Immunosuppressive low-density neutrophils in the blood of cancer patients display a mature phenotype

The presence of human neutrophils in the tumor microenvironment is strongly correlated to poor overall survival. Most previous studies have focused on the immunosuppressive capacities of low-density neutrophils (LDN), also referred to as granulocytic myeloid-derived suppressor cells, which are elevated in number in the blood of many cancer patients. We observed two types of LDN in the blood of lung cancer and ovarian carcinoma patients: CD45high LDN, which suppressed T-cell proliferation and dis-played mature morphology, and CD45low LDN, which were immature and non-suppressive. We simultaneously evaluated the classical normal-density neutrophils (NDN) and, when available, tumor-associated neutrophils. We observed that NDN from cancer patients suppressed T-cell proliferation, and NDN from healthy donors did not, despite few transcriptomic differences. Hence, the immunosuppression mediated by neutrophils in the blood of cancer patients is not dependent on the cells' density but rather on their maturity.

Automated summary

The presence of human neutrophils in the tumor microenvironment is strongly associated with poor overall survival. There are two types of low-density neutrophils (LDN) in the blood of lung cancer and ovarian carcinoma patients, one suppresses T-cell proliferation and has mature morphology, while the other is immature and non-suppressive. Normal-density neutrophils (NDN) from cancer patients can also suppress T-cell proliferation, but NDN from healthy donors cannot, and this immunosuppression is not dependent on cell density but rather on cell maturity.