Evidence for antibody-catalyzed ozone formation in bacterial killing and inflammation.
ABSTRACT Recently, we showed that antibodies catalyze the generation of hydrogen peroxide (H2O2) from singlet molecular oxygen (1O2*) and water. Here, we show that this process can lead to efficient killing of bacteria, regardless of the antigen specificity of the antibody. H2O2 production by antibodies alone was found to be not sufficient for bacterial killing. Our studies suggested that the antibody-catalyzed water-oxidation pathway produced an additional molecular species with a chemical signature similar to that of ozone. This species is also generated during the oxidative burst of activated human neutrophils and during inflammation. These observations suggest that alternative pathways may exist for biological killing of bacteria that are mediated by potent oxidants previously unknown to biology.
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ABSTRACT: There are numerous defense proteins present in the saliva. Although some of these molecules are present in rather low concentrations, their effects are additive and/or synergistic, resulting in an efficient molecular defense network of the oral cavity. Moreover, local concentrations of these proteins near the mucosal surfaces (mucosal transudate), periodontal sulcus (gingival crevicular fluid) and oral wounds and ulcers (transudate) may be much greater, and in many cases reinforced by immune and/or inflammatory reactions of the oral mucosa. Some defense proteins, like salivary immunoglobulins and salivary chaperokine HSP70/HSPAs (70 kDa heat shock proteins), are involved in both innate and acquired immunity. Cationic peptides and other defense proteins like lysozyme, bactericidal/permeability increasing protein (BPI), BPI-like proteins, PLUNC (palate lung and nasal epithelial clone) proteins, salivary amylase, cystatins, prolin-rich proteins, mucins, peroxidases, statherin and others are primarily responsible for innate immunity. In this paper, this complex system and function of the salivary defense proteins will be reviewed.International Journal of Molecular Sciences 01/2012; 13(4):4295-320. · 2.60 Impact Factor
Article: Potential immunological functions of salivary Hsp70 in mucosal and periodontal defense mechanisms.[show abstract] [hide abstract]
ABSTRACT: Molecular chaperones were considered to be intracellular, but there is increasing evidence demonstrating their cytoprotective and immune modulator properties outside the cell. The major extracellular chaperone (Hsp70) was also found in saliva, indicating a possible effect of Hsp70 on mucosal surfaces. Here we summarize the immune-modulatory role of the 70-kDa stress protein family, with special attention on the potential impact of salivary Hsp70 on oral defense mechanisms. There are three major facets of Hsp70-induced immune activation: 1) the appearance of Hsp70 on the surface of certain tumor cells or virally infected cells, leading to their phagocytosis and subsequent lysis; 2) the role of extracellular uncomplexed Hsp70 as a danger signal, leading to the secretion of proinflammatory cytokines from antigen-presenting cells and T lymphocytes and of nitric oxide from macrophages as well as to complement activation; 3) receptor-mediated uptake of peptide-loaded Hsp70 to antigen-presenting cells and cross-presentation of the Hsp70-peptide complex as an antigen to cytotoxic T cells and natural killer lymphocytes. The immune-activating effect of salivary Hsp70 may also be highly important in oral defense, especially in areas where molecular and cellular participants of the immune response appear on the surface of the oral cavity (i.e. several lesions of the mucosa and the periodontal tissues).Archivum Immunologiae et Therapiae Experimentalis 55(2):91-8. · 2.54 Impact Factor