Fig. 2

Protein expression, validation of identified proteins and protein interaction network. A Summary of protein spots as obtained by 2DE DIGE gels. Each protein spot has one RF calculated as a ratio between the mean fluorescence intensity of the HDACi-untreated samples versus that of the HDACi-treated samples for each age group separately. All the spots detected for young and old with an RF < 0.66 and > 1.5 were determined as biologically significant. These spots were further divided into spots with an increased expression (RF > 1.5) and with a decreased expression (RF < 0.66). Statistical significance was determined with a t-test and a p value < 0.05. B qPCR validation of identified proteins. The mRNA levels of selected proteins were measured with qPCR. The ∆∆Cq value is presented, and the housekeepers were TBP and SDHA. N = 4–8. C Relative protein expression of 14-3-3 ζ/δ and HSP90. The relative protein expression is presented as a ratio between the untreated and treated activated CD8⁺ T cells and it was normalized to the total protein staining with Ponceau S. N = 5. D Representative blots for the relative protein expression. Two donors are presented for each condition and for each protein. E STRING network analysis of the identified proteins. All the proteins identified were introduced into STRING protein–protein association network analysis online tool. The presented network was obtained with the option “multiple proteins” and a confidence of 0.7. F Overview of GO terms found for the identified proteins. The GO terms found were automatically divided into several categories. A total of 404 GO terms were returned and the proportion of each category is presented in a pie chart