title: Transfection of L929 cells with complement subcomponent C1q B-chain antisense cDNA inhibits tumor necrosis factor-alpha binding to mediate cytotoxicity and nitric oxide generation.
abstract: The role of complement subcomponent C1q in the modulation of TNF-alpha binding to L929 cells to mediate cytotoxicity and nitric oxide (NO) generation was investigated. Transfection of L929 with murine C1q B-chain antisense plasmid cDNA rendered them markedly less susceptible to TNF-mediated cytotoxicity coincident with a decreased capacity for TNF-alpha binding and expression of cell surface C1q protein. The inhibitory effects of L929 transfection with C1q B-chain antisense were transiently expressed at 24 hr post-transfection with full recovery of cellular functions by 72 hr. Transfected L929 cells were fully reconstituted in their TNF-alpha binding and in their cytotoxic response following exposure to soluble C1q which was bound to their cell surface. Transfection with C1q B-chain antisense also significantly inhibited NO generation by L929 cells in response to stimulation by TNF-alpha, IFN-alpha/beta, and LPS. Taken together, these results indicate that endogenously synthesized C1q is prerequisite for binding of TNF-alpha to L929 cells to mediate cytotoxicity and NO generation.
authors.affiliation: Oklahoma Medical Research Foundation, Oklahoma City 73104-5046, USA.
authors.forename: H
authors.initials: H
authors.lastname: Jiang
authors.forename: C A
authors.initials: CA
authors.lastname: Stewart
authors.forename: S Y
authors.initials: SY
authors.lastname: Tan
authors.forename: D J
authors.initials: DJ
authors.lastname: Fast
authors.forename: J A
authors.initials: JA
authors.lastname: Rummage
authors.forename: R W
authors.initials: RW
authors.lastname: Leu
mesh_terms: D000818:Animals; D015922:Complement C1q / Q000502:physiology*; D003602:Cytotoxicity, Immunologic; D016373:DNA, Antisense; D018076:DNA, Complementary / Q000235:genetics; D007739:L Cells; D008264:Macrophages / Q000502:physiology; D051379:Mice; D009569:Nitric Oxide / Q000096:biosynthesis*; D015398:Signal Transduction; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
chemical_list: D016373:DNA, Antisense; D018076:DNA, Complementary; D014409:Tumor Necrosis Factor-alpha; D009569:Nitric Oxide; D015922:Complement C1q