Sensing of mycobacterial arabinogalactan by galectin‐9 exacerbates mycobacterial infection

Wu, Xiangyang; Wu, Yong; Zheng, Ruijuan; Tang, Fengyan; Qin, Lianhua; Lai, Detian; Zhang, Lu; Chen, Lingming; Yan, Bo; Yang, Hua; Wang, Yang; Li, Feifei; Zhang, Jinyu; Wang, Fei; Wang, Lin; Cao, Yinhe; Ma, Mingtong; Z, Liu; Chen, Jianxia; Huang, Xiaochen; Wang, Jie; Jin, Ruiliang; Wang, Peng; Sun, Qin; Wang, Sha; Lyu, Liang-Dong; Moura-Alves, Pedro; Dorhoi, Anca; Pei, Gang; Zhang, Peng; Chen, Jiayu; Gao, Shaorong; Randow, Felix; Zeng, Gucheng; Chen, Chang; Ye, Xin‐Shan; Kaufmann, Stefan H. E.; Liu, Haipeng; Ge, Baoxue

doi:10.15252/embr.202051678

Cited by 16 publications

(29 citation statements)

References 123 publications

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“…Wasabi and Tdtomato fluorescently labeled M strain M. marinum (ATCC BAA-535) were generated by Dr. Ramakrishnan’s group ( 40 ). Zebrafish embryo infections were performed by microinjection of M. marinum via the duct of Cuvier unless otherwise indicated ( 46 ). For live imaging and Sudan Black (SB) staining, infections were by subcutaneous injection ( 47 ).…”

Section: Methodsmentioning

confidence: 99%

Negative Regulator Nlrc3-like Maintain the Balanced Innate Immune Response During Mycobacterial Infection in Zebrafish

et al. 2022

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The NOD-like receptors (NLRs) have been shown to be involved in infection and autoinflammatory disease. Previously, we identified a zebrafish NLR, nlrc3-like, required for macrophage homeostasis in the brain under physiological conditions. Here, we found that a deficiency of nlrc3-like leads to decreased bacterial burden at a very early stage of Mycobacterium marinum infection, along with increased production of pro-inflammatory cytokines, such as il-1β and tnf-α. Interestingly, myeloid-lineage specific overexpression of nlrc3-like achieved the opposite effects, suggesting that the impact of nlrc3-like on the host anti-mycobacterial response is mainly due to its expression in the innate immune system. Fluorescence-activated cell sorting (FACS) and subsequent gene expression analysis demonstrated that inflammasome activation-related genes were upregulated in the infected macrophages of nlrc3-like deficient embryos. By disrupting asc, encoding apoptosis-associated speck-like protein containing a CARD, a key component for inflammasome activation, the bacterial burden increased in asc and nlrc3-like double deficient embryos compared with nlrc3-like single deficient embryos, implying the involvement of inflammasome activation in infection control. We also found extensive neutrophil infiltration in the nlrc3-like deficient larvae during infection, which was associated with comparable bacterial burden but increased tissue damage and death at a later stage that could be alleviated by administration of dexamethasone. Our findings uncovered an important role of nlrc3-like in the negative regulation of macrophage inflammasome activation and neutrophil infiltration during mycobacterial infection. This highlights the importance of a balanced innate immune response during mycobacterial infection and provides a potential molecular basis to explain how anti-inflammatory drugs can improve treatment outcomes in TB patients whose infection is accompanied by a hyperinflammatory response.

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Section: Methodsmentioning

confidence: 99%

Negative Regulator Nlrc3-like Maintain the Balanced Innate Immune Response During Mycobacterial Infection in Zebrafish

et al. 2022

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“…In the host immune system, pioneer macrophages phagocytize Mycobacterium and trigger an antimicrobial response by producing pro-inflammatory cytokines such as TNF-a, IL-6, and reactive oxygen species (49), after which the process of killing bacilli is initiated (61). When comparing the transcriptome data in this study with those of another study, in which macrophages were exposed to a pure AG compound (28), unbiased DEG enrichment analysis highlighted the overlapping pathways in cell growth and death, oxidative phosphorylation, and signal transduction. Although more subsequent validations are needed, we assume that the elevated oxidative metabolism in macrophages infected by knock-down mutants contributes to the impaired intracellular proliferation of M. marinum.…”

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confidence: 94%

“…On the other hand, AG isolated from M.tb was shown to inhibit the immune responses of lymphocytes in humans and guinea pigs (25)(26)(27). Chemically synthetic AG was proven to bind to the galactoside-binding protein galectin9, triggering the transforming-activated factor kinase 1/extracellular receptor kinase/matrix metalloproteins (MMPs) signaling axis and promoting the expression of MMPs, leading to aggravated lung damage and M.tb infection (28,29).…”

Section: Introductionmentioning

confidence: 99%

“…An altered macrophage cell cycle also contributed to the reduced virulence and quick elimination of the EmbA_KD strain in vivo/vitro (63) as proven by CCK8 assay and CFU counting results. Though chemically synthetic AG was proven to bind to galectin9 (28), the recognition mechanism of native AG in the Mycobacterium is not yet fully understood, not to mention when narrowing down the galactose backbone and arabinose branches in AG separately. Due to finding that the cell wall was recognized as a whole, demystifying AG effects on the virulence in living bacteria could help to reveal the pathogenic mechanisms of AG in real life.…”

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confidence: 99%

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Arabinogalactan enhances Mycobacterium marinum virulence by suppressing host innate immune responses

Liu

Wang

et al. 2022

Front. Immunol.

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Arabinogalactan (AG) participates in forming the cell wall core of mycobacteria, a structure known as the mAGP complex. Few studies have reported the virulence of inartificial AG or its interaction with the host immune system. Using clustered regularly interspaced short palindromic repeats interference gene editing technology, conditional Mycobacterium marinum mutants were constructed with a low expression of embA or glfT2 (EmbA_KD or GlfT2_KD), which are separately involved in the biosynthesis of AG arabinose and galactose domains. High-performance gel permeation chromatography and high-performance liquid chromatography assays confirmed that the EmbA_KD strain showed a remarkable decrease in AG content with fragmentary arabinose chains, and the GlfT2_KD strain displayed less reduction in content with cut-down galactose chains. Based on transmission and scanning electron microscopy observations, the cell walls of the two mutants were found to be dramatically thickened, and the boundaries of different layers were more distinct. Phenotypes including the over-secretion of extracellular substances and enhanced spreading motility with a concomitant decreased resistance to ethambutol appeared in the EmbA_KD strain. The EmbA_KD and GlfT2_KD strains displayed limited intracellular proliferation after infecting murine J774A.1 macrophages. The disease progression infected with the EmbA_KD or GlfT2_KD strain significantly slowed down in zebrafish/murine tail infection models as well. Through transcriptome profiling, macrophages infected by EmbA_KD/GlfT2_KD strains showed enhanced oxidative metabolism. The cell survival measured using the CCK8 assay of macrophages exposed to the EmbA_KD strain was upregulated and consistent with the pathway enrichment analysis of differentially expressed genes in terms of cell cycle/apoptosis. The overexpression of C/EBPβ and the increasing secretion of proinflammatory cytokines were validated in the macrophages infected by the EmbA_KD mutant. In conclusion, the AG of Mycobacterium appears to restrain the host innate immune responses to enhance intracellular proliferation by interfering with oxidative metabolism and causing macrophage death. The arabinose chains of AG influence the Mycobacterium virulence and pathogenicity to a greater extent.

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“…Additionally, some galectins can interact directly with bacteria and their cell wall glycans [22–25]. In particular, Gal-9 was recently shown to bind Mtb via recognition of the cell wall polysaccharide, arabinogalactan [25]. During infection, galectin recruitment and signaling promote antibacterial autophagy and bacterial growth restriction [9,15,20], proinflammatory signaling [25], and recruitment of antibacterial guanylate-binding proteins [21].…”

Section: Introductionmentioning

confidence: 99%

Deficiency in Galectin-3, -8, and -9 impairs immunity to chronicMycobacterium tuberculosisinfection but not acute infection with multiple intracellular pathogens

Morrison

Craft

Rivera‐Lugo

et al. 2022

Preprint

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Macrophages employ an array of pattern recognition receptors to detect and eliminate intracellular pathogens that access the cytosol. The cytosolic carbohydrate sensors Galectin-3, -8, and -9 (Gal-3, Gal-8, and Gal-9) recognize damaged pathogen-containing phagosomes, and Gal-3 and Gal-8 are reported to restrict bacterial growth via autophagy in cultured cells. However, the contribution of these galectins to host resistance during bacterial infection remains unclear. We found that Gal-9 binds directly toMycobacterium tuberculosis(Mtb) andSalmonella entericaserovar Typhimurium (Stm) and localizes toMtbin macrophages. To determine the combined contribution of membrane damage-sensing galectins to immunity in vivo, we generated Gal-3, -8, and -9 triple knockout (TKO) mice.Mtbinfection of primary macrophages from TKO mice resulted in defective lysosomal trafficking but normal bacterial replication. Surprisingly, these mice had no discernable defect in resistance to acute infection withMtb,StmorListeria monocytogenes, and had only modest impairments in bacterial growth restriction and CD4 T cell activation during chronicMtbinfection. Collectively, these findings indicate that while Gal-3, -8, and -9 respond to an array of intracellular pathogens, together these membrane damage-sensing galectins play a limited role in host resistance to bacterial infection.

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Sensing of mycobacterial arabinogalactan by galectin‐9 exacerbates mycobacterial infection

Cited by 16 publications

References 123 publications

Negative Regulator Nlrc3-like Maintain the Balanced Innate Immune Response During Mycobacterial Infection in Zebrafish

Negative Regulator Nlrc3-like Maintain the Balanced Innate Immune Response During Mycobacterial Infection in Zebrafish

Arabinogalactan enhances Mycobacterium marinum virulence by suppressing host innate immune responses

Deficiency in Galectin-3, -8, and -9 impairs immunity to chronicMycobacterium tuberculosisinfection but not acute infection with multiple intracellular pathogens

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