Figure 2: Activation of T cells by an immunomodulatory protein targeting the CD4bs of HIV Env and CD3.

(a) CD4⁺ and (b) CD8⁺ T cells are specifically activated by the bispecific protein. Enriched human T cells were co-cultured with either uninfected or HIV-infected CEM cells (indicated by − or + at the top of each column) in the presence of the indicated bispecific proteins (0.5 μg ml⁻¹) and Brefeldin A overnight. The T cells were then stained with an antibody against IFN-γ, and the percentage of T cells expressing IFN-γ was measured using flow cytometry. Representative data from three independent experiments are shown, with each experiment performed with three technical replicates. The error bar represents the s.e. (c) Effector cells comprising PBMCs were co-cultured with or without target cells that were either uninfected or HIV-infected CEM cells (indicated by HIV− or HIV+ at the top of each column) in the presence of increasing concentrations of the indicated bispecific proteins and Brefeldin A overnight. The T cells were then stained with an antibody against CD69, and the percentage of T cells expressing CD69 was measured using flow cytometry. The mean of the values at each concentration from three naive donors are shown, with each experiment performed with three technical replicates. Error bars indicate the s.e. at each concentration.