Sex-Dependent,Early Cytokine Production by NK-Like Spleen Cells Following Infection with the D Variant of Encephalomyocarditis Virus (EMCV-D)

Spleen cell cultures from diabetes-resistant ICR Swiss females exhibited an increase in expression of Ia antigens 24 hours post-infection (PI) with EMCV-D while comparable spleen cell cultures from diabetes-susceptible males of this strain did not exhibit this increase in Ia antigens expression. A monoclonal antibody specific for mouse interferon-γ (IFN-γ) eliminated this increase in Ia antigens expression. Interferon-γ (IFN-γ) and interleukin 2 (IL-2) production by EMCV-D-infected spleen cell cultures were monitored at 4-hour intervals for 24 hours. Female spleen cells produced IFNγ earlier (< 16 hours PI) and in greater amounts than did comparably treated male spleen cells. Addition of a monoclonal rat anti-mouse IL-2 to virus-infected cultures did not significantly affect the early (< 16 hours PI) production of IFNγ by spleen cells of females. Treatment of the spleen cell donors with rabbit anti-asialo GM1 (AAGM1) abolished early production of IFNγ in virus-infected female spleen cell cultures and reduced the early IL-2 production by infected male and female cells. These results suggest that an NK-like cell is responsible for the early female IFNγ production; this may be a factor in the resistance of female ICR Swiss mice to EMCV-D-induced diabetes.