Microbial and cellular components (Reactive chlorine species targets) (RCS targets)

Non-specific microbial and cellular components refers to the diverse array of biological molecules—including proteins, lipids, and nucleic acids—that are susceptible to modification by reactive chlorine species (RCS) such as hypochlorous acid (HOCl) (Winterbourn et al., 2016). This target profile is a fundamental component of the innate immune system's oxidative burst, where the enzyme myeloperoxidase produces RCS within phagosomes to neutralize invading pathogens through widespread oxidative damage (Klebanoff et al., 2013). Because RCS target ubiquitous chemical groups like thiols and amines, they exhibit potent, broad-spectrum antimicrobial activity against bacteria, viruses, and fungi (Nagl et al., 2018). In a therapeutic context, this mechanism is utilized by topical antiseptics and disinfectants, which provide rapid microbicidal effects with a very low risk of resistance development due to the multi-target nature of the attack (Mainnemare et al., 2004). However, the lack of specificity means that high concentrations of RCS can also damage host cellular structures, necessitating careful formulation to ensure a favorable therapeutic index in clinical applications (Wang et al., 2007).

Other names

Reactive chlorine species targetsHypochlorous acid targetsHOCl targetsOxidative stress targetsChlorination targetsMicrobial proteins and lipids

Non-specific oxidation and chlorination of various molecular components including thiols, amines, and unsaturated lipids, leading to irreversible damage and microbial lysis (Winterbourn et al., 2016).