Janusz Marcinkiewicz* and Maria Walczewska Pages 1 - 12 ( 12 )
For decades neutrophils were generally regarded as major cells of innate immunity with pro- inflammatory and phagocytic properties involved in a dual activity, beneficial (antimicrobial) and detrimental (tissue damage). Importantly, until discovery of toll-like receptors (TLRs), a role of neutrophils in adaptive immunity was limited to the effector stage of humoral response and phagocytosis of opsonized antigens. Moreover, in a common opinion, neutrophils as well as entire innate immune system were not functionally associated with adaptive immunity. At the time we demonstrated that protein chlorination by HOCl, the major product of neutrophil MPO-halide system, enhances protein immunogenicity. Basing on this discovery we proposed, as the first, a new role for neutrophils as APC-accessory cells involved in the induction stage of adaptive immunity. Thereafter, we developed our theory concerning a role of neutrophils as the cells which link innate and adaptive immunity. We proposed that protein modification by HOCl may act as a neutrophil-dependent molecular tagging system, by which sentinel dendritic cells can faster recognise pathogen-derived antigens. Contemporaneously, it was demonstrated that taurine, the most abundant free amino acid in neutrophil cytosol and the major scavenger of HOCl, is a part of the oxidant-antioxidant network and is responsible for the regulation and termination of acute inflammation. Moreover, it has been described, that taurine chloramine (TauCl), the physiological products of the reaction of HOCl with taurine, show anti-microbial and anti-inflammatory properties.
In this review a role of HOCl, taurine and TauCl in innate and adaptive immunity will be discussed. .
Neutrophils, myeloperoxidase, hypochlorous acid, taurine, taurine chloramine, inflammation, protein oxidation, antigen processing.
Chair of Immunology, Jagiellonian University Medical College, 18 Czysta Street, 31-121 Krakow, Chair of Immunology, Jagiellonian University Medical College, 18 Czysta Street, 31-121 Krakow