Induction of phagocyte oxidase components during human myeloid differentiation: Independent protein expression and discrepancy with the function

We investigated the content of four components of the O-2(-)-producing enzy me (p47, p67, p22, and gp91) and the O-2(-)-producing capacity in human mye loid cell lines. The content of the four components of the phagocyte oxidas e was minimal before differentiation induction. During differentiation, exp ression of p22 and gp91 was at consistently low levels, even when the O-2(- )-producing capacity was equivalent to that of normal neutrophils. On the o ther hand, p47 was consistently and rapidly induced to the level comparable to normal neutrophils. The results indicate that low expression of p22 and gp91 is sufficient to obtain normal O-2(-) production, and that p47 might play an important regulatory role in the functional differentiation.