The observation on the in vitro phagocytosis-enhancing effect of mouse interferon has now been confirmed in the same host system and expanded to the human system. Morphological and cytochemical evidence of the activated state of mouse macrophages has also been reported. The interferon-elicited enhanced state of macrophages has been demonstrated in intact animals. The exact mechanism of the macrophage-enhancing effect of interferon remains to be elucidated.
