Fig. 5.

Effects of antibody treatment on molecules that localize to the DIM fraction of HL60 cells. (A) Antibody stimulation affects HL60 cell growth. Cells were cultured in the presence of rGL-7 (≈5–80 pmol per 10⁶ cells), GL-2 (20 pmol per 10⁶ cells), or the Fab fragments of Vj41 or DH59B. To block Fc-R, cells were pretreated with an unrelated human IgM (for Vj41) or IgG (for DH59B), then treated with GL-2 (i.e., entire antibody). Results are means ± SEM, with statistical significance (P < 0.05) determined by Student's t test. (B) SM stimulation increased apoptosis. (Left) HL60 cells were treated with rGL-7 (≈5–80 pmol), GL-2, or Fab fragments of Vj41 or DH59B for 48 h, and annexin-positive cells were counted by using a flow cytometer. (Right) Cells treated with 20 pmol per 10⁶ cells of rGL-7, Vj41 (IgM) after pretreatment with human IgM and DH59B (IgG) after pretreatment with human IgG for 48 h were stained with the terminal deoxynucleotidyltransferase-mediated dUTP endlabeling method. Arrow points to a typical cell with apoptotic bodies.