AGM1+ spleen cells contain gamma interferon (IFN-gamma) gene transcripts in the early, sex-dependent production of IFN-gamma after picornavirus infection

Encephalomyocarditis D variant (EMCV-D)-infected spleen cell cultures prepared from diabetes-resistant ICR Swiss female mice produce more gamma interferon (IFN-gamma) activity over a 24-h period than do spleen cell cultures from diabetes-susceptible male mice of this strain. Pretreatment of mice with anti-asialo GM1 eliminates early in vitro IFN-gamma production from 4 to 16 h postinfection (p.i.) and reduces IFN-gamma production from 16 to 24 h p.i. In this study, depletion of spleen cells with anti-Thy-1 by panning greatly reduced IFN-gamma activity in EMCV-D-infected spleen cell cultures throughout a 24-h period. Populations of asialo GM1 (AGM1), L3T4, and Lyt-2-positive cells were isolated from cells harvested at 9 h p.i. from EMCV-D-infected spleen cell cultures by a modified panning technique on polystyrene microscope slides. By in situ hybridization with a [35S]dATP-labeled IFN-gamma cDNA probe, only the AGM1-bearing cells were found to contain detectable IFN-gamma gene transcripts. An AGM1+, Thy-1+ natural killer-like cell is the probable producer of the early, sex-dependent IFN-gamma activity in this system.