Impairment of immunocompetent mouse spleen cell functions by infection with coxsackievirus B3.

Early after infection, mice inoculated with coxsackievirus B3 showed consistent reduction of antibody responsiveness. Beginning one week after infection they also evidenced progressive spleen atrophy. The cellular basis of the reduced antibody response exhibited in vitro by spleen cells of infected mice at the onset of atrophy was investigated by the use of different antigens, by supplementation with different subpopulations of immunocompetent cells from normal donors, and by cross-recombination with normal lymphoid cells. Whereas B cell functions appeared to be preserved, a deficit of macrophage accessory functions was clearly evident, possibly at the level of antigen presentation. In infected spleens, nonspecific suppressor T cells were also observed, but their activity did not correlate strictly with the degree of immunodepression. Because no evidence for a direct effect of virus on, or for viral replication in, immunocompetent cells was found, these alterations were tentatively ascribed to activation of the host's suppressor system. Such changes may have implications in the pathogenesis of coxsackievirus infections.