6-formylpterin intracellularly generates hydrogen peroxide and restores the impaired bactericidal activity of human neutrophils.

The effects of 6-formylpterin on the impaired bactericidal activity of human neutrophils were examined ex vivo. When neutrophils isolated from fresh blood were incubated with 6-formylpterin, the intracellular production of hydrogen peroxide (H(2)O(2)) occurred. The H(2)O(2) generation by 6-formylpterin in neutrophils occurred in the presence of diphenyleneiodonium (DPI), an inhibitor of NADPH-oxidase. When neutrophils were incubated with DPI, the killing rate of catalase-positive bacteria, Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus), significantly decreased. This impaired bactericidal activity of the DPI-treated neutrophils was a mimic for chronic granulomatous disease (CGD). However, the killing rate of the DPI-treated neutrophils against E. coli and S. aureus significantly increased when 6-formylpterin was administered. Since 6-formylpterin intracellularly generates H(2)O(2) independent from the NADPH-oxidase, it was considered to improve the impaired bactericidal activity of the DPI-treated neutrophils. The use of 6-formylpterin may serve as an option of therapy for CGD.