Diet-induced dyslipidemia leads to enhanced IFN-g production by mycolic acid-specific T cells
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PROVIDER: PRJNA1162498 | ENA |
REPOSITORIES: ENA
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Project description:Diet-induced dyslipidemia, characterized by elevated plasma LDL-cholesterol levels, has been shown to affect host defense against infections, including Mycobacterium tuberculosis (Mtb). Although the impact of diet-induced dyslipidemia on conventional T cell functions is well studied, its influence on group 1-restricted T cells during Mtb infection is very limited. In this study, we generated a unique double-transgenic mouse model expressing human CD1 and mycolic acid (MA)-specific CD1b-restricted T cell receptor in a Rag-deficient and low-density lipoprotein receptor-deficient background to investigate how diet-induced dyslipidemia impacts functionality of MA-specific T cells and its effect on anti-Mtb immunity. While dyslipidemia augmented IFN-g production by MA-specific T cells, it paradoxically led to increased apoptosis and thus compromised their ability to restrict Mtb growth in vivo. These findings may elucidate the complex interplay between diet-induced dyslipidemia and lipid antigen-specific T-cell responses in the context of Mtb infection, offering insights that could inform potential therapeutic approaches addressing dyslipidemia-induced changes in T-cell functions.
2025-08-13 | GSE277479 | GEO
Project description:Mycobacterium tuberculosis has a complex cell envelope that is remodelled throughout infection to respond and survive the hostile and variable intracellular conditions within the host. Despite the importance of cell wall homeostasis in pathogenicity, little is known about the environmental signals and regulatory networks controlling cell wall biogenesis in mycobacteria. The mycolic acid desaturase regulator (MadR) is a transcriptional repressor responsible for regulation of the essential aerobic desaturases desA1 and desA2 that are differentially regulated throughout infection along with mycolate modification genes and thus, likely involved in mycolic acid remodelling. Here we generated a madR null mutant in M. smegmatis that exhibited traits of an impaired cell wall with increased permeability, susceptibility to rifampicin and cell surface disruption as a consequence of desA1/desA2 dysregulation. Analysis of mycolic acids revealed the presence of a highly desaturated mycolate in the null mutant that exists in relative trace amounts in the wildtype, but increases in abundance upon cell surface disruption as a result of relieved repression on the desA1/desA2 promoters. Transcriptomic profiling confirmed MadR as a cell surface disruption responsive regulator of desA1/desA2 and further implicating it in the control of bespoke β-oxidation pathways and transport evolutionarily diversified subnetworks associated with virulence. In vitro characterisation of MadR using electromobility shift assays and analysis of binding affinities is suggestive of a unique acyl-CoA pool sensing mechanism, whereby MadR is able to bind a range of acyl-CoA but MadR repression of desA1/desA2 promoters is only relieved upon binding of saturated acyl-CoA of chain length C16-C24. We propose this acyl effector ligand mechanism as distinct to other regulators of mycolic acid biosynthesis or fatty acid desaturases and places MadR as the key regulatory checkpoint that coordinates mycolic acid remodelling in response to host derived cell surface perturbation
2022-01-01 | GSE171759 | GEO
Project description:We constructed mycolic acid synthesis key gene pks13 mutant strain and analyzed its impacts on whole cell at gene expression level compared to the wild-type ATCC13869.
2018-01-01 | GSE104833 | GEO
Project description:Mycolic acid nanoparticle vaccination leads to lipid antigen persistence and unique differentiation of mycobacterial-specific T cells
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Project description:Mycobacterium tuberculosis (Mtb) infection elicits both protein and lipid antigen-specific T cell responses. However, the incorporation of lipid antigens into subunit vaccine strategies and formulations has been underexplored, and the properties of vaccine-induced Mtb lipid-specific memory T cells remained elusive. Mycolic acid (MA), a major lipid component of the Mtb cell wall, is presented by human CD1b molecules to T cells. MA-specific CD1b-restricted T cells have been detected in the blood and disease sites of Mtb-infected individuals, suggesting MA is a promising lipid antigen for incorporation into multicomponent subunit vaccines. In this study, we utilized bicontinuous nanospheres (BCN) to efficiently encapsulate MA and deliver it to MA-specific T cells both alone and in combination with an immunodominant Mtb protein antigen (Ag85B). Pulmonary delivery of MA-loaded BCN (MA-BCN) elicited MA-specific T cell responses in humanized CD1 transgenic mice. Simultaneous delivery of MA and Ag85B within BCN activated both MA- and Ag85B-specific T cells. Interestingly, pulmonary vaccination with MA-Ag85B-BCN led to the persistence of MA, but not Ag85B, within alveolar macrophages in the lung. Vaccination of MA-BCN through intravenous or subcutaneous route, or with attenuated Mtb likewise reproduced MA persistence. Moreover, MA-specific T cells in MA-BCN-vaccinated mice differentiated to have a T follicular helper-like phenotype. Overall, BCN platform allows for the dual encapsulation of lipid and protein antigen and leads to persistent lipid depots that could offer long-lasting immune response and protection.
2023-04-25 | GSE226075 | GEO
Project description:Monocyte exhaustion characterized by sustained pathogenic inflammatory and immune-suppressive features underlies the pathogenesis of sepsis induced by systemic polymicrobial infections. However, effective strategies in blocking monocyte exhaustion and restoring innate homeostasis are currently not available. In this study, we found that Methoxy-Mycolic Acid (M-MA), a branched mycolic acid derived from Mycobacterium Bovis Bacillus Calmette–Guérin (BCG), to be a potent agent in alleviating monocyte exhaustion and restoring immune homeostasis. Co-treatment of monocytes with M-MA can effectively block the expansion of exhausted Ly6Chi /CD38hi/PD-L1hi monocytes induced by repetitive LPS challenges, and restore the expression of immune-enhancing CD86 on co-treated monocytes. Functionally, M-MA treatment restored mitochondrial functions of exhausted monocytes and alleviated their suppressive activities on co-cultured T cells. Mechanistically, M-MA exerts its protective effects independent of cellular receptor TREM2, and relieves cellular stress signaling through blocking Src-STAT1 mediated pathogenic inflammatory polarization as well as reducing the production of compensatory immune suppressors TAX1BP1 and PLAC8. Our whole genome methylation analyses further revealed that M-MA can effectively erase methylation memory of exhausted monocytes, with validated restoration of plac8 methylation by M-MA. Together, our data reveal M-MA as a potent agent in restoring monocyte homeostasis with future therapeutic potential for the treatment of sepsis.
2023-12-19 | GSE242825 | GEO
Project description:IL-27 induces IFN/STAT1-dependent genes and leads to enhanced function of TIGIT+ HIVGag-specific T cells
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Project description:HIV-specific T cells have diminished effector function and fail to control/eliminate the virus. IL-27, a member of the IL-6/IL-12 cytokine superfamily has been shown to inhibit HIV replication however whether IL-27 can enhance function on HIV-specific T cell is largely unknown. Because of the important implication in cure strategies, in the present manuscript, we investigated the role of IL-27 signaling in human T cells by evaluating the global transcriptional changes and its impact in the function of HIV-specific T cells. We found that T cells from people living with HIV (PLWH), expressed higher levels of STAT1 that leads to enhanced STAT1 activation upon IL-27 stimulation. IL-27 induced transcriptional changes associated with IFN/STAT1-dependent pathways in CD4 and CD8 T cells. More importantly, IL-27 promoted cytokine secretion of TIGIT+HIVGag-specific T cell function by modulating the expression levels of T-bet. This new immunomodulatory property of IL-27 on HIV-specific T cell function suggests its potential therapeutic use in cure strategies.
2021-12-09 | GSE189997 | GEO
Project description:Intracellular pathogens including the apicomplexan and opportunistic parasite Toxoplasma gondii profoundly modify their host cells in order to establish infection. We have shown previously that intracellular T. gondii inhibit up-regulation of regulatory and effector functions in murine macrophages (MΦ) stimulated with interferon (IFN)-γ, which is the cytokine crucial for controlling the parasites’ replication. Using genome-wide transcriptome analysis we show herein that infection with T. gondii leads to global unresponsiveness of murine macrophages to IFN-γ. More than 61% and 89% of the transcripts, which were induced or repressed by IFN-γ in non-infected MΦ, respectively, were not altered after stimulation of T. gondii-infected cells with IFN-γ. These genes are involved in a variety of biological processes, which are mostly but not exclusively related to immune responses. Analyses of the underlying mechanisms revealed that IFN-γ-triggered nuclear translocation of STAT1 still occurred in Toxoplasma-infected MΦ. However, STAT1 bound aberrantly to oligonucleotides containing the IFN-γ-responsive gamma-activated site (GAS) consensus sequence. Conversely, IFN-γ did not induce formation of active GAS-STAT1 complexes in nuclear extracts from infected MΦ. Mass spectrometry of protein complexes bound to GAS oligonucleotides showed that T. gondii-infected MΦ are unable to recruit non-muscle actin to IFN-γ-responsive DNA sequences, which appeared to be independent of stimulation with IFN-γ and of STAT1 binding. IFN-γ-induced recruitment of BRG-1 and acetylation of core histones at the IFN-γ-regulated CIITA promoter IV, but not β-actin was diminished by >90% in Toxoplasma-infected MΦ as compared to non-infected control cells. Remarkably, treatment with histone deacetylase inhibitors restored the ability of infected macrophages to express the IFN-γ regulated genes H2-A/E and CIITA. Taken together, these results indicate that Toxoplasma-infected MΦ are unable to respond to IFN-γ due to disturbed chromatin remodelling, but can be rescued using histone deacetylase inhibitors. Comparison of 4 different RNA pools with a 2-Color-Loop Design including 10 microarrays: [1] T. gondii infected and IFN-gamma treated, [2] T. gondii infected and untreated, [3] Non-infected and IFN-gamma treated, and [4] Non-infected and untreated.
2012-01-25 | E-GEOD-28499 | biostudies-arrayexpress
Project description:Purpose: Treatment of midgestation chorionic villus explants with recombinant IFN-b leads to morphological changes including formation of syncitial knots. However, treatment of explants with IFN-l, which is constitutively expressed by syncytiotrophoblasts, is not sufficient to cause these same changes. To understand the different transcriptional changes induced by IFN-b and IFN-l and underlying cause of these morphological changes, we performed RNAsequencing after these different treatments. Methods: Chorionic villi of 18-21 gestation week placentas were dissected. Explants were cultured in DMEM F/12 with 1000 U recombinant IFN-b or 1000U recombinant IFN-l for 24 hours. RNA was then isolated from explants, and RNAsequencing was performed to assess transcriptional changes. Results/ Conclusions: IFN-b but not IFN-l induces interferon stimulated genes (ISGs) in mid gestation chorionic villus explants.
2017-12-31 | GSE104348 | GEO