scholarly journals T cell fate following Salmonella infection is determined by a STING-IRF1 signaling axis in mice

2019 ◽  
Vol 2 (1) ◽  
Author(s):  
Sung-Moo Park ◽  
Tatsushi Omatsu ◽  
Yun Zhao ◽  
Naohiro Yoshida ◽  
Pankaj Shah ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Fate ◽  
Bacterial Species ◽  
Innate Immune ◽  
Disease Mechanisms ◽  
Signaling Axis ◽  
Cell Cytosol ◽  
Microbial C ◽  
Microbial Dna ◽  
Host Cell Cytosol

AbstractThe innate immune response following infection with entero-invasive bacterial species is triggered upon release of cyclic di-guanylate monophosphate (c-di-GMP) into the host cell cytosol. Bacterial c-di-GMP activates the intracellular Sensor Stimulator of Interferon Genes (STING), encoded by Tmem173 in mice. Here we identify Interferon Regulatory Factor (IRF) 1 as a critical effector of STING-mediated microbial DNA sensing that is responsible for TH17 cell generation in the mucosal immune system. We find that STING activation induces IRF1-dependent transcriptional programs in dendritic cells (DCs) that define T cell fate determination, including induction of Gasdermin D, IL-1 family member cytokines, and enzymes for eicosanoid synthesis. Our results show that IRF1-dependent transcriptional programs in DCs are a prerequisite for antigen-specific TH17 subspecification in response to microbial c-di-GMP and Salmonella typhimurium infection. Our identification of a STING-IRF1 signaling axis for adaptive host defense control will aid further understanding of infectious disease mechanisms.

scholarly journals Intramolecular Dimerization Is Required for the Chlamydia-Secreted Protease CPAF To Degrade Host Transcriptional Factors

2004 ◽  
Vol 72 (7) ◽  
pp. 3869-3875 ◽  
Author(s):  
Feng Dong ◽  
Jyotika Sharma ◽  
Yanming Xiao ◽  
Youmin Zhong ◽  
Guangming Zhong
Keyword(s):  
Transcription Factors ◽  
Host Cell ◽  
Proteolytic Activity ◽  
Bacterial Species ◽  
Antigen Expression ◽  
Obligate Intracellular ◽  
Histocompatibility Complex ◽  
Activity Factor ◽  
Cell Cytosol ◽  
Host Cell Cytosol

ABSTRACT We previously identified a chlamydial protein designated CPAF (chlamydia protease/proteasome-like activity factor) that is secreted into host cell cytosol for degrading host transcription factors required for major histocompatibility complex antigen expression. Here we report that CPAF, synthesized as a 70-kDa proprotein, is processed into two fragments (designated CPAFn and CPAFc) to form intramolecular dimers that are much more stable than the naïve CPAF. Precipitation with antibodies that recognized CPAF dimers removed the proteolytic activity responsible for degrading host transcription factor RFX5 from chlamydia-infected host cell cytosol, while precipitation with antibodies that recognized free CPAF fragments alone did not remove this activity. Separation of CPAFn from CPAFc resulted in a loss of proteolytic activity. Furthermore, neither expressed full-length CPAF that was not processed nor coexpressed CPAFn and CPAFc fragments that failed to form dimers degraded RFX5. These observations demonstrate that intramolecular dimerization is required for CPAF to degrade host transcription factors, a strategy that is utilized by an obligate intracellular bacterial species to evade host defenses.

scholarly journals Neutrophils in Tuberculosis: Cell Biology, Cellular Networking and Multitasking in Host Defense

2021 ◽  
Vol 22 (9) ◽  
pp. 4801
Author(s):  
Rachana R. Borkute ◽  
Sören Woelke ◽  
Gang Pei ◽  
Anca Dorhoi
Keyword(s):  
Cell Fate ◽  
Cell Biology ◽  
Pulmonary Infection ◽  
Innate Immune ◽  
Innate Immune Cells ◽  
Biological Processes ◽  
Short Lifespan ◽  
Disease Outcomes ◽  
Disease Mechanisms ◽  
Technical Advances

Neutrophils readily infiltrate infection foci, phagocytose and usually destroy microbes. In tuberculosis (TB), a chronic pulmonary infection caused by Mycobacterium tuberculosis (Mtb), neutrophils harbor bacilli, are abundant in tissue lesions, and their abundances in blood correlate with poor disease outcomes in patients. The biology of these innate immune cells in TB is complex. Neutrophils have been assigned host-beneficial as well as deleterious roles. The short lifespan of neutrophils purified from blood poses challenges to cell biology studies, leaving intracellular biological processes and the precise consequences of Mtb–neutrophil interactions ill-defined. The phenotypic heterogeneity of neutrophils, and their propensity to engage in cellular cross-talk and to exert various functions during homeostasis and disease, have recently been reported, and such observations are newly emerging in TB. Here, we review the interactions of neutrophils with Mtb, including subcellular events and cell fate upon infection, and summarize the cross-talks between neutrophils and lung-residing and -recruited cells. We highlight the roles of neutrophils in TB pathophysiology, discussing recent findings from distinct models of pulmonary TB, and emphasize technical advances that could facilitate the discovery of novel neutrophil-related disease mechanisms and enrich our knowledge of TB pathogenesis.

scholarly journals Deubiquitinase enzyme STAMBP plays a broad role in both Toll-like and Nod-like receptor mediated inflammation

2020 ◽  
Vol 18 ◽  
pp. 205873922096084
Author(s):  
Lahiru Gangoda ◽  
Thanh Kha Phan ◽  
Sushma Anand ◽  
Mark D Hulett ◽  
Suresh Mathivanan
Keyword(s):  
Molecular Mechanisms ◽  
Inflammatory Responses ◽  
Critical Role ◽  
Innate Immune ◽  
Microbial Infection ◽  
Inflammatory Stimuli ◽  
Cell Cytosol ◽  
Host Cell Cytosol ◽  
Broad Role

The innate immune system in mammals include pattern recognition receptors (PRRs), which initiate immune responses to microbial infection via several mechanisms. These PRRs include cell surface Toll-like receptors (TLRs) and cytosolic Nod-like receptors (NLRs) that recognizes extracellular and intracellular danger signals respectively. NLRs are poised to respond specifically to pathogens that access the host cell cytosol. The molecular mechanisms by which NLRs are activated to form inflammasomes and exert downstream inflammatory responses remain poorly understood. Additionally, very little is known about the regulation of cytosolic pathogen sensory NLR family members, except for NLRP3. Recently a deubiquitinase known as STAMBP has been implicated as a regulator of NLRP7 inflammasome assembly. We have investigated the role of STAMBP in regulation of other inflammasome components and its broader role in inflammation using genetic removal of STAMBP protein from cells using CRISPR/Cas9 gene editing and challenging these gene edited cells with an inflammatory stimuli. Our study demonstrated that STAMBP has a critical role in inflammation both in the context of NLR pathway, through NLRP stabilization and TLR pathway, through JNK signaling and downstream cytokine production. The findings indicate that STAMBP has a wider role in inflammation than previously thought to be the case.

scholarly journals Innate Immune Cells and Their Contribution to T-Cell-Based Immunotherapy

2020 ◽  
Vol 21 (12) ◽  
pp. 4441 ◽  
Author(s):  
Pierpaolo Ginefra ◽  
Girieca Lorusso ◽  
Nicola Vannini
Keyword(s):  
T Cells ◽  
T Cell ◽  
Cancer Immunotherapy ◽  
Cancer Patients ◽  
Immune Cells ◽  
Adoptive Cell Therapy ◽  
Adaptive Immune Response ◽  
Immune Checkpoint Blockade ◽  
Innate Immune ◽  
Innate Immune Cells

In recent years, immunotherapy has become the most promising therapy for a variety of cancer types. The development of immune checkpoint blockade (ICB) therapies, the adoptive transfer of tumor-specific T cells (adoptive cell therapy (ACT)) or the generation of T cells engineered with chimeric antigen receptors (CAR) have been successfully applied to elicit durable immunological responses in cancer patients. However, not all the patients respond to these therapies, leaving a consistent gap of therapeutic improvement that still needs to be filled. The innate immune components of the tumor microenvironment play a pivotal role in the activation and modulation of the adaptive immune response against the tumor. Indeed, several efforts are made to develop strategies aimed to harness innate immune cells in the context of cancer immunotherapy. In this review, we describe the contribution of innate immune cells in T-cell-based cancer immunotherapy and the therapeutic approaches implemented to broaden the efficacy of these therapies in cancer patients.

scholarly journals The microbiota is dispensable for the early stages of peripheral regulatory T cell induction within mesenteric lymph nodes

2021 ◽  
Author(s):  
Carolin Wiechers ◽  
Mangge Zou ◽  
Eric Galvez ◽  
Michael Beckstette ◽  
Maria Ebel ◽  
...  
Keyword(s):  
T Cell ◽  
Lymph Nodes ◽  
Regulatory T Cell ◽  
De Novo ◽  
Bacterial Species ◽  
Short Chain Fatty Acids ◽  
Mesenteric Lymph Nodes ◽  
Direct Role ◽  
Early Stages ◽  
Mesenteric Lymph

AbstractIntestinal Foxp3+ regulatory T cell (Treg) subsets are crucial players in tolerance to microbiota-derived and food-borne antigens, and compelling evidence suggests that the intestinal microbiota modulates their generation, functional specialization, and maintenance. Selected bacterial species and microbiota-derived metabolites, such as short-chain fatty acids (SCFAs), have been reported to promote Treg homeostasis in the intestinal lamina propria. Furthermore, gut-draining mesenteric lymph nodes (mLNs) are particularly efficient sites for the generation of peripherally induced Tregs (pTregs). Despite this knowledge, the direct role of the microbiota and their metabolites in the early stages of pTreg induction within mLNs is not fully elucidated. Here, using an adoptive transfer-based pTreg induction system, we demonstrate that neither transfer of a dysbiotic microbiota nor dietary SCFA supplementation modulated the pTreg induction capacity of mLNs. Even mice housed under germ-free (GF) conditions displayed equivalent pTreg induction within mLNs. Further molecular characterization of these de novo induced pTregs from mLNs by dissection of their transcriptomes and accessible chromatin regions revealed that the microbiota indeed has a limited impact and does not contribute to the initialization of the Treg-specific epigenetic landscape. Overall, our data suggest that the microbiota is dispensable for the early stages of pTreg induction within mLNs.

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