The role of T cells in the microenvironment of Hodgkin lymphoma.

The cellular microenvironment in HL is dominated by a mixed infiltrate of inflammatory cells with typically only 1 or a few percent of HRS tumor cells. HRS cells orchestrate this infiltrate by the secretion of a multitude of chemokines. T cells are usually the largest population of cells in the HL tissue, encompassing Th cells, T(regs), and CTLs. Th cells and T(regs) presumably provide essential survival signals for the HRS cells, and the T(regs) also play an important role in rescuing HRS cells from an attack by CTLs and NK cells. The interference with this complex interplay of HRS cells with other immune cells in the microenvironment may provide novel strategies for targeted immunotherapies.