The effects of bone marrow humoral components of B-cell acute lymphoblastic leukemia patients on natural killer cell suppression

B-cell acute lymphoblastic leukemia (B-ALL) is the most common form of cancer diagnosed in children. While the majority of patients survive with conventional treatment, chemotherapeutic agents have adverse effects and the potential for relapse persists even after full recovery. Given their pivotal function in anti-cancer immunity, there has been a surge in research exploring the potential of natural killer (NK) cells in immunotherapy, which has emerged as a promising avenue for treating leukemia. Nevertheless, the efficacy of NK cell immunotherapy is less pronounced than expected, which suggests the external conditions that affect NK cell functions after the administration to patients with leukemia. In this study, the effects of humoral components in the bone marrow humoral components of B-ALL patients on healthy NK cells were investigated. Healthy peripheral blood mononuclear cells were cultured with and without bone marrow-derived plasma samples of B-ALL patients. The expression of PD-1 and IL-10 were found to be increased whereas the proliferative capacities of NK cells were found to be decreased at the presence of B-ALL plasma samples. Moreover, high IL-10 versus low IL-18 levels were detected in bone marrow plasma samples of B-ALL patients. These findings indicate that humoral components in the bone marrow of B-ALL patients exert a suppressive effect on NK cell functions.