Figure 5

Impaired T proliferation by SRA-ECD could be reverted by IL-2. (A) CFSE-labeled naïve T cells were stimulated with immobilized anti-CD3 (0.5 μg/mL) and anti-CD28 (0.5 μg/mL) antibodies or anti-CD3/28 plus SRA-ECD in the presence or absence of recombinant IL-2 (100 U/mL). After 72 h, cells were stained for CD3, and proliferation and cell death induction was determined for CD3⁺ T cells. The data are representative of one experiment among three independent experiments. (B) Purified T cells were activated on plates coated with anti-CD3 and anti-CD28 antibodies in the absence or presence of SRA-ECD protein. Phosphorylation of ZAP-70 was determined by western blot analysis at different time points. GAPDH was used as a loading control. Immunoblot bands were quantified by densitometry analysis using ImageJ software. The data are presented as ratio of protein expression compared with GAPDH expression for each sample. The result presented is from one representative experiment among two independent experiments. N.S. stands for not statistically significant.