PRODUCTION OF NITRIC OXIDE BY ENDOTHELIAL CELLS INFECTED WITH HERPES SIMPLEX VIRUS TYPE 1, UNDER THE INFLUENCE OF INTERFERON - Biochemistry and Biotechnology: Research and Development - page 21

at the highest MOI (0,1) the small nitrite increase was observed (on 10-12 %) through 6 hours
after infection, however in later terms decrease in formation NO was observed (Figure 2а,
curve 1). From the results presented in figure 2b it is visible dose-dependence between MOI
of virus and the level of an infectious virus in cultural medium of ECs: at more larger MOI it
was shown fast and to higher titers of virus accumulation, at lower MOI virus accumulation
was slower and values of virus titers were more low.
Increased NO production in cells infected with the virus at MОI 0.1 was somewhat
unexpected. Although it is known that NO has antiviral effect [4, 5, 9, 22], however, a
reproduction of the virus at this multiplicity was the highest. On the other hand, increased
production of NO by ingestion of massive doses of virus can lead to vasodilation, slowing
blood flow, accumulation of leucocytes, which may contribute to the development of long-
term inflammation [15, 21].
Figure 3. shows the results of influence of pretreatment of ECs by IFN-α for 24 h and
then infected with HSV-1 (MОI 0.1) on NO production and reproduction of the virus. It is
seen that the joint effect of viruses and interferon in a concentration both 1x10 5 IU / ml and
1x10 6 IU / ml to 24 hours after infection leads to a decrease in nitrite content in culture
medium by 30-40% compared with the content of nitrite in the control (intact) cultures. After
48 hours, with the use of IFN in a concentration 1x10 6 IU / ml, a gradual recovery of nitrite
content to values from 10 to 15% higher than in the control group was observed, whereas at
the concentration 1x10 5 IU / ml nitrite level remained low (Fig 3a).
The joint effect of the virus and interferon in a concentration both 1х10 5 IU / ml and
1x10 6 IU / ml through 24 hours resulted in significant reduction of viral titers in the culture
medium (10 -1 −10 -1,5 TCID 50 /cell) compared with their values in the culture medium of EC
not treated with IFN. Virus titers in the culture medium of EC treated with IFN and infected
with HSV-1 to 48 hours increased to a value of 1x10 -4 and as in the control samples it was 10 -
6,5 TCID 50 /cell (Figure 3b).
Figure 3. (Continued).