A gene signature of inhibitory MHC receptors identifies a BDCA3(+) subset of IL-10-induced dendritic cells with reduced allostimulatory capacity in vitro

Dendritic cells (DC) are crucial gatekeepers in regulating immunity. Whereas mature immunostimulatory myeloid DC (DC(ims)) potently promote immune responses, IL-10-induced myeloid DC (DC-IL-10) counteract T cell activation. To elucidate the molecular repertoire by which DC-IL-10 secure reduced T cell activation, comparative gene expression profiling was done using Affymetrix U133A microarrays. Among the genes overexpressed in DC-IL-10, eight immunoreceptor tyrosine-based inhibitory motif (ITIM)-containing inhibitory molecules (ILT2, ILT3, ILT4, ILT5, DCIR, PILRA, FcgammaRIIB, SLAM) were found. Phenotypic analysis of DC-IL-10 defined an ILT(high) DC subset further characterized by expression of CD14, TLR2, DC-SIGN, and CD123 and the lack of lymphocyte, monocyte/macrophage, and plasmacytoid DC markers such as CD3, CD8, and CD68. A unique feature of the ILT(high) DC subset was expression of the novel DC marker BDCA3, which was not detected on monocytes, immature DC, DC(ims), or ILT(low) DC-IL-10. While the allogeneic T cell proliferation induced by the entire DC-IL-10 population was approximately 30% of that stimulated by DC(ims), allogeneic MLR responses driven by the ILT(high) DC subset were reduced to 8% of the allostimulatory capacity of DC(ims), although secretion of the inhibitory cytokine IL-10 and other Th1/Th2-associated cytokines was similar in these cells.     

The receptor for interleukin-17E is induced by Th2 cytokines in antigen-presenting cells

Interleukin-17E (IL-17E) (IL-25) is a recently identified cytokine capable to induce Th2-associated cytokine production (IL-5 and IL-13) and T helper 2 (Th2)-type pathologies in animal models. The IL-17E-responsive cell population in vivo was described to be a further uncharacterized non-T-, non-B-splenic accessory cell. Despite the identification of IL-17BR as the receptor for IL-17E, the cell population expressing IL-17BR has hitherto not been identified. Here, we show that human monocyte-derived Th2-skewed antigen-presenting cells (APC2) express membrane-bound and soluble forms of IL-17BR on the mRNA and protein level upon stimulation with IL-4, IL-10, IL-13 or transforming growth factor-betain vitro. These results indicate that IL-17BR-expressing APC2s may mediate the development of the IL-17E-mediated immunological reaction patterns observed in vivo.     

Clinical spectrum of primary cutaneous CD30‐positive anaplastic large cell lymphoma: an analysis of the Mannheim Cutaneous Lymphoma Registry

Background: Primary cutaneous CD30⁺ anaplastic large cell lymphomas (C‐ALCL) have indolent clinical behavior with an estimated 5‐year survival rate of 95%. The clinical features and disease courses of C‐ALCL identified in the lymphoma registry of Mannheim University hospital are described in the following. Patients and methods: All C‐ALCL patients identified in the database were analyzed in regard to clinical picture, histology, immunohistochemistry, molecular biology, staging, therapy, follow‐up, and outcome. Results: 14 C‐ALCL patients were identified. The mean age was 69 years and 57% were men. Solitary skin lesions in one anatomical region were seen in 12 patients upon initial diagnosis. Two patients presented with multiple lesions at different anatomical sites. In 2 patients there was specific lymph node involvement. In one C‐ALCL patient, follow‐up over 17 months revealed extracutaneous infiltration. Half of the patients relapsed and 36% had multiple episodes. The majority of our patients were treated with surgical excision followed by electron beam radiotherapy. The 5‐year survival rate was 93% in C‐ALCL. Conclusions: The clinical presentation of C‐ALCL varies. Staging procedures and a close clinical pathological correlation at initial diagnosis are essential. Due to a high rate of relapses and the possibility of developing extranodal manifestations over the course of the disease, close follow‐up is recommended.     

Cutaneous side effects of inhibitors of the RAS/RAF/MEK/ERK signalling pathway and their management

Mutations in genes encoding for proteins along the RAS‐RAF‐MEK‐ERK pathway have been detected in a variety of tumor entities, including malignant melanoma, thyroid, colonic and ovarian carcinomas, and some sarcomas. Thus, a number of inhibitors of this pathway have been developed, whose antitumor potential is currently being assessed in different clinical trials. Up to now one drug of this category (vemurafenib) has been approved by the FDA and the European Commission for late‐stage melanoma. Although these new targeted anticancer therapies are generally considered to be safe and well tolerated, certain toxicities have been attributed to them, with cutaneous side effects being perhaps the most frequent amongst them. Based on results of clinical trials and on case series, a distinct profile of cutaneous toxicity has been observed, which is similar to that of EGFR and multikinase inhibitors. As exanthema, palmar‐plantar erythrodysesthesia syndrome, hyperkeratosis, xerosis, pruritus, photosensitivity, and paronychia, can be controlled in most cases with common conservative modalities, special attention should be given to the early detection of epithelial skin tumors (mainly keratoakanthomas) that can be induced during therapy with these agents. This report reviews all current published data on cutaneous side effects of RAS‐RAF‐MEK‐ERK pathway inhibitors, and attempts to provide the clinician with clear hints for their management.     

Molecular genetics of Xeroderma pigmentosum variant

Xeroderma pigmentosum (XP) is an autosomal recessive disease characterized by sun sensitivity, early onset of freckling and subsequent neoplastic changes on sun-exposed skin. Skin abnormalities result from an inability to repair UV-damaged DNA because of defects in the nucleotide excision repair (NER) machinery. Xeroderma pigmentosum is genetically heterogeneous and is classified into seven complementation groups (XPA-XPG) that correspond to genetic alterations in one of seven genes involved in NER. The variant type of XP (XPV), first described in 1970 by Ernst G. Jung as 'pigmented xerodermoid', is caused by defects in the post replication repair machinery while NER is not impaired. Identification of the XPV gene was only achieved in 1999 by biochemical purification and sequencing of a protein from HeLa cell extracts complementing the PRR defect in XPV cells. The XPV protein, polymerase (pol)eta, represents a novel member of the Y family of bypass DNA polymerases that facilitate DNA translesion synthesis. The major function of (pol)eta is to allow DNA translesion synthesis of UV-induced TT-dimers in an error-free manner; it also possesses the capability to bypass other DNA lesions in an error-prone manner. Xeroderma pigmentosum V is caused by molecular alterations in the POLH gene, located on chromosome 6p21.1-6p12. Affected individuals are homozygous or compound heterozygous for a spectrum of genetic lesions, including nonsense mutations, deletions or insertions, confirming the autosomal recessive nature of the condition. Identification of POLH as the XPV gene provides an important instrument for improving molecular diagnostics in XPV families.     

Allergische Reaktion nach Kontakt mit Hura crepitans (Sandbüchsenbaum)

We describe a 36-year-old female patient with angioedema-like swellings and rhinoconjunctivitis for 1 year occurring exclusively at her home. The clinical history revealed no correlation with foods, food additives, drugs, or aeroallergens. The complaints always started immediately after contact with the sandbox tree (Hura crepitans) placed in her apartment. Scratch testing resulted in a two-fold positive reaction towards leaves and stem, while five controls remained negative. Thus we suggest the reaction of the patient to be allergic in nature. Hura crepitans belongs to the family of Euphorbiaceae, whose largest genera are Euphorbia and Croton. The toxic reactions to the milky sap, the so-called latex, of these plants are caused by ingredients such as phorbol esters, croton oil, lectins, and terpens. Various terpens are also well known as allergens. Phytotoxic and phytoallergic reactions are growing increasingly important and should therefore be included in the differential diagnosis in dermatology.