CD25(+) T cell depletion impairs murine squamous cell carcinoma development via modulation of antitumor immune responses

Squamous cell carcinoma (SCC) constitutes a microenvironment that could modulate the antitumor immune response. Also, tumor-infiltrating lymphocytes are believed to play complex regulatory roles in antitumor immunity against SCC. The presence of regulatory T cells (Tregs) has been associated with the suppression of tumor-reactive T cells. However, the underlying mechanism for this T cell dysfunction is not clear. We used a multistage model of SCC to examine the role of Treg cells during tumor development. 7,12-dimethylbenz[a]-anthracene/phorbol 12-myristate 13-acetate treatment and systemic depletion of Treg cells using an anti-CD25 monoclonal antibody (PC61) resulted in a decrease in the number and incidence of papilloma. Furthermore, CD25 depletion increased the proportion of CD8(+) and CD4(+) T cells that were isolated from tumor lesions. The levels of interleukin (IL)-1 beta, IL-10, IL-12, IL-13, interferon-gamma, transforming growth factor-beta and tumor necrosis factor-alpha, but not IL-17, were increased in the tumor microenvironment after Treg depletion. Therefore, our results indicated involvement of CD25(+) T cells in SCC development and in the suppression of the inflammatory immune response.

Melanoma Staging Where Are We Now?

The seventh version of the American Joint Committee on Cancer (AJCC) Melanoma Staging guidelines, published in 2009, has significant revisions compared with the previous version. The current schema was based on the largest melanoma patient cohort analyzed to date and is the result of a multivariate analysis of 30,946 patients with stages I, II, and III melanoma and 7972 patients with stage IV melanoma. This article summarizes the findings and the new definitions included in the 2009 AJCC Melanoma Staging and Classification. The TNM categories and the stage groupings are defined. Changes in the melanoma staging system are summarized.

Interleukin-10 production by tumor infiltrating macrophages plays a role in Human Papillomavirus 16 tumor growth

Abstract Background Human Papillomavirus, HPV, is the main etiological factor for cervical cancer. Different studies show that in women infected with HPV there is a positive correlation between lesion grade and number of infiltrating macrophages, as well as with IL-10 higher expression. Using a HPV16 associated tumor model in mice, TC-1, our laboratory has demonstrated that tumor infiltrating macrophages are M2-like, induce T cell regulatory phenotype and play an important role in tumor growth. M2 macrophages secrete several cytokines, among them IL-10, which has been shown to play a role in T cell suppression by tumor macrophages in other tumor models. In this work, we sought to establish if IL-10 is part of the mechanism by which HPV tumor associated macrophages induce T cell regulatory phenotype, inhibiting anti-tumor activity and facilitating tumor growth. Results TC-1 tumor cells do not express or respond to IL-10, but recruit leukocytes which, within the tumor environment, produce this cytokine. Using IL-10 deficient mice or blocking IL-10 signaling with neutralizing antibodies, we observed a significant reduction in tumor growth, an increase in tumor infiltration by HPV16 E7 specific CD8 lymphocytes, including a population positive for Granzyme B and Perforin expression, and a decrease in the percentage of HPV specific regulatory T cells in the lymph nodes. Conclusions Our data shows that in the HPV16 TC-1 tumor mouse model, IL-10 produced by tumor macrophages induce regulatory phenotype on T cells, an immune escape mechanism that facilitates tumor growth. Our results point to a possible mechanism behind the epidemiologic data that correlates higher IL-10 expression with risk of cervical cancer development in HPV infected women.

Diagnostic value of serum activin A and follistatin levels in women with peritoneal, ovarian and deep infiltrating endometriosis

Activin A is a growth factor, produced by the endometrium, whose actions are modulated by the binding protein follistatin. Both proteins are detectable in the peripheral serum and their concentrations may be increased in women with endometriosis. The present study was designed to evaluate whether serum levels of activin A and follistatin are altered, and therefore have a potential diagnostic value, in women with peritoneal, ovarian and deep infiltrating endometriosis. We performed a multicenter controlled study evaluating simultaneously serum activin A and follistatin concentrations in women with and without endometriosis. Women with endometriosis (n 139) were subdivided into three groups: peritoneal endometriosis (n 28); ovarian endometrioma (n 61) and deep infiltrating endometriosis (n 50). The control group (n 75) consisted of healthy women with regular menstrual cycles. Blood samples were collected from a peripheral vein and assayed for activin A and follistatin using commercially available enzyme immunoassay kits. The ovarian endometrioma group had serum activin A levels significantly higher than healthy controls (0.22 0.01 ng/ml versus 0.17 0.01 ng/ml, P 0.01). None of the endometriosis groups had serum follistatin levels which were significantly altered compared with healthy controls; however, levels found in the endometrioma group (2.34 0.32 ng/ml) were higher than that in the deep endometriosis group (1.50 0.17 ng/ml, P 0.05). The area under the receiver operating characteristic curve of activin A was 0.700 (95 confidence interval: 0.6050.794), while that of follistatin was 0.620 (95 confidence interval: 0.5100.730) for the diagnosis of ovarian endometrioma. The combination of both markers into a duo marker index did not improve significantly their diagnostic accuracy. The present study demonstrated that serum activin A and follistatin are not significantly altered in peritoneal or deep infiltrating endometriosis and have limited diagnostic accuracy in the diagnosis of ovarian endometrioma.

DNA damage defines sites of recurrent chromosomal translocations in B lymphocytes

Recurrent chromosomal translocations underlie both haematopoietic and solid tumours. Their origin has been ascribed to selection of random rearrangements, targeted DNA damage, or frequent nuclear interactions between translocation partners; however, the relative contribution of each of these elements has not been measured directly or on a large scale. Here we examine the role of nuclear architecture and frequency of DNA damage in the genesis of chromosomal translocations by measuring these parameters simultaneously in cultured mouse B lymphocytes. In the absence of recurrent DNA damage, translocations between Igh or Myc and all other genes are directly related to their contact frequency. Conversely, translocations associated with recurrent site-directed DNA damage are proportional to the rate of DNA break formation, as measured by replication protein A accumulation at the site of damage. Thus, non-targeted rearrangements reflect nuclear organization whereas DNA break formation governs the location and frequency of recurrent translocations, including those driving B-cell malignancies.

Expression of Mast Cell Proteases Correlates with Mast Cell Maturation and Angiogenesis during Tumor Progression

Tumor cells are surrounded by infiltrating inflammatory cells, such as lymphocytes, neutrophils, macrophages, and mast cells. A body of evidence indicates that mast cells are associated with various types of tumors. Although role of mast cells can be directly related to their granule content, their function in angiogenesis and tumor progression remains obscure. This study aims to understand the role of mast cells in these processes. Tumors were chemically induced in BALB/c mice and tumor progression was divided into Phases I, II and III. Phase I tumors exhibited a large number of mast cells, which increased in phase II and remained unchanged in phase III. The expression of mouse mast cell protease (mMCP)-4, mMCP-5, mMCP-6, mMCP-7, and carboxypeptidase A were analyzed at the 3 stages. Our results show that with the exception of mMCP-4 expression of these mast cell chymase (mMCP-5), tryptases (mMCP-6 and 7), and carboxypeptidase A (mMC-CPA) increased during tumor progression. Chymase and tryptase activity increased at all stages of tumor progression whereas the number of mast cells remained constant from phase II to III. The number of new blood vessels increased significantly in phase I, while in phases II and III an enlargement of existing blood vessels occurred. In vitro, mMCP-6 and 7 are able to induce vessel formation. The present study suggests that mast cells are involved in induction of angiogenesis in the early stages of tumor development and in modulating blood vessel growth in the later stages of tumor progression.

Gene expression of peripheral blood lymphocytes may discriminate patients with schizophrenia from controls

To identify a classifier in schizophrenia, blood gene expression profiling was applied to patients with schizophrenia under different treatments and to controls. Expression of six genes discriminated patients with sensitivity of 89.3% and specificity of 90%, supporting the use of peripheral blood as biological material for diagnosis in schizophrenia. (C) 2012 Elsevier Ireland Ltd. All rights reserved.

Activation of Survival and Apoptotic Signaling Pathways in Lymphocytes Exposed to Palmitic Acid

The toxicity of palmitic acid (PA) towards a human T-lymphocyte cell line (Jurkat) has been previously investigated but the mechanism(s) of PA action were unknown. In the current study, Jurkat cells were treated with sub-lethal concentrations of PA (50-150 mu M) and the activity of various signaling proteins was investigated. PA-induced apoptosis and mitochondrial dysfunction in a dose-dependent manner as evaluated by DNA fragmentation assay and depolarization of the mitochondrial membrane, respectively. PA treatment provoked release of cytochrome c from the inner mitochondrial membrane to the cytosol, activated members of the MAPK protein family JNK, p38, ERK, activated caspases 3/9, and increased oxidative/nitrosative stress. Exposure of cells to PA for 12 h increased insulin receptor (IR) and GLUT-4 levels in the plasma membrane. Insulin treatment (10 mU/ml/30 min) increased the phosphorylation of the IR beta-subunit and Akt. A correlation was found between DNA fragmentation and expression levels of both IR and GLUT-4. Similar results were obtained for PA-treated lymphocytes from healthy human donors and from mesenteric lymph nodes of 48-h starved rats. PA stimulated glucose uptake by Jurkat cells (in the absence of insulin), stimulated accumulation of neutral lipids (triglyceride), and other lipid classes (phospholipids and cholesterol ester) but reduced glucose oxidation. Our results suggest that parameters of insulin signaling and non-oxidative glucose metabolism are stimulated as part of a coordinated response to prompt survival in lymphocytes exposed to PA but at higher concentrations, apoptosis prevails. These findings may explain aspects of lymphocyte dysfunction associated with diabetes. J. Cell. Physiol. 227: 339-350, 2012. (C) 2011 Wiley Periodicals, Inc.

Proinflammatory profile of in vitro monocytes in the ageing is affected by lymphocytes presence

Background: Aging is associated with complex and constant remodeling of the immune function, resulting in an increasing susceptibility to infection and others diseases. The infections caused by Gram-negative microorganisms, present in nursing homes and hospitals, constitute one of the most common infections in the elderly, and are mainly combated by innate immune cells. Although the functions of innate immunity seem more preserved during aging than of adaptive immune mechanisms, two systems operate in an integrated way in the body, so that injury in one part of the immune system inevitably affects the other as they are part of a defensive network. The aim of this study was to investigate the in vitro production of proinflammatory (TNF-α, IL-6, IL-1α, CXCL-8 and MCP-1) and antiinflammatory (TGF-α and IL-10) cytokines by monocytes, stimulated or not (basal) with lipopolysaccharide, from healthy young and elderly subjects. By means of PBMCs, we also studied if cytokine profile is altered in these different patient groups, in the presence of lymphocytes, under the same experimental conditions. Results: The monocytes from elderly presented higher basal production of TNF-α, MCP-1 and lower of TGF-α than young monocytes. PBMC showed similar cytokines production, irrespective age or stimulation presence. In the presence of lymphocytes, the spontaneous production of IL-10 was higher and of TGF-α was lower than monocytes, regardless of age. After LPS-stimulation, the presence of lymphocytes resulted in increased IL-6, IL-1α, MCP-1 and IL-10 and decreased CXCL-8 and TGF-α in comparison to pure culture of monocytes from young patients. With age, the same differences were observed, except for CXCL-8 and TGF-α which production was the same between monocytes and PBMC stimulated with LPS.

Dendritic cells and T lymphocytes interactions in a novel 3D system

We describe the interactions between monocyte-derived DCs, in different stages of maturation, with allogeneic T lymphocytes in a 3D system. Maturation of DCs increased their interaction time with T lymphocytes from 43 to 138 minutes. The average motility of T lymphocytes interacting or not with DCs was also affected, varying from 0.21μm-0.37μm/minute to 0.36μm- 0.52μm/minute. These data indicate that this 3D BiotekTM scaffold enables interactions between lymphocytes and DCs at different stages of maturation and may be useful for the characterization of these interactions, the cellular subtypes and patterns of response induced.