An intrinsic T cell defect is responsible for the decrease in antigen-specific IFN-gamma production.

<p>CD3⁺ T cells and CD11c⁺ DCs were isolated from splenocytes of infected mice 7 dpi. Cells were mixed at a ratio of 5∶1 (T:DC) and incubated for 72 hours +/− STAg. IFN-gamma was measured from supernatants by ELISA. (A) B6.<i>lpr</i>; (B) BXSB; each assay was performed 3 times in triplicate. B6.<i>lpr</i> mice were 20 weeks of age and BXSB mice were 14 weeks of age.