TLR7 stimulation causes elevation of CD4⁺ T cell death mediated by NO and PGE₂.

<p>(A) Co-cultures of 5 x 10⁵ OT-II CD4⁺ T cells and 1 x 10⁵ DC were stimulated with 1 μg/ml CpG or 1 μg/ml CL097 in the presence or absence of 25 μg/ml OVA protein for three days. CL097, but not CpG, increased OT-II CD4⁺ T cell death regardless of antigenic stimulation. (B) 1 x 10⁶ splenocytes from wild-type mice were mixed with 1 x 10⁵ DC and then stimulated with CL097 in the presence or absence of L-NMMA or Indo for three days. CD4⁺ T cell death was reduced by L-NMMA and Indo. (C) Co-cultures of 5 x 10⁵ OT-II CD4⁺ T cells stained with CFSE and 1 x 10⁵ DC were stimulated with OVA protein plus CL097 in the presence or absence of L-NMMA or Indo for four days. Data are representative of two independent experiments.