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J Charreire

Publications and source records attributed to J Charreire.

At least 55 records · Page 3Linked to original sources
PubMed1989

Characteristics of cytotoxic thyroglobulin-specific T cell hybridomas.

Clones of cytotoxic thyroid-specific T cell hybridomas were generated by fusion of thyroglobulin-primed, "in vitro"-boosted CBA lymph node cells with the AKR-derived lymphoma cell line BW 5147. One hundred and thirty one clones were obtained. Among them, 15 were able to induce the lysis of 51Cr-labeled syngeneic thyroid epithelial cells after 5 h of incubation at 37 degrees C. Two T cell clones, HTC1 and HTC2, were further studied. These clones, which exhibit cell surface characteristics of cytotoxic cells, were specific for only syngeneic thyroid cells (allogeneic thyroid cells or syngeneic epithelial cells were never lysed by these hybridomas). Moreover, by using Ag-pulsed syngeneic macrophages as targets, syngeneic cytotoxicity was shown to be specific for thyroglobulin and not for a nonrelated Ag. The lysis obtained with these autoreactive thyroid-specific T cell clones is restricted to class I major histocompatibility Ag. This property is assessed by both the blocking of syngeneic cytotoxicity toward thyroid epithelial cells or thyroglobulin-pulsed macrophages only by anti-class I mAb and by the detection of specific lysis of target cells exclusively when effector hybrid cells and target thyroid epithelial cells or thyroglobulin-pulsed macrophages shared at least class I major histocompatibility Ag.

Animals↗
PubMed1988

Genetic control of the humoral response to cryptococcal capsular polysaccharide in mice.

Cryptococcus neoformans is responsible for opportunistic infections in patients with cellular immune defects. However, C. neoformans-specific capsular polysaccharide antibodies have been shown to participate in host defenses during cryptococcosis. We investigated the humoral response after primary immunization in various inbred strains of mice and the genetic control. Our data strengthen the arguments for the T-independent type-2 nature of cryptococcal antigen, since CBA/N mice were unable to produce specific antibodies. They show that the influence of the genetic background is predominant for the good response with at least four independent autosomal genes governing this response, including an Igh control as reported for other polysaccharides. Immunization of intra-H-2 recombinant mice on a B10 background allowed us to identify a major histocompatibility complex control located in the subregion E alpha. The genetic control of antibody production following immunization with cryptococcal polysaccharide might explain the high variability of humoral responses during cryptococcosis.

Animals↗
PubMed1987

Experimental autoimmune thyroiditis induced by a 5-10-kDa tryptic fragment from porcine thyroglobulin.

Monoclonal autoantibodies obtained using the native porcine thyroglobulin (Tg) molecule for immunization were shown to react against a defined epitope of the Tg molecule. Its biochemical characterization was undertaken, using trypsin treatment of Tg, followed by gel filtration, affinity chromatography, sodium dodecyl sulfate-polyacrylamide gel electrophoresis and high pressure liquid chromatography analysis. Immunoreactivity tested by immunoblotting with appropriate monoclonal anti-Tg antibody allowed the detection of one peptide fragment of 5-10 kDa, after limited proteolysis with trypsin. We demonstrated that this peptide reacts exclusively with monoclonal anti-Tg antibodies which block in vitro proliferative T cell response; moreover, the 5-10-kDa tryptic fragments from porcine Tg were able to induce thyroiditis when injected into normal CBA mice, while porcine Tg depleted from these fragments was not able to do so.

Animals↗
PubMed1987

Primary syngeneic sensitization on monolayers of thyroid epithelial cells. X. Inhibition of T-cell proliferative response by thyroglobulin-specific monoclonal antibodies.

We studied the biochemical properties and the reactivity of 13 monoclonal anti-thyroglobulin antibodies, obtained by fusing P3 X 63 (8653) myeloma cells with spleen cells from CBA and C57BL/6 mice previously immunized with syngeneic thyroglobulin. We demonstrated that among the 13 anti-thyroglobulin monoclonal antibodies that we studied, each of them was specific for only syngeneic thyroglobulin, as each of them was able to cross-react with heterologous or xenogeneic thyroglobulin. Two major kinds of monoclonal antibodies were obtained: the first ones are able to block in vitro primary syngeneic sensitization and, moreover, they mutually compete for thyroglobulin binding; the second ones are not involved in this in vitro PSS and do not compete for binding to thyroglobulin. These results suggest that a defined particular epitope, borne by thyroglobulin and expressed on the thyroid epithelial cells, is responsible for in vitro primary syngeneic sensitization.

Animals↗
PubMed1987

Protection of mice against experimental cryptococcosis by anti-Cryptococcus neoformans monoclonal antibody.

Humoral immunity does not play a prominent role during experimental cryptococcosis. However, previous studies have shown that immunoglobulin G (IgG) anti-Cryptococcus neoformans antibodies can mediate cell-dependent yeast killing in vitro. Therefore, the protective effect of a previously described monoclonal IgG1 anti-C. neoformans antibody (E1) administered intraperitoneally 24 h before intravenous infection with a C. neoformans serotype A strain was evaluated in mice. Heavily infected (3 X 10(6) cells) untreated mice died in 2.9 +/- 0.5 (standard deviation) days. Survival time was 17.9 +/- 1.6 days for mice treated with 100 micrograms of E1 and 3.0 +/- 0.7 days for mice treated with 100 micrograms of a monoclonal IgG1 anti-thyroglobulin antibody used as a control. Protection was dose dependent and required at least 10 micrograms of E1 (mean antibody concentration in serum +/- standard deviation, 6.6 +/- 2.3 micrograms/ml). Insufficient concentrations of IgG anti-C. neoformans antibody could explain previous negative results obtained with polyclonal immune serum. After infection with a smaller inoculum (5 X 10(3) to 5 X 10(4)), the protective effect of E1 was confirmed by the presence of fewer CFUs in the spleens and brains of treated mice than in those of controls. CFU were still detected in the brains of protected mice 5 days after infection, although soluble antigen was negative in sera. These results suggest that passive serotherapy with monoclonal IgG antibodies could participate in the prevention or treatment of experimental cryptococcosis.

Animals↗
PubMed1987

Covalent cross-linking of thyrotropin to its receptor on cloned hybrid human thyroid cells (GEJ).

Purification of the TSH binding sites from cloned human thyroid hybrid cells (GEJ) was performed after biosynthetic labeling of the cells, and affinity chromatography on a human TSH-Sepharose column and polyacrylamide gel electrophoresis in sodium dodecyl sulfate. The relative Mr of the GEJ cell TSH receptor (TSH-R) was found to be approximately 48,000. This was confirmed by cross-linking [125I]TSH to GEJ binding sites with two homobifunctional agents: dimethyl suberimidate and disuccinimidyl suberate. We found that the cross-linked complexes had a Mr of 78,000 thus yielding a TSH-R size of 48 kilodaltons, after subtraction of the 30 kilodalton TSH, based upon the cross-linking of one TSH molecule per binding site. Moreover, the absence of a dithiothreitol effect demonstrated that the TSH binding site on GEJ cells was formed by a single chain lacking disulfide bonds. Finally trypsinization of TSH/TSH-R complexes detected two tryptic sites yielding two fragments with respective Mr of approximately 2,000 and 15,000.

Cell Membrane↗
PubMed1987

Normal suppressive T cell function of Epstein-Barr virus-induced B cell activation in Graves' disease.

Several studies have demonstrated abnormalities of T cell regulation of Epstein-Barr virus (EBV)-induced B cell activation in systemic autoimmune diseases, such as rheumatoid arthritis, systemic lupus erythematosus, and systemic sclerosis. To investigate whether this abnormality is a common feature of other autoimmune diseases, we studied 10 EBV-immune normal subjects and 22 EBV-immune patients with Graves' disease (GD); 11 had newly diagnosed hyperthyroidism, and 11 had received carbimazole treatment for hyperthyroidism for at least 6 months. Peripheral B lymphocytes infected with EBV were cultured for 20 days in the presence or absence of autologous T cells at different ratios. Immunoglobulins M and G secretion into the supernatants was determined using an enzyme-linked immunosorbent assay. The extent of suppression when T cells were added, as measured by a suppression ratio, was not significantly different in normal subjects and newly diagnosed GD patients (0.65 vs. 0.63 on the 16th day and 0.77 vs. 0.72 on the 20th day of culture, respectively). In carbimazole-treated patients, the appearance of functional suppressor T cells was delayed slightly, but the overall suppression ratios on the 16th and 20th days were normal. Thus, a T cell regulation abnormality of EBV-induced B cell activation could not be demonstrated in patients with untreated hyperthyroid GD, suggesting that the autoimmune reactivity in such patients is probably dependent upon a specific thyroid suppression defect rather than a generalized suppression defect.

Adult↗
PubMed1987

Properties of thyrotropin receptor on cloned hybrid human thyroid cells.

Purification of the thyrotropin (TSH) binding sites from cloned human thyroid cells (GEJ) was performed after biosynthetic labelling of the cells, affinity chromatography on a human TSH-sepharose column and polyacrylamide gel electrophoresis in sodium dodecyl sulphate (PAGE-SDS). The relative molecular mass (Mr) of the GEJ cell TSH receptor (TSH-R) was approximately 48,000. This was confirmed by cross-linking [125I]TSH to GEJ binding sites with two homobifunctional agents: dimethyl suberimidate and disuccinimidyl suberate. Moreover, the absence of a dithiothreitol effect demonstrated that the TSH binding site on GEJ cells is formed by a single chain lacking disulphide bonds.

Cell Line↗
PubMed1986

Human autologous rosette-forming cells. V. Study of MHC control in erythrocyte-lymphocyte interaction.

The role of the major histocompatibility complex (MHC) in human autorosette formation was studied. On a large series of healthy subjects who were typed for HLA antigens, we tested in blind rosette formation with 90 autologous and 295 allogeneic red blood cells (RBC). We found that the mean levels of auto- and allorosettes were similar, being significantly higher in females than in males. However, we failed to find any role for blood group antigens and any involvement of HLA antigens in the interactions between lymphocytes and RBC in rosette formation. Moreover, high or low autorosette levels were not associated with a particular HLA allele. The comparison of individual percentages of auto- and allorosettes indicated that 51% of the subjects displayed identical levels of auto- and allorosettes whereas 29% formed preferentially rosettes with auto- rather than allo-RBC and 20% exhibited lower autorosette than allorosette levels. Among the group of subjects who were better responders for autorosettes than allorosettes, we found an increased frequency of the haplotype A29, B44. Taken together these findings suggest that in contrast to the murine situation, the autorosetting phenomenon in humans is not HLA restricted.

Erythrocytes↗
PubMed1986

Thyroid stimulating immunoglobulin (TSI) synthesis by pokeweed mitogen (PWM) stimulated peripheral blood lymphocytes (PBL) from Graves' disease (GD) patients.

Lymphocytes from freshly diagnosed untreated GD patients can be induced to produce in-vitro IgG, and more precisely TSI in the presence of PWM, a T cell dependent polyclonal activator of B cells. TSI were measured from days 8 to 41 of culture, using a functional cAMP production assay, after the deposition of culture supernatants on HTEC. Spontaneous or PWM induced IgG synthesis was optimal on day 28 of culture for GD MNC, with amounts of IgG in PWM stimulated GD culture supernatants twice those found in unstimulated GD MNC. Moreover only PWM stimulated GD MNC produce IgG which induce cAMP production by cultured HTEC, with a significant correlation between in-vitro IgG and cAMP levels.

Adult↗
PubMed1986

Syngeneic sensitization of mouse lymphocytes on monolayers of thyroid epithelial cells. IX. Thyroid epithelial cells are antigen presenting cells.

We observed T lymphoblast generation after three days of culture of normal spleen lymphocytes on monolayers of syngeneic thyroid epithelial cells. It appears that only these T lymphoblasts sensitized on thyroid monolayers are specifically labelled by fluorescein-conjugated thyroglobulin. In this study, the role of thyroglobulin, and the manner in which it is presented to syngeneic T cells bearing receptors for thyroglobulin were investigated. It appears that thyroglobulin plays a key role in primary syngeneic sensitization of spleen cells in vitro, but its action is not exclusive. Proteins, which are encoded by a gene located in the I-A subregion level of the major histocompatibility complex, are capable of inducing a primary proliferative signal when the presentation of syngeneic class II antigens by syngeneic thyroid epithelial cells is simultaneous. In addition, thyroglobulin-pulsed macrophages are not able to do so. In contrast, once this primary syngeneic T cell proliferation has been accomplished, soluble thyroglobulin is sufficient to induce a secondary response by these syngeneic T cells.

Animals↗
PubMed1985

Syngeneic sensitization of mouse lymphocytes on monolayers of thyroid epithelial cells. VII. Generation of thyroid-specific cytotoxic effector cells.

During primary syngeneic sensitization of lymphocytes on monolayers of thyroid epithelial cells (TEC), lymphoblasts are generated as assessed by thymidine uptake. When these thyroid-sensitized lymphoblasts are deposited onto 51Cr labeled TEC used as target cells, syngeneic cytotoxicity (SC) occurs after 5 hr. The effector cell of this SC is a T lymphocyte, belonging to the Lyt-2 T-cell subset. Moreover, blocking experiments demonstrated that SC involves class I major histocompatibility complex and thyroglobulin (Tg) antigens. These data demonstrate that SC can be compared to the classical hapten or virus self-mediated cytotoxicity, but in this case Tg plays the role of these agents. The in vivo relevance of this SC is discussed.

Animals↗
PubMed1985

Induction of Ia antigens on thyroid cultures by syngeneic T lymphocytes: a model of autoimmune disease.

We previously reported that the expression of Ia antigens on cultured monolayers of murine thyroid epithelial cells (TEC) occurred with a particular distribution exclusively on the basal part of the cultured thyroid cells, while class I antigens of the major histocompatibility complex (MHC) are only detected on the apical surface. It appears that deposition of syngeneic lymphocytes induces, 24 h later, Ia expression on the apical side of cultured TEC, the surface that is in direct contact with the responder lymphocytes during syngeneic sensitization of T lymphocytes. We hypothesized that this phenomenon could represent, in syngeneic situations, the restriction process in antigen recognition by T cells, as demonstrated by Ia restricted primary syngeneic sensitization (PSS) on murine TEC.

Animals↗
PubMed1985

Monoclonal human thyroid cell line GEJ expressing human thyrotropin receptors.

By using the hybridoma technology, a monoclonal human thyroid cell line was obtained by fusing fresh normal human thyroid cells with a human lymphoblastoid cell line. The resultant cell line, called GEJ, has been selected for its expression of thyrotropin (TSH) receptors and has morphological and functional characteristics of normal human thyroid cells. In the presence or absence of human TSH, the GEJ cell line accumulates iodide, produces thyroid hormones, expresses thyroid membrane antigens, and binds approximately equal to 600 molecules of TSH per cell. The binding site for TSH has all the characteristics of specific receptor (i.e., temperature and time dependencies, dissociation of bound TSH only by high amounts of TSH, and a glycoprotein nature). Scatchard analysis described a curvilinear graph with two dissociation constants (Kd = 0.12 X 10(-9) M and 1.6 X 10(-9) M) with, respectively, 1.2 X 10(3) and 7.2 X 10(3) binding sites per cell. This human thyroid cell line that expresses TSH receptors could be a useful tool for the study of human thyroid disorders.

Cell Line↗
PubMed1985

Syngeneic sensitization of mouse lymphocytes on monolayers of thyroid epithelial cells (TEC). VIII: Gamma interferon induced Ia antigen expression on TEC cultures.

We previously reported that the expression of Ia antigens on cultured monolayers of murine thyroid epithelial cells (TEC) occurred with a particular distribution exclusively on the basal part of the cultured thyroid cells, while class I antigens of the major histocompatibility complex (MHC) and thyroglobulin (Tg) are only detected on the apical surface. It appears that, 24 to 48 h after the deposition of syngeneic lymphocytes, Ia antigens are expressed on the apical side of cultured TEC, i.e. the surface that bears Tg and is in direct contact with the responder lymphocytes during syngeneic sensitization of T lymphocytes. We hypothesized that this phenomenon could represent, in syngeneic situations, the restriction process in antigen recognition by T cells, as demonstrated by I-A restricted primary syngeneic sensitization (PSS) on murine TEC. Moreover, we found that the addition of either PSS supernatants or gamma interferon (gamma IFN) to monolayers of TEC induced the expression of Ia antigens on the apical cell surface of these TEC cultures 24 to 48 h later. Taken together our data demonstrate that during the first hours of PSS, class II antigen and Tg are expressed on murine TEC cultures. This simultaneous expression of these antigens explains the strict in vitro I-A restricted PSS we previously observed.

Animals↗