title: Characterization of the dengue virus-induced helper cytokine.
abstract: Dengue type 2 virus (DV) induces a subpopulation of T lymphocytes of mouse spleen to secrete a soluble helper cytokine (HF) which enhances the DV-specific IgM antibody plaque forming cells (PFC). The present study undertaken to purify and characterize HF shows that it can be purified by low pressure liquid chromatography (LPLC) using Sephacryl S-200 column. HF consisted of two subunits, having a M(r) of 65-68 kDa on SDS-PAGE, and both had similar activity. The isoelectric point of HF was 6.5. HF-specific antisera (HFAS) raised in mice neutralized the activity of HF in mice, reacted with it in a Western blot assay, and bound HF in an immunosorbent column. HF bound to DV-antigen in an immunosorbent column and enhanced only the DV-specific PFC. HF had no effect on PFC against heterologous antigens such as Japanese encephalitis virus, Coxsackie B4 virus or sheep red blood cells. HF generated in mice of H-2k haplotype, enhanced DV-specific PFC in the same strain of mice but had no effect on that in the H-2d or H-2q haplotype strains of mice. Thus, DV-induced HF with a M(r) of 65-68 kDa, antigen-specificity and genetic-restriction differs from most of the similarly acting cytokines but appears similar to the cell-free form of T cell receptor alpha beta dimer.
authors.affiliation: Postgraduate Department of Microbiology, KG Medical College, Lucknow, India.
authors.forename: P
authors.initials: P
authors.lastname: Chaturvedi
authors.forename: R
authors.initials: R
authors.lastname: Mukherjee
authors.forename: U C
authors.initials: UC
authors.lastname: Chaturvedi
authors.forename: A
authors.initials: A
authors.lastname: Mathur
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002845:Chromatography; D016207:Cytokines / Q000032:analysis* / Q000235:genetics; D003715:Dengue / Q000276:immunology; D003716:Dengue Virus / Q000276:immunology*; D004591:Electrophoresis, Polyacrylamide Gel; D000939:Epitopes / Q000032:analysis; D007075:Immunoglobulin M / Q000276:immunology; D007526:Isoelectric Point; D051379:Mice; D008815:Mice, Inbred Strains; D008970:Molecular Weight; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*
chemical_list: D016207:Cytokines; D000939:Epitopes; D007075:Immunoglobulin M