Identification of an interferon in murine placentas

It is becoming increasingly apparent that interferon exerts a major role in cellular regulatory processes. Besides its well known antiviral properties 1 , interferon has been shown to affect cell surface antigen expression 2,3 , lymphoid cell function 4,5 , as well as cellular protein synthesis 6,7 and growth 8–11 . To date, however, there is little information available on the mechanism of interferon production in vivo except in response to a variety of exogenously administered viral and nonviral systemic inducers. We report here the detection of a pregnancy-associated elevation of interferon, or an interferon-like component, in selected reproductive tissues of mice.