Antimicrobial peptides and proteins (AMPs) are endogenous compounds that have a direct antimicrobial effect on bacteria (e.g. by disrupting bacterial membranes) as well as on fungi and viruses. AMPs are the main components of the innate immunity of living organisms and are produced by both epithelial cells (skin cells, cells of respiratory tract, intestines, urinary and genital tracts) and cells of the immune system and are secreted into secretory fluids. AMPs can also act as chemoattractants for immunocompetent cells (neutrophils, monocytes, T lymphocytes, dendritic cells) in the inflammation site and affect the antigen presenting cells by modulating adaptive T cell immune responses. The representatives of the main 15 AMP classes, that we describe in this review, are the most studied group of the large pool of these compounds. We discuss their localization, expression, and concentration in various human biofluids under normal and pathological conditions.

Histatins are the most significant antimicrobial peptides (AMP) of saliva and there are 12 types of such AMP. Histatin molecules contain relatively high percent of histidine and tyrosine residues. This property allows to use well known from organic chemistry Pauly reaction for detection of protein bounded histidine and tyrosine residues (BHT), which are in fact characterize the summary content of all histatins in saliva. Aim of the present study was comparison of BHT with antimicrobial activity of salivary AMP fraction in patients with inflammatory diseases of upper airways (IDUA). Group of examined persons include 28 patients with different diagnoses: chronic pharyngitis (n=11), chronic tonsillitis (n=7), nasopharyngitis (n=5), pollinosis (n=5). Degree of intensity of inflammatory symptoms was estimated in balls. The algorithm of BHT analysis include following steps: freezing - thawing of saliva; removal of microparticles by centrifugation; separation of fraction lower than100 kDa; dialysis for free amino acids removal; Pauly reaction carrying out. Antimicrobial activities of saliva and its low molecular fractions were estimated towards Candida albicans cells by the spectrophotometric method with bromocresol purpur. Analysis of saliva sediments for coccoid microbiota was carried out by PCR method. Pauly reaction for histatins estimation in saliva of IDUA patients use here for the first time. The histatins levels (BHT) were significantly correlated with the intensity of inflammatory symptoms (r=0,975) and activity of low molecular salivary fraction (AMP activity) (r=0,824). The AMP activity/ BHT ratio, i.e. antimicrobial activity of histatin unit, decreased together with growth of inflammatory symptoms intensity (r=-0,944). Any considerable differences in coccoid microbiota frequency of finding at different diagnoses were not detected. The S. aureus frequency of occurrence was connected neither with inflammatory symptoms intensity (r=0,118), nor with BHT concentration (r=0,318). However S. pyogenes and S. pneumoniae frequencies of occurrence demonstrated the invert correlation towards these indexes: (r=-0,627/-0,614) and (r=-0,827/-0,864). Probably at the exacerbation forms of IDUA the S. pyogenes and S. pneumoniae growth controlled by high levels of histatins.