Hypothiocyanite and host-microbe interactions.

The pseudohypohalous acid hypothiocyanite/hypothiocyanous acid (OSCN /HOSCN) has been known to play an antimicrobial role in mammalian immunity for decades. It is a potent oxidant that kills bacteria but is non-toxic to human cells. Produced from thiocyanate (SCN ) and hydrogen peroxide (H O ) in a variety of body sites by peroxidase enzymes, HOSCN has been explored as an agent of food preservation, pathogen killing, and even improved toothpaste.

RclA is a highly active hypothiocyanite reductase.

Hypothiocyanite and hypothiocyanous acid (OSCN/HOSCN) are pseudohypohalous acids released by the innate immune system which are capable of rapidly oxidizing sulfur-containing amino acids, causing significant protein aggregation and damage to invading bacteria. HOSCN is abundant in saliva and airway secretions and has long been considered a highly specific antimicrobial that is nearly harmless to mammalian cells. However, certain bacteria, commensal and pathogenic, are able to escape damage by HOSCN and other harmful antimicrobials during inflammation, which allows them to continue to grow and, in some cases, cause severe disease.