Transcriptomic analysis of monocytes and macrophages derived from CLL patients which display differing abilities to respond to therapeutic antibody immune complexes.

Chronic lymphocytic leukemia (CLL) is the most common adult leukemia. While therapeutic antibodies show clinical activity in CLL patients, resistance inevitably develops resulting in treatment failure. Identifying mechanisms of antibody resistance and methods to reduce resistance would be valuable in managing CLL. Monocyte derived cells (MDCs), also known as nurse like cells (NLCs) in CLL [1], [2], are known to be crucial components of the CLL microenvironment network and following "maturation" in in vitro culture systems are able to provide support for the survival of the malignant B cells from CLL patients. In addition to their protective role, MDCs are key effector cells in mediating responses to therapeutic antibody therapies [3]. We have determined that macrophages from patients with early stable CLL are able to elicit superior cytotoxic response to therapeutic antibodies than macrophages derived from patients with progressive CLL. We have exploited this unique finding to gain insight into antibody resistance. Thus, we have profiled monocytes on day 0 and MDCs on day 7 from antibody sensitive and antibody resistant CLL patients (GEO accession number GEO: GSE71409). We show that there are no significant differences in transcriptomes from the monocytes or MDCs derived from sensitive or resistant patient samples. However, we show that MDCs acquire an M2-like macrophage transcriptomic signature following 7 days culture regardless of whether they were derived from sensitive or resistant patient samples.