The role of non-malignant B cells in malignant hematologic diseases

The tumor microenvironment (TME) represents a heterogeneous, complicated ecosystem characterized by intricate interactions between tumor cells and immune cells. During the past decade, immune cells especially T cells were found to play an important role in the progression of tumor and many related immune checkpoints drugs were created. In recent years, more and more scientists revealed the critical role of B-cells within the TME, particularly various populations of non-malignant B cells. Some studies indicated that non-malignant B cells may exert a 'double-edged sword' role in solid tumors. However, there has been comparatively less focus on the role of non-malignant B cells in hematologic malignancies. In this review, we characterized the development of B cells and summarized its functions of antitumor immunity within TME, with an emphasis on elucidating the roles and potential mechanisms of non-malignant B cells in the progression of hematologic diseases including classical Hodgkin's lymphoma, non-Hodgkin's B-cell lymphoma, non-Hodgkin's T-cell lymphoma, leukemia and multiple myeloma.