Summary B cells regulate immune responses by producing antigen-specific antibody1. However, specific B cell subsets can also negatively regulate immune responses, validating the existence of regulatory B cells2–4. Human and mouse regulatory B cells (B10 cells) with the ability to express the inhibitory cytokine IL-10 have been identified2–5. Although rare, B10 cells are potent negative regulators of antigen-specific inflammation and T cell-dependent autoimmune diseases in mice5–7. How B10 cell IL-10 production and regulation of antigen-specific immune responses are controlled in vivo without inducing systemic immunosuppression are unknown. Using a mouse model for multiple sclerosis, we show here that B10 cell maturation into functional IL-10-secreting effector cells that inhibit in vivo autoimmune disease requires IL-21 and CD40-dependent cognate interactions with T cells. Moreover, the ex vivo provision of CD40 and IL-21 receptor signals can drive B10 cell development and expansion by four-million-fold and generate B10 effector cells producing IL-10 that dramatically inhibit disease symptoms when transferred into mice with established autoimmune disease. Thereby, the ex vivo expansion and reinfusion of autologous B10 cells may provide a novel and effective in vivo treatment for severe autoimmune diseases that are resistant to current therapies.

Purpose Advanced-stage mycosis fungoides (MF; stage IIB to IV) and Sézary syndrome (SS) are aggressive lymphomas with a median survival of 1 to 5 years. Clinical management is stage based; however, there is wide range of outcome within stages. Published prognostic studies in MF/SS have been single-center trials. Because of the rarity of MF/SS, only a large collaboration would power a study to identify independent prognostic markers. Patients and Methods Literature review identified the following 10 candidate markers: stage, age, sex, cutaneous histologic features of folliculotropism, CD30 positivity, proliferation index, large-cell transformation, WBC/lymphocyte count, serum lactate dehydrogenase, and identical T-cell clone in blood and skin. Data were collected at specialist centers on patients diagnosed with advanced-stage MF/SS from 2007. Each parameter recorded at diagnosis was tested against overall survival (OS). Results Staging data on 1,275 patients with advanced MF/SS from 29 international sites were included for survival analysis. The median OS was 63 months, with 2- and 5-year survival rates of 77% and 52%, respectively. The median OS for patients with stage IIB disease was 68 months, but patients diagnosed with stage III disease had slightly improved survival compared with patients with stage IIB, although patients diagnosed with stage IV disease had significantly worse survival (48 months for stage IVA and 33 months for stage IVB). Of the 10 variables tested, four (stage IV, age > 60 years, large-cell transformation, and increased lactate dehydrogenase) were independent prognostic markers for a worse survival. Combining these four factors in a prognostic index model identified the following three risk groups across stages with significantly different 5-year survival rates: low risk (68%), intermediate risk (44%), and high risk (28%). Conclusion To our knowledge, this study includes the largest cohort of patients with advanced-stage MF/SS and identifies markers with independent prognostic value, which, used together in a prognostic index, may be useful to stratify advanced-stage patients.

Purpose: Both patients with cutaneous T-cell lymphoma (CTCL) and those with atopic dermatitis (AD) have pruritus, T H 2-biased T cells, and a tendency to have bacterial infections, suggesting a common pathologic basis for these two diseases. Recently, interleukin (IL)-22-producing T cells were reported in skin of patients with AD. In this study, we investigated expression levels of T H 22-and T H 17-related molecules in lesional skin and sera isolated from patients with CTCL.Experimental Design: Skin biopsies and sera were collected from patients with CTCL or psoriasis and from healthy volunteers. Protein and mRNA expression levels of IL-22, IL-17A, IL-17F, IL-23p19, IL-10, IL-4, CCL20, CCR6, IL-8, and IL-20 were examined in lesional tissue and a subset of these molecules in sera. Phosphorylation of STAT3 was also assessed in lesional skin of CTCL and psoriasis by immunohistochemistry.Results: IL-22, IL-10, IL-4, CCL20, and CCR6 mRNA and protein levels, but not IL-17A, IL-17F, IL-23p19, IL-8, or IL-20, were significantly elevated in lesional skin of CTCL. Phosphorylation of STAT3 was detected in epidermis of CTCL skin. Moreover, serum IL-22, IL-10, and CCL20 levels were increased in CTCL and correlated with disease severity.Conclusions: Our results suggest that IL-22 is important in establishing the tumor microenvironment for CTCL. Enhanced expression of CCL20 may explain epidermal hyperplasia and migration of CCR6 þ cells, such as Langerhans cells, into lesional skin. Relatively low expression of IL-17 may explain the lack of neutrophils in lesions of CTCL, which correlates with bacterial infections that commonly occur in skin affected by CTCL. Clin Cancer Res; 17(24); 7529-38. Ó2011 AACR.

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CC chemokine receptor 3 (CCR3), the sole receptor for eotaxins, is expressed on eosinophils and T helper type 2 (Th2) cells. In Hodgkin's disease, eotaxin-1 secreted by fibroblasts collects Th2 cells and eosinophils within the tissue. Similarly, many Th2 cells infiltrate the lesional skin of cutaneous T-cell lymphoma (CTCL). In this study, we investigated the role of eotaxins in the development of the Th2 environment of CTCL. We revealed that fibroblasts from lesional skin of CTCL expressed higher amounts of eotaxin-3 messenger RNA (mRNA) compared with those from normal skin. Lesional skin of CTCL at advanced stages contained significantly higher levels of eotaxin-3 and CCR3 mRNA, compared with early stages of CTCL. IL-4 mRNA was expressed in some cases at advanced stages. Immunohistochemistry revealed that keratinocytes, endothelial cells, and dermal fibroblasts in lesional skin of CTCL showed a stronger expression of eotaxin-3 than did normal skin. CCR3(+) lymphocytes and IL-4 expression were observed in some cases of advanced CTCL. Furthermore, both serum eotaxin-3 and eotaxin-1 levels of CTCL patients at advanced stages were significantly higher than those of healthy individuals. The concentrations of these chemokines correlated with serum soluble IL-2 receptor levels. These results suggest that interaction of eotaxins and CCR3 regulates the Th2-dominant tumor environment, which is closely related to the development of CTCL.

This large multicenter retrospective study shows that there exist a large treatment heterogeneity in advanced MF/SS and differences between USA and non-USA centers but these were not related to survival, while our data reveal that chemotherapy as first treatment is associated with a higher risk of death and/or change of therapy and thus other therapeutic options should be preferable as first treatment approach.

B cells have been generally considered to be positive regulators of immune responses because of their ability to produce antigen-specific antibodies and to activate T cells through antigen presentation. Impairment of B cell development and function may cause inflammatory and autoimmune diseases. Recently, specific B cell subsets that can negatively regulate immune responses have been described in mouse models of a wide variety of inflammatory and autoimmune diseases. The concept of those B cells, termed regulatory B cells, is now recognized as important in the murine immune system. Among several regulatory B cell subsets, IL-10-producing regulatory B cells are the most widely investigated. On the basis of discoveries from studies of such mice, human regulatory B cells that produce IL-10 in most cases are becoming an active area of research. There have been emerging data suggesting the importance of human regulatory B cells in various diseases. Revealing the immune regulation mechanisms of human regulatory B cells in human inflammatory and autoimmune diseases could lead to the development of novel B cell targeted therapies. This review highlights the current knowledge on regulatory B cells, mainly IL-10-producing regulatory B cells, in animal models of inflammatory and autoimmune diseases and in clinical research using human samples.

The immunological significance of IL-27 has been reported and discussed in various Th1/Th17-mediated inflammatory diseases. However, its importance in psoriasis is unknown. We investigated pathophysiological roles of IL-27 in psoriasis in this study. Serum IL-27 levels in psoriatic patients were significantly higher than those in healthy controls, and correlated with disease severity and serum IFN-gamma levels. An immunohistochemical analysis revealed the infiltration of IL-27-secreting cells in the papillary dermis of psoriatic skin lesions but not in skin lesions with atopic dermatitis or normal skin. Furthermore, IL-27 alone greatly induced in vitro CXCL9, CXCL10, and CXCL11 production and tyrosine phosphorylation of signal transducer and activator of transcription 1 in normal human keratinocytes, while it suppressed the tumor necrosis factor-alpha-induced production of IL-1alpha and CCL20. These results indicate that IL-27 may promote the onset of psoriasis, while it may simultaneously attenuate the expanded inflammation in this disease. Our results implicate potential therapeutic effects of IL-27 for psoriasis.