Document 0156
 DOCN  M9480156
 TI    [Tumor necrosis factor (TNF) and oxygen free radicals: potential effects
       for immunity]
 DT    9410
 AU    Ferlat S; Favier A; Groupe de recherche sur les pathologies oxydatives,
       GREPO,; Universite de Grenoble, La Tronche.
 SO    C R Seances Soc Biol Fil. 1993;187(3):296-307. Unique Identifier :
       AIDSLINE MED/94290960
 AB    During various biological processes as inflammation or septic shock,
       free radical damages are produced by a direct production of oxygen
       radicals by phagocytes, but also by a TNF-mediated generation in target
       cells. Antioxidants have been demonstrated as protective against TNF
       cytotoxicity. We try to measure directly the free radical produced by
       murine recombinant TNF on L929 cells, by detecting the direct light
       produced by decomposition of superoxide using an adapted
       chemiluminometer. We measure also the chemiluminescence after addition
       of luminol. These techniques demonstrate the effective production of
       oxygen radicals. Unfortunately they have a rather poor specificity and
       sensitivity. So we use the protective effect of antioxidants on
       cytotoxicity to investigate the origin of the productive mechanism. We
       evaluate cytotoxicity of 1 U/ml TNF on L929 murine fibroblasts after 24
       hours incubation with actinomycin D by the MTT and Cr51 release. Using
       the MTT test we observe that addition of thiourea or catalase has the
       better protecting effect when Zu-Zn SOD had few effect. Reversely using
       the Cr51 release we observe a good protective effect of Cu-Zn SOD
       simultaneously with a good protective effect of catalase. So the
       difference in the effect of various antioxidant agent do not permit to
       identify the species generated, but depend more on the ability of the
       antioxidant to reach the cell compartment tested by the method
       (membrane, or mitochondria). The oxidative effect of TNF is beneficial
       in physiological condition to destroy cancerous or virus infested cells
       infested by virus inside the body. But this effect can be deleterious in
       situation of deficiency in some antioxidant. TNF-induced free radicals
       can increase the replication of virus as HIV-1 and destroy
       immunocompetent cells as T cells. This last action explains the defect
       in cellular immunity observed in oxidative stress and the
       immunostimulatory effect of many antioxidants.
 DE    Animal  Antioxidants/PHARMACOLOGY  Cell Line  Cytotoxicity,
       Immunologic/DRUG EFFECTS  English Abstract  Free Radicals/ANALYSIS
       Human  Immunity/*DRUG EFFECTS  Oxygen/*CHEMISTRY  Tumor Necrosis
       Factor/*PHARMACOLOGY  JOURNAL ARTICLE  REVIEW  REVIEW, TUTORIAL

       SOURCE: National Library of Medicine.  NOTICE: This material may be
       protected by Copyright Law (Title 17, U.S.Code).