fig2
Figure 2. Mechanisms of impaired T-cells and immunosuppressive environment in CLL. (1) T-cells from patients with CLL demonstrate a diminished CD4 to CD8 ratio and increased numbers of Tregs. (2) Tregs, in turn, further cause increased IL-2 production, reducing Th1 differentiation. (3) Increased expression of inhibitory cytokines such as IL-4 causes upregulation of the anti-apoptotic signal, BCL2. (4) T-cells have impaired synapse formation with APCs from impaired actin polymerization. (5) Increased expression of T-cell exhaustion markers such as PD-1. (6) An immunosuppressive environment composed of multiple inhibitory cells further diminishes T-cell function and supports CLL cell survival. CLL: Chronic lymphocytic leukemia; Treg: T-regulatory cell; IL: interleukin; Th1: T-helper type 1; BCL2:
