Sex-related differences in the rapid production of cytotoxic spleen cells active against uninfected myofibers during Coxsackievirus B-3 infection.

Spleen cells from BALB/c mice immunized with a cardiotropic strain of Coxsackie B-3 virus were more cytolytic to uninfected myofibers than were spleen cells from mice immune to a noncardiotropic strain of the virus. Spleen cells immune to either virus were equally cytolytic to endothelial cells. Cytotoxicity was greater in female mice than in males. Analysis of individual reactivities showed that the male response was heterogeneous with only half of the animals developing cytolytic activity. All females responded. Early (day 3) cytolytic cells in both male and female mice appear to be natural killer (NK) cells, since they are not sensitive to anti-thy 1.2 or anti-Ig serum and complement, and lyse allogeneic (CBA) as well as syngeneic (BALB/c) targets. Later (days 4 to 6), the cytolytic cells in males become sensitive to anti-thy 1.2 serum and are restricted to lysis of syngeneic targets, while the cytolytic cells in females maintain the characteristics of NK cells.