After intracerebral challenge with 100 PFU of Lassa virus (strain Josiah),
all infected mice (CBA/calac) died (control group). Production of pro-infla
mmatory cytokines (IL-1 beta, TNF-alpha) significantly increased in the blo
od of these Nice during the infection. For neutralization of increasing con
centrations of these cytokines recombinant IL-IRA was used intraperitonealy
at a dose 100 mu g kg(-1), everyday, within 5 days from the third day afte
r the challenge. Injections of IL-IRA decreased the concentration of IL-1 b
eta and TNF-alpha and resulted in survival of all infected mice (treatment
group). Marburg fever (strain Popp) caused in guinea pigs by 5 LD50 of viru
s lead to the significant increase of TNF-alpha in the animal's blood and c
aused a lethal outcome (control group). Treatment of infected guinea pigs b
y IL-IRA or anti-TNF serum decreased the concentration of TNF-alpha and res
ulted in survival of half of the animals (treatment group). For the treatme
nt recombinant IL-IRA was used at a dose 100 mu g kg(-1) intramuscularly, e
veryday, within 6 days from the third day after the challenge or anti-TNF s
erum, intramuscularly 0.5 mi (2000 U ml(-1); 1 U of the antiserum neutralis
es 0.03 ng of TNF-alpha), everyday, within 6 days from the third day after
the challenge. (C) 2000 Elsevier Science B.V. All rights reserved.