In-vivo CD40 signals cause non-autoimmune CD4^loCD40⁺ T cells to appear more like autoimmune CD4^loCD40⁺ T cells.

<p>(<b>A</b>) 10–12 week old, female BALB/c mice were injected i.p. with 1C10+FGK45 agonistic CD40 antibodies (CD40-inj.) or with isotype control (control) antibody. Three days post-injection, splenic CD4^loCD40⁺ and CD4^hi T cells were purified and stained with L-PHA. Graph depicts the difference in L-PHA stain compared to control. Data are represented as means with SEM. Images are H&E stained sections of pancreata. (<b>B</b>) BALB/c mice were treated and CD4^loCD40⁺ T cells purified as in A. CD4^loCD40⁺ T cells from 10–12 weeks old female NOD spleens were purified for comparison. Cells were CFSE labeled then CD40-stimulated for 4 days. CFSE dilution was measured. Dotted line – isotype treated; solid line – CD40-stimunlated. (<b>C</b>) 10 week old female BALB/c mice were injected and CD4^loCD40⁺ T cells purified as in A, then cells were labeled with CFSE and isotype treated (Isotype) or CD40 stimulated (CD40XL) in the absence/presence of galectin-9. CFSE dilution was measured. Percentages in B and C are means +/− SEM. Experiments were performed at least three separate times.