Differential expansion of circulating human MDSC subsets in patients with cancer, infection and inflammation

Background Myeloid-derived suppressor cells (MDSC) are a functional myeloid cell subset that includes myeloid cells with immune suppressive properties. The presence of MDSC has been reported in the peripheral blood of patients with several malignant and non-malignant diseases. So far, direct comparison of MDSC across different diseases and Centers is hindered by technical pitfalls and a lack of standardized methodology. To overcome this issue, we formed a network through the COST Action Mye-EUNITER (www.mye-euniter.eu) with the goal to standardize and facilitate the comparative analysis of human circulating MDSC in cancer, inflammation and infection. In this manuscript, we present the results of the multicenter study Mye-EUNITER MDSC Monitoring Initiative, that involved 13 laboratories and compared circulating MDSC subsets across multiple diseases, using a common protocol for the isolation, identification and characterization of these cells. Methods We developed, tested, executed and optimized a standard operating procedure for the isolation and immunophenotyping of MDSC using blood from healthy donors. We applied this procedure to the blood of almost 400 patients and controls with different solid tumors and non-malignant diseases. The latter included viral infections such as HIV and hepatitis B virus, but also psoriasis and cardiovascular disorders. Results We observed that the frequency of MDSC in healthy donors varied substantially between centers and was influenced by technical aspects such as the anticoagulant and separation method used. Expansion of polymorphonuclear (PMN)-MDSC exceeded the expansion of monocytic MDSC (M-MDSC) in five out of six solid tumors. PMN-MDSC expansion was more pronounced in cancer compared with infection and inflammation. Programmed death-ligand 1 was primarily expressed in M-MDSC and e-MDSC and was not upregulated as a consequence of disease. LOX-1 expression was confined to PMN-MDSC. Conclusions This study provides improved technical protocols and workflows for the multi-center analysis of circulating human MDSC subsets. Application of these workflows revealed a predominant expansion of PMN-MDSC in solid tumors that exceeds expansion in chronic infection and inflammation

Assessment of the Influence Systemic Cryotherapy Exerts on Chosen Skin Scores of Patients with Atopic Dermatitis: Pilot Study

Background. One of the most important tasks in the treatment of atopic dermatitis (AD) is alleviation of racking skin dryness and persistent pruritus, because these factors exert a significant influence on worsening patients’ quality of life. Cryotherapy being a new form of rehabilitation in AD may supplement and support a long-term process of AD treatment, because it has anti-inflammatory and antipruritic effects and exerts a positive influence on the nervous system. Methods. 14 adults (mean age 32±10.8) with mild to moderate AD were enrolled. WBC (15 treatments in total) took place in winter 2018/2019. Patient skin parameters (hydration of the epidermis, sebum level, and skin pH level) were measured with probes produced by Courage + Khazaka Electronic GmbH. Results. Changes were observed in the hydration level of the epidermis. The SCORAD index evaluating the AD intensity level also changed (decreased). Conclusion. Due to these properties, hypothesis has been put forward that WBC can be an effective, supporting method in the treatment of AD

Secretory leukocyte protease inhibitor regulates nerve reflex-mediated skin barrier function in psoriasis

BACKGROUND: Secretory leukocyte protease inhibitor (SLPI), a ~12 kDa protein is an important regulator of innate and adaptive immunity and a component of tissue regenerative programmes. SLPI expression is markedly elevated in chronically inflamed skin, including that of individuals suffering from psoriasis. However, the role of SLPI in these diseases remains elusive. OBJECTIVES: The poor understanding of the early stages of the development of psoriasis is a major obstacle to successful intervention in the skin pathology. We hypothesized that SLPI and peripheral nerves that might be activated early in the progression of the disease likely form a functional relationship to maintain skin barrier homeostasis and respond to a variety of threats. METHODS: We used skin biopsies of healthy donors and individuals with psoriasis to show expression pattern of SLPI. A role of SLPI in psoriasis was mechanistically assessed using SLPI‐deficient mice and an imiquimod (IMQ)‐induced experimental model of psoriasis. RESULTS: We show that mice lacking SLPI had exaggerated skin alterations that extended beyond the treatment site in an imiquimod‐induced psoriasis. The spatiotemporally distinct skin responses in SLPI‐deficient mice, compared to their wild‐type littermates, resulted from a compromised skin barrier function that manifested itself in heightened transepidermal water loss through the larger skin area surrounding the IMQ‐challenged skin. The increased pathogenic skin changes in the absence of SLPI were reversible through pharmacological treatment that blocks a nerve‐reflex arc. CONCLUSIONS: Together, these data indicate that SLPI plays a protective role in psoriasis through preventing skin dryness, inherent in the pathogenesis of psoriasis and that this SLPI action depends on neuronal input operating in a reflex manner. These findings reveal a previously unrecognized mechanism that maintains cutaneous homeostasis, which involves a crosstalk between the nervous system and a protein anatomically poised to fortify the epidermal permeability barrier

The Skin as a Mirror of Internal Disease : comorbidities and Epidemiology of Acne Vulgaris and Adult Female Acne - A Cross-sectional Study and Current State of Knowledge

Acne vulgaris is a common skin condition affecting an increasing number of adults and might be a clue to identifying systemic disease. Objective of this study is assessment of the demographic and clinical characteristic, including comorbidities, of patients with acne with a special focus on adult female acne (AFA). This cross-sectional study analyzed the medical records of 354 patients with acne (323 outpatients and 31 hospitalized). Data concerning patient age, sex, lesions morphology and distribution on body areas, duration of the disease, Body Mass Index, and dermatologic and systemic comorbidities were collected. 61% of all patients were female, 45.37% of women were classified as AFA. The median age of patients with acne was 24 years and 32.5 years for AFA. The face was the most commonly affected area; patients with AFA had lesions on their back than less frequently non-AFA. Predominant eruptions were pustules and papules. 38.7% of patients had concomitant systemic chronic disease, 15.25% had an endocrinologic disorder, and 6.21% had thyroid gland dysfunction. Women with AFA had endocrinologic disorders more frequently (P=0.002), whereas cutaneous signs of hyperandrogenism were observed less frequently than in the non-AFA group (P=0.034). AFA possess distinct clinical features and it should raise suspicion towards possible underlying endocrinologic disturbance

Secretory leukocyte protease inhibitor is present in circulating and tissue-recruited human eosinophils and regulates their migratory function

Eosinophils and secretory leukocyte protease inhibitor (SLPI) are both associated with Th2 immune responses and allergic diseases, but whether the fact that they are both implicated in these conditions is pathophysiologically related remains unknown. Here we demonstrate that human eosinophils derived from normal individuals are one of the major sources of SLPI among circulating leukocytes. SLPI was found to be stored in the crystalline core of eosinophil granules, and its dislocation/rearrangement in the crystalline core likely resulted in changes in immunostaining for SLPI in these cells. High levels of SLPI were also detected in blood eosinophils from patients with allergy-associated diseases marked by eosinophilia. These include individuals with eosinophilic granulomatosis with polyangiitis (EGPA) and atopic dermatitis (AD), who were also found to have elevated SLPI levels in their plasma. In addition to the circulating eosinophils, diseased skin of AD patients also contained SLPI-positive eosinophils. Exogenous, recombinant SLPI increased numbers of migratory eosinophils and supported their chemotactic response to CCL11, one of the key chemokines that regulate eosinophil migratory cues. Together, these findings suggest a role for SLPI in controlling Th2 pathophysiologic processes via its impact on and/or from eosinophils

The expression and regulation of chemerin in the epidermis.

Chemerin is a protein ligand for the G protein-coupled receptor CMKLR1 and also binds to two atypical heptahelical receptors, CCRL2 and GPR1. Chemerin is a leukocyte attractant, adipokine, and antimicrobial protein. Although chemerin was initially identified as a highly expressed gene in healthy skin keratinocytes that was downregulated during psoriasis, the regulation of chemerin and its receptors in the skin by specific cytokines and microbial factors remains unexplored. Here we show that chemerin, CMKLR1, CCRL2 and GPR1 are expressed in human and mouse epidermis, suggesting that this tissue may be both a source and target for chemerin mediated effects. In human skin cultures, chemerin is significantly downregulated by IL-17 and IL-22, key cytokines implicated in psoriasis, whereas it is upregulated by acute phase cytokines oncostatin M and IL-1β. Moreover, we show that human keratinocytes in vitro and mouse skin in vivo respond to specific microbial signals to regulate expression levels of chemerin and its receptors. Furthermore, in a cutaneous infection model, chemerin is required for maximal bactericidal effects in vivo. Together, our findings reveal previously uncharacterized regulators of chemerin expression in skin and identify a physiologic role for chemerin in skin barrier defense against microbial pathogens

The inhibitory effect of secretory leukocyte protease inhibitor (SLPI) on formation of neutrophil extracellular traps

Neutrophil extracellular traps (NETs), web-like DNA structures, provide efficient means of eliminating invading microorganisms but can also present a potential threat to its host because it is a likely source of autoantigens or by promoting bystander tissue damage. Therefore, it is important to identify mechanisms that inhibit NET formation. Neutrophil elastase (NE)-dependent chromatin decondensation is a key event in the release of NETs release. We hypothesized that inhibitors of NE, secretory leukocyte protease inhibitor (SLPI) and α(1)-proteinase inhibitor (α(1)-PI), has a role in restricting NET generation. Here, we demonstrate that exogenous human SLPI, but not α(1)-PI markedly inhibited NET formation in human neutrophils. The ability of exogenous SLPI to attenuate NET formation correlated with an inhibition of a core histone, histone 4 (H4), cleavage, and partial dependence on SLPI-inhibitory activity against NE. Moreover, neutrophils from SLPI(−/−) mice were more efficient at generating NETs than were neutrophils from wild-type mice in vitro, and in experimental psoriasis in vivo. Finally, endogenous SLPI colocalized with NE in the nucleus of human neutrophils in vitro, as well as in vivo in inflamed skin of patients with psoriasis. Together, these findings support a controlling role for SLPI in NET generation, which is of potential relevance to infectious and autoinflammatory diseases