Assessment of the antimicrobial and immunomodulatory activity of QS-CATH, a promising therapeutic agent isolated from the Chinese spiny frogs (Quasipaa spinosa).

Cathelicidins are important antimicrobial peptides in various vertebrate species where they are crucial parts of the innate immune system. The current understanding of amphibian cathelicidins is limited, particularly with regard to their immunomodulatory effects. To address this knowledge gap, we produced the cDNA sequence of the cathelicidin gene from a skin transcriptome of the Chinese spiny frog Quasipaa spinosa. The amino acid sequence of the Quasipaa spinosa cathelicidin (QS-CATH) was predicted to consist of a signal peptide, a cathelin domain, and a mature peptide. Comparative analysis of the QS-CATH amino acid sequence with that of other amphibian cathelicidins revealed high variability in the functional mature peptide among amphibians, whereas the cathelin domain was conserved. The QS-CATH gene was expressed in several tissues, with the highest level of expression in the spleen. Upregulation of QS-CATH after Aeromonas hydrophila infection occurred in the kidney, gut, spleen, skin, and liver. Chemically synthesized QS-CATH exhibited pronounced antibacterial activity against Shigella flexneri, Staphylococcus warneri, Escherichia coli, Salmonella enterica, and Listeria monocytogenes. Furthermore, QS-CATH disrupted the cell membrane integrity of S. flexneri, as evidenced by a lactate dehydrogenase release assay, and it hydrolyzed the genomic DNA of S. flexneri. Additionally, QS-CATH elicited chemotaxis and modulated the expression of inflammatory cytokine genes in RAW264.7 mouse leukemic monocyte/macrophage cells. These findings confirm the antimicrobial effects of amphibian cathelicidin and its ability to influence immune cell function. This will expedite the potential utilization of amphibian antimicrobial peptides as therapeutic agents.

Retrospective assessment of immunologic and histologic heterogeneity in granuloma annulare by cytokine staining.

BACKGROUND: Type 1 (Th1) and Type 2 (Th2) immunity have both been implicated in granuloma annulare (GA). To what extent these pathways contribute to clinical/histologic heterogeneity and/or distinct disease endotypes remains unexplored. METHODS: We retrospectively analyzed 30 GA biopsies with either palisaded or interstitial histology with and without eosinophils. We performed RNA in situ hybridization to assess how markers of Type 1 (interferon gamma), Type 2 (interleukin [IL]4, IL13, IL5), and Type 3 (IL17A) immunity in GA compared with canonical inflammatory disorders and whether markers correlated with histology. We analyzed another cohort of 14 patients who had multiple biopsies across anatomic space and time for individual conservation of histologic features. RESULTS: Interferon (IFN)G staining is highest in GA relative to other cytokines. Type 2 cytokine staining is less prominent, with IL4 increased in interstitial pattern cases. Eosinophils did not correlate with Type 2 markers. Patients with multiple biopsies display intrapatient variability in histology. CONCLUSION: Type 1 inflammation predominates over Type 2 inflammation in GA irrespective of histologic pattern. Distinct disease endotypes were not detected.

An ultra-low-cost electroporator with microneedle electrodes (ePatch) for SARS-CoV-2 vaccination.

Vaccination against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and other pathogens with pandemic potential requires safe, protective, inexpensive, and easily accessible vaccines that can be developed and manufactured rapidly at a large scale. DNA vaccines can achieve these criteria, but induction of strong immune responses has often required bulky, expensive electroporation devices. Here, we report an ultra-low-cost (<1 USD), handheld (<50 g) electroporation system utilizing a microneedle electrode array ("ePatch") for DNA vaccination against SARS-CoV-2. The low cost and small size are achieved by combining a thumb-operated piezoelectric pulser derived from a common household stove lighter that emits microsecond, bipolar, oscillatory electric pulses and a microneedle electrode array that targets delivery of high electric field strength pulses to the skin's epidermis. Antibody responses against SARS-CoV-2 induced by this electroporation system in mice were strong and enabled at least 10-fold dose sparing compared to conventional intramuscular or intradermal injection of the DNA vaccine. Vaccination was well tolerated with mild, transient effects on the skin. This ePatch system is easily portable, without any battery or other power source supply, offering an attractive, inexpensive approach for rapid and accessible DNA vaccination to combat COVID-19, as well as other epidemics.

Quantitative assessment of sensitizing potency using a dose-response adaptation of GARDskin.

Hundreds of chemicals have been identified as skin sensitizers. These are chemicals that possess the ability to induce hypersensitivity reactions in humans, giving rise to a condition termed allergic contact dermatitis. The capacity to limit hazardous exposure to such chemicals depends upon the ability to accurately identify and characterize their skin sensitizing potency. This has traditionally been accomplished using animal models, but their widespread use offers challenges from both an ethical and a scientific perspective. Comprehensive efforts have been made by the scientific community to develop new approach methodologies (NAMs) capable of replacing in vivo assays, which have successfully yielded several methods that can identify skin sensitizers. However, there is still a lack of new approaches that can effectively measure skin sensitizing potency. We present a novel methodology for quantitative assessment of skin sensitizing potency, which is founded on the already established protocols of the GARDskin assay. This approach analyses dose-response relationships in the GARDskin assay to identify chemical-specific concentrations that are sufficient to induce a positive response in the assay. We here compare results for 22 skin sensitizers analyzed using this method with both human and LLNA potency reference data and show that the results correlate strongly and significantly with both metrics (rLLNA = 0.81, p = 9.1 × 10-5; rHuman = 0.74, p = 1.5 × 10-3). In conclusion, the results suggest that the proposed GARDskin dose-response methodology provides a novel non-animal approach for quantitative potency assessment, which could represent an important step towards reducing the need for in vivo experiments.

Assessment of cytotoxicity and sensitization potential of intradermally injected tattoo inks in reconstructed human skin.

BACKGROUND: The number of people within the European population having at least one tattoo has increased notably, and with it the number of tattoo-associated clinical complications. Despite this, safety information and testing regarding tattoo inks remain limited. OBJECTIVE: To assess cytotoxicity and sensitization potential of 16 tattoo inks after intradermal injection into reconstructed human skin (RHS). METHODS: Commercially available tattoo inks were injected intradermally into RHS (reconstructed epidermis on a fibroblast-populated collagen hydrogel) using a permanent makeup device. RHS biopsies, tissue sections, and culture medium were assessed for cytotoxicity (thiazolyl blue tetrazolium bromide assay [MTT assay]), detrimental histological changes (haematoxylin and eosin staining), and the presence of inflammatory and sensitization cytokines (interleukin [IL]-1α, IL-8, IL-18; enzyme-linked immunosorbent assay). RESULTS: Varying degrees of reduced metabolic activity and histopathological cytotoxic effects were observed in RHS after ink injection. Five inks showed significantly reduced metabolic activity and enhanced sensitization potential compared with negative controls. DISCUSSION: Using the RHS model system, four tattoo inks were identified as highly cytotoxic and classified as potential sensitizers, suggesting that allergic contact dermatitis could emerge in individuals carrying these inks. These results indicate that an RHS-based assessment of cytotoxicity and sensitization potential by intradermal tattoo ink injection is a useful analytical tool to determine ink-induced deleterious effects.

Intraepithelial autoimmune bullous dermatoses disease activity assessment and therapy.

Intraepithelial autoimmune blistering dermatoses are a rare group of skin disorders characterized by disruptions of inter-keratinocyte connections within the epidermis through the action of autoantibodies. The second article in this continuing medical education series presents validated disease activity scoring systems, serologic parameters of disease, treatments, and clinical trials for pemphigus and its subtypes.

Updating exposure assessment for skin sensitization quantitative risk assessment for fragrance materials.

In 2008, a proposal for assessing the risk of induction of skin sensitization to fragrance materials Quantitative Risk Assessment 1 (QRA1) was published. This was implemented for setting maximum limits for fragrance materials in consumer products. However, there was no formal validation or empirical verification after implementation. Additionally, concerns remained that QRA1 did not incorporate aggregate exposure from multiple product use and included assumptions, e.g. safety assessment factors (SAFs), that had not been critically reviewed. Accordingly, a review was undertaken, including detailed re-evaluation of each SAF together with development of an approach for estimating aggregate exposure of the skin to a potential fragrance allergen. This revision of QRA1, termed QRA2, provides an improved method for establishing safe levels for sensitizing fragrance materials in multiple products to limit the risk of induction of contact allergy. The use of alternative non-animal methods is not within the scope of this paper. Ultimately, only longitudinal clinical studies can verify the utility of QRA2 as a tool for the prevention of contact allergy to fragrance materials.

Clinical Relevance of Skin Pain in Atopic Dermatitis.

Skin pain is increasingly recognized as an impactful symptom in atopic dermatitis (AD) because of its association with patient discomfort, disease burden, and reduced quality of life. Although the nature of skin pain in AD has not been systematically studied and is therefore not well understood, patients report soreness, discomfort, and tenderness that may reflect peripheral and central pain sensitization. The high prevalence of skin pain suggests that it is not adequately addressed by current therapies for AD and may be undertreated compared with other symptoms. This review discusses the clinical relevance of skin pain with respect to its experience, pathophysiology, relationship with itch, and treatment implications. Recent studies suggest that skin pain presents as a neuropathic symptom independent from itch and the “itch-scratch cycle”, and poses a unique burden to patients. Recognition of the significant consequences of skin pain and discomfort should reinforce the need to assess and treat this symptom in patients with moderate-to-severe AD. J Drugs Dermatol. 2020;19(10)921-926. doi:10.36849/JDD.2020.5498.

High-quality nuclear genome for Sarcoptes scabiei-A critical resource for a neglected parasite.

The parasitic mite Sarcoptes scabiei is an economically highly significant parasite of the skin of humans and animals worldwide. In humans, this mite causes a neglected tropical disease (NTD), called scabies. This disease results in major morbidity, disability, stigma and poverty globally and is often associated with secondary bacterial infections. Currently, anti-scabies treatments are not sufficiently effective, resistance to them is emerging and no vaccine is available. Here, we report the first high-quality genome and transcriptomic data for S. scabiei. The genome is 56.6 Mb in size, has a a repeat content of 10.6% and codes for 9,174 proteins. We explored key molecules involved in development, reproduction, host-parasite interactions, immunity and disease. The enhanced 'omic data sets for S. scabiei represent comprehensive and critical resources for genetic, functional genomic, metabolomic, phylogenetic, ecological and/or epidemiological investigations, and will underpin the design and development of new treatments, vaccines and/or diagnostic tests.

Immune-microbiota interaction in Finnish and Russian Karelia young people with high and low allergy prevalence.

BACKGROUND: After the Second World War, the population living in the Karelian region was strictly divided by the "iron curtain" between Finland and Russia. This resulted in different lifestyle, standard of living, and exposure to the environment. Allergic manifestations and sensitization to common allergens have been much more common on the Finnish compared to the Russian side. OBJECTIVE: The remarkable allergy disparity in the Finnish and Russian Karelia calls for immunological explanations. METHODS: Young people, aged 15-20 years, in the Finnish (n = 69) and Russian (n = 75) Karelia were studied. The impact of genetic variation on the phenotype was studied by a genome-wide association analysis. Differences in gene expression (transcriptome) were explored from the blood mononuclear cells (PBMC) and related to skin and nasal epithelium microbiota and sensitization. RESULTS: The genotype differences between the Finnish and Russian populations did not explain the allergy gap. The network of gene expression and skin and nasal microbiota was richer and more diverse in the Russian subjects. When the function of 261 differentially expressed genes was explored, innate immunity pathways were suppressed among Russians compared to Finns. Differences in the gene expression paralleled the microbiota disparity. High Acinetobacter abundance in Russians correlated with suppression of innate immune response. High-total IgE was associated with enhanced anti-viral response in the Finnish but not in the Russian subjects. CONCLUSIONS AND CLINICAL RELEVANCE: Young populations living in the Finnish and Russian Karelia show marked differences in genome-wide gene expression and host contrasting skin and nasal epithelium microbiota. The rich gene-microbe network in Russians seems to result in a better-balanced innate immunity and associates with low allergy prevalence.

Immune response and Raman scattering assessment in rats skin after contact with Fusarium oxysporum metabolites.

The secondary metabolites produced by Fusarium can cause disease and death when consumed and produce biological responses even in the absence of the microorganism. The IL-6, TNF-α and TGF-ß1 cytokines immune reactivity was associated with histopathological and physico-chemical changes in skin of immune competent rats after administration of Fusarium oxysporum crude extract. Rats were intradermally injected with 50 µl of 0.5 mg/ml crude extract and were euthanized at 3, 6, 12 and 24 h after injection. The inflammatory response was quantified by enzyme myeloperoxidase activity and by immunohistochemical method to detect the IL-6, TNF-α and TGF-ß1. Physico-chemical analysis was performed using FT-Raman Spectroscopy. The inflammatory response was most intense at 6 and 12 h after crude extract administration and the most significant histopathological changes were observed in the dermis. Myeloperoxidase activity was intense from 3 to 24 h after injection. The immunostaining of pro-inflammatory cytokines IL-6 and TNF-α peaked at 6 h. Immunostaining for TGF-ß1 was highest at 12 and 24 h. FT-Raman spectral analysis showed both, the most intense Fusarium interaction with the skin at 6 h, as revealed by the changes in the stretching of -CH bands (3100-2800 cm-1) in the dermis, and skin recovery trending after 12 h after crude extract injection. The results showed that secondary metabolites stimulated histopathologic changes and inflammatory responses even in the absence of the fungus, increasing myeloperoxidase activity and pro-inflammatory cytokine expression besides promoting physico-chemical changes.

Willingness-to-pay stated preferences in cutaneous lupus erythematosus: a pilot study.

Cutaneous lupus erythematosus (CLE) is a chronic skin disease that significantly impacts quality of life (QOL). This study tested a novel method to measure QOL in CLE using willingness-to-pay (WTP) stated preferences, and aimed to determine which of nine domains of life are most affected by CLE. Twenty-one participants with CLE ranked the domains in order of impact on CLE-related QOL, and then stated how many United States dollars they would be willing to pay for a hypothetical cure for each domain. Eighty-one percent of participants were female; mean age was 42.4 years. Photosensitivity was ranked highest by 71.4% of respondents. Participants were willing to pay the most for a hypothetical cure for CLE specific to photosensitivity (median = $200,000), the least for a cure specific to self-care (median = $0). Participants were willing to pay a median of $1,000,000 for an overall cure for CLE. Limitations include a small sample size for this pilot study and that willingness-to-pay may be influenced by individual perception of money and socioeconomic factors. This study successfully pilot-tested a WTP method and ranking task for health-related QOL. Photosensitivity was the domain of life most affected by CLE, which is a domain unique to our novel tool.

Clinical assessment of tolerability, immunological and cutaneous reactivity effects of an abbreviated schedule with Olea europaeanative extract of subcutaneous immunotherapy.

Summary: Objectives. To evaluate the tolerability and efficacy of Olea europaea subcutaneous immunotherapy (SCIT) on patients with rhinoconjunctivitis. Methods. In this open clinical trial patients were assigned to an abbreviated build-up scheme. The outcomes were: number, percentage, and severity of adverse reactions. Secondary outcomes included: changes in immunoglobulin titers and changes in dose-response skin prick tests. Results. Only 8 systemic reactions were registered, which represented 7/47 (14.9%) of patients and 8/429 (1.9%) of administered doses. Regarding immunological parameters the significant increases of sIgG and sIgG4 evidenced the changes in the patient immune system. Cutaneous reactivity decreased significantly. Conclusions. Olea europaea SCIT (Allergovac® depot ROXALL Medicina España S.A.) showed a good safety and tolerability profile. Immunological changes with induction of blocking IgG and decreases in cutaneous reactivity were detected in the patients.

Validation of the GARD™skin Assay for Assessment of Chemical Skin Sensitizers: Ring Trial Results of Predictive Performance and Reproducibility.

Proactive identification of chemicals with skin sensitizing properties is a key toxicological endpoint within chemical safety assessment, as required by legislation for registration of chemicals. In order to meet demands of increased animal welfare and facilitate increased testing efficiency also in nonregulatory settings, considerable efforts have been made to develop nonanimal approaches to replace current animal testing. Genomic Allergen Rapid Detection (GARD™) is a state-of-the-art technology platform, the most advanced application of which is the assay for assessment of skin sensitizing chemicals, GARD™skin. The methodology is based on a dendritic cell (DC)-like cell line, thus mimicking the mechanistic events leading to initiation and modulation of downstream immunological responses. Induced transcriptional changes are measured following exposure to test chemicals, providing a detailed evaluation of cell activation. These changes are associated with the immunological decision-making role of DCs in vivo and include among other phenotypic modifications, up-regulation of co-stimulatory molecules, induction of cellular and oxidative stress pathways and xenobiotic responses, and provide a holistic readout of substance-induced DC activation. Here, results from an inter-laboratory ring trial of GARD™skin, conducted in compliance with OECD guidance documents and comprising a blinded chemical test set of 28 chemicals, are summarized. The assay was found to be transferable to naïve laboratories, with an inter-laboratory reproducibility of 92.0%. The within-laboratory reproducibility ranged between 82.1% and 88.9%, whereas the cumulative predictive accuracy across the 3 laboratories was 93.8%. It was concluded that GARD™skin is a robust and reliable method for the identification of skin sensitizing chemicals and suitable for stand-alone use or as a constituent of integrated testing. These data form the basis for the regulatory validation of GARD™skin.

Assessment of seven protocols to prepare Cutibacterium acnes bacterial lysates to measure its immunogenic potential and review of the literature.

Seven protocols were tested to prepare cell wall extracts from live Cutibacterium acnes. Different parameters were modified: thawing/freezing and sonication/freezing cycles, to impact on mechanical degradation of the bacteria. Finally, the immunogenic potential of the extracts generated was evaluated by measuring IL-8 releases using an in vitro skin explants system. The aim of this article was to compare the existing protocols from the scientific literature, and also propose a standardized method developed in our facilities.

Retrospective review of insurance coverage for patch testing.

BACKGROUND: There is a paucity of data on the burden of insurance limitations for patients undergoing patch testing. OBJECTIVE: To characterize the burden of insurance limitations and its impact on differences in management and execution of patch testing. METHODS: A retrospective chart review was performed on patients with a diagnosis of contact dermatitis (International Classification of Disease [ICD], Ninth Edition, code ICD 692) who received patch testing (Current Procedural Terminology code 95044) at the George Washington Medical Faculty Associates Dermatology Clinic between January 1, 2015 and June 30, 2017. Variables including allergen limitations were compared between government-sponsored insurance and private insurance providers (eg, Insurers A, B, C, and D). RESULTS: A total of 371 records were identified. Government-sponsored insurance patients encountered allergen limitations more frequently than private insurance patients (86.8% vs 14.2%, P < .0001). Insurer C and D patients were least likely to encounter allergen limitations (1.2% vs 0%, P < .0001) and were tested to the most allergens (mean = 146 vs 152, P < .0001). Insurer A patients had the least allergens tested among those privately insured. CONCLUSION: Considering modification of insurance policies to allow patch testing with a larger number of allergens without restrictions is needed, with the goal of improving quality of life of these patients while saving costs from chronic use of topical corticosteroids.

The diagnosis and classification of amyopathic dermatomyositis: a historical review and assessment of existing criteria.

BACKGROUND: Diagnostic criteria are used to identify a patient having a disease in a clinical setting, whereas classification criteria create a well-defined population for research purposes. The diagnosis and classification of amyopathic dermatomyositis (ADM) have not been recognized by most existing criteria for idiopathic inflammatory myopathies (IIMs). To address this, several criteria were proposed to define ADM either as a distinct disease entity or as a subset of the spectrum of IIMs. OBJECTIVES: To discuss the diagnosis and classification of ADM and to assesses the available criteria in identifying cases of ADM and/or distinguishing it from dermatological mimickers such as lupus erythematosus. METHODS: We conducted an extensive literature search using the PubMed database from June 2016 to August 2018, using the search terms 'amyopathic dermatomyositis', 'diagnosis' and 'classification'. RESULTS: The European League Against Rheumatism (EULAR)/American College of Rheumatology (ACR) criteria, which are the only validated classification criteria for adult and juvenile IIM and their major subgroups, include three cutaneous items (Göttron sign, Göttron papules, heliotrope rash) to be able to classify ADM. This international and multispecialty effort is a huge step forward in the classification of skin-predominant disease in dermatomyositis. However, about 25% of the population with ADM do not meet two out of the three skin features and are misdiagnosed or classified as having a different disease entity, most commonly lupus erythematosus. CONCLUSIONS: These gaps rationalize the continuous assessment and improvement of existing criteria and/or the development of validated, separate and skin-focused criteria for DM.

Skin sensitization: Uncertainties, challenges, and opportunities for improved risk assessment.

At the ESCD congress held in Manchester in 2016, a session was organized to encourage more dialogue between clinicians with expertise in skin sensitization and toxicologists seeking to provide effective risk assessment to prevent human health issues. That session focused on the remaining uncertainties regarding the induction and regulation of skin sensitization in humans, and the opportunities and challenges associated with the refinement and improvement of risk assessment methodologies. This short article, prompted by those discussions, debates what the authors regard as being among the most important and most intriguing uncertainties about skin sensitization and allergic contact dermatitis in humans, and the most significant opportunities for improving risk assessment. The aim has been to provide a basis for mapping out the areas that might benefit from a closer alignment between the relevant clinical community and toxicologists charged with the responsibility of ensuring that skin sensitization risks are understood and managed.

Quantitative Assessment of T Cell Clonotypes in Human Acute Graft-versus-Host Disease Tissues.

Owing to the difficulty in isolating T cells from human biopsy samples, the characteristics of T cells that are infiltratinghuman acute graft-versus-host disease (GVHD) tissues remain largely uninvestigated. In the present study, TCR-ß deep sequencing of various GVHD tissue samples and concurrent peripheral blood obtained from transplant recipients was performed in combination with functional assays of tissue-infiltrating T cell clones. The T cell repertoire was more skewed in GVHD tissues than in the peripheral blood. The frequent clonotypes differed from tissue to tissue in the same patient, and the frequent clonotypes in the same tissue differed from patient to patient. Two T cell clones were successfully isolated from GVHD skin of a patient. In a cytotoxicity assay, both Tcell clones lysed patient peripheral blood mononuclear cells, but not donor-derived Epstein-Barr virus-transformed lymphoblastoid cells. Their clonotypes were identical to the most and second most frequent T cell clonotypes in the original GVHD skin and accounted for almost all of the skin-infiltrating T cells. These results suggest that human acute GVHD may result from only a few different alloreactive cytotoxic T cell clones, which differ from tissue to tissue and from patient to patient. The characterization of T cells infiltrating human GVHD tissues should be further investigated.

Allergic contact dermatitis: Adequacy of the default 10X assessment factor for human variability to protect infants and children.

When evaluating consumer products for safety, one must consider the heterogeneity of the population that might use those products, including the potential for different sensitivity based on factors such as age, gender, and genetics. For both systemic endpoints and allergic contact dermatitis (ACD), quantitative safety evaluations typically include a default 10-fold uncertainty/assessment factor to account for inter-individual variability. While this factor is intended to include age, the adequacy of the default 10-fold factor has been questioned for infants, for whom a precautionary assumption is often made that they are more sensitive. In-depth evaluations of the adequacy of the 10-fold factor have been published for systemic endpoints, but relatively little has been published to substantiate this for ACD. This paper reviews the state of the science regarding the etiology of ACD and factors that suggest an overall decreased sensitivity associated with early life exposures, thus confirming the sufficiency of the 10-fold inter-individual factor to provide protection for children and infants. While it remains prudent for all age groups to avoid contact with sensitizers, it is concluded that the quantitative methods used in safety evaluation to prevent the induction of skin sensitization are protective for infants, including neonates and premature infants.