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F Battye

Publications and source records attributed to F Battye.

10 recordsLinked to original sources
PubMed2001

Web servlet-assisted, dial-in flow cytometry data analysis.

BACKGROUND: The obvious benefits of centralized data storage notwithstanding, the size of modern flow cytometry data files discourages their transmission over commonly used telephone modem connections. The proposed solution is to install at the central location a web servlet that can extract compact data arrays, of a form dependent on the requested display type, from the stored files and transmit them to a remote client computer program for display. METHODS: A client program and a web servlet, both written in the Java programming language, were designed to communicate over standard network connections. The client program creates familiar numerical and graphical display types and allows the creation of gates from combinations of user-defined regions. Data compression techniques further reduce transmission times for data arrays that are already much smaller than the data file itself. RESULTS: For typical data files, network transmission times were reduced more than 700-fold for extraction of one-dimensional (1-D) histograms, between 18 and 120-fold for 2-D histograms, and 6-fold for color-coded dot plots. Numerous display formats are possible without further access to the data file. CONCLUSIONS: This scheme enables telephone modem access to centrally stored data without restricting flexibility of display format or preventing comparisons with locally stored files.

Computer Communication Networks↗
PubMed1989

Nature of the thymocytes associated with dendritic cells and macrophages in thymic rosettes.

Thymic rosettes, structures consisting of 3-30 thymic lymphoid cells attached to a central macrophage or dendritic cell, were released from mouse thymus tissue by collagenase digestion. They were shown to be preexistent structures within the thymus, but to be subject to extensive exchange with free thymocytes under certain conditions. An isolation procedure was developed, using a new technique of zonal unit-gravity elutriation, which minimized exchange and produced a completely pure sample of the larger rosettes. The rosette-associated thymocytes were analyzed by two- and three-color immunofluorescent staining and flow cytometry. The dominant cell type was a small, CD4+CD8+, cortical-type thymocyte. However, all of the established thymus subpopulations defined by CD4 and CD8, including CD4-CD8+ and CD4+CD8- mature thymocytes and CD4-CD8- early thymocytes, were also present in rosettes. Very few of the cells present were of an intermediate or transitional phenotype. Rosette-associated thymocytes were somewhat enriched in large dividing thymocytes, in CD4-CD8- thymocytes, and in mature thymocytes expressing the T-cell antigen receptor-CD3 complex. Their most striking characteristic was a marked depletion in small thymocytes lacking surface H-2K expression, a major population among free thymocytes. The physiological role of the rosette structure is discussed, and it is suggested that the heterogeneity of the associated thymocytes in part reflects the existence of different types of rosettes in different areas of the thymus.

Animals↗
PubMed1988

Clonal proliferation in vitro of individual murine and human hemopoietic cells after fluorescence-activated cell sorting.

A modification of the fluorescence-activated cell sorter (FACS) was used to rapidly and reliably study the clonal proliferation of single hemopoietic cells. Murine FDC-P1 and human cord blood progenitor cells were examined for their ability to proliferate from single cells in 96-well microtiter plates containing agar medium and appropriate stimuli. FACS-sorted FDC-P1 single cells formed colonies in 345 out of 558 wells (62%), which compared favorably with control cultures (53%) and micromanipulated single cells (55%). Similarly, the frequency and type of day-14 colonies arising from cord blood progenitor cells when sorted as single cells by the FACS compared favorably with those grown from micromanipulated single cells or in control cultures.

Animals↗
PubMed1986

Clonal expansion of T cells: a cytotoxic T-cell response in vivo that involves precursor cell proliferation.

The response of peritoneal exudate lymphocytes to allogeneic tumor cells was used to determine whether the in vivo generation of cytotoxic T cells (CTL) involved the proliferation of precursor cells. Ten days post-injection, both cytotoxic activity and the formation of conjugates between lymphocytes and target cells were shown to be specific for the immunizing tumor alloantigens and to be effected by Ly-2+ cells. A cell-sorting-based procedure was developed to isolate specific conjugates between red-fluorescence-tagged CTL and blue-fluorescence-tagged tumor target cells. When [3H]thymidine was administered during the response, almost all isolated conjugate-forming CTL were 3H-labeled on autoradiography. Thus, the CTL were clearly products of dividing cells, a result that contradicts published data. Reassessment of a previously studied system, which suggested that CTL were not products of cell division, indicated that in that system many of the conjugate-forming cytotoxic cells studied were Ly-2- and nonspecific, and thus perhaps not T cells. We conclude that the clonal selection model is applicable to at least one in vivo T-cell response.

Animals↗
PubMed1983

Intramucosal lymphocytes of the gut: Lyt-2 and thy-1 phenotype of the granulated cells and evidence for the presence of both T cells and mast cell precursors.

The gut mucosa contains lymphocyte-like cells, a proportion of which contain a small number of granules that resemble those of mast cells in that they contain histamine and stain metachromatically. It has been suggested that these granulated lymphocytes represent transitional forms in the differentiation of T cells into mast cells. We used monoclonal antibodies and the fluorescence-activated cell sorter to analyze the expression of Thy-1 and Lyt-2 antigens on gut intramucosal lymphocytes with particular emphasis on the granulated cells. A minority of the granulated cells (10 to 20%) expressed Thy-1 antigen at high levels equivalent to those on cortical thymocytes. A much higher proportion of the granulated cells (about 90%) expressed readily detectable levels of Lyt-2 antigen and the most prevalent phenotype of the granulated lymphocytes (60 to 70%) was Lyt-2+, Thy-1-. Two operationally specific preparations of growth factors, one maintaining the proliferation of T cells and containing T cell growth factor, and the other containing a factor stimulating the growth of persisting (P) cells that are probably mast cell progenitors, were tested on lymphocytes from the gut mucosa. By using the appropriate preparation of growth factors, both T and P cells could be grown readily from the preparation of gut intramucosal lymphocytes. Estimates of the frequency of P cell precursors among these cells indicated a minimum of one in 300 could give rise to cells resembling mast cells. Fractions of Lyt-2+ cells that were enriched in granulated cells had few detectable P cell precursors, an observation lessening the likelihood that the granulated cells were progenitors of the P cells. The precise relationship of the granulated lymphocytes (mainly Lyt-2+, Thy-1-) to T cells remains to be established.

Animals↗
PubMed1982

Expression of Thy-1 antigen is not limited to T cells in cultures of mouse hemopoietic cells.

Large numbers of Thy-1-positive cells were observed in cultures of bone marrow cells that had been depleted of T cells and grown for 3 to 4 days in the presence of medium conditioned by concanavalin A-activated spleen cells. Cells bearing levels of Thy-1 comparable with those on the bulk of thymocytes were isolated by using the fluorescence-activated cell sorter. Although many were large blasts, the Thy-1-positive cells failed to grow in response to T-cell growth factor and concanavalin A; about one-third, however, proliferated in the presence of factors stimulating hemopoietic progenitor cells. Furthermore, the Thy-1-positive population included cells capable of forming large colonies of macrophages and granulocytes in agar and cells forming splenic colonies in lethally irradiated mice. The appearance of the Thy-1-positive cells did not correlate with the presence of either T-cell growth factor or T-cell-derived granulocyte/macrophage colony-stimulating factor. These findings indicate that Thy-1 can occur on various murine hemopoietic stem and progenitor cells and myeloid cells; Thy-1 can no longer be regarded as an unambiguous marker of commitment to the T-cell lineage.

Animals↗
PubMed1980

Analysis of rat hemopoietic cells on the fluorescence-activated cell sorter. I. Isolation of pluripotent hemopoietic stem cells and granulocyte-macrophage progenitor cells.

A scheme is presented whereby pluripotent hemopoietic stem cells (PHSC) from rat bone marrow can be enriched 320-fold with the aid of the fluorescence- activated cell sorter. This scheme is based on the observations that PHSC are strongly positive for Thy-1 antigen (upper 10th percentile); have light- scattering properties (size distribution) between those of bone marrow lymphocytes and myeloid progenitor cells; and are relatively resistant to cortisone. It is estimated that PHSC may constitute 80 percent of the cells isolated according to these parameters. Candidate PHSC are described at the light and electron microscopic levels. At least two populations of accessory cells appear to influence the number and/or the nature of the hemopoietic colonies that form in the in vivo spleen colony-forming unit assay. Putative amplifier cells are strongly Thy-1(+) and cortisone sensitive; putative suppressor cells are weakly Thy-1(+) and cortisone resistant. Three subsets of granulocyte (G) -macrophage (M) progenitor cells (in vitro colony-forming cells [CFC]) are identified on the basis of relative fluorescence intensity for Thy-1 antigen: G-CFC are strongly Thy-l(+); M-CFC are weakly Thy-l(+); and cells that produce mixed G and M CFC have intermediate levels of Thy-1. GM-cluster-forming cells and mature G and M are Thy-1(-). The results suggest that G-CFC are bipotential cells that give rise to G and M-CFC; and that the latter produce mature M through a cluster- forming cell intermediate. Thy-1 antigen is also demonstrated on members of the eosinophil, megakaryocyte, erythrocyte, and lymphocyte cell series in rat bone marrow. In each instance, the relative concentration of Thy-1 antigen is inversely related to the state of cellular differentiation.

Animals↗
PubMedDate not supplied

Inducible expression of H-2 and Ia antigens on brain cells.

Cells in the brain express unusually low levels of antigens encoded by the major histocompatibility complex (MHC). This is somewhat surprising as class I (H-2) and class II (Ia) MHC antigens have critical roles in immune responses. The activation of T lymphocytes is associated with the enhanced expression of these antigens and this effect is mediated by a specific T-cell lymphokine, gamma-interferon (IFN-gamma). Here we show that IFN-gamma induces a dramatic increase in the expression of H-2 antigens on the cells of the brain. After exposure to IFN-gamma in vitro, all surviving cells, including most astrocytes, oligodendrocytes, microglia and at least some neurones, express H-2 antigens. Direct injection of IFN-gamma into the brains of mice indicated that H-2 antigens were also induced in vivo. Furthermore, IFN-gamma induced Ia antigens on a subpopulation of astrocytes. The induction of H-2 antigens by IFN-gamma may render brain cells competent to initiate and participate in immune reactions and may therefore contribute to both immunoprotective and immunopathological responses in the brain.

Animals↗