Suppressive mechanisms of regulatory B cells in mice and humans.

B cells include immune-suppressive fractions, called regulatory B cells (Bregs), which regulate inflammation primarily through an interleukin 10 (IL-10)-mediated inhibitory mechanism. Several B-cell fractions have been reported as IL-10-producing Bregs in murine disease models and human inflammatory responses including autoimmune diseases, infectious diseases, cancer and organ-transplant rejection. Although the suppressive functions of Bregs have been explored through the hallmark molecule IL-10, inhibitory cytokines and membrane-binding molecules other than IL-10 have also been demonstrated to contribute to Breg activities. Transcription factors and surface antigens that are characteristically expressed in Bregs are also being elucidated. Nevertheless, defining Bregs is still challenging because their active periods and differentiation stages vary among disease models. The identity of the diverse Breg fractions is also under debate. In the first place, since regulatory functions of Bregs are mostly evaluated by ex vivo stimulation, the actual in vivo phenotypes and functions may not be reflected by the ex vivo observations. In this article, we provide a historical overview of studies that established the characteristics of Bregs and review the various suppressive mechanisms that have been reported to be used by Bregs in murine and human disease conditions. We are only part-way through but the common phenotypes and functions of Bregs are still emerging.

NRF2 Augments Epidermal Antioxidant Defenses and Promotes Atopy.

Atopic dermatitis is a chronic form of allergic contact dermatitis that is closely associated with a compromised epidermal barrier. Immunogenicity of a given electrophilic hapten after penetration of this barrier depends directly on biochemical reactions in the thiol-rich layer in the stratum granulosum. In response to electrophilic hapten, NF-erythroid 2-related factor 2 (NRF2) in keratinocytes efficiently induces the production of antioxidants. In this study, we show that the immunogenicity of a given hapten depends directly on the extent to which it induces antioxidant host defenses within the epidermal tissue. We found that allergic contact dermatitis did not develop in NRF2-deficient mice because of compromise of the epidermal innate immune responses that upregulate IL-1α. We also analyzed epidermal NRF2 in association with congenital disorders with features similar to atopic dermatitis in humans. Epidermal samples from patients with Netherton syndrome and peeling skin syndrome exhibited elevated levels of NRF2 and also elevated levels of its downstream target, small proline-rich protein 2. Taken together, these results suggest that the thiol-mediated biochemical responses in the stratum granulosum provide a critical link between defective epidermal barrier function and the development of atopy. Likewise, our results suggested that NRF2 may have a profound impact on the generation of cutaneous immunological memory.

Immune response to dermatomyositis-specific autoantigen, transcriptional intermediary factor 1γ can result in experimental myositis.

OBJECTIVES: To investigate whether autoimmunity to transcriptional intermediary factor 1 (TIF1)γ, a ubiquitous nuclear autoantigen for myositis-specific autoantibodies detected in patients with dermatomyositis (DM) is pathogenetic for inflammatory myopathy. METHODS: Wild-type, ß2-microglobulin-null, perforin-null, Igµ-null and interferon α/ß receptor (IFNAR)-null mice were immunised with recombinant human TIF1γ whole protein. A thymidine incorporation assay was performed using lymph node T cells from TIF1γ-immunised mice. Plasma was analysed using immunoprecipitation followed by western blot analysis and enzyme-linked immunosorbent assays. Femoral muscles were histologically and immunohistochemically evaluated. CD8+ or CD4+ T cells isolated from lymph node T cells or IgG purified from plasma were adoptively transferred to naïve mice. TIF1γ-immunised mice were treated with anti-CD8 depleting antibody and a Janus kinase inhibitor, tofacitinib. RESULTS: Immunisation with TIF1γ-induced experimental myositis presenting with necrosis/atrophy of muscle fibres accompanied by CD8+ T cell infiltration successfully in wild-type mice, in which TIF1γ-specific T cells and antihuman and murine TIF1γ IgG antibodies were detected. The incidence and severity of myositis were significantly lower in ß2-microglobulin-null, perforin-null, CD8-depleted or IFNAR-null mice, while Igµ-null mice developed myositis normally. Adoptive transfer of CD8+ T cells induced myositis in recipients, while transfer of CD4+ T cells or IgG did not. Treatment with tofacitinib inhibited TIF1γ-induced myositis. CONCLUSIONS: Here we show that TIF1γ is immunogenic enough to cause experimental myositis, in which CD8+ T cells and type I interferons, but not CD4+ T cells, B cells or antibodies, are required. This murine model would be a tool for understanding the pathologies of DM.

Nuclear Factor Erythroid 2-Related Factor 2 (Nrf2) Regulates Epidermal Keratinization under Psoriatic Skin Inflammation.

Psoriasis is an autoinflammatory/autoimmune skin disease and the epitome of an exaggerated primary inflammatory response in the surface barrier tissue. Despite the efficacy of dimethyl fumarate, an electrophilic drug for psoriasis management, there is a paucity of mechanistic evidence in vivo. In response to electrophiles, the Kelch-like erythroid cell-derived protein with cap-n-collar homology-associated protein 1/nuclear factor erythroid 2-related factor 2 (NRF2) system mediates a myriad of cytoprotective mechanisms, including the regulation of excessive inflammatory response and epidermal differentiation. Because the psoriasiform tissue reaction comprises neutrophil infiltration and parakeratotic scaling, it is hypothesized that Nrf2 not only regulates inflammatory responses but also maintains epidermal differentiation, a hallmark of epidermal homeostasis. By using the imiquimod-induced cutaneous inflammation model, an exaggerated inflammatory response and impaired epidermal differentiation in Nrf2-/- mice was detected. Dimethyl fumarate treatment in Nrf2+/+ mice attenuated a psoriasiform tissue reaction and rescued epidermal differentiation, which was not observed in Nrf2-/- mice. In accordance with the fact that psoriasis plaques form well-demarcated parakeratotic lesions in association with the psoriasiform tissue reaction, the lesional skin showed reduced expression levels of NRF2 and its downstream target genes compared with nonlesional skin. In conclusion, Nrf2 attenuates the psoriasiform tissue reaction and underscores the mechanistic legitimacy of the electrophile-based approach for the management of psoriasis.

Malignant and Benign T Cells Constituting Cutaneous T-Cell Lymphoma.

Cutaneous T-cell lymphoma (CTCL) is a heterogeneous group of non-Hodgkin lymphoma, including various clinical manifestations, such as mycosis fungoides (MF) and Sézary syndrome (SS). CTCL mostly develops from CD4 T cells with the skin-tropic memory phenotype. Malignant T cells in MF lesions show the phenotype of skin resident memory T cells (TRM), which reside in the peripheral tissues for long periods and do not recirculate. On the other hand, malignant T cells in SS represent the phenotype of central memory T cells (TCM), which are characterized by recirculation to and from the blood and lymphoid tissues. The kinetics and the functional characteristics of malignant cells in CTCL are still unclear due, in part, to the fact that both the malignant cells and the T cells exerting anti-tumor activity possess the same characteristics as T cells. Capturing the features of both the malignant and the benign T cells is necessary for understanding the pathogenesis of CTCL and would lead to new therapeutic strategies specifically targeting the skin malignant T cells or benign T cells.

Correlation between blood cell count and outcome of melanoma patients treated with anti-PD-1 antibodies.

BACKGROUND: Anti-programmed cell death protein 1 monoclonal antibodies (αPD-1mAbs) have been shown to be effective for advanced malignant melanoma. Treatment with αPD-1mAbs can also cause immune-related adverse events (irAEs). However, clinical predictive factors for treatment responses or irAE risk remain unclear. OBJECTIVE: To identify useful blood biomarkers for response and occurrence of irAEs with αPD-1mAbs treatment. METHODS: We retrospectively collected data from patients with melanoma treated with αPD-1mAbs at the University of Tsukuba Hospital. Clinical data including age, sex, clinical type, metastatic site, treatment course, blood laboratory tests, irAEs and treatment outcome were collected. RESULTS: Multivariate logistic regression analysis showed that increased baseline neutrophil-lymphocyte ratio (NLR) was significantly associated with poor response (odds ratio [OR]: 2.638, P = 0.0227, cutoff value = 2.8). Similarly, multivariate Cox regression analysis revealed that NLR at baseline were significantly associated with shorter progression survival (hazard ratio: 1.343, P = 0.0095). As for irAEs, logistic regression analysis revealed that baseline absolute eosinophil count was positively associated with occurrence of endocrine irAEs (OR: 1.601, P = 0.045, cutoff value = 240/µL). Additionally, a higher relative eosinophil count at 1 month was significantly correlated with occurrence of endocrine irAEs (OR: 1.229, P = 0.0296, cutoff value = 3.2%). CONCLUSION: Our results suggested that NLR > 2.8 could be a useful baseline biomarker for indicating poor response to αPD-1mAbs treatment and that absolute eosinophil count >240/µL at baseline and relative eosinophil count at 1 month >3.2% could be useful biomarkers to predict endocrine irAEs in patients receiving αPD-1mAbs.

Unusual Bone Lesions with Osteonecrosis Mimicking Bone Metastasis of Squamous Cell Carcinoma in Recessive Dystrophic Epidermolysis Bullosa.

Some bone lesions are reported to mimic bone metastasis on imaging tests. Herein, we report a case of a 55-year-old Japanese man who presented with a skin tumor on the left lower extremity. He also had a history of recurrent generalized cutaneous blister and erosion formation since childhood. His skin lesions were diagnosed as cutaneous squamous cell carcinoma complicated by recessive dystrophic epidermolysis bullosa. Magnetic resonance imaging of the left lower extremity detected multiple focal bone lesions mimicking bone metastases in the left femur and tibia. However, bone biopsy revealed that the bone lesions were osteonecrosis without tumor cells. We suggest that cancer-induced osteonecrosis should be included in the differential diagnosis of bone lesions suspected of being metastases on magnetic resonance imaging.

Staged development of long-lived T-cell receptor αß TH17 resident memory T-cell population to Candida albicans after skin infection.

BACKGROUND: Candida albicans is a dimorphic fungus to which human subjects are exposed early in life, and by adulthood, it is part of the mycobiome of skin and other tissues. Neonatal skin lacks resident memory T (TRM) cells, but in adults the C albicans skin test is a surrogate for immunocompetence. Young adult mice raised under specific pathogen-free conditions are naive to C albicans and have been shown recently to have an immune system resembling that of neonatal human subjects. OBJECTIVE: We studied the evolution of the adaptive cutaneous immune response to Candida species. METHODS: We examined both human skin T cells and the de novo and memory immune responses in a mouse model of C albicans skin infection. RESULTS: In mice the initial IL-17-producing cells after C albicans infection were dermal γδ T cells, but by day 7, αß TH17 effector T cells were predominant. By day 30, the majority of C albicans-reactive IL-17-producing T cells were CD4 TRM cells. Intravital microscopy showed that CD4 effector T cells were recruited to the site of primary infection and were highly motile 10 days after infection. Between 30 and 90 days after infection, these CD4 T cells became increasingly sessile, acquired expression of CD69 and CD103, and localized to the papillary dermis. These established TRM cells produced IL-17 on challenge, whereas motile migratory memory T cells did not. TRM cells rapidly clear an infectious challenge with C albicans more effectively than recirculating T cells, although both populations participate. We found that in normal human skin IL-17-producing CD4+ TRM cells that responded to C albicans in an MHC class II-restricted fashion could be identified readily. CONCLUSIONS: These studies demonstrate that C albicans infection of skin preferentially generates CD4+ IL-17-producing TRM cells, which mediate durable protective immunity.

Anal canal adenocarcinoma with neuroendocrine features accompanying secondary extramammary Paget disease, successfully treated with modified FOLFOX6: a case report.

BACKGROUND: Anal canal cancer occasionally accompanies extramammary Paget disease. Although most of them are squamous cell carcinoma, anal canal adenocarcinoma with neuroendocrine features accompanying secondary extramammary Paget disease has never been reported. CASE PRESENTATION: Here, we report a 76-year-old man presented with pruritus in the perianal area. Investigation revealed a fist-sized perianal erythema, diffuse liver tumors, and right inguinal lymph node swelling. Pathological examination of biopsies from the erythema suggested secondary extramammary Paget disease with positive cytokeratin-7 and -20 expressions and negative GCDFP-15 expression. The anal canal tumor was confirmed by digital examination and endoscopy. Biopsies from the anal canal tumor, swollen lymph node, and Paget lesion all showed poorly differentiated adenocarcinoma with neuroendocrine features expressing synaptophysin and chromogranin A. Serum CEA and NSE levels were high, 809.4 ng/ml and 85.8 ng/ml, respectively. After chemotherapy with modified FOLFOX6 for 2 months, the Paget lesion disappeared, and the primary anal canal tumor and liver metastases shrunk remarkably. Serum CEA and NSE levels decreased promptly to within normal ranges. CONCLUSIONS: This is a clinically significant case, as it reveals novel pathological features about anal canal cancer with secondary Paget disease and successfully treated with modified FOLFOX6. Careful pathological investigation and appropriate treatment choice are needed for this rare cancer.

Specific protein-labeling and ligand-binding position analysis with amidopyrene probes as LDI MS tags.

To readily analyze the binding mode of protein-ligand interactions, we developed ligand-bound-type and ligand-dissociation-type probes having 6-amidopyrene (apy) as a detecting group. Matrix- and label-assisted laser desorption/ionization mass spectrometry (MALDI and LA-LDI MS) analyses and a covalent docking simulation using these probes precisely determined the binding position of the ligand biotin on the target protein avidin (RMSD = 0.786 and 0.332 Å). Our apy-probe-labeling method may be useful for determining the unknown ligand-binding sites of various target proteins.

[Blastic plasmacytoid dendritic cell neoplasm accompanied by chronic myelomonocytic leukemia successfully treated with azacitidine].

Blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a rare disease that develops with a skin lesion and is often accompanied by leukemic transformation. The normal counterparts of BPDCN tumor cells are progenitors of plasmacytoid dendritic cells, whereas the origins are thought to be hematopoietic stem cells. Approximately 10%-20% of BPDCN patients develop other hematologic malignancies, including chronic myelomonocytic leukemia (CMML). Mutations in epigenetic regulators are frequently observed in both BPDCN and CMML tumors. Azacitidine, a drug that targets epigenetic dysregulation, is known to be an effective treatment for CMML. However, it has been used in few BPDCN patients. Here, we report a BPDCN patient with skin lesions, bone marrow infiltration, and lymphadenopathy. CMML also developed during the course of BPDCN. Azacitidine had positive effects on CMML; however, BPDCN aggressively relapsed during treatment. Two TET2 mutations were found in both BPDCN and CMML tumors; one of which was commonly identified in both tumors.

Topical resiquimod can induce disease regression and enhance T-cell effector functions in cutaneous T-cell lymphoma.

Early-stage cutaneous T-cell lymphoma (CTCL) is a skin-limited lymphoma with no cure aside from stem cell transplantation. Twelve patients with stage IA-IIA CTCL were treated in a phase 1 trial of 0.03% and 0.06% topical resiquimod gel, a Toll-like receptor 7/8 agonist. Treated lesions significantly improved in 75% of patients and 30% had clearing of all treated lesions. Resiquimod also induced regression of untreated lesions. Ninety-two percent of patients had more than a 50% improvement in body surface area involvement by the modified Severity-Weighted Assessment Tool analysis and 2 patients experienced complete clearing of disease. Four of 5 patients with folliculotropic disease also improved significantly. Adverse effects were minor and largely skin limited. T-cell receptor sequencing and flow cytometry studies of T cells from treated lesions demonstrated decreased clonal malignant T cells in 90% of patients and complete eradication of malignant T cells in 30%. High responses were associated with recruitment and expansion of benign T-cell clones in treated skin, increased skin T-cell effector functions, and a trend toward increased natural killer cell functions. In patients with complete or near eradication of malignant T cells, residual clinical inflammation was associated with cytokine production by benign T cells. Fifty percent of patients had increased activation of circulating dendritic cells, consistent with a systemic response to therapy. In summary, topical resiquimod is safe and effective in early-stage CTCL and the first topical therapy to our knowledge that can induce clearance of untreated lesions and complete remissions in some patients. This trial was registered at www.clinicaltrials.gov as #NCT813320.

Recent advances in dermatomyositis-specific autoantibodies.

PURPOSE OF REVIEW: In dermatomyositis, disease-specific autoantibodies now cover more than 70% of patients. These autoantibodies closely correlate with distinct clinical manifestations. In the past few years, extensive evidence has been accumulated on clinical significance of dermatomyositis-specific autoantibodies including autoantibodies against melanoma differentiation antigen 5 (MDA5), transcriptional intermediary factor 1 (TIF1), nuclear matrix protein 2 (NXP2), and small ubiquitin-like modifier activating enzyme (SAE). RECENT FINDINGS: Anti-MDA5 antibodies are found with high specificity in clinically amyopathic dermatomyositis presenting rapidly progressive interstitial lung disease (ILD) especially in Asian population. Similar tendency has been reported in the US/Europe, although the frequency of positivity and the type of ILD may differ. Anti-TIF1 antibodies are present in juvenile and adult dermatomyositis patients with close correlation with malignancy in adult population. Anti-NXP2 antibodies share similar phenotype with anti-TIF1 antibodies, except that anti-NXP2 antibodies are associated with calcinosis and severe muscle disease. Although numbers are still small, patients with anti-SAE antibodies tend to present skin disease first and then progress to muscle weakness with systematic symptoms including dysphagia. Moreover, distinct cutaneous manifestations and muscle histopathology findings for each autoantibody have been reported. SUMMARY: 'Autoantibody-based classification' of dermatomyositis subsets is now a useful strategy for comprehending the heterogeneous spectrum of dermatomyositis.

Binding position analysis of target proteins with the use of amidopyrene probes as LA-LDI enhancing tags.

Amidopyrene-conjugated compounds can be detected by label-assisted laser desorption/ionization mass spectrometry (LA-LDI MS) without matrixes. When actin, a cytoskeletal protein, was labeled with an excess amount of amidopyrene N-hydroxysuccinate (apy-OSu), eight apy-labeled actin peptides were predominantly detected by LA-LDI MS. Then actin was labeled with an amidopyrene NHS ester of the antitumor marine macrolide aplyronine A (ApA-apy-OSu) to form a 1 : 1 conjugate. The sequence of an apy-labeled peptide was established as A(108)PLNPKANR(116) by MS/MS analysis, in which the NHS ester moiety specifically reacted with the ε-amino group of K113. While the fragmentation at the linker part reduces the detection sensitivity of apy-labeled peptides on LA-LDI MS, our chemical probe method is useful for analyzing the binding modes of various ligands and target biomacromolecules that include multiple and weak interactions.

Galectin-1 inhibits the viability, proliferation, and Th1 cytokine production of nonmalignant T cells in patients with leukemic cutaneous T-cell lymphoma.

Tumor-derived galectin-1 (Gal-1), a ß-galactoside-binding S-type lectin, has been shown to encourage T-cell death and promote T cell-mediated tumor immune escape. In this report, we show that patients with leukemic cutaneous T-cell lymphomas, known to have limited complexity of their T-cell repertoires, have a predominant T helper type-2 (Th2) cytokine profile and significantly elevated plasma levels of Gal-1 compared with healthy controls. Circulating clonal malignant T cells were a major source of Gal-1. The conditioned supernatant of cultured malignant T cells induced a ß-galactoside-dependent inhibition of normal T-cell proliferation and a Th2 skewing of cytokine production. These data implicate Gal-1 in development of the Th2 phenotype in patients with advanced-stage cutaneous T-cell lymphoma and highlight the Gal-1-Gal-1 ligand axis as a potential therapeutic target for enhancing antitumor immune responses.

Efficacy of serial excisions of melanocytic nevi on the face using a carbon dioxide laser: a cosmetic point of view.

UNLABELLED: In cosmetic clinical practice, many patients express the desire for removal of melanocytic nevi, especially those on the face. The carbon dioxide (CO2) laser currently is the preferred for treatment of such lesions because of less scar formation, less bleeding, and simplicity of the procedure. However, if the diameter of the lesion is greater than 5 mm, many clinicians prefer surgical resection to laser resection because laser resection of relatively large nevi often results in the formation of a conspicuous dimple. The authors developed a serial laser excision method for melanocytic nevi larger than 5 mm, with division of the lesion into multiple segments, which allowed the ablated area to gain optimal granulation and reepithelialization, leading to a satisfactory cosmetic appearance. This novel procedure was performed for 25 patients with melanocytic nevi ranging from 5 to 10 mm in diameter. The lesions were divided into two segments in 21 patients, three segments in 3 patients, and four segments in 1 patient. The divided parts of the lesions were ablated by CO2 laser serially at intervals of 2-4 weeks. All the patients obtained optimal granulation and epithelialization in the treated lesions, and the final appearance was satisfactory. Although the therapeutic period was longer than for a surgical excision or a single laser treatment, the new treatment approach of serial excision by CO2 laser achieved favorable outcomes for the treatment of relatively large nevi 5-10 mm in size. LEVEL OF EVIDENCE V: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .