scholarly journals Macrophage-specific MHCII expression is regulated by a remote Ciita enhancer controlled by NFAT5

2018 ◽  
Vol 215 (11) ◽  
pp. 2901-2918 ◽  
Author(s):  
Maria Buxadé ◽  
Hector Huerga Encabo ◽  
Marta Riera-Borrull ◽  
Lucía Quintana-Gallardo ◽  
Pilar López-Cotarelo ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Immune Responses ◽  
T Lymphocyte ◽  
Cell Type ◽  
Adaptive Immune Responses ◽  
Adaptive Immune ◽  
Cell Type Specific ◽  
Antigen Presenting ◽  
Mhcii Expression

MHCII in antigen-presenting cells (APCs) is a key regulator of adaptive immune responses. Expression of MHCII genes is controlled by the transcription coactivator CIITA, itself regulated through cell type–specific promoters. Here we show that the transcription factor NFAT5 is needed for expression of Ciita and MHCII in macrophages, but not in dendritic cells and other APCs. NFAT5-deficient macrophages showed defective activation of MHCII-dependent responses in CD4+ T lymphocytes and attenuated capacity to elicit graft rejection in vivo. Ultrasequencing analysis of NFAT5-immunoprecipitated chromatin uncovered an NFAT5-regulated region distally upstream of Ciita. This region was required for CIITA and hence MHCII expression, exhibited NFAT5-dependent characteristics of active enhancers such as H3K27 acetylation marks, and required NFAT5 to interact with Ciita myeloid promoter I. Our results uncover an NFAT5-regulated mechanism that maintains CIITA and MHCII expression in macrophages and thus modulates their T lymphocyte priming capacity.

scholarly journals Specialized Proresolving Mediators in Innate and Adaptive Immune Responses in Airway Diseases

2018 ◽  
Vol 98 (3) ◽  
pp. 1335-1370 ◽  
Author(s):  
Nandini Krishnamoorthy ◽  
Raja-Elie E. Abdulnour ◽  
Katherine H. Walker ◽  
Braden D. Engstrom ◽  
Bruce D. Levy
Keyword(s):  
Immune Responses ◽  
Dynamic Process ◽  
Cell Type ◽  
Organ Function ◽  
Cellular Mechanisms ◽  
Adaptive Immune Responses ◽  
Disease Pathogenesis ◽  
Adaptive Immune ◽  
Airway Diseases ◽  
Cell Type Specific

Airborne pathogens and environmental stimuli evoke immune responses in the lung. It is critical to health that these responses be controlled to prevent tissue damage and the compromise of organ function. Resolution of inflammation is a dynamic process that is coordinated by biochemical and cellular mechanisms. Recently, specialized proresolving mediators (SPMs) have been identified in resolution exudates. These molecules orchestrate anti-inflammatory and proresolving actions that are cell type specific. In this review, we highlight SPM biosynthesis, the influence of SPMs on the innate and adaptive immune responses in the lung, as well as recent insights from SPMs on inflammatory disease pathophysiology. Uncovering these mediators and cellular mechanisms for resolution is providing new windows into physiology and disease pathogenesis.

scholarly journals The colonic macrophage transcription factor RBP-J orchestrates intestinal immunity against bacterial pathogens

2020 ◽  
Vol 217 (4) ◽  
Author(s):  
Lan Kang ◽  
Xiang Zhang ◽  
Liangliang Ji ◽  
Tiantian Kou ◽  
Sinead M. Smith ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Immune Responses ◽  
Inflammatory Responses ◽  
Late Phase ◽  
Intestinal Immunity ◽  
Adaptive Immune Responses ◽  
Cell Lineages ◽  
Adaptive Immune ◽  
Intestinal Macrophage ◽  
Pathogen Clearance

Macrophages play pleiotropic roles in maintaining the balance between immune tolerance and inflammatory responses in the gut. Here, we identified transcription factor RBP-J as a crucial regulator of colonic macrophage–mediated immune responses against the enteric pathogen Citrobacter rodentium. In the immune response phase, RBP-J promoted pathogen clearance by enhancing intestinal macrophage-elicited Th17 cell immune responses, which was achieved by maintenance of C/EBPβ-dependent IL-6 production by overcoming miRNA-17∼92–mediated suppressive effects. RBP-J deficiency–associated phenotypes could be genetically corrected by further deleting miRNA-17∼92 in macrophages. In the late phase, noneradicated pathogens in RBP-J KO mice recruited abundant IL-1β–expressing CD64+Ly6C+ colonic macrophages and thereby promoted persistence of ILC3-derived IL-22 to compensate for the impaired innate and adaptive immune responses, leading to ultimate clearance of pathogens. These results demonstrated that colonic macrophage–intrinsic RBP-J dynamically orchestrates intestinal immunity against pathogen infections by interfacing with key immune cells of T and innate lymphoid cell lineages.

scholarly journals Role of Type I Interferons on Filovirus Pathogenesis

Vaccines ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 22 ◽  
Author(s):  
Beatriz Escudero-Pérez ◽  
César Muñoz-Fontela
Keyword(s):  
Animal Models ◽  
Immune Responses ◽  
Marburg Virus ◽  
Type I Interferons ◽  
Type I ◽  
Adaptive Immune ◽  
Antigen Presenting

Filoviruses, such as Ebola and Marburg virus, encode viral proteins with the ability to counteract the type I interferon (IFN-I) response. These IFN-I antagonist proteins are crucial to ensure virus replication, prevent an antiviral state in infected and bystander cells, and impair the ability of antigen-presenting cells to initiate adaptive immune responses. However, in recent years, a number of studies have underscored the conflicting data between in vitro studies and in vivo data obtained in animal models and clinical studies during outbreaks. This review aims to summarize these data and to discuss the relative contributions of IFN-α and IFN-β to filovirus pathogenesis in animal models and humans. Finally, we evaluate the putative utilization of IFN-I in post-exposure therapy and its implications as a biomarker of vaccine efficacy.

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