Evaluation of the effects of mesenchymal stem cells on neutrophils isolated from severe congenital neutropenia patients.

Neutrophils are the most abundant, yet with the shortest lifespan among the circulating leukocytes. These cells are produced in the bone marrow during granulopoiesis process. Severe congenital neutropenia (SCN) is a hematological disorder with disturbance in granulopoiesis process, in which the neutrophils apoptosis rate is escalated. Previous reports indicated that mesenchymal stem cells (MSCs), as an immunomodulator cell, could increase neutrophil lifespan in addition to the supportive effects on cardiomyocytes or the neuroprotective effects. In this study, MSCs were co-cultured with neutrophils isolated from SCN patients and healthy individuals. Then, we evaluated the MSC co-culture effects on neutrophils survival (annexin V/PI assay), reactive oxygen species (ROS) production (colorimetric NBT assay), and phagocytic activity (Giemsa staining after exposure to yeasts). It was demonstrated that MSC co-culture could increase neutrophil lifespan and phagocytic activity of the neutrophils isolated from SCN patients. Regarding healthy donors' neutrophils, only phagocytic activity improvement was seen. It could be concluded that MSCs could be considered as novel candidates for treatment of SCN patients.