Biomedical subjects
Publications and source records attributed to J Lohmeyer.
A murine monoclonal antibody (called H-11) that binds to the p 24 core protein of HIV-1 was characterized by radioimmuno-precipitation, immunofluorescence, western blot assays, immunocytochemistry and immunohistochemistry. This antibody was found to be especially suited for demonstrating the presence of HIV-1 in formalin-fixed, paraffin-embedded tissues.
Leukocytopenia and bacterial infections are common and serious complications in patients with AIDS. We report here on three patients in whom the administration of high IgG doses led to gradual (two patients) or prompt (one patient) increases in circulating leukocyte counts (from 200-600 to 2500-5900/microliters), inducing definite improvement in two patients; one patient died from Pneumocystis carinii pneumonia. Although the rise in leukocyte counts lasted for only approximately 3 weeks, high-dose IgG might be a useful therapeutic adjunct in such patients.
Leukotriene (LT) generation has been implicated in the pathogenesis of the acute respiratory distress syndrome, ARDS. In the present study, we analysed broncho-alveolar lavage fluids of patients on mechanical ventilation because of ARDS (17 samples taken from 9 patients) or because of cardiogenic edema (8 samples taken from 6 patients) and of healthy volunteers (10 samples from different donors). LTs were separated as methylated and non-methylated compounds using different HPLC procedures, and were identified by chromatographic mobility, on-line UV-spectrum analysis and post HPLC immunoreactivity. In the lavage samples of the healthy volunteers and the patients with cardiogenic edema, no LTs were detected by these techniques (detection limit congruent to 0.1-0.2 ng/ml lavage fluid). By contrast, in 15 out of 17 samples from patients with ARDS LTB4 or its metabolites 20-OH-LTB4 and 20-COOH-LTB4 were detected. The endproduct of omega-oxidation, 20-COOH-LTB4, represented the quantitatively predominant compound, detected in the range of 0.3-2.6 ng/ml perfusate. We conclude that the chemotactic agent LTB4 may be involved in the amplification of inflammatory events encountered in ARDS, and that the oxidized metabolites of LTB4 are particularly suitable for monitoring lung leukotriene generation under conditions of neutrophil efflux and oxidative stress.
Monoclonal antibodies (MAbs) directed against Xiphophorus melanoma cells were developed and tested by indirect immunofluorescence and immunoperoxidase staining for reactivity with a panel of 15 allogeneic tissues and 12 allogeneic cell lines. The reactivity of such MAbs was restricted to melanoma cells from tumor biopsies and melanoma-derived cell lines. In addition, all embryonic cells of all histiotypes from developmental stages later than mid-organogenesis and from corresponding short term in vitro cultures reacted with these MAbs. In contrast, normal tissues and organs from adult fish displayed no reactivity, thus implying that the melanoma-associated antigens detected by the MAbs described are oncofetal antigens.
The distal breakpoint of inv(14) in T cell clones, established from patients with ataxia telangiectasia, lies outside the immunoglobulin heavy chain gene locus on 14q32.3, and more proximal to the centromere than the distal breakpoint of inv(14) in the T cell lymphoma cell line SUP-T1. We report 3 cases of T cell lymphoma cytogenetically showing the same type of inv(14) as the AT T cell clones. All 3 cases express a similar immunophenotype, which is that of peripheral T lymphocytes with phenotypic remnants of thymic or postthymic lymphoblasts. This finding provides evidence that this type of inv(14) is involved in the malignant transformation of mature T lymphocytes.
A human myeloma cell line designated LOPRA-1 has been established from ascites fluid containing malignant plasma cells of a patient with IgA2/kappa multiple myeloma. The cultured cells which are Epstein-Barr virus (EBV) negative have retained the morphological, cytochemical, ultrastructural and immunophenotypical features of well-differentiated plasma cells. They express the plasma cell antigen PCA-1, the antigens CD28 (Kolt-2) and CD38 (OKT10), the transferrin-receptor (OKT9), and some epitopes of the CD24 antigen (HB8, VIB E3), but are negative for surface immunoglobulins. HLA class II antigens (HLA-DP, -DQ, -DR) and other B-cell markers such as CD10 (CALLA), CD19 (B4), CD20 (B1), CD21 (B2), CD22 (HD39), CD23 (MHM6), CD37 (BL14) and CD39 (G28-8) as analysed by both flow cytometry and immunocytochemistry (PAP/APAAP). With respect to immunoglobulin synthesis, two stable clones were selected by single cell cloning: clone LOPRA-1/5 synthesizes large amounts of alpha 2 heavy and kappa light chains, but secretes only small amounts of these molecules, whereas clone LOPRA-1/4 is clearly devoid of intracellular immunoglobulin heavy and light chains and thus appears to be a chain loss variant. Cytogenetic analysis revealed a pseudotriploid phenotype with several structurally abnormal marker chromosomes: 3n + -, 70, XX, -X, -1, -4, -6, -8, -8, -13, -16, +7, +18, +21, +i(1q), +i(1q), +6q-, +3mar.
Leukemic cells of a 19 year old patient with prolymphocytic leukemia of T-cell type (T-PLL) were characterized by surface markers and immunologic functions. Phenotypic analysis using a large panel of monoclonal antibodies corresponding to the clusters (CD) of differentiation antigens established on the Leukocyte Typing Workshops I and II revealed a unique T-cell phenotype not yet reported in the literature: CD1 (T6)-, CD2 (T11)+, CD3 (T3)+, CD4 (T4)-, CD5 (T1)-, CD6 (T411)+, CD7 (Leu9)+, CD8 (T811)-, CD10 (J5)-, CD11 (M22)+, CD12 (M67)-, CD13 (My7)-, CD14 (Mo2)-, CD16 (Vep13, 3G8, Leu11)+, CD18 (MHM23)+, CD19 (B4)-, CD20 (B1)-, CD25 (TAC)-, MHC-class II (HLA-DR, HLA-DQ)-, NKH1A+, Leu7-. Despite the expression of surface structures associated with natural killer (NK) function (CD16, CD18, NKH 1 A) the T-PLL cells were inactive in NK assays in vitro. Low in vitro ADCC activity was detectable. This unusual T-PLL phenotype might help to identify a new distinct T-cell differentiation stage.
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44 patients undergoing comparable gynaecological operations received either halothane- modified neuroleptanaesthesia or a combination of epidural and NLA. Monoclonal antibodies were used to determine 8 different lymphocyte subpopulations in blood samples drawn before and after anaesthesia and on the first postoperative day. Cell populations were counted by fluorescent microscopy. Halothane anaesthesia produced both a depression of T-cells (72.67% preoperatively to 52.79% postoperatively) and of the helper/suppressor ratio (1.46 to 1.10); meanwhile activated T-cells increased from 2.33% to 6.83%. After neuroleptanaesthesia as well as after halothane the HLA-DR positive cells decreased (21.05% to 19.29%; 25.22% to 20.29%). The B-cell fraction was elevated from 2.33% to 6.83% following combined anaesthesia. The potential of the anaesthetics to produce subsequent alterations in host defense is discussed.
Monoclonal antibodies were produced against human platelets. Four antibodies (PA1, PA2, PA3 and PA4) reacted specifically with platelets and megakaryocytes, but not with peripheral blood lymphocytes, granulocytes, erythrocytes or monocytes. The antibodies belonged to the mouse IgG subclass 2a (PA1, PA2, PA3), or 1 (PA4) respectively. PA1 and PA4 did not precipitate, their antigens have not yet fully been characterized. PA3 was directed against the glycoprotein (Gp) complex IIb/IIIa; PA2 precipitated Gp IIb/IIIa, and, in addition, Gp Ia. PA4 revealed specificity against the human platelet alloantigen Zw(a).
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Fifteen 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.
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A patient with chronic leukemia exhibited uncommon clinical features, such as hypergammaglobulinemia and activation of intravascular coagulation after low-dose irradiation of the enlarged spleen. By light and electron microscopy, the leukemic cells resembled large granular lymphocytes. The following markers were simultaneously expressed on their surface: receptors for sheep erythrocytes and the Fc part of IgG; common T-cell antigens as revealed by a heteroantiserum (HuTLA) and monoclonal antibodies (OKT3, T411); antigens shared by cytotoxic/suppressor T cells (OKT8, T811) as well as myelomonocytic antigens defined by the OKM1 and M522 monoclonal antibodies. The leukemic cells showed both spontaneous (NK) and antibody-dependent (ADCC) cytotoxicity, but they did not suppress B-cell differentiation in vitro.
Monoclonal antibodies were induced against leukemic T cells from a patient with chronic lymphocytic leukemia exhibiting natural killer (NK) activity. Two antibodies, termed T811 and M522, reacted by indirect immunofluorescence with distinct sub-populations of normal human mononuclear blood cells. The antibody T811 defines a surface antigen which is restricted to a subset of the T cell lineage. The antigen recognized by the second antibody, M522, is expressed on monocytes and polymorphonuclear leukocytes and, in addition, on 9-17% of nonadherent peripheral blood leukocytes (NAL). It is shown that the total NK activity of NAL is confined to the subset of cells expressing the M522-defined antigen. Moreover, the portion of NK cytotoxicity associated with T lymphocytes is mediated by a subpopulation which is characterized by the simultaneous expression of the T811- and the M522-defined antigens. This population comprises about 4% of NAL and could be isolated to a purity of greater than 85%.
Monoclonal antibodies were raised against the leukemic T cells from a patient with chronic lymphocytic leukemia. Two antibodies, termed T411 and T811, were obtained which were reactive by indirect immunofluorescence only with cells of the T cell lineage. The T411 antibody recognized a polypeptide chain of 100,000 dalton apparent molecular weight which was present on the surface of 94 +/- 4% of peripheral blood T lymphocytes, but only on 20 +/- 8% of thymus cells. The antibody T811 reacted with a surface molecule composed of 2 poly-peptide chains of 32,000 and 34,000 dalton apparent molecular weight, which was expressed only on 25 +/- 10% of blood T lymphocytes and on 90 +/- 4% of thymus cells. Functional analysis of the T811+ and T811- T cell subsets isolated by rosetting with anti-mouse Ig coated ox erythrocytes revealed that both subpopulations were able to mount a proliferative response to allo-antigens, whereas allo-antigen induced cytotoxic cells and their precursors were only found in the T811+ subset. The pokeweed mitogen induced in vitro differentiation of B lymphocytes into immunoglobulin secreting cells was dependent on the presence of the T811- subset, whereas the T811+ T cells efficiently suppressed this differentiation.
Adherence of human lymphocytes to allogeneic tumour cell monolayers was found to depend on the presence of monocytes. Adherent lymphocytes could be separated from tumour cells by treatment with lidocaine followed by nylon wool passage. Tumour-adherent cells (70% E-RFC, 45% Fc gamma-R, 23% Fc mu-R, 5% monocytes) exhibited enriched natural killer (NK) activity not only against the tumour cell line used for isolation but also against seven other targets. When T cells were isolated subsequently as E-rosettes by density gradient centrifugation through Percoll, the enrichment in cytotoxicity was even more pronounced. Tumour-adherent T cells were severalfold enriched in both NK and antibody-dependent cell-mediated cytotoxicity (ADCC) activity. However, this enrichment was not paralleled by a concomitant increase in the number of T gamma cells (tumour-adherent T cells: 17% T gamma, 40% T mu ; tumour-nonadherent T cells: 12% T gamma, 60% T mu). Marked differences could be observed by staining with a monoclonal antibody that was raised against human leukaemic T gamma cells of high NK and ADCC activity. This antibody (T 8-11) stained 60% of tumour-adherent T cells, 20% of nonadherent T cells and 29% of T-cell controls. These results indicate that the spontaneous cytotoxic activity of human T cells resides within a small population, most of which are characterized by a specific surface antigen but not by conventional Fc gamma receptors.
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