{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,11]],"date-time":"2026-02-11T13:08:42Z","timestamp":1770815322986,"version":"3.50.1"},"reference-count":44,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2026,2,4]],"date-time":"2026-02-04T00:00:00Z","timestamp":1770163200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["82172317"],"award-info":[{"award-number":["82172317"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"the State Key Laboratory of Pathogen and Biosecurity","award":["SKLPBS2419"],"award-info":[{"award-number":["SKLPBS2419"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pathogens"],"abstract":"<jats:p>Bacillus anthracis displays susceptibility to penicillin despite harboring a \u03b2-lactamase gene, a phenotype governed by the anti-sigma factor RsiP. While RsiP represses \u03c3P-dependent \u03b2-lactamase expression, its broader roles in physiology and virulence remain unclear. This study aimed to define the global regulatory functions of RsiP beyond antibiotic resistance. Deletion of rsiP significantly upregulated the nprR gene, which is an important quorum-sensing (QS) system regulator and enhanced protease secretion. The \u0394rsiP mutant caused higher mortality in cellular and Galleria mellonella models and triggered elevated inflammatory cytokines (IL-6, IL-1\u03b2, TNF-\u03b1, MIP-2) in macrophages models. Surprisingly, in DBA\/2 mice models, \u0394rsiP was attenuated, with increased host survival and reduced bacterial loads. Competitive indices (CI) confirmed fitness defects in mice (spleen CI = 0.39; liver CI = 0.42). These defects were not due to altered oxidative stress tolerance but were attributed to impaired macrophage internalization of \u0394rsiP spores, reducing early colonization. Our findings indicate that RsiP not only modulates \u03b2-lactam resistance but also influences extracellular protease activity and host adaptation.<\/jats:p>","DOI":"10.3390\/pathogens15020166","type":"journal-article","created":{"date-parts":[[2026,2,4]],"date-time":"2026-02-04T09:02:01Z","timestamp":1770195721000},"page":"166","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["The Dual Role of RsiP in Regulating Virulence and Host Adaptation in Bacillus anthracis"],"prefix":"10.3390","volume":"15","author":[{"given":"Sicheng","family":"Shen","sequence":"first","affiliation":[{"name":"School of Medicine, Zhejiang University, Hangzhou 310063, China"},{"name":"National Key Laboratory of Advanced Biotechnology, Academy of Military Medical Sciences, Beijing 100071, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4654-409X","authenticated-orcid":false,"given":"Yufei","family":"Lyu","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Advanced Biotechnology, Academy of Military Medical Sciences, Beijing 100071, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiankai","family":"Liu","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Advanced Biotechnology, Academy of Military Medical Sciences, Beijing 100071, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yan","family":"Guo","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Advanced Biotechnology, Academy of Military Medical Sciences, Beijing 100071, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9975-8978","authenticated-orcid":false,"given":"Li","family":"Zhu","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Advanced Biotechnology, Academy of Military Medical Sciences, Beijing 100071, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7077-1992","authenticated-orcid":false,"given":"Dongshu","family":"Wang","sequence":"additional","affiliation":[{"name":"National Key Laboratory of Advanced Biotechnology, Academy of Military Medical Sciences, Beijing 100071, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8476-4320","authenticated-orcid":false,"given":"Hengliang","family":"Wang","sequence":"additional","affiliation":[{"name":"School of Medicine, Zhejiang University, Hangzhou 310063, China"},{"name":"National Key Laboratory of Advanced Biotechnology, Academy of Military Medical Sciences, Beijing 100071, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,2,4]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"185","DOI":"10.1146\/annurev-micro-091014-104523","article-title":"Anthrax Pathogenesis","volume":"69","author":"Moayeri","year":"2015","journal-title":"Annu. Rev. Microbiol."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Goossens, P.L. (2024). Bacillus anthracis, \u201cla maladie du charbon\u201d, Toxins, and Institut Pasteur. Toxins, 16.","DOI":"10.3390\/toxins16020066"},{"key":"ref_3","doi-asserted-by":"crossref","unstructured":"Sangwan, N., Gangwal, A., Jain, P., Langtso, C., Srivastava, S., Dhawan, U., Baweja, R., and Singh, Y. (2025). Anthrax: Transmission, Pathogenesis, Prevention and Treatment. Toxins, 17.","DOI":"10.3390\/toxins17020056"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1048","DOI":"10.3201\/eid0810.020329","article-title":"Epidemiologic investigations of bioterrorism-related anthrax, New Jersey, 2001","volume":"8","author":"Greene","year":"2002","journal-title":"Emerg. Infect. Dis."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Mondange, L., Tessier, \u00c9., and Tournier, J.N. (2022). Pathogenic Bacilli as an Emerging Biothreat?. Pathogens, 11.","DOI":"10.3390\/pathogens11101186"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"1019","DOI":"10.3201\/eid0810.020353","article-title":"Investigation of bioterrorism-related anthrax, United States, 2001: Epidemiologic findings","volume":"8","author":"Jernigan","year":"2002","journal-title":"Emerg. Infect. Dis."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"104054","DOI":"10.1016\/j.resmic.2023.104054","article-title":"Early expression of capsule during Bacillus anthracis germination","volume":"174","author":"Fastenackels","year":"2023","journal-title":"Res. Microbiol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"e0020022","DOI":"10.1128\/jb.00200-22","article-title":"Structural and Functional Analysis of Toxin and Small RNA Gene Promoter Regions in Bacillus anthracis","volume":"204","author":"Pomerantsev","year":"2022","journal-title":"J. Bacteriol."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"6509","DOI":"10.1128\/JB.181.20.6509-6515.1999","article-title":"Sequence and organization of pXO1, the large Bacillus anthracis plasmid harboring the anthrax toxin genes","volume":"181","author":"Okinaka","year":"1999","journal-title":"J. Bacteriol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"722","DOI":"10.1128\/jb.171.2.722-730.1989","article-title":"Molecular characterization and protein analysis of the cap region, which is essential for encapsulation in Bacillus anthracis","volume":"171","author":"Makino","year":"1989","journal-title":"J. Bacteriol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"5134","DOI":"10.1128\/JB.00422-09","article-title":"A new minimal replicon of Bacillus anthracis plasmid pXO1","volume":"191","author":"Pomerantsev","year":"2009","journal-title":"J. Bacteriol."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"2717","DOI":"10.1128\/JB.186.9.2717-2723.2004","article-title":"Isolation of a minireplicon of the virulence plasmid pXO2 of Bacillus anthracis and characterization of the plasmid-encoded RepS replication protein","volume":"186","author":"Tinsley","year":"2004","journal-title":"J. Bacteriol."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Wang, Y., Jiang, N., Wang, B., Tao, H., Zhang, X., Guan, Q., and Liu, C. (2020). Integrated Transcriptomic and Proteomic Analyses Reveal the Role of NprR in Bacillus anthracis Extracellular Protease Expression Regulation and Oxidative Stress Responses. Front. Microbiol., 11.","DOI":"10.3389\/fmicb.2020.590851"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"111381","DOI":"10.1016\/j.ijfoodmicro.2025.111381","article-title":"The mechanism of curcumin inhibits Bacillus cereus protease production by modulating the LuxS\/AI-2 system","volume":"442","author":"Wang","year":"2025","journal-title":"Int. J. Food Microbiol."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"143","DOI":"10.1007\/s11274-025-04353-3","article-title":"Pleiotropic functions of CpdB in Bacillus anthracis","volume":"41","author":"Yao","year":"2025","journal-title":"World J. Microbiol. Biotechnol."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"6683","DOI":"10.1128\/JB.00691-09","article-title":"An extracytoplasmic function sigma factor controls beta-lactamase gene expression in Bacillus anthracis and other Bacillus cereus group species","volume":"191","author":"Ross","year":"2009","journal-title":"J. Bacteriol."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"122","DOI":"10.1016\/j.mib.2016.02.002","article-title":"Bacillus subtilis extracytoplasmic function (ECF) sigma factors and defense of the cell envelope","volume":"30","author":"Helmann","year":"2016","journal-title":"Curr. Opin. Microbiol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"eadg4846","DOI":"10.1126\/sciadv.adg4846","article-title":"Essential autoproteolysis of bacterial anti-\u03c3 factor RsgI for transmembrane signal transduction","volume":"9","author":"Chen","year":"2023","journal-title":"Sci. Adv."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Wettstadt, S., Marcos-Torres, F.J., Otero-Asman, J.R., Garc\u00eda-Puente, A., Ortega, \u00c1., and Llamas, M.A. (2024). Bacterial TonB-dependent transducers interact with the anti-\u03c3 factor in absence of the inducing signal protecting it from proteolysis. PLoS Biol., 22.","DOI":"10.1371\/journal.pbio.3002920"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"1245","DOI":"10.3390\/biom5031245","article-title":"Bacterial Sigma Factors and Anti-Sigma Factors: Structure, Function and Distribution","volume":"5","author":"Paget","year":"2015","journal-title":"Biomolecules"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"e00179-21","DOI":"10.1128\/mBio.00179-21","article-title":"The Penicillin-Binding Protein PbpP Is a Sensor of \u03b2-Lactams and Is Required for Activation of the Extracytoplasmic Function \u03c3 Factor \u03c3(P) in Bacillus thuringiensis","volume":"12","author":"Nauta","year":"2021","journal-title":"mBio"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"e03707-21","DOI":"10.1128\/mbio.03707-21","article-title":"Signal Peptidase-Mediated Cleavage of the Anti-\u03c3 Factor RsiP at Site 1 Controls \u03c3(P) Activation and \u03b2-Lactam Resistance in Bacillus thuringiensis","volume":"13","author":"Nauta","year":"2021","journal-title":"mBio"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"e00154-18","DOI":"10.1128\/msystems.00154-18","article-title":"Analysis of Whole-Genome Sequences for the Prediction of Penicillin Resistance and \u03b2-Lactamase Activity in Bacillus anthracis","volume":"3","author":"Gargis","year":"2018","journal-title":"mSystems"},{"key":"ref_24","doi-asserted-by":"crossref","unstructured":"Wang, Y., Wang, D., Wang, X., Tao, H., Feng, E., Zhu, L., Pan, C., Wang, B., Liu, C., and Liu, X. (2019). Highly Efficient Genome Engineering in Bacillus anthracis and Bacillus cereus Using the CRISPR\/Cas9 System. Front. Microbiol., 10.","DOI":"10.3389\/fmicb.2019.01932"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"210","DOI":"10.1016\/j.mimet.2011.05.006","article-title":"Reference genes for quantitative, reverse-transcription PCR in Bacillus cereus group strains throughout the bacterial life cycle","volume":"86","author":"Reiter","year":"2011","journal-title":"J. Microbiol. Methods"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"210","DOI":"10.3390\/pathogens4020210","article-title":"Pathogenicity of Isolates of Serratia Marcescens towards Larvae of the Scarab Phyllophaga Blanchardi (Coleoptera)","volume":"4","author":"Villalobos","year":"2015","journal-title":"Pathogens"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1700","DOI":"10.1111\/jam.14226","article-title":"A disclosure gel for visual detection of live Bacillus anthracis spores","volume":"126","author":"Robinson","year":"2019","journal-title":"J. Appl. Microbiol."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Norris, M.H., Kirpich, A., Bluhm, A.P., Zincke, D., Hadfield, T., Ponciano, J.M., and Blackburn, J.K. (2020). Convergent evolution of diverse Bacillus anthracis outbreak strains toward altered surface oligosaccharides that modulate anthrax pathogenesis. PLoS Biol., 18.","DOI":"10.1371\/journal.pbio.3001052"},{"key":"ref_29","doi-asserted-by":"crossref","unstructured":"Jiranantasak, T., Bluhm, A.P., Chabot, D.J., Friedlander, A., Bowen, R., McMillan, I.A., Hadfield, T.L., Hartwig, A., Blackburn, J.K., and Norris, M.H. (2024). Toxin and capsule production by Bacillus cereus biovar anthracis influence pathogenicity in macrophages and animal models. PLoS Negl. Trop. Dis., 18.","DOI":"10.1371\/journal.pntd.0012779"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"lxad040","DOI":"10.1093\/jambio\/lxad040","article-title":"Expression of the 2Duf protein in wild-type Bacillus subtilis spores stabilizes inner membrane proteins and increases spore resistance to wet heat and hydrogen peroxide","volume":"134","author":"Korza","year":"2023","journal-title":"J. Appl. Microbiol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"676","DOI":"10.1128\/AEM.01715-07","article-title":"Identification by quantitative carrier test of surrogate spore-forming bacteria to assess sporicidal chemicals for use against Bacillus anthracis","volume":"74","author":"Majcher","year":"2008","journal-title":"Appl. Environ. Microbiol."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"112024","DOI":"10.1016\/j.jep.2019.112024","article-title":"Anti-inflammatory activity of Protium spruceanum (Benth.) Engler is associated to immunomodulation and enzymes inhibition","volume":"241","author":"Amparo","year":"2019","journal-title":"J. Ethnopharmacol."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"e01122-18","DOI":"10.1128\/MRA.01122-18","article-title":"Genome Sequences of Penicillin-Resistant Bacillus anthracis Strains","volume":"8","author":"Gargis","year":"2019","journal-title":"Microbiol. Resour. Announc."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"3869","DOI":"10.1021\/acs.est.4c10304","article-title":"Impact of Canadian Wildfire-Emitted Particulate Matter on THP-1 Lung Macrophage Health and Function","volume":"59","author":"Bazina","year":"2025","journal-title":"Environ. Sci. Technol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"1069","DOI":"10.1007\/s00253-011-3775-4","article-title":"Evolution and some functions of the NprR-NprRB quorum-sensing system in the Bacillus cereus group","volume":"94","author":"Rocha","year":"2012","journal-title":"Appl. Microbiol. Biotechnol."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"573","DOI":"10.15698\/mic2016.11.542","article-title":"NprR, a moonlighting quorum sensor shifting from a phosphatase activity to a transcriptional activator","volume":"3","author":"Perchat","year":"2016","journal-title":"Microb. Cell"},{"key":"ref_37","first-page":"31408","article-title":"Secreted neutral metalloproteases of Bacillus anthracis as candidate pathogenic factors","volume":"281","author":"Chung","year":"2006","journal-title":"J. Biol. Chem."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"424","DOI":"10.1128\/JB.00690-13","article-title":"Modulation of the Bacillus anthracis secretome by the immune inhibitor A1 protease","volume":"196","author":"Pflughoeft","year":"2014","journal-title":"J. Bacteriol."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"3069","DOI":"10.1128\/IAI.72.5.3069-3072.2004","article-title":"Macrophages release tumor necrosis factor alpha and interleukin-12 in response to intracellular Bacillus anthracis spores","volume":"72","author":"Pickering","year":"2004","journal-title":"Infect. Immun."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1111\/imr.12607","article-title":"The NLRC4 Inflammasome","volume":"281","author":"Duncan","year":"2018","journal-title":"Immunol. Rev."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"29811","DOI":"10.1073\/pnas.2002747117","article-title":"Type 1 interferon-dependent repression of NLRC4 and iPLA2 licenses down-regulation of Salmonella flagellin inside macrophages","volume":"117","author":"Akhade","year":"2020","journal-title":"Proc. Natl. Acad. Sci. USA"},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Thelaus, J., Lundmark, E., Lindgren, P., Sj\u00f6din, A., and Forsman, M. (2018). Galleria mellonella Reveals Niche Differences Between Highly Pathogenic and Closely Related Strains of Francisella spp.. Front. Cell Infect. Microbiol., 8.","DOI":"10.3389\/fcimb.2018.00188"},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"396","DOI":"10.1007\/s12257-014-0720-2","article-title":"A novel RpoD complementary system to stabilize plasmid and protein production in recombinant Escherichia coli","volume":"20","author":"Wu","year":"2015","journal-title":"Biotechnol. Bioprocess Eng."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"105566","DOI":"10.1016\/j.micpath.2022.105566","article-title":"The lip gene contributes to the virulence of Aeromonas veronii strain TH0426","volume":"167","author":"Wang","year":"2022","journal-title":"Microb. Pathog."}],"container-title":["Pathogens"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-0817\/15\/2\/166\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,2,11]],"date-time":"2026-02-11T05:22:53Z","timestamp":1770787373000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-0817\/15\/2\/166"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,2,4]]},"references-count":44,"journal-issue":{"issue":"2","published-online":{"date-parts":[[2026,2]]}},"alternative-id":["pathogens15020166"],"URL":"https:\/\/doi.org\/10.3390\/pathogens15020166","relation":{},"ISSN":["2076-0817"],"issn-type":[{"value":"2076-0817","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,2,4]]}}}