Figure 5.

Modulation of PBN and PEN apoptosis by TNF-α in A1-a^−/−, A1-a^+/−, and wild-type mice. Aliquots (0.4 ml, 0.5 × 10⁶/ml) of PBN (a, c, and e) and PEN (b, d, and f) were incubated for a period of up to 12 h in the presence or absence of recombinant human TNF-α (100 U/ml). The numbers of apoptotic neutrophils were determined by light microscopic observation, as described in Materials and Methods. The results are expressed as means and SEs of five experiments. The unpaired t test was used to identify significant differences (*P < 0.01) between the groups in the presence and absence of TNF-α.