Biomedical subjects

Y D Kuang

Publications and source records attributed to Y D Kuang.

3 recordsLinked to original sources

PubMed1991

Decrease in cytokine production by HIV-infected macrophages in response to LPS-mediated activation.

The capacity of human monocytes/macrophages (M/M) infected with a human immunodeficiency virus-1 (HIV-1) isolate to produce several immunomodulating cytokines including interleukin-1 alpha (IL-1 alpha), IL-1 beta, tumor necrosis factor-alpha (TNF-alpha), IL-6, IL-8, and macrophage chemoattractant and activating factor (MCAF) was examined. Although HIV infection itself induced significant increases in the level of mRNAs for IL-1 beta, TNF-alpha, IL-6, and IL-8, the levels of lipopolysaccharide (LPS)-induced mRNAs for IL-1 alpha, IL-1 beta, TNF-alpha, IL-6, IL-8, and MCAF were decreased over those of uninfected LPS-stimulated cells. In addition, HIV-infected M/M produced lower amounts of IL-8 protein, as measured by radioimmunoassay over an 18-day culture period. These results suggest that HIV infection generally suppresses the LPS-inducible cytokine production in human M/M. The impact of the role of these cytokines in the immunity and pathogenesis of HIV-1 infection is discussed.

Acquired Immunodeficiency Syndrome↗

PubMed1985

Effects of recombinant interferon-gamma on HLA-DR antigen shedding by human peripheral blood adherent mononuclear cells.

Two reproducible and sensitive assays have been developed for the detection of cell-free HLA-DR antigen, an antibody-mediated complement-dependent cytotoxicity inhibition assay (CIA) and a competition enzyme-linked immunosorbent assay (CELISA). One unit of cell-free HLA-DR antigen has been quantitated to be the equivalent of 27.5 ng pure DR antigen/ml. Human peripheral blood adherent mononuclear cells (PBAMC), as well as DR+ monocytes and B lymphoblastoid cell lines but not T lymphocytes, were observed to shed DR-bearing vesicles in vitro. Human recombinant IFN-gamma induces the expression of Ia/DR antigen by PBAMC by increasing both the number of cells expressing DR antigen and the density per cell. After incubation with IFN-gamma, PBAMC also shed significantly more DR antigen. The degree of DR expression and shedding is dependent on the dose of IFN-gamma. The shedding of DR antigen occurred concomitantly with the inductive phase of cell membrane antigen expression, and very little DR antigen appeared in culture supernatants subsequent to the removal of IFN-gamma. The possible physiologic significance of shed DR antigen is discussed.

Cell Adhesion↗

PubMed1985

B-cell-derived interleukin 1 (IL-1)-like factor. I. Relationship of production of IL-1-like factor to accessory cell function of Epstein-Barr virus-transformed human B-lymphoblast lines.

The relationship of production of interleukin 1 (IL-1)-like factor to accessory function of Epstein-Barr virus (EBV)-transformed B lymphocytes was examined. Six of eight human EBV-B cell lines spontaneously produced and released detectable levels of thymocyte comitogenic factor in vitro, but no interleukin 2 (IL-2) activity. Eight of eight produced fibroblast proliferation activity. Culture supernatants from the two apparent nonproducers of thymocyte comitogenic activity induced the proliferation of the IL-1-dependent murine helper-T-cell clone D10G4.1 in the presence of concanavalin A (Con A). One of the EBV-B cell lines produced a potent inhibitory factor in addition to IL-1-like thymocyte comitogenic and fibroblast proliferation factors. The inhibitory factor inhibited mouse thymocyte proliferative response to Con A, and the proliferation of the IL-2-dependent CT6 cell line, but not human fibroblast growth. All but one of the eight EBV-B cell lines tested, the exception being the line that produced an inhibitory factor, were able to serve as antigen-presenting cells that enabled purified human T lymphocytes to proliferate in one-way mixed lymphocyte reactions (MLR) and in response to Con A. The supernatants of 14 of 16 clones derived from two of the EBV-B cell line cells contained thymocyte comitogenic activity and all 16 stimulated fibroblast proliferation. The phenotypic characteristics of the EBV-B cell lines were heterogeneous, but there was no clear-cut relationship between the cell surface phenotypes of either the cloned or uncloned EBV-B cells and their ability to produce these factors. These studies show that all of the EBV-B cell lines that can function as accessory cells have the capacity to produce an IL-1-like factor.

Animals↗