Iodine and thyroid autoimmune disease in animal models.

Thyroid autoimmune diseases are complex, polygenic afflictions the penetrance of which is heavily dependent on various environmental influences. In their pathogenesis, an afferent stage (enhanced autoantigen presentation), a central stage (excessive expansion and maturation of autoreactive T and B cells), and an efferent stage (effects of autoreactive T cells and B cells on their targets) can be discerned. At each stage, a plethora of inborn, endogenous or exogenous factors is able to elicit the abnormalities characteristic of that stage, thus opening the gateway to thyroid autoimmunity. Iodine is an important exogenous modulating factor of the process. In general, iodine deficiency attenuates, while iodine excess accelerates autoimmune thyroiditis in autoimmune prone individuals. In nonautoimmune prone individuals, the effects of iodine are different. Here iodine deficiency precipitates a mild (physiological) form of thyroid autoimmune reactivity. Iodine excess stimulates thymus development. Iodine probably exerts these effects via interference in the various stages of the autoimmune process. In the afferent and efferent stage, iodine-induced alterations in thyrocyte metabolism and even necrosis most likely play a role. By contrast, in the central phase, iodine has direct effects on thymus development, the development and function of various immune cells (T cells, B cells macrophages and dendritic cells) and the antigenicity of thyroglobulin.     

Mycophenolate mofetil in animal models of autoimmune disease

Mycofenolate mofetil (MMF-Cellcept) is an immunomodulatory drug utilized extensively in transplant medicine. The efficacy of regimes including Cellcept in preventing allograft rejection, and in the treatment of rejection, is now firmly established. The immunosuppressive actions of this drug enabled the investigation for the beneficial effects in autoimmune diseases. We review the evidence for the contribution of MMF in autoimmunity in animal models of systemic lupus erythematosus (SLE), mercury induced autoimmune glomerulonephritis, diabetes mellitus, experimental autoimmune uveoretinitis, and experimental allergic encephalitis. MMF has an influence on the T and B cell pathways. It is immunosuppressive and anti-inflammatory.     

CD5 B lymphocyte antigen in monoclonal gammopathy.

Because B lymphocytes bearing the CD5 antigen have been involved in many B-cell malignancies, we have investigated the presence of the CD5 B-cell antigen on B and plasma cells in monoclonal gammopathy. Quantification of CD5 B cells was made in the peripheral blood of seven individuals with monoclonal gammopathy of undetermined significance (MGUS) and in that of 21 patients with multiple myeloma (MM). The bone marrow of ten patients with MM was also studied. Patients with progressive MM presented a significant reduction in both B and CD5 B lymphocytes (i.e., percentages and absolute numbers), when compared with individuals with MGUS and patients with stable MM. These latter individuals and patients did not differ from healthy donors. No CD5 B cells were found in the bone marrow of patients with MM. Moreover, no CD5 antigen could be detected on eight freshly established human myeloma cells lines including six totally dependent on interleukin-6. However, it was weakly expressed on two standard myeloma cell lines not requiring exogenous interleukin-6 (i.e., RPMI 8226 and U 266). In conclusion, our data show mainly an overall reduction of the polyclonal CD5 B lymphocytes similar to what is observed for the other polyclonal B lymphocytes in patients with active MM. Finally, the expression of the CD5 antigen human myeloma cell lines is not constant.     

T lymphocyte subsets in autoimmune thyroid diseases and subacute thyroiditis detected with monoclonal antibodies

Peripheral T lymphocyte subsets were analysed with monoclonal antibodies, by highly standardized fluorescence-activated cell sorter analysis instead of manual counting by the indirect immunofluorescence method, in autoimmune thyroid diseases and subacute thyroiditis. Total lymphocyte counts were increased in patients with thyrotoxic Graves' disease and subacute thyroiditis. The percentage of total T (Leu 1) cells was significantly lower in patients with thyrotoxic Graves' disease and Hashimoto's disease with destructive thyrotoxicosis than in normal subjects. No significant changes were observed in the percentages of suppressor-cytotoxic T (Leu 2a) cells or helper-inducer T (Leu 3a) cells or in the Leu 3a-Leu 2a ratio in different groups of patients. There were no correlations between the percentages of E rosette-forming cells and Leu 1 cells and between the percentages of T gamma cells and Leu 2a cells in normal subjects and patients. The peak position of fluorescence intensity of Leu 2a cells showed a significant sex difference even in normal controls. The most important finding was a significant decrease in the peak position of Leu 2a cells in patients with thyrotoxic Graves' disease and with hypothyroid or thyrotoxic Hashimoto's disease. These findings indicate the significant association of qualitative, but not quantitative, abnormality of suppressor-cytotoxic T (Leu 2a) cells with thyroid dysfunction in autoimmune thyroid diseases.     

Differential priming of CD8 and CD4 T-cells in animal models of autoimmune hepatitis and cholangitis

The pathogenesis of autoimmune liver diseases is poorly understood. Animal models are necessary to investigate antigen presentation and priming of T-cells in the context of autoimmunity in the liver. Transgenic mouse models were generated in which the model antigen ovalbumin is expressed in hepatocytes (TF-OVA) or cholangiocytes (ASBT-OVA). Transgenic OT-I (CD8) or OT-II (CD4) T-cells specific for ovalbumin were adoptively transferred into TF-OVA and ASBT-OVA mice to induce in vivo priming of antigen-specific T-cells. T-cell migration and activation, as well as induction of liver inflammation, were studied. OT-I T-cells preferentially located to the liver of both mouse strains whereas no migration of OT-II T-cells to the liver was observed. OT-I T-cells proliferated in the liver of TF-OVA mice and the liver and liver draining lymph nodes of ASBT-OVA mice. OT-II CD4 T-cells were activated in spleen and liver draining lymph node of TF-OVA mice but not in ASBT-OVA mice. Transfer of OT-I T-cells led to histologically distinct inflammatory conditions in the liver of ASBT-OVA and TF-OVA mice and caused liver injury as determined by the elevation of serum alanine aminotransferase. CONCLUSION: An antigen expressed in hepatocytes is presented to CD8 and CD4 T-cells, whereas the same antigen expressed in cholangiocytes is presented to CD8 but not CD4 T-cells. In both models, activation of CD8 T-cells occurs within the liver and causes liver inflammation. The models presented here are valuable to investigate the priming of T-cells in the liver and their role in the development of autoimmune disease of the liver.     

Pristane induced arthritis in mice. IV. Immunotherapy with monoclonal antibodies directed against lymphocyte subsets.

Pristane induced arthritis (PIA), a seropositive experimental disease model in mice, was used to investigate the influence of immunotherapy with monoclonal antibodies against lymphocyte subsets. Treatment with L3T4, a monoclonal antibody specific for murine CD4+ T cells, significantly reduced the incidence of pristane arthritis, and delayed the disease onset. Monoclonal antibody to Lyt2, the murine CD8+ T cell marker, significantly reduced the levels of rheumatoid factor in pristane injected animals compared with controls, but did not influence the clinical course of PIA. Our experiments demonstrate the ability of anti-CD4 antibodies to modify the course of PIA, and provide support for the hypothesis that CD4+ T lymphocytes have an important role in the pathogenesis of this experimental autoimmune arthritis.     

Study of B and T lymphocyte surface markers in breast cancer patients using anti-B and anti-T cell monoclonal antibodies

The immune status of 34 breast cancer patients was investigated by measuring several parameters of peripheral blood lymphocytes--monoclonal antibodies against T cell (Leu-1) and B cell (HLA-DR) antigens, and against cytotoxic/suppressor (Leu-2a) and helper/inducer T cells (Leu-3a); E rosette formation as a T cell marker and surface Ig as a B cell marker; FcIgG receptor expression; and mitogen responsiveness of the peripheral blood lymphocytes to PHA, Con A, and PWM. Most of the patients had normal percentages of B and T cells and T cell subsets but there was a trend to lower percentages of T cells and their subsets in stage IV patients. Due to lymphopenia in stages I and IV and in patients which had received radio- or chemotherapy, the total number of B and T cells and T cell subsets was less in these groups than in the controls. The percentage of FcIgG positive cells was higher in these groups than in controls and therefore the absolute number remained unchanged. In general, a decrease in T cells seems to be indicative of a poor prognosis. Mitogen responsiveness does not have prognostic significance since a patient in stage III, in good general health, had a low mitogenic response and a terminal stage IV patient had a normal mitogenic response.     

Detection of human lymphocyte subpopulations by using monoclonal antibodies and protein A-coated erythrocytes

The results obtained by using the protein A-rosette assay for human peripheral blood lymphocytes treated with a series of monoclonal antibodies were very close to the estimates obtained by indirect fluorescence. The percentages of T3-, T4-, T8- and DR-positive cells (T3 = T lymphocytes, T4 = helper T lymphocytes, T8 = suppressor T lymphocytes, DR = B, L and null cells) in normal and pathological peripheral blood were found to vary within the limits reported by many other authors using different techniques for the identification of cells binding the specific monoclonal antibody.     

Development and application of CD19-specific T cells for adoptive immunotherapy of B cell malignancies

The graft-versus-leukemia (GVL)-effect achieved by donor-derived T cells arising from transplanted allogeneic hematopoietic stem cells or given as donor-leukocyte infusions (DLI) after allogeneic transplant, demonstrates that donor-derived T cells can eradicate B-lineage malignancies. However, graft-versus-host-disease (GVHD) occurring after allogeneic hematopoietic stem-cell transplant (HSCT) or polyclonal DLI can limit the efficacy of these interventions. This toxicity can be avoided by using autologous T cells and/or tumor-specific cytotoxic T lymphocytes (CTLs). To generate antigen-specific T cells that can be derived from the allogeneic donor or the patient, we have genetically manipulated T cells to express a CD19-specific chimeric immunoreceptor. This renders T cells specific for CD19, a cell surface molecule found on B-lineage leukemia and lymphoma. This review will demonstrate the redirected specificity of CD19-specific T cells and implementation of clinical trials using these cellular agents.     

Relevance, advantages and limitations of animal models used in the development of monoclonal antibodies for cancer treatment

Antibody humanisation through recombinant DNA technology was a key step in allowing monoclonal antibodies (mAbs) to reach the clinic, particularly for the treatment of cancer. As a consequence, they are less adapted to animal studies, although these studies continue to be important tools to study antibody distribution and action at the level of a whole organism. Moreover, preclinical studies in animals are mandatory before the approval of biologics license applications for mAbs by the U.S. Food and Drug Administration (FDA) or European Agency for the Evaluation of Medicinal Products (EMEA). Different parameters should be taken in consideration before starting animal experiments with recombinant mAbs, including antibody cross-reactivity, immunogenicity, pharmacokinetics, and possible interactions with the host immune system. The various interspecies differences are reviewed and discussed in light of the pharmacological properties expected in patients. In doing so, this article aims to provide a critical review of the animal models used in preclinical studies of mAbs for cancer treatment. In particular, their relevance, advantages and limitations will be discussed.     

Characteristics of the PIVKA-II found in hepatocellular carcinoma,investigation using monoclonal antibodies MU-3 and 19B7

We classified PIVKA-II into two subtypes using a new monoclonal antibody (19B7) to PIVKA-II and a previously available monoclonal antibody (MU-3) and demonstrated differences in composition of PIVKA-II subtypes between HCC and benign liver diseases. These two monoclonal antibodies recognize almost the same site of PIVKA-II molecule, and the three-dimensional conformation of this site due to Gla formation might be important in differences of recognition by the two antibodies.     

Contribution of animal models to the study and treatment of systemic autoimmune disease

Animal models of autoimmune diseases, either spontaneous or induced, have been very useful tools to investigate the mechanisms involved in the pathogenesis of human autoimmune diseases as well as in the design of new therapeutic strategies for their treatment. The development of biotechnology and molecular biology resulted in the production of transgenic animals overexpressing or lacking a given protein. As a result of this technology, a great number of animal models of human diseases have been developed in recent years. A further evolution in transgenic methodology allows the selective control of gene expression in a particular organ or tissue at desired time points during embryonic or postnatal development. In the present article the authors discuss the advantages and inconveniences of animal models and describe the most frequently employed models in the study of 4 rheumatologic syndromes with an autoimmune origin: rheumatoid arthritis, systemic lupus erythematosus, scleroderma, and spondiloarthritis.     

Intrahepatic lymphocyte subpopulation defined by monoclonal antibodies in anti-HBe positive type B chronic active hepatitis

The composition of the mononuclear cell infiltrates in the liver was studied in patients with hepatitis B virus (HBV)-induced chronic active hepatitis (CAH). Lymphocyte subpopulations as defined by Leu monoclonal antibodies (Leu-1: pan T cell, Leu-2a: cytotoxic/suppressor T cell, Leu-3a: helper/inducer T cell, Leu-7: natural killer/K cells, and Leu 10: B cell) and distribution of both HBsAg and HBcAg in the liver have been evaluated in 10 anti-HBe-positive patients compared to 36 HBeAg-positive ones. In anti-HBe-positive patients, a general decrease of Leu-1+ cells associated with decreased numbers of Leu-2a+ and Leu-3a+ cells were observed in both portal/periportal and lobular areas. In 3 patients who had been seroconverted to anti-HBe longer than 17 months before the time of liver biopsy, there was a tendency toward a more decrease of Leu-2a+ cells and a higher ratio of Leu-3a+/Leu-2a+ cells. In respect of viral replication in the liver, HBcAg and membranous HBsAg was clearly decreased in anti-HBe-positive patients as compared with HBeAg-positive ones. These findings suggest that in patients with CAH, T cell-mediated cytotoxicity to HBV-infected hepatocytes is diminished in accordance with the decrease of active HBV replication shown by seroconversion from HBeAg to anti-HBe.     

Detection of Rh D-associated epitopes in human and animal tissues using human monoclonal anti-D antibodies

The distribution of Rh D-associated epitopes in human and animal tissues has been assessed by immunochemical techniques using six human monoclonal anti-D antibodies. The IgM antibody MAD-2 reacted predominantly with endothelial cells lining blood vessels and with animal leucocytes and human leucocytes from both Rh D-positive and Rh D-negative donors. Immunoblotting revealed reactivity with a 55 kDa tissue component which was most prominent in homogenates of heart, lung and spleen. In contrast, the IgG antibodies UCHD4 and FOG-1 stained smooth muscle, and UCHD4 in addition weakly stained cardiac and skeletal muscle and the glomeruli of kidney. Immunoblotting with UCHD4 revealed reactivity with a 27 kDa tissue component which was most prominent in heart homogenates. The results show that the six monoclonal anti-D antibodies recognize at least four different epitopes and that Rh D-associated epitopes may occur in non-erythroid cell types.     

Prospects for radiolabeled monoclonal antibodies in metastatic disease

Many monoclonal antibodies are now available that bind to human cancer cells with varying degrees of specificity. These antibodies can be labeled with various radionuclides, permitting tumor sites in the body to be imaged with scintillation cameras. SPECT, the emission counterpart of x-ray computed tomography, provides both qualitative and quantitative information in three dimensions about antibody distribution. We have detected a metastasis as small as 5 mm in a patient, and the theoretical limit of detection size is less than 1 mm. Tumors that are imaged with radiolabeled antibodies can be effectively treated with the same substance (radioimmunotherapy).     

B cells CD19+ in patients with B-cell chronic lymphocytic leukaemia and autoimmune haemolytic anaemia

The study presents results of B and T lymphocytes population analysis in patients with chronic lymphocytic leukaemia B cells and autoimmune haemolytic anaemia (CLL-B + AIHA). We evaluated the following groups of patients: (1) with newly recognized CLL-B and co-existent AIHA (untreated), (2) after short-term treatment with corticosteroids, (3) after treatment with chemotherapy and corticosteroids. The control groups were made of patients with CLL-B without AIHA. The populations of lymphocytes and determination of cells immunophenotype were performed by means of flow cytometry. The analysed data were obtained from 25 patients. The untreated patients with CLL-B + AIHA presented significantly more numerous population of neoplastic cells CD19+ CD5+ in comparison with patients without AIHA. The patients with AIHA showed a reduced percentage of B CD19+ CD22+ cells in comparison with those without AIHA. Untreated patients with AIHA or after a short-term corticosteroid treatment showed a higher ratio of the number of CD19+ CD5+ cells to the number of T CD4+ and T CD8+ lymphocytes than CLL-B patients without AIHA. It can be presumed that the differences found may be related to the pathogenesis of the autoimmune haemolysis syndrome in patients with CLL-B.