Protein biosynthesis in mature neutrophils

The following sections review the importance of macromolecular biosynthesis in neutrophil function, and describe how this gene activation is selectively up-regulated during priming with cytokines. 

it is widely appreciated that mature neutrophils are biosyntheti-cally active, and that this biosynthesis can be rapidly and selectively up- 

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In mature neutrophils, interferon-7induces the expression of FC7RI, increases antibody-dependent cytotoxicity, primes the ability to generate reactive oxidants and selectively stimulates protein biosynthesis. These effects are described in detail in Chapter 7. Additionally, this cytokine has been used clinically for the treatment of chronic granulomatous disease (CGD), which is associated with an increased susceptibility to infections due to an impairment of NADPH oxidase function ( 8.2). 

It has long been known that peptides of bacterial origin, such as N-formylat-ed oligopeptides, are potent activators of neutrophils. Bacterial protein biosynthesis is initiated by the codon AUG, which codes for polypeptide chains at the NH2 terminus to start with N-formylmethionine. However, very few mature bacterial proteins actually have this amino acid at the NH2 terminus because Af-formylmethionine is cleaved off by proteolytic processing. Sometimes just this amino acid is cleaved, but often several adjacent residues are also removed with it. These observations formed the basis for the chemical synthesis of a variety of N-formylated oligopeptides and an assessment of their ability to activate neutrophils in vitro. The most potent of these formylated peptides is TV-formylmethionyl-leucyl-phenylalanine (fMet-Leu-Phe). 

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