HL60 cell activation is moderated by incubation in varying concentrations of human plasma

The purpose was to investigate the responsiveness of HL‐60 cells (HL60s) to short‐term incubation in varying concentrations of human plasma and RPMI‐1640 standard culture media (SCM), HL60s were incubated up to 4‐hrs in SCM supplemented with either 10%, 50%, 75% or 100% plasma. Measurements were made at baseline and after 2‐ and 4‐hrs of IL‐6, IL‐8, TNFα and MPO and surface expression of CD11B, CD62L, CD66B, and Caspase‐3. Release of MPO was higher with increasing [plasma], and the [plasma] effect was much stronger at 4 hrs (slope=1.17±0.14) than 2 hrs (slope=0.75±0.14), p<0.0001. IL‐8 varied with time (p<0.0001) and [plasma] (p=0.042); and was higher at 2 hrs (p<0.0001) and 4 hrs (p<0.0001) than baseline. IL‐6 and TNFα levels remained stable. Except for CD11B, all other activation markers were highest in the cells bathed in 10% plasma (p<0.01). Short‐term incubation of HL‐60s in SCM supplemented with higher [plasma] release greater amounts of MPO and IL‐8 than cells supplemented with 10% plasma. Apoptosis and adhesion levels were highest in the cells incubated in 10% plasma media. Many translational studies now involve incubation of cells in plasma from healthy controls or patients. This work highlights the attention that must be paid in interpreting results. This work was supported by NIH grants T32AR047752, RO1‐HL080947, P01‐HD048721 and the UCI ICTS MO1‐RR00827‐28.