Frank Reyes - Academia.edu (original) (raw)

Papers by Frank Reyes

Blood, 1984

The phenotype of fresh and cultured leukemic cells from patients with hairy cell leukemia was stu... more The phenotype of fresh and cultured leukemic cells from patients with hairy cell leukemia was studied using a panel of monoclonal antibodies in addition to the detection of peroxidase activity under electron microscopy. In fresh samples, the leukemic cells from 11 patients displayed predominantly a B phenotype, as judged by their reactivity with the B1 monoclonal antibody and surface immunoglobulin expression. Ultrastructural peroxidase activity, characteristic of hairy cells, was observed in all cases studied. When hairy cells were cultured in the presence of phytohemagglutinin and irradiated T cells, their phenotype converted from surface Ig+, B1+, OKT3-, OKT11- to surface Ig-, B1+, OKT3-, OKT11+. In contrast, the peroxidase activity remained unchanged. Some hairy cells were also OKM1+, but no conclusion could be made about the MO2 antigen, a more specific marker of monocytes. The variability of the phenotype in vivo and in vitro indicates that reliable markers are required for id...

Blood, 1978

The nature of cells present in the blood, marrow, and spleen of patients with hairy cell leukemia... more The nature of cells present in the blood, marrow, and spleen of patients with hairy cell leukemia is largely debated. These cells have been tentatively categorized on the basis of either monocytic or lymphocytic markers, and the accumulating data points to the fact that they share some characteristics of both cell types. Although hairy cells are known to lack myeloperoxidase-positive granules, present in normal human monocytes, we investigated the possible presence of other peroxidase activities differing from the granule-bound myeloperoxidase. The study was carried out with several methods based on the incubation of fixed and unfixed cells in the presence of diaminobenzidine and hydrogen peroxide. A peroxidase activity was found in hairy cells, located always in the endoplasmic reticulum but not in the Golgi apparatus or in any granule. By its cytochemical characteristics it appears to be closely related to that of tissue macrophages, activated blood monocytes, and other nonlymphoc...

Leukemia Research, 1983

Human T lymphocytes require the cooperation of accessory cells to generate lymphocyte colonies in... more Human T lymphocytes require the cooperation of accessory cells to generate lymphocyte colonies in agar culture under PHA stimulation. Various hairy cell enriched fractions, as well as normal monocytes, have been found to be able to initiate colony formation by normal lymphocytes. Leukemic monocytes from CMML patients were also effective, but not the leukemic lymphocytes from CLL patients. The phenotype expressed by HC in agar colonies was further studied using cell surface and enzymatic markers. We have concluded that HC in agar culture in the presence of both normal T lymphocytes and PHA lose the B phenotype that they express in vivo and function like an accessory cell in contrast to normal or leukemic B lymphocytes.

Separation of large quantities of mononuclear cells from human blood using a blood processor

Transfusion, 1985

THE DEVELOPMENT of allogeneic bone marrow transplantation in the treatment of acute leukemias re-... more THE DEVELOPMENT of allogeneic bone marrow transplantation in the treatment of acute leukemias re-quires further research for better understanding of the graft-versus-host disease that often results in the death of the patients. There is a need to harvest large quantities of ...

Journal of Immunological Methods, 1988

Monoclonal T cell colonies can be grown in agar culture from quiescent T lymphocytes under PHA st... more Monoclonal T cell colonies can be grown in agar culture from quiescent T lymphocytes under PHA stimulation, provided that (1) a low number of T lymphocytes (< 5 x 104/ml) is seeded, (2) IL-2 is added to the culture, and (3) a high number of accessory B cells (> 5 × 105/ml) is present in contact with the T lymphocytes. Under these culture conditions the colony progenitors can be ascribed to the CD4 subset, whereas CD8 lymphocytes do not generate colonies. This finding is surprising since both CD4 and CD8 lymphocytes may be cloned in liquid culture. We now report the appropriate conditions required to grow cytotoxic CD8 lymphocyte colonies in agar. CD8 colony growth is dependent upon IL-2-IL-2 receptor interaction and is inhibited by anti-IL-2 receptor antibodies. In addition to PHA, accessory B cells and IL-2, an additional signal provided by recombinant IL-1 is necessary for CD8 colony formation. Exogenous IL-1 can be replaced by irradiated CD4 lymphocytes which stimulate the expression of membrane IL-1 activity in the accessory B cells. In addition, colony growth from quiescent but not preactivated CD8 lymphocytes is inhibited by anti-IL-1 antibodies. Altogether, the data show that an IL-1 signal is required for the induction of IL-2 responsive IL-2 receptors on quiescent CD8 colony forming cells.

Journal of Experimental Medicine, 1975

Surface immunoglobulins (sIg) were detected on human lymphocytes by immunoelectron microscopy wit... more Surface immunoglobulins (sIg) were detected on human lymphocytes by immunoelectron microscopy with peroxidase-conjugated antibodies. Blood, marrow, and thymus cells from normal individuals and patients with lymphoproliferative disorders were examined. Samples were fixed before exposure to specific reagents. Normal lymphocyts with detectable sIg, i.e. B lymphocytes, were characterized by a villous surface; nonlabeled blood lymphocytes and thymocytes were smooth cells. Intermediate cells were also found which in sections appeared moderately villous and labeled, thus identified as B lymphocytes. Further evidence for a relationship between villous surface and sIg was given by the finding of a few lymphocytes with polar concentration of labeled microvilli. In chronic lymphocytic leukemia patients, most cells exhibited a villous surface with parallel variations of the number of microvilli and of anti-immunoglobulin-binding capacity. However, some labeled smooth blastic cells were also obs...

Journal of Clinical Immunology, 1990

HTLV-I seronegative patients in nonendemic areas have been described with T-cell proliferations t... more HTLV-I seronegative patients in nonendemic areas have been described with T-cell proliferations the DNA of which contains specific HTLV-I viral sequences. We have looked for the presence of HTLV-I DNA sequences in 27 HTLV-I seronegative patients with peripheral T-cell lymphomas, distinct from adult T-cell leukemia (ATL), and four HTLV-I seropositive patients, three with an ATL and one with a tropical spastic paraparesis. Using HTLV-I pol specific primers, the genomic DNA from peripheral blood mononuclear cells and lymph nodes massively infiltrated by tumor cells was analyzed by the enzymatic gene amplification procedure. In contrast to the peripheral blood lymphocytes from the four HTLV-I seropositive patients, the peripheral T-cell lymphoma samples did not harbor HTLV-I pol sequences. The data show that the detection of HTLV-I nucleotide sequences by the polymerase chain reaction correlates with serologic analysis in this series.

Journal of Clinical Immunology, 1988

The recovery of T-cell populations after bone marrow transplantation (BMT) is characterized by a ... more The recovery of T-cell populations after bone marrow transplantation (BMT) is characterized by a persistent expansion of CD8 lymphocytes. Previously, we have shown that beyond 1 year posttransplantation the CD8 lymphocytes consist, to a large extent, of CD8 ÷ HNK1 +, cells that suppress, like normal CD8 lymphocytes, immunoglobutin production in vitro. We have further investigated the functional capabilities of CD8 lymphocytes, mostly HNK1 + (from 50 to 77%), in seven long-term BMT patients. As normal, patient CD8 lymphocytes do not suppress (1) phytohemagglutinin (PHA)-induced interleukin 2 (IL2) receptor expression andlL2 responsiveness by normal T cells or (2) the mixed lymphocyte reaction of donor cells. Also as normal, patient CD8 lymphocytes can be activated into potent cytotoxic effectors. Therefore, under the present experimental conditions, the increase in the absolute number of CD8 lymphocytes in the tong-term BMT patients is characterized by an expansion of the CD8 ÷ HNKI+-cell subpopulation and a normal suppressor/cytotoxic potential on a per-CD8 + cell basis.

Gut, 1992

A retrospective study of the clinical and endoscopic features of low grade gastric lymphomas of m... more A retrospective study of the clinical and endoscopic features of low grade gastric lymphomas of mucosa associated lymphoid tissue (MALT) in 16 patients together with treatment and outcome was undertaken. Immunohistochemical studies of fresh tissue easily distinguished MALT lymphoma from benign reactive lymphoid hyperplasia (pseudolymphoma) and showed that tumour cells had the characteristic phenotype indicative of their origin from MALT. Persistant epigastric pain was the main presenting complaint, and was often associated with acute bleeding, anaemia, or weight loss. Eight patients had a past history of recurrent peptic ulcers or gastritis. The endoscopic appearance suggested malignancy in only half the cases and was compatible with gastritis or a benign peptic ulcer in the remainder. There was extragastric involvement of other mucosal sites in eight patients (mainly the lung, but also the parotid gland and small bowel), but rarely was bone marrow and never the spleen or peripheral lymph nodes affected. Conservative treatment with long term cyclophosphamide was effective in both stage I and stage IV disease, and all the patients are alive after a median follow up of 4.5 years. These findings confirm that low grade gastric MALT lymphomas are usually indolent tumours with non-specific endoscopic aspects and show that dissemination to other mucosal sites was more frequent than previously reported. Monochemotherapy could be an effective alternative treatment to surgery.

Cellular Immunology, 1984

Mitogen-driven T cell proliferation in liquid culture requires accessory cells that cooperate in ... more Mitogen-driven T cell proliferation in liquid culture requires accessory cells that cooperate in interleukin 2 production. We have investigated the accessory cell requirement for human lymphocyte colony formation under PHA stimulation. Semisolid medium limits cell-to-cell contact emphasizing the role of cooperating cells both in growth factor production and in triggering events. Culturing at high T cell density demonstrates that accessory cells can be substituted for colony formation by exogenous IL-2. Culturing at low T cell density in the presence of IL-2 also demonstrates that accessory cells are required for activation of a subset of progenitors into IL-2 responsive colony-forming cells. Consequently, T colony progenitors, contained in the E-rosetting cell fraction of peripheral blood, are heterogeneous in their triggering signals: a minor subset is directly inducible by PHA, and a major subset is inducible by PHA in the presence of accessory cells. We found that monocytes and some leukemic B cells support effective accessory function in both colony growth factor production and colony progenitor sensitization.

The Blast Crisis of Chronic Granulocytic Leukaemia: Megakaryoblastic Nature of Cells as Revealed by the Presence of Platelet-Peroxidase—A Cytochemical Ultrastructural Study

British Journal of Haematology, 1978

The origin of cells in the blast crisis of some cases of chronic granulocytic leukaemia (CGL) rem... more The origin of cells in the blast crisis of some cases of chronic granulocytic leukaemia (CGL) remains controversial. Difficulties arise from the lack of cytochemical characteristics of differentiation. This report concerns the nature of cells in the blast crisis of a case of CGL in which blast cells exhibited an undifferentiated or lymphoid appearance by light and electron microscopy. The majority (90%) of such cells contained a peroxidase in the endoplasmic reticulum distinct from myeloperoxidase. In addition, some micromegakaryocytes could be recognized among the peroxidase reactive cells, by the presence of typical granules and demarcation membranes. Since this peroxidase exhibited identical characteristics to that of normal megakaryocytic precursors, these blast cells could be identified as megakaryoblasts. These data emphasize the possible megakaryoblastic nature of cells occurring in other cases of CGL blast crisis.

Human mononuclear phagocyte differentiation: a study of the U-937 cell line by ultrastructural cytochemistry and surface antigen analysis

British Journal of Haematology, 1985

U-937 represents a well-established permanent human haematopoietic cell line, which exhibits char... more U-937 represents a well-established permanent human haematopoietic cell line, which exhibits characteristics of the monocyte/macrophage series. U-937 cells were investigated by peroxidase ultrastructural cytochemistry in order to determine the normal developmental stage to which they correspond. This study was performed in non- and TPA-stimulated cells, in conjunction with surface analysis by monoclonal antibodies. It is concluded: (1) peroxidase-positive U-937 cells are monoblasts and promonocytes involved in myeloperoxidase synthesis; (2) TPA-stimulation caricatures transformation of these cells into monocytes but not into resident macrophages, as far as peroxidase cytochemistry is concerned; (3) the reactivity of myeloperoxidase present in the endoplasmic reticulum of synthesizing cells is inhibited by glutaraldehyde fixation.

Unusual intracytoplasmic immunoglobulin inclusions in chronic lymphocytic leukaemia

British Journal of Haematology, 1982

Unusual intracytoplasmic immunoglobulin inclusions were found by immunofluorescence in three pati... more Unusual intracytoplasmic immunoglobulin inclusions were found by immunofluorescence in three patients with chronic lymphocytic leukaemia. The inclusions contained the same immunoglobulin chains as those detected on the plasma membrane, except for delta chains which were expressed on the cell surface and not in the cytoplasmic inclusions. The cytoplasmic staining persisted throughout culture for 8 or more days. An initial study of patients 1&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s cells showed that the inclusions contained only mu chains, and kappa chains gradually became apparent after in vitro culture. In a second study, the fresh lymphocytes contained both mu and and kappa chains. Initially, biosynthetic experiments showed production of mu chains which polymerized in the cytoplasm and were not secreted. Subsequently there was synthesis of heavy and light chains which assembled into monomeric subunits that were retained and secretion of free light chains. The apparent molecular weight of these immunoglobulin chains was larger than that of their secretory counterparts. Immunoelectronmicroscopy revealed cytoplasmic mu chains in strands of endoplasmic reticulum. In the two other patients, immunofluorescence displayed unusual staining patterns of bright networks in perinuclear areas.

The Heterogeneity of Erythrocyte Antigen Distribution in Human Normal Phenotypes: an Immunoelectron Microscopy Study

British Journal of Haematology, 1976

A and A1 antigen were detected on human blood erythrocytes by immunoelectron microscopy using per... more A and A1 antigen were detected on human blood erythrocytes by immunoelectron microscopy using peroxidase-conjugated antibodies. Cells were obtained from various normal A subgroups, including rare weak A phenotypes and infant (cord blood) samples. Erythrocytes were fixed prior to incubation with specific reagents. The detection of surface antigens was carried out by an indirect method involving anti-A and anti-A1 antibodies and conjugated anti-immunoglobulin antibodies. The surface labelling was seen as a diffuse dense layer. Haemperoxidase-like activity resulted in a faint background which did not interfere at the level of ultrathin sections, with surface staining due to exogeneous peroxidase. The most significant finding was the existence, in a given sample, of several populations of cells as revealed by their antibody-binding capacity. The distribution of the various populations varied from one sample to another according to its subgroup. The progressive weakening of phenotype expression which characterizes the various subgroups from A1 to A weak was paralleled by a decreasing number of "antigen rich" cells, which were still detectable in weak phenotypes as a minor population. This study confirms that a given normal phenotype in fact represents a mixture of antigenically different populations of erythrocytes.