Search results for " t-lymphocytes"
showing 10 items of 495 documents
Reciprocal regulation of the Il9 locus by counteracting activities of transcription factors IRF1 and IRF4.
2017
The T helper 9 (Th9) cell transcriptional network is formed by an equilibrium of signals induced by cytokines and antigen presentation. Here we show that, within this network, two interferon regulatory factors (IRF), IRF1 and IRF4, display opposing effects on Th9 differentiation. IRF4 dose-dependently promotes, whereas IRF1 inhibits, IL-9 production. Likewise, IRF1 inhibits IL-9 production by human Th9 cells. IRF1 counteracts IRF4-driven Il9 promoter activity, and IRF1 and IRF4 have opposing function on activating histone modifications, thus modulating RNA polymerase II recruitment. IRF1 occupancy correlates with decreased IRF4 abundance, suggesting an IRF1-IRF4-binding competition at the I…
Activation of silent mating type information regulation 2 homolog 1 by human chorionic gonadotropin exerts a therapeutic effect on hepatic injury and…
2017
Incidence and prevalence of inflammatory liver diseases has increased over the last years, but therapeutic options are limited. Pregnancy induces a state of immune tolerance, which can result in spontaneous improvement of clinical symptoms of certain autoimmune diseases including autoimmune hepatitis (AIH). We investigated the immune-suppressive mechanisms of the human pregnancy hormone, chorionic gonadotropin (hCG), in the liver. hCG signaling activates silent mating type information regulation 2 homolog 1 (SIRT1), which deacetylates forkhead box o3 (FOXO3a), leading to repression of proapoptotic gene expression, because the immunosuppressive consequence attributed to the absence of caspas…
Melanoma Lesions Independently Acquire T-cell Resistance during Metastatic Latency
2016
Abstract Melanoma often recurs after a latency period of several years, presenting a T cell–edited phenotype that reflects a role for CD8+ T cells in maintaining metastatic latency. Here, we report an investigation of a patient with multiple recurrent lesions, where poorly immunogenic melanoma phenotypes were found to evolve in the presence of autologous tumor antigen–specific CD8+ T cells. Melanoma cells from two of three late recurrent metastases, developing within a 6-year latency period, lacked HLA class I expression. CD8+ T cell–resistant, HLA class I–negative tumor cells became clinically apparent 1.5 and 6 years into stage IV disease. Genome profiling by SNP arrays revealed that HLA …
Immunomodulatory activity of microRNAs: potential implications for multiple myeloma treatment
2015
Multiple myeloma (MM) is an incurable plasma cell neoplasm accounting for about 10% of all hematologic malignancies. Recently, emerging evidence is disclosing the complexity of bone marrow interactions between MM cells and infiltrating immune cells, which have been reported to promote proliferation, survival and drug resistance of tumor cells. MicroRNAs (miRNAs) are small non-coding RNA molecules with regulatory functions in the cell, whose expression has predictive and prognostic value in different malignancies. MiRNAs are gaining increasing interest due to their capability to polarize the immune-response through different mechanisms, which include the molecular reprogramming of immune cel…
Tnfaip3 expression in pulmonary conventional type 1 Langerin‐expressing dendritic cells regulates T helper 2‐mediated airway inflammation in mice
2020
Abstract Background Conventional type 1 dendritic cells (cDC1s) control anti‐viral and anti‐tumor immunity by inducing antigen‐specific cytotoxic CD8+ T‐cell responses. Controversy exists whether cDC1s also control CD4+ T helper 2 (Th2) cell responses, since suppressive and activating roles have been reported. DC activation status, controlled by the transcription factor NF‐κB, might determine the precise outcome of Th‐cell differentiation upon encounter with cDC1s. To investigate the role of activated cDC1s in Th2‐driven immune responses, pulmonary cDC1s were activated by targeted deletion of A20/Tnfaip3, a negative regulator of NF‐κB signaling. Methods To target pulmonary cDC1s, Cd207 (Lan…
Tc17 biology and function: Novel concepts
2020
Research over the past years has provided increasing understanding about IL-17-producing CD8+ T cells termed Tc17 or IL-17+ CD8+ T cells, their distribution and role in a range of diverse immune processes. These comprise resistance to pathogens and tissue homeostasis, but also contribution to autoimmunity and cancer, as well as involvement in gut inflammation, lung diseases and graft-versus-host-disease. Tc17 cells are regulated by unique differentiation mechanisms distinguishing them from other IL-17-producing T cells, including Th17, mucosal-associated invariant T cells, and γδ17 T cells, thus ensuring their specific function in immune responses. Here, we review recent advances in underst…
IL-33/ST2 pathway drives regulatory T cell dependent suppression of liver damage upon cytomegalovirus infection.
2017
Regulatory T (Treg) cells dampen an exaggerated immune response to viral infections in order to avoid immunopathology. Cytomegaloviruses (CMVs) are herpesviruses usually causing asymptomatic infection in immunocompetent hosts and induce strong cellular immunity which provides protection against CMV disease. It remains unclear how these persistent viruses manage to avoid induction of immunopathology not only during the acute infection but also during life-long persistence and virus reactivation. This may be due to numerous viral immunoevasion strategies used to specifically modulate immune responses but also induction of Treg cells by CMV infection. Here we demonstrate that liver Treg cells …
TGF-β inhibitor Smad7 regulates dendritic cell-induced autoimmunity
2017
TGF-β is an anti-inflammatory cytokine whose signaling is negatively controlled by Smad7. Previously, we established a role for Smad7 in the generation of autoreactive T cells; however, the function of Smad7 in dendritic cells (DCs) remains elusive. Here, we demonstrate that DC-specific Smad7 deficiency resulted in elevated expression of the transcription factors Batf3 and IRF8, leading to increased frequencies of CD8(+)CD103(+) DCs in the spleen. Furthermore, Smad7-deficient DCs expressed higher levels of indoleamine 2,3-dioxygenase (IDO), an enzyme associated with tolerance induction. Mice devoid of Smad7 specifically in DCs are resistant to the development of experimental autoimmune ence…
Mouse Model of Cytomegalovirus Disease and Immunotherapy in the Immunocompromised Host: Predictions for Medical Translation that Survived the “Test o…
2018
Human Cytomegalovirus (hCMV), which is the prototype member of the β-subfamily of the herpesvirus family, is a pathogen of high clinical relevance in recipients of hematopoietic cell transplantation (HCT). hCMV causes multiple-organ disease and interstitial pneumonia in particular upon infection during the immunocompromised period before hematopoietic reconstitution restores antiviral immunity. Clinical investigation of pathomechanisms and of strategies for an immune intervention aimed at restoring antiviral immunity earlier than by hematopoietic reconstitution are limited in patients to observational studies mainly because of ethical issues including the imperative medical indication …
Antigen-dependent competition shapes the local repertoire of tissue-resident memory CD8+ T cells.
2016
Muschaweckh et al. show that antigen presentation in the skin regulates the generation of tissue-resident memory T (TRM) cells by orchestrating local competition of antiviral CD8+ T cells, revealing a mechanism to fine-tune the repertoire of regional pools of TRM cells.