Asrar Ahmad Malik, Mohd Shariq, Javaid Ahmad Sheikh, Udyeshita Jaiswal, Haleema Fayaz, Gauri Shrivastava, Nasreen Z Ehtesham, Seyed E Hasnain
{"title":"Mechanisms of immune evasion by <i>Mycobacterium tuberculosis</i>: the impact of T7SS and cell wall lipids on host defenses.","authors":"Asrar Ahmad Malik, Mohd Shariq, Javaid Ahmad Sheikh, Udyeshita Jaiswal, Haleema Fayaz, Gauri Shrivastava, Nasreen Z Ehtesham, Seyed E Hasnain","doi":"10.1080/10409238.2024.2411264","DOIUrl":null,"url":null,"abstract":"<p><p><i>Mycobacterium tuberculosis</i> (<i>M. tb</i>) is one of the most successful human pathogens, causing a severe and widespread infectious disease. The frequent emergence of multidrug-resistant (MDR) strains has exacerbated this public health crisis, particularly in underdeveloped regions. <i>M. tb</i> employs a sophisticated array of virulence factors to subvert host immune responses, both innate and adaptive. It utilizes the early secretory antigenic target (ESAT6) secretion system 1 (ESX-1) type VII secretion system (T7SS) and cell wall lipids to disrupt phagosomal integrity, inhibiting phagosome maturation, and fusion with lysosomes. Although host cells activate mechanisms such as ubiquitin (Ub), Ub-ligase, and cyclic GMP-AMP synthase-stimulator of interferon genes 1 (CGAS-STING1)-mediated autophagy to inhibit <i>M. tb</i> survival within macrophages, the pathogen counteracts these defenses with its own virulence factors, thereby inhibiting autophagy and dampening host-directed responses. T7SSs are critical for transporting proteins across the complex mycobacterial cell envelope, performing essential functions, including metabolite uptake, immune evasion, and conjugation. T7SS substrates fall into two main families: ESAT-6 system proteins, which are found in both Firmicutes and Actinobacteria, and proline-glutamic acid (PE) and proline-proline-glutamic acid (PPE) proteins, which are unique to mycobacteria. Recent studies have highlighted the significance of T7SSs in mycobacterial growth, virulence, and pathogenesis. Understanding the mechanisms governing T7SSs could pave the way for novel therapeutic strategies to combat mycobacterial diseases, including tuberculosis (TB).</p>","PeriodicalId":10794,"journal":{"name":"Critical Reviews in Biochemistry and Molecular Biology","volume":" ","pages":"310-336"},"PeriodicalIF":6.2000,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Critical Reviews in Biochemistry and Molecular Biology","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1080/10409238.2024.2411264","RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"2024/10/8 0:00:00","PubModel":"Epub","JCR":"Q1","JCRName":"BIOCHEMISTRY & MOLECULAR BIOLOGY","Score":null,"Total":0}
引用次数: 0
Abstract
Mycobacterium tuberculosis (M. tb) is one of the most successful human pathogens, causing a severe and widespread infectious disease. The frequent emergence of multidrug-resistant (MDR) strains has exacerbated this public health crisis, particularly in underdeveloped regions. M. tb employs a sophisticated array of virulence factors to subvert host immune responses, both innate and adaptive. It utilizes the early secretory antigenic target (ESAT6) secretion system 1 (ESX-1) type VII secretion system (T7SS) and cell wall lipids to disrupt phagosomal integrity, inhibiting phagosome maturation, and fusion with lysosomes. Although host cells activate mechanisms such as ubiquitin (Ub), Ub-ligase, and cyclic GMP-AMP synthase-stimulator of interferon genes 1 (CGAS-STING1)-mediated autophagy to inhibit M. tb survival within macrophages, the pathogen counteracts these defenses with its own virulence factors, thereby inhibiting autophagy and dampening host-directed responses. T7SSs are critical for transporting proteins across the complex mycobacterial cell envelope, performing essential functions, including metabolite uptake, immune evasion, and conjugation. T7SS substrates fall into two main families: ESAT-6 system proteins, which are found in both Firmicutes and Actinobacteria, and proline-glutamic acid (PE) and proline-proline-glutamic acid (PPE) proteins, which are unique to mycobacteria. Recent studies have highlighted the significance of T7SSs in mycobacterial growth, virulence, and pathogenesis. Understanding the mechanisms governing T7SSs could pave the way for novel therapeutic strategies to combat mycobacterial diseases, including tuberculosis (TB).
期刊介绍:
As the discipline of biochemistry and molecular biology have greatly advanced in the last quarter century, significant contributions have been made towards the advancement of general medicine, genetics, immunology, developmental biology, and biophysics. Investigators in a wide range of disciplines increasingly require an appreciation of the significance of current biochemical and molecular biology advances while, members of the biochemical and molecular biology community itself seek concise information on advances in areas remote from their own specialties.
Critical Reviews in Biochemistry and Molecular Biology believes that well-written review articles prove an effective device for the integration and meaningful comprehension of vast, often contradictory, literature. Review articles also provide an opportunity for creative scholarship by synthesizing known facts, fruitful hypotheses, and new concepts. Accordingly, Critical Reviews in Biochemistry and Molecular Biology publishes high-quality reviews that organize, evaluate, and present the current status of high-impact, current issues in the area of biochemistry and molecular biology.
Topics are selected on the advice of an advisory board of outstanding scientists, who also suggest authors of special competence. The topics chosen are sufficiently broad to interest a wide audience of readers, yet focused enough to be within the competence of a single author. Authors are chosen based on their activity in the field and their proven ability to produce a well-written publication.