Characterization of human CD34+ HSC-derived neutrophils without myeloid-derived immunosuppressive cell activity

Neutrophils have limited utility as transfusion product due to their short lifespan. Culturing neutrophils from stem cell sources holds potential as a fundamental research model and transfusion product. Here, we cultured CD34+ hematopoietic stem cell-derived neutrophils and compared them with peripheral blood neutrophils in terms of morphology, phenotype, and function. Our culture system resulted in morphologically mature CD15+CD11b+CD16high neutrophils with most effector functions almost indistinguishable from blood neutrophils, confirmed by a high similarity in transcription and protein abundance patterns. While exhibiting strong microbial killing capacity and antibody-dependent cellular cytotoxicity against tumor cells, these cells were deficient in myeloid-derived suppressor cell activity. Upon dissecting the underlying mechanism, this deficiency in immunosuppressive activity correlated with their distinct granular composition in comparison to blood neutrophils. Taken together, our cultured neutrophils closely resemble blood neutrophils, offering a repository for fundamental research and a step towards an effective transfusion product without immunosuppressive activity. Bulk RNAseq profiling of HSC-derived neutrophils cultured in SL-II medium at Day0, Day10, Day14 and Day17 of maturation. At day 14 and day 17 these cells were MACS sorted for CD16+ creating positive, negative and bulk fractions. PMNs and IMDM derived neutrophils at the endstage were included.