MTS mice have peripheral CD4⁺ T cells that are skewed toward the inflammatory T_H1 and T_H17 lineages and develop spontaneous autoantibody production. (A) Cells were stimulated with PMA plus ionomycin for 4 hours, and cytokine production was assessed by intracellular staining for inflammatory cytokines IFN-γ, IL-2, IL-17A, and IL-17F. Populations shown are gated on CD4⁺ T cells. Data are representative of at least 5 independent experiments of 1 to 3 mice per group. (B) RNA isolated from unstimulated purified T cells of WT (□) and MTS (▩) mice were analyzed for mRNA encoding ROR-γt (rorc) and T-bet (tbx21) by real-time PCR analysis. Data are mean ± SEM and are representative of 3 independent experiments of 2 or 3 mice per group. (C) Sera isolated from WT (●) and MTS () mice were analyzed for the presence of anti-dsDNA antibodies and antinuclear antibodies (IgG). Horizontal lines represent averages. Significance was determined using the Mann-Whitney test. ***P < .001. Images were obtained with a Nikon Eclipse E600 microscope (40× objective and 1:40 serum dilution) and captured with a Nikon DXM 1200 camera. Images were processed with IP Labs Scientific Image Processing (Scanalytics Inc).