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.

The contribution of the antimicrobial activity of sIgA, lactoferrin, -lactalbumin, serum albumin, and lysozyme to the total antimicrobial activity of whey was evaluated. 66 breast milk samples from healthy women aged from 23 to 45 years collected at different periods of lactation were studied. It was found that along with proceeding the lactation period, not only the total antimicrobial activity (r = 0.944) decreased, but also the activity of the low molecular weight fraction containing the sum of antimicrobial peptides (r = 0.950). The median lactoferrin level varied from 3.46 mg/ml in colostrum down to 0.94 mg/ml one year after the onset of lactation that correlated with whey activity (r = 0.616). The concentration of sIgA was peaked in the whey of colostrum (5.01 mg/ml) and significantly reduced in mature milk, remaining approximately at the same level in subsequent periods of lactation (1.0 mg/ml). Serum albumin concentration significantly decreased while proceeding through lactation period (from 5.52 to 4.68 mg/ml) and correlated with whey activity (r = 0.589). Evaluating effects of the purified -lactalbumin on C. albicans cells within the range of 520 mg/ml by spectrophotometry and microscopy showed the absence of fungicidal activity. At the same time, purified lactoferrin, IgA, lysozyme, and serum albumin demonstrated a direct fungicidal effect. The activity of the IgA preparation at a concentration relevant to the sIgA content in the whey of the first day colostrum was 50.0%, and in the whey after 12 months 31.0%; lactoferrin 26.7% and 3.4%; serum albumin 15.0% and 17.7%; lysozyme 0.1% and 1.8%. Thus, the sum of the activities of these polypeptides at concentrations typical for the first-day colostrum was 91.7%, which is comparable to the total activity of this whey 82.4%. The sum of the activities of these polypeptides, typical for 12 months of lactation, was 53.9%, and the total whey activity relevant to this period was 64.5%. Therefore, IgA and lactoferrin contribute the most significant antimicrobial activity in the whey of colostrum, whereas after 12 month-breastfeeding IgA and serum albumin become most significant.

Patients with atopic dermatitis (AD) can develop autoantibodies against intracellular proteins. AD patients often suffer from herpes viruses (HV) infection which complicates the inflammatory process in the skin. The aim of the study was to reveal IgE and IgG antibodies (abs) specific to some skin antigens and to compare their levels with the severity of AD with HV infection in children. IgE and IgG abs specific to tissue antigens, total IgE, IgE-abs to environmental common allergens as well as IgG abs specific to HV were detected in serum samples by ELISA in 157 AD children. IgE and IgG antibody production to keratin and elastin was observed in children with AD and elevated proportionally to the severity of AD. IgG – abs to herpes simplex virus was increased in children and associated with the severity of clinical course of AD. Our data shown that clinical course of severe AD is accompanied with autoimmune response to epidermal antigens (keratin and elastin). Elevated levels of the autoantibodies, especially against the background of HV infection may be useful serological parameter for monitoring of the disease activity.

Антимикробные пептиды и белки (АМПБ) – это эндогенные соединения, оказывающие прямое противомикробное действие на бактерии, а также на грибы и вирусы. АМПБ являются основным компонентом врожденного иммунитета живых организмов и вырабатываются как эпителиальными клетками (клетки кожи, дыхательных путей, кишечника, мочевыводящих и половых путей), так и клетками иммунной системы, и выделяются в секреторные жидкости. Помимо антимикробной функции АМПБ могут выполнять роль хемоаттрактантов иммунокомпетентных клеток (нейтрофилы, моноциты, Т лимфоциты, дендритные клетки) в очаг воспаления. АМПБ оказывают влияние также на антигенпрезентирующие клетки, модулируя адаптивные T-клеточные иммунные ответы. Из большого количества описанных АМПБ наиболее изученными являются 15 основных классов, которые мы рассматриваем в данном обзоре, включая их локализацию, экспрессию и концентрацию в различных биожидкостях в норме и при патологии.

Intense training loads alter the skin microbiome and defence mechanisms in athletes, yet adaptation profiles remain insufficiently characterised. This study evaluated the relationships between skin bacterial microbiome structure, antimicrobial activity, dermcidin levels, and acne severity in male professional hockey players compared with amateur athletes and non-athletes. One hundred men (18–57 years) were examined and allocated to six subgroups by exercise intensity and acne status. Microbiota composition was assessed by culture-based methods and MALDI-TOF identification, antimicrobial activity measured spectrophotometrically, dermcidin quantified by ELISA, and sweat proteome characterised by HPLC-MS. Staphylococcus epidermidis and Micrococcus luteus predominated in all groups. Exercise intensity, rather than acne, was the main determinant of total bacterial colonisation, which increased approximately tenfold from non-athletes to professional hockey players. In non-athletes, higher antimicrobial activity correlated with greater acne severity, whereas in professionals this relationship was absent and dermcidin levels showed an inverse association with acne severity. Proteomic analysis identified 17 polypeptides; dermcidin and prolactin-inducible protein were dominant in all groups, and calprotectin (S100-A8/A9) was detected exclusively in healthy professionals.

Currently, a significant portion of the food consists of multiple different ingredients. Soybean proteins have been widely used for production of these combined foodstuffs. Meanwhile, soy proteins may contain a wide range of allergens, and even, if present in small amounts, they can cause severe allergic reactions due to cross-reactivity. The aims of our study were to evaluate the prevalence of sensitization to soybean allergen components Gly m 4, Gly m 5 and Gly m 6, and to map their IgE cross-reactivity with homologous proteins of Bet v1-like proteins and cupin proteins in patients with atopic disorders. We have studied IgE’s to 112 allergenic components of plant and animal origin in blood sera from 54 patients with history of allergy, using the ImmunoCap ISAC method. The results were analyzed by means of MS Excel program using parametric statistical criteria. Results: In patients with atopic diseases, we have detected serum IgE to the rGly m 4 allergic component (5 patients out of 29; 17.24%). Frequency of sIgE detection to rGly m 5 (3 patients of 29; 10.24%) and rGly m 6 (1 patient of 29; 3.44%) was less pronounced. Cross-reactive sIgE was detected only to allergens of the Bet v1 superfamily. The strongest relationship was found between sIgE level to rGly m 4 and rBet v1 (R = 0.68; p = 0.001). Another IgE cross-reaction was found between soybean rGly m 4 and alder pollen rAln g1 (R = 0.681; p = 0.000). IgE antibodies to rGly m 4 may also cross-react with kiwi rAct d8 (R = 0.59; p = 0.001). We have also found a weak correlation between sIgE to soybean rGly m 4 and two hazelnut rCor a1 isoforms: rCor a 1.01 (R = 0.42; p = 0.023), and rCor a 1.04 (R = 0.39; p = 0.036). The IgE cross-reactivity profile of the soy allergens revealed in this study is important for improvement of testing strategy for the presence of causally significant allergens. This finding will help to avoid the development of hidden cross-reactions that trigger both oral and respiratory allergic processes in subjects with allergic pathology. Moreover, this will enable administration of optimal diets and develop technologies for development of hypoallergenic food products.