelial maturation.

Animals↗
PubMed1989

Cellular immune response in Echinococcus multilocularis infection in humans. II. Natural killer cell activity and cell subpopulations in the blood and in the periparasitic granuloma of patients with alveolar echinococcosis.

In animal models, the development of Echinococcus multilocularis larvae has been shown to correlate with the immune status of the host, and particularly with cellular immunity. In humans, a defect in immune regulation may explain the persistence of cellular infiltration and fibrogenesis. We assessed natural killer (NK) activity in the peripheral blood mononuclear cells (PBMC) of patients with alveolar echinococcosis, and compared in 12 patients who underwent a surgical procedure the cell populations in the PBMC with those present in the periparasitic granuloma. The results indicated that (i) the NK cell activity of the PBMC was significantly altered at the lower NK cell: target cell ratios; (ii) the percentage of CD8+ cells was significantly decreased in the PBMC with an increased CD4:CD8 cell ratio; (iii) inversely, the CD8+ cells constituted the main population of T cells in the liver of most patients; and (iv) the periparasitic granuloma was mainly composed of macrophages, T cells and myofibroblasts in close association with the developing fibrosis. A relatively high number of CD4+ cells in the periparasitic granuloma of two patients with 'abortive' parasitic lesions suggested that, as it is observed in experimental E. multilocularis infection, differential evolution of the phenotypic pattern of the periparasitic granuloma could be related to resistance or sensitivity to infection by E. multilocularis in humans.

Adult↗
PubMed1987

Relationship of B cell Fc receptors to T cell recognition of Mls antigen.

The Mls locus on chromosome 1 controls the expression of cellular determinants that are responsible for stimulating mixed lymphocyte reactions between H-2-identical strains. However, the biochemical nature of Mls antigenic determinants remains undefined. It has been proposed that Ly-17 lymphoid cell surface antigens (also known as Ly.m.20.2 and LyM-1) and Mls antigens could be identical because they are both encoded by loci on chromosome 1 and display similar tissue distribution. The Ly-17 locus encodes polymorphic alleles of the IgG Fc receptor (Fc gamma R). In the present study, two approaches were used to address the question of whether Fc gamma R are involved in T cell recognition of Mls antigen. In the first approach we tested the effect of Fc gamma R blockade by heat-aggregated mouse IgG or anti-Fc gamma R monoclonal antibodies (2.4.G2) on the ability of an Ia+, Fc gamma R+ Mlsa-expressing B cell hybrid (LBB.3.4.16) to stimulate interleukin 2 secretion by an anti-Mlsa-specific T cell hybrid. We show that blockade of Fc gamma R does not inhibit the Mlsa-specific stimulation of T cells during a 24-h culture period in which Fc gamma R remain blocked. In the second approach, we derived irradiation-induced variants of LBB.3.4.16 to dissociate Fc gamma R expression and Mls antigen expression. We describe 2 LBB variants which no longer stimulate Mlsa-reactive T cells but do express Fc gamma R. Compared to parental LBB cells, the capacity of variant LBB cells to present soluble antigen to Ia-restricted T cells is unaffected. Collectively, these results indicate that Fc gamma R expression and Mlsa antigen stimulation can be dissociated. We conclude that Fc gamma R expression may be necessary, but not sufficient for T cell recognition of Mls antigen.

Animals↗
PubMed1987

Production of murine leukemia virus in the immunodeficient wasted mutant mouse is associated with the wst allele.

The recessive mutation "wasted" (wst) is responsible for a neuroimmunological syndrome and premature death in homozygous wst/wst mice. In contrast, +/wst heterozygotes appear phenotypically normal. The present study assessed the production of endogenous murine leukemia virus (MuLV) in lymphoid organs of homozygous wasted (wst/wst), heterozygous wasted (+/wst) and control wild type (+/+) mice. Neither mutant nor control mice produced ecotropic MuLV. In contrast, lymphoid organs from wst/wst and +/wst mice produced endogenous xenotropic MuLV. MuLV production was not detectable in the same organs of +/+ control mice. +/wst heterozygotes produced xenotropic MuLV in the thymus, spleen and mesenteric lymph nodes but not in the bone marrow. Wst/wst mutants produced xenotropic MuLV, but only in the thymus. These findings demonstrate an association between the production of endogenous xenotropic MuLV and the wasted mutation.

Alleles↗