Figure 1.

IgG1 Immune Complexes Bind T cells (A) Overview of antibody/antigen preparations added to activated T cells. (B) Confocal microscopy of purified T cells stained with anti-CD3 (blue), anti-TCRαβ (green), and fluorescent ICs (red). T cells were incubated with either WT IgG1-ICs or Fc5 IgG1-ICs. White arrows show fluorescent IC clusters. Large and strip images pertain to the x-y and y-z/x-z planes, respectively (C) Schematic overview of experimental protocol. Various T cell subsets are incubated with antibody/antigen preparations; activated with anti-CD3/anti-CD28 beads; and cultured with recombinant interleukin-2 (IL-2). IC-binding experiments were performed on ice using negatively selected, resting CD3+ T cells.