Fig. 3

The immunomodulatory effects of imatinib in GIST. A The general immunological effects of imatinib in GIST. Short-term administration of imatinib enhanced the antitumor immune response via increasing the infiltration and activity of immune cells and the secretion of IFNγ. While, long-term usage of imatinib may weaken the antitumor immune response by enriching the M2 macrophages and decreasing the amounts of CD8⁺ T and DC cells, as well as the expression of MHC-I molecules. B Dissected immunological effects of imatinib on various types of cells within the GIST, including GIST cells, CD8⁺ T cells, γδ T cells, Treg cells, NK cells, Macrophages and DC cells. GIST: gastrointestinal stromal tumor; DC: dendritic cell; NK: natural killer cell; IFNγ: interferon gamma; PD-L1: programmed death-ligand 1; MHC-I: major histocompatibility complex class I; IDO: indoleamine 2,3-dioxygenase; Treg: regulatory T cells; MΦ: macrophages; γδ T cell: gamma delta T cell with T cell receptors (TCRs) composed of γ- and δ-chains