Prevalence of Skin-specific Autoantibodies in HIV-infected Patients and Uninfected Controls

Various autoantibodies are detected more frequently in HIV-infected individuals than in HIV-negative controls; however, limited data exist regarding autoimmune blistering skin diseases. Using enzyme-linked immunoassay (ELISA) and indirect immunofluore-scence, no difference in the frequency and magnitude of autoantibodies against BP180, BP230, desmoglein 1 and 3 was found between 594 HIV-infected patients and 248 uninfected controls in this cross-sectional study (16.0% vs. 11.7%, respectively, for at least one positive ELISA, p = 0.11). Interestingly, reactive syphilis serology in both HIV-infected individuals and uninfected controls was associated with positive anti-BP180 ELISA results (adjusted odds ratio (OR) 2.14, 95% confidence interval (CI) 1.07-4.29, p = 0.03 and OR 4.70, CI 1.3-16.86; p = 0.0180). Our study shows a comparably low prevalence of cutaneous autoantibodies in both HIV-infected patients and uninfected controls lacking signs of autoimmune blistering skin disease. Positive BP180 ELISA in the absence of clinical signs of bullous pemphigoid should prompt further evaluation for syphilis antibodies.

The cytokine environment influence on human skin-derived T cells

Skin resident T cells provide immediate immunologic responses at their specific location and play a role in the pathogenesis of skin diseases such as psoriasis. Recently, IL-9-producing T cells were described as a major T-cell subtype present in the skin, but knowledge on the biology and in situ regulation of this T-cell subtype is scarce. Here, we investigated the cytokine influence on skin T cells with focus on IL-9-producing T cells because a better understanding of their biology may identify novel therapeutic approaches. Healthy human skin biopsies were cultured either in the presence of IL-2, IL-4, and TGF-β [T helper (T_h)9-promoting condition (T_h9-PC)] or IL-2 and IL-15 [standard condition (SC)]. Paired analysis of enzymatically isolated skin T cells and emigrated T cells after 4 wk of skin culture showed significant alterations of T-cell phenotypes, cytokine production, and IL-9-producing T-cell frequency. RNA sequencing analysis revealed differentially regulated pathways and identified CXCL8 and CXCL13 as top up-regulated genes in T_h9-PC compared with SC. Functionally supernatant of stimulated skin-derived T cells, CXCL8 and CXCL13 increased neutrophil survival. We report that the cytokine environment alters skin-derived T-cell phenotype and functional properties.-Kienzl, P., Polacek, R., Reithofer, M., Reitermaier, R., Hagenbach, P., Tajpara, P., Vierhapper, M., Gschwandtner, M., Mildner, M. Jahn-Schmid, B., Elbe-Bürger, A. The cytokine environment influence on human skin-derived T cells.

Epicutaneous administration of the pattern recognition receptor agonist polyinosinic-polycytidylic acid activates the MDA5/MAVS pathway in Langerhans cells

Together with keratinocytes (KCs) and the dense network of Langerhans cells (LCs), the epidermis is an ideal portal for vaccine delivery. Pattern recognition receptor agonists, in particular polyinosinic–polycytidylic acid [p(I:C)], are promising adjuvant candidates for therapeutic vaccination to generate protective T-cell immunity. Here we established an ex vivo skin explant model to study the expression and activation of double-stranded RNA (dsRNA)-sensing pattern recognition receptors in LCs and KCs in human skin. Whereas KCs expressed all known dsRNA sensing receptors at a constitutive and inducible level, LCs exclusively expressed melanoma differentiation–associated protein 5 (MDA5) in untreated skin and freshly isolated cells. Comparative assessments of downstream signaling pathways induced by p(I:C) revealed distinct mitochondrial antiviral-signaling protein, IFN-regulatory factor 3, and NF-κB activation in LCs and KCs. Consequently, p(I:C) treatment of LCs significantly induced IFN-α and IFN-β mRNA expression, while in KCs an up-regulation of IFN-β and TNF-α mRNA was detectable. Stimulation of LCs with specific ligands revealed that not the TLR3- but only the MDA5-specific ligand induced IFN-α2, IFN-β, and TNF-α cytokines, but no IL-6 and -8. In KCs, both ligands induced production of high IL-6 and IL-8 levels, and low IFN-α2 and IFN-β levels, indicating that different dsRNA-sensing receptors and/or downstream signaling pathways are activated in both cell types. Our data suggest that MDA5 may be an attractive adjuvant target for epicutaneous delivery of therapeutic vaccines with the goal to target LCs.—Tajpara, P., Schuster, C., Schön, E., Kienzl, P., Vierhapper, M., Mildner, M., Elbe-Bürger, A. Epicutaneous administration of the pattern recognition receptor agonist polyinosinic–polycytidylic acid activates the MDA5/MAVS pathway in Langerhans cells.

Dietary curcumin post-treatment enhances the disappearance of B(a)P-derived DNA adducts in mouse liver and lungs

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Effects of dietary curcumin on disappearance of DNA adducts were studied.

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Curcumin post-treatment enhanced the disappearance of BPDE-DNA adducts in liver/lungs.

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Curcumin post-treatment augmented B(a)P-induced apoptosis during 24–120 h.

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Curcumin post-treatment increased PCNA in B(a)P-treated tissues during 7–28 days.

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Curcumin-mediated increase in apoptosis and cell proliferation decreased DNA adducts.

To study the post-treatment effects of dietary curcumin on the levels of benzo(a)pyrene [B(a)P]-induced DNA adducts, mice were administered oil or B(a)P and randomized into 7 subgroups after 24 h. One of the subgroups from both the oil and B(a)P groups was killed at 24 h while the remaining 6 subgroups were shifted to powdered control or 0.05% curcumin diet and killed after 24, 72 and 120 h (experiment 1), and 7, 14, and 28 days (experiment 2). Quantitative comparisons of BPDE-DNA nuclear adducts (area and intensity) in immunohistochemically stained lungs and liver sections was carried out by IHC profiler. A time-dependent decrease in the levels of adducts in B(a)P-treated animals was further enhanced by curcumin exposure compared to the levels in time-matched controls. To assess the contribution of apoptosis and cell proliferation in observed curcumin-mediated enhanced decrease of BPDE-DNA adducts, comparative evaluation of apoptosis and cell proliferation markers was undertaken. Results suggested enhancement of B(a)P-induced apoptosis in liver and lungs by curcumin during 24–120 h while no such enhancement was observed at 7–28 days. Results suggest curcumin-mediated enhancement in apoptosis (experiment 1) and adduct dilution (experiment 2) to be the reason for the observed higher decrease of BPDE-DNA adducts.