Figure 3.

Activation of Jurkat T cells is inhibited by HA-49K orthologs to an equal extent. Jurkat cells were previously incubated with cell supernatants (red) containing HA-49K orthologs. Cells were washed and stimulation was conducted via receptor cross-linking using immobilized α-CD3 and soluble α-CD28 Abs for 6h. After cell fixation the activation level was determined by flow cytometry-based monitoring of the cell surface expression of the early activation marker CD69. Relative numbers of CD69 positive cells were normalized to CD3/CD28 stimulation control (not shown). Untreated (unstim.) and isotype control (ISO) treated samples were used as negative controls (grey). To show the efficiency of the CD3/CD28 stimulation we treated the cells also with 50 ng/ml Phorbol-12-myristate-13-acetate and 1 µg/ml ionomycin (PMA/Iono, blue). Administration using CD3/CD28 stimulation and unreactive A549 supernatant was utilized to control the effect of the supernatant on CD3/CD28 stimulation (A549, blue) (A). pErk1/2 levels were identified by immunoblot analysis upon CD3 stimulation of Jurkat cells with 1 µg/ml for 2 min. Sample loading was controlled by detection of β-actin. One representative blot for Jurkat and CD45-/- Jurkat is shown (B) and the relative expression levels of pErk1/2 to β-actin ratios were normalized to the pos. ctrl. (C). The columns represent the mean of 3 individual experiments (dots), the error-bars represents the standard deviation for A and (C) Statistical differences compared toPMA/ionomycin treatment in (A) and CD3-stimulation in the presence of A549 supernatants in (C) positive controls were analyzed using the two-way ANOVA test. Only significant results were indicated in the figure.