Shirley G. Quan

Deficient expression of a B cell cytoplasmic tyrosine kinase in human X-linked agammaglobulinemia

We describe a novel cytoplasmic tyrosine kinase, termed BPK (B cell progenitor kinase), which is expressed in all stages of the B lineage and in myeloid cells. BPK has classic SH1, SH2, and SH3 domains, but lacks myristylation signals and a regulatory phosphorylation site corresponding to tyrosine 527 of c-src. BPK has a long, basic amino-terminal region upstream of the SH3 domain. BPK was evaluated as a candidate for human X-linked agammaglobulinemia (XLA), an inherited immunodeficiency characterized by a severe deficit of B and plasma cells and profound hypogammaglobulinemia. BPK mapped to within 100 kb of a probe defining the polymorphism most closely linked to XLA at DXS178. Reduction in or the absence of BPK mRNA, protein expression, and kinase activity was observed in XLA pre-B and B cell lines. BPK is likely the XLA gene and functions in pathways critical to B cell expansion.

A Second Isolate of HTLV-II Associated with Atypical Hairy-Cell Leukemia

THE human T-cell lymphotropic viruses Type I (HTLV-I) and Type II (HTLV-II) and the bovine leukemia virus, which are members of a family of leukemogenic mammalian retroviruses, share some of the sa...

Origin of Human Bone Marrow Fibroblasts

We investigated the origin of bone marrow fibroblasts in three bone marrow transplant recipients with aplastic anaemia and leukaemia who received grafts from HLA‐identical siblings of opposite sex. The patients were conditioned for transplantation with high doses of cytotoxic drugs and 300–1000 rads total body irradiation. After transplantation, bone marrow cells wrere cultured in T flasks for 3 weeks and the adherent cells were then trypsinized and passaged weekly. After several passages the cells had the typical morphology and growth pattern of fibroblasts. Metaphases from these cells were all of recipient sex type. In contrast, haematopoietic cells and lymphocytes obtained at the same time were of donor sex type. Our findings indicate that the human bone marrow fibroblast is not derived from a precursor common to haematopoietic cells or lymphocytes. The bone marrow fibroblast appears to be a mesenchymal cell, unrelated to haematopoietic stem cells, which is capable of in vitro proliferation after as much as 1000 rads of total body irradiation.

Immunoglobulin Synthesis in Hairy Cell Leukaemia

In vitro studies were performed with leukaemic cells from two patients with hairy cell leukaemia in order to define the nature and kinetics of immunoglobulin synthesis by the neoplastic cells. Both patients had clinically and morphologically well‐defined disease and their cells contained abundant tartrate‐resistant acid phosphatase. One patient had associated macroglobulinaemia. The hairy cells had B‐lymphocyte characteristics as determined by fluorescent immunoglobulin staining and surface receptor properties. They synthesized monoclonal IgM and IgG respectively in vitro. The kinetics of immunoglobulin synthesis were different in cells from the two patients as measured by equilibration time, intracellular degradation, and secretion. Permanent cell lines were established with cells from these patients. The lines grow as typical B‐lymphoblastoid cultures and continue to produce tartrate‐resistant acid phosphatase and immunoglobulin. These studies unequivocally demonstrate the B‐lymphocyte nature of the hairy cells in these patients and provide evidence for their clonal origin both in terms of immunoglobulin and enzyme synthesis.

Production of granulocyte-macrophage colony-stimulating factor in two patients with lung cancer, leukocytosis, and eosinophilia

Leukocytosis in association with malignancy has been well described, but the cause is not known. One potential explanation is production of a colony‐stimulating factor by the tumor, and this has been demonstrated in vitro. The authors report two patients with lung cancer, leukocytosis, and eosinophilia. The pleural fluid of both patients contained malignant cells and biologically active granulocyte‐macrophage colony‐stimulating factor (GM‐CSF), as demonstrated by radioimmunoassay, enzyme‐linked immunosorbent assay (ELISA), and colony‐forming unit‐granulocyte‐macrophage (CFU‐GM) assay. To determine whether GM‐CSF is normally detectable in pleural fluid, the authors performed assays on an additional 11 patients with pleural effusions of various origins but without peripheral blood leukocytosis and eosinophilia; only 1 patient had a detectable level of GM‐CSF (i.e., ⩾ 0.1 ng/ml). Because GM‐CSF usually is not present in pleural fluid, the authors postulate that the high levels of GM‐CSF found in the pleural fluid of these two patients was produced by their tumors, and production of GM‐CSF by their lung cancers likely caused the leukocytosis with eosinophilia. Cancer 1992; 69:1342‐1346.

Trimethoprim and Sulphamethoxazole Inhibition of Haematopoiesis in Vitro

Summary. The effect of trimethoprim and sulphamethoxazole on haematopoiesis was studied in vitro using cloning techniques for human and murine erythroid and granulocytic precursor cells. Trimethoprim was found to inhibit granulopoiesis and erythropoiesis in vitro in a dose‐dependent fashion with approximately 50% inhibition of human erythroid and granulocytic colonies at a therapeutically achievable concentration of 7 μg/ml. Sulphamethoxazole was also shown to impair haematopoiesis in vitro. The inhibition caused by both these constituents of co‐trimoxazole was completely reversed by folinic acid. The data suggest that co‐trimoxazole can impair human haematopoiesis by inhibition of tetrahydrofolate synthesis. These observations suggest that the clinical haematopoietic toxicity of trimethoprim‐sulphamethoxzole can be abrogated by simultaneous administration of folinic acid.

Response of human glioblastoma cells to recombinant interleukin-2.

We investigated the ability of glioma cells to respond to T cell-derived lymphokines. The growth of astrocytoma and mixed glioblastoma cell lines, as assessed by DNA synthesis, was inhibited in the presence of supernatants derived from mitogen-stimulated human T cells, an HTLV-II-transformed human T cell line, Mo, and human interleukin-2 (IL-2). The mixed glioblastoma cell line, 138-MG-C, was subjected to limiting dilution analysis, and two cell lines (5D7, 5C5) were derived which were homogeneous with respect to staining for galactocerebroside (GalC) (100%). These two GalC+ glioblastoma cell lines proliferated in the presence of high concentrations of recombinant human interleukin-2 (RIL-2). Additionally, these cell lines bear receptors for the IL-2 molecule as determined by immunofluorescent staining with various anti-IL-2 receptor antibodies.

Ultrastruct and tartrate-resistant acid phosphatase localization in a T-cell hairy-cell leukemia cell line.

Hairy-cell leukemia is characterized clinically in splenomegaly and pancytopenia and pathologically by the proliferation in hematopoietic tissue of cells containing the tartrate-resistant isozyme 5 of acid phosphatase. We have described a patient with a T-lymphocyte variant of this disease. A permanent cell line obtained from the spleen of this patient has the biological and enzymatic characteristics of the fresh leukemic cells. We have used this line to study the surface morphology, ultrastructure, and ultrastructural localization of acid phosphatase in defined T-lymphoid hairy cells. The surface of the cells of the permanent line was smooth but many hair-like projections appeared after exposure to phytohemagglutinin (PHA). There was little acid phosphatase reaction produce visualized when beta-glycerophosphate was used as a substrate. With sodium haphthol AS-BI phosphoric acid heavy deposits were seen in the perinuclear membrane, mitochondria, and rough endoplasmic reticulum. Exposure to PHA and pokeweed mitogen resulted in increased reaction product, suggesting increased enzyme synthesis. Tartrate-resistant acid phosphatase was localized in the same organelles.

Hairy Cell Leukemia: In-Vitro Culture Studies

Excerpt Hairy cell leukemia, or leukemic reticuloendotheliosis, is a well-defined clinical entity characterized by peripheral blood cytopenias and diffuse infiltration of the bone marrow and spleen...

Interferon-induced expression of class II major histocompatibility antigens in the major histocompatibility complex (MHC) class II deficiency syndrome

Class II antigens encoded by genes of the major histocompatibility complex (MHC) are expressed by a variety of cell types and have a vital role in the cellular interactions required for an effective immune response. We have analyzed the regulation of HLA-DR, DP, and DQ class II antigen expression on cells of different lineage from an immunodeficient patient with the MHC class II deficiency syndrome. T and B lymphocytes, monocytes, and fibroblasts, which initially expressed no class II antigens, were treated with inductive stimuli that normally lead to enhanced expression of class II antigens. Monocytes, but not fibroblasts, cultured for 48–96 hr in the presence of recombinant gamma interferon expressed all three types of class II antigens. In contrast, T lymphocytes did not express class II antigens following their exposure to a variety of stimuli, including activation with phytohemagglutinin and culture in the presence of interleukin-2, transformation by the retrovirus HTLV-1 or HTLV-2, or exposure to the demethylating agent 5-azacytidine. Similarly, class II antigens were not induced on B cells by cross-linkage of surface immunoglobulin molecules with anti-mu, exposure to Epstein-Barr virus, or treatment with soluble factors secreted by activated T cells. These results demonstrate that the regulation of class II MHC antigen expression by monocytes and lymphocytes is dissimilar and suggest that different regulatory genes are involved in the control of class II antigen expression by cells of different lineage.