Studies of virus-induced myocardial injury in mice: value of the scid mutation on different genetic backgrounds and combined with other mutations.

The mechanism of cardiac muscle damage in virus-induced myocarditis remains to be fully understood. In particular, a direct role for viral replication has been obscured by evidence of immune-mediated injury. The combined use of severe combined immunodeficient (scid) and doubly mutant scid/beige mice of different genetic backgrounds has provided a unique opportunity to study the consequences of viral proliferation apart from the influence of immunologic responses. In these immunodeficient animals, inoculation with coxsackievirus B3 caused severe myocardial injury, indicating a profound and direct pathogenic potential of viral infection. These studies, in turn, serve to illustrate the value of the scid mutation in experimental biology, as defined among different genetic backgrounds and combined with other mutations.