摘要:

Thyroid lymphocyte RNA from a Hashimoto patient with high serum levels of autoantibodies to thyroid peroxidase (TPO) was used to construct a phage display antibody library in the phagemid vector pComb3. The library (100,000cfu) encoded IgG 1 heavy chains together with kappa light chains. Selection of the phages displaying TPO antibody on TPO-coated ELISA plates yielded a phage population enriched for surface expression of TPO antibody Fabs. 3 different Fabs specific for TPO were subsequently isolated with affinities in the region of 109molar”’. 2 of the Fabs recognised the same, or closely related, epitopes on TPO whereas the third Fab recognised a different epitope. These 2 epitopes were recognised by TPO autoantibodies in the serum of the lymphocyte donor and a series of 10 patient sera. Available sequence data showed that several non-self antibodies and non-thyroid autoantibodies use the same V kappa and VHgermline genes as TPO autoantibodies. There appeared to be no clear relationship between gene sequence or gene family usage by TPO autoantibodies of the same or similar epitope specificity.

ISSN:0891-6934    

DOI:10.3109/08916939409010651

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

Transgenic expression of the MHC (major histocompatibility complex) class II I-Akmolecule was previously shown to effectively reduce the incidence of insulitis in non-obese diabetic (NOD) mice at the age of 20 weeks. We have further characterized the expression and function of the I-Akmolecule and examined its effects on the incidence of diabetes in NOD mice. The newly expressed I-Akmolecule was recognized as an alloantigen by the T lymphocytes of normal NOD mice as shown by mixed lymphocyte reaction (MLR). The levels of endogenous I-Ag7expression on peripheral blood lymphocytes were not affected by the transgene expression. Transgenic NOD mice were completely resistant to spontaneous diabetes, but the treatment by cyclophosphamide, which effectively induces diabetes in normal NOD mice, caused diabetes, although at a much lower incidence than that of normal NOD mice. On the basis of these findings, we discuss the role of I-Akin the prevention of diabetes in NOD mice.

ISSN:0891-6934    

DOI:10.3109/08916939409010652

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

Since the 64kDa-protein glutamic acid decarboxylase (GAD) is one of the major autoantigens in T-cell mediated Type 1 diabetes, its relevance as a T-cell antigen needs to be clarified. After isolation of splenic T-cells from non-obese diabetic (NOD) mice, a useful model for human Type 1 diabetes, we found that these T-cells proliferate spontaneously when incubated with human GAD65, but only marginally after incubation with GAD67, both recombinated in the baculovirus system. No effect was observed with non-diabetic NOD mice or with T-cells from H-2 identical NON-NOD-H-2g7control mice. It has been published previously that NOD mice develop autoantibodies against a 64kDa protein detected with mouse beta cells. In immunoprecipitation experiments with sera from the same NOD mice and33S-methionine-labelled GAD, no autoantibody binding could be detected. We conclude firstly that GAD65is an important T-cell antigen which is relevant early in the development of Type 1 diabetes and secondly that there is an antigenic epitope in the human GAD65molecule recognized by NOD T-cells, but not by NOD autoantibodies precipitating conformational epitopes. Our results therefore provide further evidence that GAD65is a T-cell antigen in NOD mice, being possibly also involved in very early processes leading to the development of human Type 1 diabetes.

ISSN:0891-6934    

DOI:10.3109/08916939409010653

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

We investigated the relative roles of B cell activity, circulating immune complexes, complement concentration and kinetics of disappearance and uptake of immune complexes from the circulation in the pathogenesis of early nephritis ofMRL/lprmice. In comparison to data in control (C57BL/6J) mice, B cell activity was enhanced and the concentration of autoantibodies and endogenous immune complexes in plasma were increased, whereas complement (C3) concentration was not significantly different inMRL/lprmice. The kinetics of disappearance of radiolabeled immune complexes from the circulation were similar inMRL/lprand control mice, whereas uptake of radiolabeled immune complexes by the liver was decreased inMRL/lprmice. Features of polyclonal B cell activation and impaired mononuclear phagocyte function are early events that may set the stage for progressive systemic involvement inMRL/lprmice.

ISSN:0891-6934    

DOI:10.3109/08916939409010654

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

In order to investigate the regulation of autoimmune response to thyroglobulin (Tg), one of the thyroid autoantigens, we established a Tg-specific T cell line by stimulation of peripheral blood mononuclear cells from a healthy volunteer with Tg and characterized its cytokine production pattern. The Tg-specific Tcell line, designated DH5D1, obtained from a limiting dilution culture bore ap”Tcell receptor and was CD4 and CD45RO positive. Upon stimulation with Tg, DH5D1 secreted little or no titers of IL-2, TNF-a, and IFN-γ, whereas activation with combination of phorbor myristate acetate and calcium ionophore produced measurable levels of these cytokines. These results indicate that the Tg-specific T cell line is not defective in its capacity to produce proinflammatory cytokines and suggest that the inability of cytokine production by autoreactive T cells of healthy individuals is one fail-safe mechanism for preventing aggression of harmful autoimmune response.

ISSN:0891-6934    

DOI:10.3109/08916939409010655

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

To evaluate the involvement of T cell immunity in the thyroiditis induced in goitrous mice by iodide administration, we analyzed the immunological changes happening in the thyroid glands and lymph nodes during goiter involution in balb/c and athymic nude mice of similar background.In both balb/c and nude mice, goiter involution was characterized by thyroid cell necrosis and inflammation. In balb/c mice, the inflammatory infiltrate was made of numerous Ia+cells. Their number was unchanged during goiter development, but was significantly increased after 2 days of involution and remained high after 8 days. CD4 + and CD8 + T cells were also observed, some of which were clearly activated since they expressed the receptor for Interleukin-2 (IL-2R). The numbers of CD4 +, CD8 + and IL-2 R + T cells were increased during goiter as compared to control mice, and they reached a maximum at day 1 of involution.In nude mice, unexpectedly, CD4 + and CD8 + T cells were also found in the thyroid. Their numbers, as well as the number of la + cells, were significantly increased at the onset of involution, but they remained systematically lower than in the corresponding groups of balb/c mice.Iodide treatment of goitrous mice also induced modifications of the lymph nodes draining the thyroid: enlargement of the paracortical T zone, presence of germinal centers in cortical follicles, and increase of the density of IL-2 R + cells. Mesenteric lymph nodes taken as controls were unchanged.Thus, three observations suggest the involvement of T cell immunity in iodine-induced thyroid inflammation: 1. Infiltration of Ia +, CD4 +, CD8 + and IL-2 R+ cells. 2. Signs of stimulation in thyroid lymph nodes, 3. Significant differences between balb/c and nude mice, in which the inflammatory reaction is weaker.

ISSN:0891-6934    

DOI:10.3109/08916939409010656

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

When MRL/Mp - + / + (MRU +) mice are lethally irradiated and then reconstituted with MRL/Mp-lpr/lpr (MRL/lpr) spleen and/or bone marrow cells (BMCs), the mice develop a graft-versus-host disease (GVHD)-like syndrome which is known as lpr-GVHD. We analyzed lpr-GVHD by adoptive transfer experiments using congenic MRL/lpr-Thy-1.1 mice to distinguish the donor and recipient cells. MRL/ + mice were lethally (9.5 Gy) irradiated and then reconstituted with BMCs of MRL/lpr-Thy-1.1 mice treated with anti-Thy-1.1 monoclonal antibody (mAb) plus complement (C). The mice were sacrificed 5 to 6 weeks after bone marrow transplantation (BMT), and the spleen cells were transferred to second recipients. The second recipients (MRL/ + or MRL/lpr mice) were non-irradiated, sublethally (6 Gy) irradiated or lethally (9.5 Gy) irradiated. The lethally irradiated mice were also injected with syngeneic BMCs treated with anti-Thy-1.2 mAb plus C. When whole spleen cells (1×108) were injected into lethally irradiated MRL/+ mice, the mice showed short survival (1.2 - 1.5 months) and severe histological changes in the spleen (atrophy and fibrosis), liver (lymphoid infiltration in the Glisson's sheath) and lung (lymphoid infiltration around the bronchus and vessel). The sublethally irradiated MRL/ + mice at 2 months after transfer showed histological changes similar to the lethally irradiated MRL/ + recipients, although the former survived more than 3 months, suggesting that histological changes do not reflect on mortality. These GVH-like diseases were not transferable to MRL/lpr mice; they developed autoimmune diseases. The percentage of donor CD4+cells in the lethally irradiated MRL/lpr mice was similar to that in the lethally irradiated MRL/ + mice, but CD8+cell numbers were substantially less. The effector cells were characterized using lethally irradiated MRL/+ mice as second recipients. The injection of T cell-enriched (nylon wool-nonadherent) effector cells induced shorter survival and more severe splenic atrophy. In contrast, the injection of effector cells treated with anti-Thy-1.1 mAb plus C induced longer survival, indicating that T cells are effector cells. The injection of CDS+cells induced shorter survival than that of CD4+cells. The injection of a mixture of CD4+and CD8+cells showed similar survival to that of CD8+cells alone. The histological grades of spleens strongly correlated with the percentage of donor CD4+cells, but only loosely with the percentage of donor CD8+cells. These findings suggest that CD8+T cells are responsible for mortality, while CD4+T cells induce splenic atrophy and fibrosis in the development of lpr-GVHD. We also discuss these findings in relation to possible mechanisms of lpr-GVHD.

ISSN:0891-6934    

DOI:10.3109/08916939409010657

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

To study the mechanisms involved in the pathogenesis of the blood- brain barrier (BBB) breakdown in autoimmune demyelinating diseases, such as experimental allergic encephalomyelitis (EAE), we investigated the cell interactionin vitrobetween myelin basic protein (MBP)- specific encephalitogenic T cells and normal and inflamed cerebral endothelial cells, and the cytotoxic effect of antigen specific T cell lines on normal and inflamed cerebral endothelial cells. The importance of relationship between cell surface adhesion and cytotoxic T lymphocyte (CTL) was examined by monoclonal antibodies (mAb) against adhesion receptors. The adhesion of encephalitogenic T cells to inflamed endothelial cells was significantly increased as compared with normal endothelial cells (P 0.001). The percentage lysis of inflamed endothelial target cells was significantly increased by incubation with MBP-encephalitogenic T cell lines in the presence of MBP as compared with those of normal endothelial targets (P<0.0001). Intercellular adhesion molecule-1 (ICAM-1) is not involved in T cell adhesion to endothelial cells or cytotoxic endothelial cell lysis. Antibodies against human a 4 integrin (HP 2/1) andβ1 (Al 1B2) inhibited T cell adhesion, but did not block cytotoxic endothelial cell lysis.These results indicate that T cell adhesion to inflamed cerebral endothelial cells and cytotoxicity of T cells for cerebral endothelial cells may play a central role in the breakdown of the BBB and development of inflammatory lesions in the central nervous system(CNS).

ISSN:0891-6934    

DOI:10.3109/08916939409010658

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

The autoantigen in adjuvant arthritis in Lewis rats is still unknown despite the knowledge that the 65 kDa mycobacterial heat-shock protein (hsp) is involved in the disease process. T cells and antibodies obtained from rats with adjuvant arthritis respond to chondrocyte membrane antigen(s). In Western blots a 65 kDa chondrocyte membrane protein (CH65) is stained by sera from arthritic rats. In addition, spleen cells from rats with adjuvant arthritis proliferate in vitro to chondrocyte membranes and CH65 as antigens. Furthermore, pretreatment of rats with CH65 or mycobacterial hsp65 but not human hsp60, induces a significant retardation of the onset of adjuvant arthritis in Lewis rats. The data suggest that CH65 is a potential autoantigen involved in the pathogenesis of adjuvant arthritis in Lewis rats.

ISSN:0891-6934    

DOI:10.3109/08916939409010659

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor

摘要:

T cell involvement in the inflammatory process of Crohn's Disease (CD) is evident by an increase in activated T cells and their cytokines in actively inflamed CD tissue. It has been suggested that CD may involve a superantigen based on the observation that a significant proportion of CD patients express elevated levels of VfJ8 + T cells in their peripheral blood compared to normal controls. In order to determine whether a superantigen might play a role in the pathogenesis of CD we have compared the TCR repertoires of four pairs of monozygotic twins discordant for CD. By using monozygotic twins, we could rule out the effects of HLA and other genes on the TCR repertoire. The TCR repertoires were analyzed by using a panel of V-segment-specific rnAb and by quantitative polymerase chain reaction (qPCR) using VP-specific oligonucleotide primers. In all cases the TCR repertoires of the affected and unaffected sibs were strikingly similar. We did not observe any TCR segment that was consistently altered in frequency or expression levels in all of the affected sibs compared to their identical twin. Furthermore, we did not see an increase in V(38 + T cells in the peripheral blood of the CD sibs relative to their normal counterpart. These studies suggest that the presence of CD does not alter the TCR repertoire of peripheral blood in any obvious way and argue against the role of a superantigen in the etiology or pathogenesis of CD.

ISSN:0891-6934    

DOI:10.3109/08916939409010660

出版商:Taylor&Francis    

年代:1994

数据来源: Taylor