Search results for "Immune system"

Mucosal T cells: mediators or guardians of inflammatory bowel disease?

2003

Because the mucosal immune system is continuously exposed to a myriad of potentially harmful environmental antigens, it frequently reacts with antiinflammatory/regulatory T cell responses driven by TGF-β-producing T H 3 cells and IL-10-producing regulatory T cells. Intestinal inflammation in patients with inflammatory bowel diseases is thought to result from an overwhelming uncontrolled activation of the mucosal immune system induced by antigens of the normal luminal flora in genetically susceptible individuals. Inflammatory bowel disease appears to be mediated by subsets of CD4 + T lymphocytes or NK T cells secreting high levels of proinflammatory cytokines such as TNF-α. The increased exp…

Isolation and subsequent analysis of murine lamina propria mononuclear cells from colonic tissue

2007

Studies on colonic cells in the lamina propria (LP) of mice are important for understanding the cellular and immune responses in the gut, especially in inflammatory bowel diseases (such as morbus crohn and colitis ulcerosa). This protocol details a method to isolate LP cells and characterize freshly isolated cells by quality control experiments to obtain cells that can be used for further investigations. After different steps of digestion of the tissue using collagenase, DNase and dispase, the resulting cells are purified using Percoll gradient. The success of the isolation can be analyzed by cell viability test (Trypan Blue exclusion test) and by flow cytometric analysis to assess apoptosi…

Isolation of T Cells from the Gut

2014

The lymphocytes of epithelial and lamina proprial compartments of the intestine are phenotypically and functionally distinct and serve a wide range of functions in the intestinal mucosa like regulating intestinal homeostasis, maintaining epithelial barrier function as well as regulating adaptive and innate immune responses. To analyze the role of these cells in different disease states, it is necessary to isolate pure cell populations of the intraepithelial lymphocytes (IEL) and lamina propria lymphocytes (LPL) of the gut. In this protocol we describe a method to isolate T cells from IEL and LPL, which can be used for further investigations like comparative studies of mRNA expression, cell …

Cutaneous RANK-RANKL Signaling Upregulates CD8-Mediated Antiviral Immunity during Herpes simplex Virus Infection by Preventing Virus-Induced Langerha…

2015

Herpes simplex virus-type 1 (HSV-1) causes the majority of cutaneous viral infections. Viral infections are controlled by the immune system, and CD8(+) cytotoxic T-lymphocytes (CTLs) have been shown to be crucial during the clearance of HSV-1 infections. Although epidermal Langerhans cells (LCs) are the first dendritic cells (DCs) to come into contact with the virus, it has been shown that the processing of viral antigens and the differentiation of antiviral CTLs are mediated by migratory CD103+ dermal DCs and CD8 alpha(+) lymph node resident DCs. In vivo regulatory T-cells (Tregs) are implicated in the regulation of antiviral immunity and we have shown that signaling via the receptor activ…

Multicolor fate mapping of Langerhans cell homeostasis

2013

The adult epidermal Langerhans cell network is formed by adjacent proliferative units composed of dividing cells and their terminally differentiated daughter cells.

Leishmania major-infected murine Langerhans cell-like dendritic cells from susceptible mice release IL-12 after infection and vaccinate against exper…

2000

Leishmania major-infected C57BL / 6 skin-dendritic cells (DC) are activated and release cytokines (including IL-12 p70), and likely initiate protective Th1 immunity in vivo (von Stebut, E. et al., J. Exp. Med.188: 1547 – 1552). To characterize differences in DC function in mice that are genetically susceptible (BALB / c) and resistant (C57BL / 6) to cutaneous leishmaniasis, we analyzed the effects of L. major on Langerhans cell-like, fetal skin-derived DC (FSDDC) from both strains. BALB / c- and C57BL / 6-FSDDC ingested similar numbers of amastigotes, but did not ingest metacyclic promastigotes. Like C57BL / 6-FSDDC, infection of BALB / c-FSDDC led to up-regulation of MHC class I and II ant…

Contact sensitivity as a model for T-cell activation in skin.

1995

Contact sensitivity has served as a useful model for the primary activation of T cells in skin and skin-associated lymphoid tissue. We have been interested in the early signals necessary for the induction of an allergen-specific T-cell response, as well as the factors controlling the intensity and extent of such an immune reaction. Because cytokines qualified as possible candidate molecules involved in directing primary immune responses in skin, we studied the early changes in the cytokine pattern of the epidermis. Apart from defining a cytokine pattern specifically induced only after application of allergen, we also identified Langerhans-cell-derived interleukin (IL)-1β as the first cytoki…

Langerinneg conventional dendritic cells produce IL-23 to drive psoriatic plaque formation in mice.

2013

Psoriasis is an autoinflammatory skin disease of unknown etiology. Topical application of Aldara cream containing the Toll-like receptor (TLR)7 agonist Imiquimod (IMQ) onto patients induces flares of psoriasis. Likewise, in mice IMQ triggers pathological changes closely resembling psoriatic plaque formation. Key cytokines like IL-23 and type-I IFN (IFN-I), both being produced mainly by dendritic cells (DCs), have been implicated in psoriasis. Although plasmacytoid DCs (pDCs) are the main source of IFNα and thought to initiate disease, conventional DCs (cDCs) appear to maintain the psoriatic lesions. Any role of cDCs during lesion formation remains elusive. Here, we report that selective ac…

Langerhans cells are negative regulators of the anti-Leishmania response

2011

Langerhans cells suppress the immune response to low-dose Leishmania major infection in part by inducing regulatory T cells.

2015

Dendritic cells (DC) are a heterogeneous family of professional antigen-presenting cells classically recognized as most potent inducers of adaptive immune responses. In this respect, Langerhans cells have long been considered to be prototypic immunogenic DC in the skin. More recently this view has considerably changed. The generation of in vivo cell ablation and lineage tracing models revealed the complexity of the skin DC network and, in particular, established the existence of a number of phenotypically distinct Langerin(+) and negative DC populations in the dermis. Moreover, by now we appreciate that DC also exert important regulatory functions and are required for the maintenance of tol…