Figure 4. Biosynthesis of serine proteases in immature neutrophils from bone marrow.

Bone marrow cells depleted of nonneutrophil lineage cells were separated into immature cells (less mature than band cells) and mature cells by density centrifugation on Lymphoprep. (A) Giemsa staining of cytospin of immature cells and mature cells from PLS and a normal control (Ctl). (B) Biosynthesis of CTSC, NE, CTSG, and PR3 in immature cells from bone marrow. Medium after 4 and 18 hours of chase (M4, 18). Cells after 4 and 18 hours of chase (C4, 18). 6.5 × 10⁷ cells from PLS patient and 3.0 × 10⁷ cells from control were used. (C) Western blotting of the immunoprecipitates from immature cells shown in B. (D) Western blotting of mature cells from bone marrow (pellet from Lymphoprep separation). These were treated, as were the immature cells for biosynthesis, and were chased for 4 and 18 hours, but were not subject to immunoprecipitation, and cell lysates were run directly for SDS-PAGE and Western blotting. The blots were stripped and reprobed with anti-lysozyme antibody as a loading control. This demonstrated equal loading, but is not shown.