Dengue virus-induced cytotoxin releases nitrite by spleen cells.
Dengue type-2 virus (DV) infection in mice induces T cells to produce a cytokine, the cytotoxic factor (CF), which induces H2-A positive macrophages to produce another cytokine, cyototoxic (CF2), which amplifies its cytotoxic effects on target cells. The present study was undertaken to investigate the production of nitrite (NO2-) by the spleen cells of mice in vitro and in vivo following inoculation of CF2. Maximum NO2- production occurred at 1 hour after inoculation of 100 micrograms CF2. Pretreatment of CF2 with anti-CF2-antisera (CF2-As) inhibited the production of NO2-. Pretreatment of the spleen cells with NG-monomethyl-L-arginine (NMA) or with arginase inhibited NO2- production. The NO2- production was diminished in a dose dependent manner by treatment of spleen cells with the Ca2+ channel blocking drug, nifedipine and Zn2+ as ZnSO4. The findings of the present study thus demonstrate that CF2 induces production of NO2- in the spleen cells in a CA(2+)-dependent manner which may be a mechanism of target cell killing.
Mukerjee
R
R
Department of Microbiology, K.G. Medical College, Lucknow, India.
Misra
A
A
Chaturvedi
U C
UC
D000818:Animals; D001119:Arginase / Q000494:pharmacology; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D002118:Calcium / Q000502:physiology; D018929:Cell Culture Techniques; D016207:Cytokines / Q000276:immunology*; D003602:Cytotoxicity, Immunologic; D003603:Cytotoxins / Q000037:antagonists & inhibitors / Q000276:immunology; D003716:Dengue Virus / Q000276:immunology*; D004306:Dose-Response Relationship, Immunologic; D007106:Immune Sera; D051379:Mice; D008815:Mice, Inbred Strains; D009569:Nitric Oxide / Q000037:antagonists & inhibitors; D009573:Nitrites / Q000378:metabolism*; D011506:Proteins; D013154:Spleen / Q000276:immunology*; D013431:Sulfates / Q000494:pharmacology; D017967:Zinc Compounds / Q000494:pharmacology; D019287:Zinc Sulfate; D019323:omega-N-Methylarginine
D016207:Cytokines; D003603:Cytotoxins; D007106:Immune Sera; D009573:Nitrites; D011506:Proteins; D013431:Sulfates; D017967:Zinc Compounds; C087354:dengue-2 virus-induced cytotoxic factor; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D019287:Zinc Sulfate; D001120:Arginine; D001119:Arginase; D002118:Calcium