Summary

Results of Studying Human Placental RNase

II. The influence of the enzyme on reproduction of flu A/H5N1 virus

In this work three partially purified and most highly active preparations of RNase from human placenta (NT-4b, NT-4ab and NT-3ab) were used to study the ability of human placental RNase to inhibit reproduction of flu A/H5N1 virus. The experiments were performed on the model system of 10 days-old chicken embryos infected with a vaccine strain of flu A/H5N1 virus. The enzyme (in certain concentrations) was introduced into the embryos simultaneously with the virus preparation, then 4 days later the production of the virus was examined by haemoagglutination of chicken erythrocytes. Results of these experiments showed that all the three preparations of RNase from human placenta can inhibit production of flu A/H5N1 virus in the chicken embryos, although there was no correlation between the degree of inhibition and enzyme concentrations used in this study.