title: Identification, purification and characterization of a receptor for dengue virus-induced macrophage cytotoxin (CF2) from murine T cells.
abstract: Dengue type-2 virus infection in mice induces a subpopulation of T lymphocytes to produce a cytokine cytotoxic factor, which induces macrophages (Mphi) to produce a biologically active cytotoxic cytokine, the Mphi cytotoxin (CF2). Previously we have identified the presence of intermediate-affinity receptors for CF2 on mouse peritoneal Mphi. The present study was undertaken to identify the CF2-receptors (CF2-R) on murine T cells followed by their purification and characterization. Receptor binding assay and Scatchard analysis revealed single, high-affinity (1.0309 nM) receptors for CF2 on T cells (22000 receptors per cell). The binding of [125I]CF2 on murine T cells was saturable and specific. Furthermore, CF2-R was purified from normal mouse T cell plasma membrane by affinity chromatography followed by reversed-phase high-pressure liquid chromatography. The presence of CF2-R was confirmed by indirect dot-blot assay and its binding with [125I]CF2. The purified CF2-R is a 90-95-kDa protein as characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblot analysis. The chemical crosslinking of [125I]CF2 and its receptor complex showed a product of 100-110 kDa on different subpopulations of murine T cells. The pretreatment of target cells with anti-CF2-R antisera inhibited the cytotoxic activity of CF2 in a dose-dependent manner and thus confirmed the biological significance of CF2-R. Moreover, the presence of CF2-R was also identified on normal human peripheral blood mononuclear cells and T and B cells by crosslinking with [125I]CF2, thus revealing the possible role of CF2 and CF2-R in the immunopathogenesis of dengue virus disease.
authors.affiliation: Postgraduate Department of Microbiology, K.G. Medical College, 226-003 Lucknow, India. khare.pranay@mayo.edu
authors.forename: Pranay Deep
authors.initials: PD
authors.lastname: Khare
authors.forename: Meenakshi
authors.initials: M
authors.lastname: Khare
authors.forename: Ritu
authors.initials: R
authors.lastname: Tandon
authors.forename: Umesh Chandra
authors.initials: UC
authors.lastname: Chaturvedi
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002851:Chromatography, High Pressure Liquid; D003603:Cytotoxins / Q000096:biosynthesis*; D003716:Dengue Virus / Q000502:physiology*; D051379:Mice; D008815:Mice, Inbred Strains; D011506:Proteins; D011991:Receptors, Virus / Q000032:analysis* / Q000302:isolation & purification; D013601:T-Lymphocytes / Q000378:metabolism* / Q000821:virology
chemical_list: D003603:Cytotoxins; D011506:Proteins; D011991:Receptors, Virus