Intratumoral interleukin-6 and myeloid cell subsets within the cholangiocarcinoma tumor microenvironment

Background: Cholangiocarcinoma (CC) is an aggressive malignancy largely resistant to conventional therapy. Although immunotherapy elicits responses in some patients, the immune tumor microenvironment remains understudied. In particular, the cytokine interleukin-6 (IL-6) acts in an autocrine/paracrine manner to enhance the growth of CC cells. Our laboratory has also shown IL-6 is instrumental for expanding myeloid-derived suppressor cells (MDSCs)...