Ernst Peter Rieber

Human interleukin-13 activates the interleukin-4-dependent transcription factor NF-IL4 sharing a DNA binding motif with an interferon-γ-induced nuclear binding factor

The effects of interleukin‐13 (IL‐13) and interleukin‐4 (IL‐4) on cellular functions were shown to be quite similar. We provide evidence that in monocytes as well as in T lymphocytes both IL‐4 and IL‐ 13 activate the same recently identified transcription factor NF‐IL4 which binds to the specific responsive element IL‐4RE. In addition, we show that a nuclear factor activated by interferon‐γ also interacts with the IL‐4RE. It differs from NF‐IL4 in the electrophoretic mobility of the complex with DNA, in its DNA‐binding specificity and in the proteins interacting with the DNA sequence. Sensitivity against various enzyme inhibitors suggests that components of the signal transduction pathway are shared by all three cytokines.

Treatment of severe cutaneous lupus erythematosuswith a chimeric CD4 monoclonal antibody, cM-T412

BACKGROUND Monoclonal CD4 antibodies are among the most potent immunomodulatory agents in various experimental models of autoimmune disease, including murine lupus erythematosus. OBJECTIVE The aim of this study was to evaluate the toxicity and therapeutic efficacy of a chimeric monoclonal CD4 antibody, cM-T412, in patients with cutaneous lupus erythematosus (LE). METHODS Five patients with severe cutaneous LE lesions received intravenously a total of 275, 400, or 475 mg of cM-T412 in single doses of 20 to 50 mg during a period of 5 to 8 weeks. RESULTS CD4 antibody treatment induced a long-lasting decrease in disease activity. It resulted in healing of LE skin lesions, a reconstituted responsiveness to conventional treatment, or both. Despite a substantial depletion of circulating CD4+ T lymphocytes, no clinical signs of immunosuppression were noted. CONCLUSION Monoclonal CD4 antibodies should be considered as a novel treatment for the management of severe cutaneous LE.

Hairy Cell Leukaemia: Surface Markers and Functional Capacities of the Leukaemic Cells Analysed in Eight Patients

Summary. In eight patients with hairy cell leukaemia (HCL) peripheral blood cells and in two patients also spleen cells were analysed for surface markers and functional capacities. Only cells containing the tartrate resistant isoenzyme 5 of the acid phosphatase were considered. Hairy cells (HC) of all patients were found to adhere spontaneously to glass and plastic surfaces and to spread after adherence like monocytes. They ingested latex particles of more than 1 μm diameter, but, in contrast to monocytes, did not phagocytose erythrocytes sensitized either by IgM or by IgG antibodies. HC of all patients bore Fc‐receptors with a high binding affinity for aggregated IgG. Using 125I‐labelled F(ab′)2‐fragments of monospecific antibodies in autoradiography, only one light chain type was detected on HC of individual patients. In four patients μ‐ and δ‐chains were simultaneously expressed on HC, whereas in two patients only γ‐chains and in one case only μ‐chains were observed on HC. One patient showed a combination of γ‐ and δ‐chains on his HC. A great variation in density of surface immunoglobulins of HC was observed within individual patients. After removal by capping, surface immunoglobulin reappeared on HC during cell culture, but more slowly than on normal B‐lymphocytes. As shown in two patients by internal labelling, HC secreted immunoglobulin light chains, but no heavy chains. On the basis of these findings the classification of HC as belonging to the B‐cell lineage, rather than to the monocytic lineage, seems to be justified.

Combinatorial functions of two chimeric antibodies directed to human CD4 and one directed to the α-chain of the human interleukin-2 receptor

The general feasibility of chimerization of monoclonal antibodies (mAbs) has already been shown for a large number of them. In order to evaluate in vitro parameters relevant to immunosuppressive therapy, we have chimerized and synthesized two anti-CD4 mAbs recognizing two different epitopes on the human T-lymphocyte antigen, CD4. The chimerized mAbs are produced at levels corresponding to those of the original hybridoma cell lines. With respect to activation of human complement, the individual Abs are negative; however, when used in combination, complement activation was performed. When applied in combination, they were found to modulate the CD4 antigen, whereas the individual mAb do not display this property. Individually they mediate an up to 60% inhibition of the mixed lymphocyte reaction (MLR). However, by combination of an anti-CD4 mAb with one directed against the alpha-chain of the human IL2 receptor, nearly 100% inhibition of the MLR was achieved, even with reduced dosage of the mAbs. Our data suggest that the combination of an anti-CD4 mAb and an anti-IL2R alpha chain mAb is more effective with respect to immunosuppression than each mAb by itself, indicating that this mAb cocktail could be a new strategy for immunosuppressive therapy.

Proliferation of Tγ-lymphocytes in two patients: Clinical features and functional properties of the proliferating cells

SummaryTwo patients suffering from proliferation of Tγ cells exhibited uncommon clinical features, such as activation of intravascular coagulation after low dose irradiation of the enlarged spleen in one patient and isolated neutropenia in the other patient. While the malignant nature of the disease was doubtless in one patient, cell proliferation in the other patient was more likely reactive. In addition to T cell determinants the proliferating cells expressed a monocytic antigen. They did not suppress B-lymphocyte differentiation into plasma cells. In contrast the proliferating cells, especially in one patient, acted as potent effectors in NK and ADCC using melanoma and MOLT 4 target cells. Erythrophagocytosis by Tγ cells was seen in one patient. The data suggest that subsets of Tγ cells are related to the monocytic lineage and that these cells can mediate both NKA and ADCC and partly can develop phagocytic activity.ZusammenfassungZwei Patienten, bei denen wir eine Proliferation von Tγ Lymphozyten nachweisen konnten, boten ein ungewöhnliches klinisches Bild (disseminierte intravasale Gerinnung im Anschluß an eine niedrigdosierte Milzbestrahlung, isolierte absolute Neutropenie). Während bei einem Patienten ohne Zweifel eine maligne Erkrankung vorlag, ist bei dem anderen Patienten eher eine reaktive Zellproliferation anzunehmen. Neben T-Zell-Oberflächeneigenschaften wiesen die proliferierenden Zellen ein monozytäres Antigen auf. Sie zeigten keine Suppression der Differenzierung von B-Lymphozyten in Plasmazellen. Im Gegensatz dazu entwickelten die proliferierenden Zellen, besonders bei einem Patienten, deutlich spontane und antikörpervermittelte Zytotoxizität mit Melanom-und MOLT 4-Zielzellen. Bei dem zweiten Patienten konnten wir phagozytäre Eigenschaften der Tγ-Zellen nachweisen. Die Ergebnisse lassen vermuten, daß Untereinheiten der Tγ-Zellen Beziehungen zu monozytären Zellen aufweisen und daß diese Zellen sowohl spontane als auch antikörpervermittelte Zytotoxizität und teilweise phagozytäre Eigenschaften entwickeln können.

Loss of FcεR2/CD23 Expression on T and B Lymphocytes During Rush Hyposensitization

Specific hyposensitization is the only causal therapy for type I hypersensitivity reactions besides allergen avoidance. Several immunologic changes are correlated with the efficacy of this treatment. They include reduced serum levels of allergen-specific IgE and a rise of allergen specific IgG antibodies, a diminished seasonal rise of pollen specific serum-IgE, a decrease in the proliferative response to stimulation with allergen of peripheral blood mononuclear cells (PBMC), and a reduced histamine release from basophils (summarized in [1]). Despite these observations, however, the working mechanisms of hyposensitization remain ill defined.

Cell-Mediated autoimmunity at the onset of insulin-dependent diabetes mellitus (IDDM)

SummaryPeripheral blood lymphocytes have been investigated in 20 newly diagnosed type-I diabetics and 10 healthy subjects using monoclonal antibodies. Mononuclear cells were marked with anti-T-lymphocytes (Leu2, 3, 4, 12) and anti-Ia-antibodies (K14, L243) using indirect immunofluorescence. The percentage of circulating K14- and L243-positive cells was significantly higher in all diabetics than in normal controls. An increase in the number of K14-bearing cells was found in newly diagnosed patients with duration of less than 7 days (n=10) compared with diabetics of longer duration (1 to 8 months;n=10). Using dual-color immunofluorescence with fluorescein-conjugated anti-T-lymphocytes and rhodamin-conjugated anti-Ia-antibodies it was not possible to identify Ia-antigen bearing cells (Ia cells) as helper or suppressor lymphocytes. In addition, there was no significant difference in the number of Ia cells in diabetics with and without islet cell antibodies. It is concluded that there is evidence of activation of cellular immune response in type I diabetes, particularly in the early days of manifestation. However, previous assumptions that Ia cells represent T-cell activation have to be questioned.

UNIQUE COMBINATION OF SURFACE MARKERS ON HUMAN NK CELLS: A PHENOTYPIC COMPROMISE AT LAST

Publisher Summary This chapter presents a study analyzing various malignant tumor cells, particularly leukemias, for natural killer (NK) activity. In the study, a remarkable chronic lymphatic leukemia afflicting a 71-year-old patient was observed. The patient had a leukocytosis of 480,000 leukocytes/mm3, 99% of the cells being medium to large granular lymphoid-like cells with the histochemical characteristics of the large granular lymphocytes. Despite a distinct splenomegaly, the patient had no lymphnode enlargement. The isolated leukemic cells were cytotoxic against MOLT 4 cells, and they showed NK activity and antibody-dependent cytotoxicity against Mel-Wei tumor cells. The T-cell nature seemed to be undisputable because of E rosette formation, reactivity with heterologous rabbit antihuman thymic antigen, and positive staining with T3 and T8 monoclonal antibodies of the OKT series. The leukemic cells had no effect on B cell differentiation in coculture experiments in which B lymphocytes were stimulated by pokeweed mitogen to transform into Ig secreting cells.

Transferrin receptors on tumor and bone marrow cells: Lack of involvement as target structure for natural killer cells

SummaryTwo different experimental approaches based on the specificity of monoclonal antibodies (mAbs) have been taken to verify the hypothesis that the transferrin receptor (TfR) on proliferating cells serves as a common target structure for natural killer (NK) cells. Thus, by the lysostrip technique the TfR was removed from the surface of K562 and Molt4 tumor cells by incubation with two different anti-TfR mAbs. The effect of removal of the TfR was controlled by uptake of radiolabeled transferrin, and by binding of non-cross-reacting monoclonal anti-TfR receptor antibodies. Though the modulation of TfR on the membrane of viable cells was nearly complete, the cells remained fully susceptible to NK lysis. The second approach consisted in removal of TfR-bearing cells from bone marrow cell suspensions by an indirect rosetting technique. Using mAbs bound to ox erythrocytes the rosetted TfR-bearing cells could be removed from bone marrow cell suspension by density centrifugation with an efficiency of >99%. It could be shown that both fractions, TfR+ and TfR− cells, could be lysed to the same degree by NK cells. Thus, the evidence obtained speaks against a role of TfR as a recognition structure for NK cells.

Monoclonal antibodies against T-cell antigens studied by immunohistochemistry.

SummaryFifteen monoclonal antibodies against different T-cell antigens were studied by immunohistochemistry in thymus, fetal thymus, fetal liver, palatine tonsils, and a few T-cell lymphomas. OKT 9 was identified as reacting with hemopoietic stem or precursor cells in fetal liver as well as with early B-determined lymphocytes in tonsillar germinal centres. OKT 10 labelled lymphocytes in thymus and surprisingly also the cytoplasm of some tonsillar cells with plasma-cell like appearance. OKT 6 and MAS 036 b reacted only with thymic cells. OKT 4, OKT 5, OKT 8, 8–11, labelled thymic cells- and portions of interfollicular cells in tonsils. OKT 3, NEI 016, NEI 015, and T 28 stained a majority of thymic cells and of tonsillar interfollicular lymphocytes. IFH-M 203, NEI 012 and 4–11 were positive with the majority of T-lymphocytes in tonsils but labelled only a few thymic cells.