Induction of alpha and beta interferons during the hyporeactive state of gamma interferon by Mycobacterium bovis BCG cell wall fraction in Mycobacterium bovis BCG-sensitized mice.

Characterization of interferon (IFN) induced by a second challenge with specific antigen was investigated during the development of hyporeactivity established after challenge of Mycobacterium bovis BCG-sensitized mice with BCG cell wall fraction (BCG-CW). When BCG-sensitized mice were challenged with BCG-CW, IFN-gamma was detected in the circulation 4 h later and rapidly disappeared. After IFN-gamma disappeared from their blood, mice became completely hyporeactive to the second challenge with BCG-CW for 1 day, and thereafter they recovered from this hyporeactive state. However, we always observed that IFN induced at first by the second challenge with BCG-CW during the hyporeactive state was type I IFN-alpha/beta, but thereafter was entirely IFN-gamma. Induction of IFN-alpha/beta by the specific antigen during restoration from the hyporeactive state in BCG-sensitized mice is discussed.