Neutrophil isolation
Peripheral blood collected from healthy volunteers was layered on
Polymorphprep (Axis-Shield, Norway) and
centrifuged for 30 min at
500g . The lower interphase having granulocytes was collected and
washed with PBS. For purification, twice lysis of red blood cells was
done using Red blood cell lysis Buffer (Beyotime, Shanghai, China)
followed by two washes with cold PBS. Isolated PMNs were suspended
in RPMI 1640 (Gibco, NY, USA) medium
containing 1% HEPES (Gibco, NY, USA). The protocol was approved by the
institutional ethics committee at Jinling Hospital (No. 2019-NJGKJ-047).