Multiparameter flow cytometric and transcriptional analyis of CD20 positive T-cells in bone marrow in patients of multiple myeloma and monoclonal gammopathy of undetermined significance

We found that CD20+ T-cells are phenotypically and transcriptionally different from CD20- T-cells. Elevated incidence of CD20+ T-cells in MGUS and MM and the expression of CD8, NKG2D, and CD28 suggests anti-tumor functionality. Increased PD-1 expression indicates T-cell exhaustion which was mostly detected in the samples of patients with a higher tumor percentage. The majority of CD20+ T-cells are effector or effector memory T-cells. Some of the differentially expressed genes suggest antitumor function via regulating T-cell activation pathways, while other genes involved in tumor escape from immune surveillance by suppressing T-cells or by reprogramming T-cells toward T-cell exhaustion. Our findings suggest that CD20+ T-cells may play a vital role both in immune surveillance and immune escape contributing to progression of multiple myeloma.