Expanded T gamma cell populations with the morphology of large granular lymphocytes -- I. Immunological, clinical and morphological characterization

Membrane allocation profiling: a method to characterize three-dimensional cell shape and attachment based on surface reconstruction

Three-dimensional surface reconstructions from high resolution image stacks of biological specimens, observed by confocal microscopy, have changed the perspective of morphological understanding. In the field of cell-cell or cell-substrate interfaces, combining these two techniques leads to new insights yet also creates a tremendous amount of data. In this article, we present a technique to reduce large, multidimensional data sets from confocal microscopy into one single curve: a membrane allocation profile. Reconstructed cells are represented in a three-dimensional surface from image sections of individual cells. We virtually cut segments of the reconstructed cell membrane parallel to the substrate and calculate the surface areas of each segment. The obtained membrane allocation profiles lead to morphological insights and yield an in vivo ratio of attached and free membrane areas without cell fixation. As an example, glass substrates were modified with different proteins (fibronectin, laminin, concavalin A, extracellular matrix gel, and both isomers of poly-lysine) and presented to HEK293 cells to examine differences in cell morphology and adhesion. We proved that proteins on a substrate could increase the attached portion of a cell membrane, facing the modified substrate, from an average of 32% (glass) to 45% (poly-lysine) of the total membrane surface area.

Lymphocytosis of large granular lymphocytes associated with anemia and neutropenia: proof of monoclonality of the LGL-population, but benign clinical course

A 37-year-old man with severe transfusion-requiring anemia and neutropenia associated with lymphocytosis of large granular lymphocytes (LGLs) has been followed over a period of 3.5 years. Detailed phenotyping of the LGL has been performed, revealing a phenotype of CD3+, CD8+, CD16+, HLA-DR+, and Leu-7+. Southern-blot analysis of the T-cell receptor beta-chain locus detected a gene rearrangement, thus providing proof of monoclonality of the peripheral blood LGLs.

Lymphocytosis of large granular lymphocytes in three dogs

The clinical course and hematologic changes of three dogs with lymphocytosis of cells morphologically resembling large granular lymphocytes are presented. Hemograms from all dogs showed leukocytosis with marked lymphocytosis. Lymphocytes were characterized by abundant basophilic cytoplasm containing distinct granules which varied in size and number. Electron microscopically the granules were membrane-bound with an electron-dense core. Lymphocytes from one dog were positive for alkaline phosphatase activity, and lymphocytes from another dog were positive for alpha naphthyl butyrate esterase activity. Lymphocytes from one dog were positive for surface receptors for the crystalline fraction portion of gamma immunoglobulins.

Autoimmunity and B-cell dysfunction in chronic proliferative disorders of large granular lymphocytes/natural killer cells

Clinical and laboratory findings of B-cell immune dysfunction were evaluated in ten patients with a large granular lymphocyte/natural killer cell proliferative disease (LGL/NK-PD). Increased immunoglobulin synthesis with autoantibody formation was documented: polyclonal hypergammaglobulinaemia (six patients), neutrophil autoantibody (one patient), antinuclear antibody (one patient), and rheumatoid factor (five patients). In addition, serum beta 2-microglobulin level was raised in seven patients, a benign monoclonal gammopathy was detected in one, and concurrent B-type hairy cell leukemia in another. Most patients experienced the complications of hemocytopenia, polyarthritis or rheumatoid arthritis, and immediate allergic reactions to drugs or environmental substances, rather than from symptoms of progressive LGL/NK-PD. A review of the literature confirms that an increased immunoglobulin production is common in LGL/NK-PD, and that patients are likely to develop multiple autoantibodies. The incapacity of proliferating, abnormal LGL/NK cells to suppress B-cell activation and immunoglobulin synthesis, documented by several in vitro studies, offers a pathogenetic explanation for these phenomena. This study shows that an anomalous B-cell function contributes greatly to the morbidity of disease in LGL/NK-PD, and points out the utility of investigating the LGL/NK cell system in patients with autoimmune pathologic characteristics of unclear origin.

Expression of natural killer cell markers in non-Hodgkin's lymphomas

One hundred forty-nine cases of non-Hodgkin's lymphoma were studied with a panel of monoclonal antibodies, including antibodies to natural killer (NK) cells--anti-NKH1, anti-Leu 7, and anti-Leu 11b. There were 95 B-cell, 51 T-cell, and three null cell lymphomas. Seventeen T-cell lymphomas (33 per cent) expressed NKH1, Leu 7, and/or Leu 11b. None of the B- or null cell lymphomas expressed the NK markers. In comparison with the NK-negative T-cell lymphomas, the NK-positive cases showed a predilection for the nasal and paranasal region. There was a more significant loss of the T-cell markers T3 (peripheral T cell) and T4 (T-helper cell) in NK-positive lymphomas. The difference was due to a high proportion of nasal/paranasal lymphomas, which were associated with a frequent loss of T-cell markers, among the NK-positive cases. However, a similar degree of loss of T-cell markers was observed among NK-positive and NK-negative nasal/paranasal lymphomas. We conclude that expression of NK markers occurs exclusively in a proportion of T-cell lymphomas, but not B-cell or null cell lymphomas. The reason this occurs predominantly in nasal and paranasal lymphomas is unknown.

OKM1-positive T-cell leukemias. Relationships among morphologic features, phenotype, and functional activities

The morphologic features, phenotype, and functions of OKM1+ leukemic T-cells were studied. The leukemic T-cells in two patients with chronic lymphocytic leukemia (CLL) had specific features of large granular lymphocytes (LGL), and those in two patients with acute lymphocytic leukemia (ALL) had L2 morphologic characteristics. The phenotype of the leukemic cells from one patient with CLL was OKM1+, ER+, OKT3+, OKT4+, OKT8-, OKIa1-, IgGFc receptor (EA gamma)+, Leu-7+, Leu-11b+, and anti-Tac-. The cells had antibody-dependent cell-mediated cytotoxicity (ADCC), but no natural killer (NK) activity. They had a definitive helper effect on pokeweed mitogen-induced normal B-cell differentiation. The leukemic cells from the other patient with CLL were Leu-7-, and Leu-11b-, and lacked both ADCC and NK activity. The leukemic cells in the two patients with ALL were ER+, OKM1+, Leu-7-, and Leu-11-, and did not have any cytotoxicity. One was EA gamma +, and the other was EA gamma -. These findings suggest that OKM1+ leukemic T-cells consist of at least two subgroups: (1) T-cells with the morphologic features of LGL; and (2) those with a lymphoblastic morphologic type. In either case, the phenotype is novel and suggests the emergence of a small, distinct lymphocyte subset.

T cells in patients with chronic T gamma lymphocytosis: morphology, cytochemistry, ultrastructure and immunological characteristics

We have studied the morphology and cytochemistry in relation to the immunological phenotyping and functional properties of T cells from eight patients with chronic T gamma lymphocytosis. At the light microscopic level the morphology of the patients' lymphocytes was similar to that described for large granular lymphocytes. Ultrastructurally, a division into two groups could be made on differences in the amount of cytoplasm and the location and the more irregular form of the nuclei. The lymphocytes of one group (five patients) had in common the phenotype Fc gamma +, T3 +, T4 -, T8 +, Ia -, M1 - and demonstrated (with the exception of one patient) the same functions: presence of K-cell activity, absence of NK, helper and suppressor cell activities. In the other group (three patients), the lymphocytes of one patient showed the same phenotype and functions as those indicated above. The other two patients both lacked the T8 antigen on their lymphocytes but were different with regard to other surface markers. In addition, their cells were functionally identical: both demonstrated NK- and K-cell activity. Thus in this group of eight patients with chronic T gamma lymphocytosis, the immunological and functional subdivision paralleled in part a morphological division at the ultrastructural level.

The fine structure of HNK-1 (Leu7) positive cells. A study using an immunoperoxidase technique

The ultrastructural characteristics of HNK-1 (Leu7) positive cells, visualized with a peroxidase labelled anti-mouse IgM serum, were analysed. Our investigation demonstrates: 1) the majority of Leu7 positive cells has a low nuclear/cytoplasmic ratio (N/C), an irregular outline, a well developed smooth endoplasmic reticulum, parallel tubular arrays (PTA) and electron dense granules; 2) the minority of Leu7 positive cells has a high N/C, regular profiles and lacks electron dense granules. The presence of two distinct ultrastructural patterns within Leu7 positive cells may represent: 1) the expression of subsequent stages of cell differentiation; 2) two distinct Leu7 positive cell subpopulations.