Influence of exogenous interferon on the peripheral white blood cell count in mice.

The effect of interferon (IF) injected intraperitoneally on the peripheral white blood-cell (WBC) count in mice was studied. Mouse serum or brain IF produced in vivo in different mouse strains by injecting various viral inducers depressed the lymphocyte count from 3 to 24 h after the injection. The effect was correlated to the antiviral titer of the preparations. The inhibitory factor exhibited physico-chemical properties of IF. Crude IF preparations obtained from mouse cell cultures, human IF and mock preparations devoid of anti-viral activity exerted no lymphocytopenic effect.