(B) Freshly isolated PBMCs were treated with SHP-1 and Cbls siRNA-loaded NPs, empty NPs, PBS as negative control or PHA as a positive control. Following incubation, supernatant from each sample was collected and the levels of human cytokines TNF-α, IL-6, IL-10 and IFN-γ were determined using ELISA. The data represent four independent experiments (n=4). P values were calculated by One way ANOVA following Tukey's post hoc analysis, and are indicated by asterisks. *P≤0.008. Data are shown as mean ± SEM. 