Figure 4

Expamers enable control over stimulation duration. (A,B) T cells were stimulated with Expamers. 48 h post-activation D-biotin was added or not to the T cell culture and T cell activation state (A) as well as cell cycle phase (B) was assessed by flow cytometry 24 h later. (C,D) T cells were stimulated as in (A) or left unstimulated. Subsequently, D-biotin was added to the culture at indicated time points. Surface marker expression (C) and proliferation (D) was measured by flow cytometry and cell counting, respectively. (E) Population of HLA-A*0201⁺ CMV seropositive donor was analyzed before and after 8 days antigen-specific stimulation using either pMHC- and CD28 Fab-loaded multimer backbone or Expamers (polyclonal stimulus—negative control). Events were pre-gated on single, living T cells.