Peculiarities of virus-specific immune response in mice with congenitally acquired influenza infection.

In this paper we show that progeny of C57BL/6 mice infected during pregnancy with influenza virus display a profound specific areactivity in situ according to their decreased capacity to give plaque-forming cell and delayed-type hypersensitivity responses to influenza virus. In spite of this specific areactivity in situ, spleen cells of mice with congenitally acquired influenza infection can easily transfer virus-specific delayed-type hypersensitivity and plaque-forming cell responses to syngeneic recipients. These results suggest that specific areactivity of mice with congenitally acquired influenza infection observed in situ is not connected with deletion of virus-specific immunocompetent cells after vertical virus transmission. It is also shown in this paper that spleen cells of mice with congenitally acquired influenza infection can specifically suppress local transfer of delayed-type hypersensitivity response to influenza virus in syngeneic mice. This suppression may be one of the possible causes of specific areactivity of mice with congenitally acquired influenza infection observed in situ. The presence of influenza virus antigens in lymphoid cells of mice with congenitally acquired influenza infection is also shown in this paper. The immunopathological consequences of viral persistence in lymphoid cells require further study.