Close

Coxiella burnetii actively blocks IL-17-induced oxidative stress in macrophages

Tatiana M. Clemente, Leonardo Augusto, Rajendra K. Angara, Stacey D. Gilk

Posted on: 16 May 2023

Preprint posted on 15 March 2023

Coxiella burnetii, the pathogen that causes Q fever, demonstrates a strategy to effectively evade the immune system by inhibiting the IL-17-induced oxidative stress in macrophages. preLight Authors: Abigail Page & Farhana Afrin Mohona

Selected by UofA IMB565

preLight Authors: Abigail Page & Farhana Afrin Mohona

Background: Coxiella burnetii is a highly infectious bacterium responsible for Q fever, a potentially fatal disease that displays flu-like symptoms or progresses into life-threatening endocarditis. The treatment for this life-threatening condition involves a two-year regimen of antibiotic combination therapy as well as valve replacement surgery. Although there is a vaccine, it is not accepted world-wide. The insufficient understanding of the bacterium’s pathogenesis imposes restrictions on these therapeutic approaches, resulting in a high mortality rate. (1-7)

Coxiella burnetii is an obligate intracellular pathogen that primarily targets alveolar macrophages. During infection, the bacterium forms phagolysosome-like vacuoles called the Coxiella-Containing Vacuole (CCV) that support their replication. Within the vacuole, the pathogen uses the Dot/Icm type IVB secretion system (T4BSS) to deliver effector proteins to control host signaling pathways and cellular processes. This T4BSS pathway helps maintain the vacuole fusogenicity, prevents host cell death, and activates inflammasomes, which are important for the immune response. But how Coxiella burnetii evades the host innate immune response is unclear.

Previous work has shown that the bacterium restricts the host immune response by blocking the signaling pathway of interleukin-17 (IL-17), a proinflammatory cytokine that aids the production of antimicrobial peptides and chemokines, leading to pathogen eradication. In this preprint, the researchers found that T4BSS downregulates the expression of IL-17 target genes and blocks IL-17-induced chemokine secretion,  protecting the pathogen from the bactericidal effect of IL-17, and promoting survival. (8-18)

In this preprint, the authors illustrate that C. burnetii T4BSS prevents the transcription pathway activated by IL-17 and disrupts the IL17RA/ACT1/TRAF6 pathway. Additionally, if the IL17R-ACT1-TRAF6 pathway is disrupted, the bactericidal effect of IL-17 is reduced.  They also show that alveolar macrophage produce high numbers of reactive oxygen species in response to IL-17, but C. burnetii T4BSS proteins completely inhibit IL-17 oxidative stress, hinting that the bacterium downregulates IL-17 signaling to avoid being killed by reactive oxygen species. (Figure 1)

Figure 1: The binding of IL-17 to the IL-17RC/IL-17RA receptor recruits ACT1, which is necessary for all known IL-17 dependant pathways. TRAF6 coordinates with ACT1 to activate NFkB, vital for the induction of proinflammatory genes. The phosphorylation of ACT1 reduces the affinity of Act1 for TRAF6, promoting TRAF2/5 interactions. This binding activates MAP kinase signaling, leading to the transcription of chemokine mRNAs. [26]

 

Key Findings:

Coxiella burnetii blocks activation of IL-17 signaling in alveolar macrophages

The researchers theorized that the T4BSS effector proteins block the ACT1/TRAF6 pathway downstream of the IL-17 transcription receptor. To test this, they conducted a colorimetric enzyme assay using HEK-Blue IL-17 cells, which stably express the IL-17RA/IL-17RC heterodimer IL-17 receptor, ACT1, and secreted embryonic alkaline phosphatase (SEAP) reporter. The authors showed that IL-17 binding to the IL-17 receptor triggers the ACT1/TRAF6 signaling cascade to activate NFkB, inducing SEAP expression. They revealed a more than 70% decrease in SEAP expression in cells infected with WT C. burnetii compared to mock and T4BSS defective mutant (ΔdotA)-infected cells. This indicated that C. burnetii inhibits the activation of the ACT1- TRAF6/ NFkB and AP-1 pathways via T4BSS effector proteins.

C. burnetii T4BSS blocks IL-17 activation of NFkB p65, MAPK, and SAPK/JNK pathways

The researchers then sought to assess whether C. burnetii targets NFkB and/or Map kinases following stimulation by IL-17 by measuring the phosphorylation levels of NFkB p-65, JNK/SAPK, and p38 MAPK in infected mouse alveolar macrophages (MH-S cells). Observed through immunoblots, the researchers observed less activation of NFkB p-65 and p38 MAPK, and a drastic reduction in JNK/SAPK activation. These findings imply that during IL-17 stimulation, C. burnetii T4BSS targets the NFkB and MAP kinase pathways, namely JNK/SAPK, as a means of preventing the transcription of IL-17 downstream genes.

Disruption of the IL17R-ACT1-TRAF6 pathway neutralizes the IL-17 bactericidal effect

The researchers sought to find out whether the IL-17R-ACT1-TRAF6 pathway is required for the bactericidal effects of IL-17. While wild type macrophage stimulated with IL-17 were able to restrict C. burnetii growth (32.7%) and reduce CCV size, knockouts of IL-17RA and TRAF6 abrogated the IL-17-mediated restriction. Depletion of ACT1 protein with siRNA resulted in recovery of bacterial growth and size of CCV which stands in contrast to the effects observed in the presence of IL-17. These contrasting outcomes strongly indicate that the IL-17-ACT1-TRAF6 pathway is essential for the bactericidal effects against Coxiella burnetii.

Coxiella burnetii T4BSS inhibits IL-17-mediated oxidative stress in macrophages

IL-17 can trigger reactive oxygen species (ROS) production by activating NADPH-oxidases (NOX) through ACT1 and TRAF6. High ROS levels inhibit growth of the bacterium. The researchers aimed to see whether Coxiella burnetii T4BSS inhibits IL-17 signaling in macrophages to avoid elevated ROS levels. They conducted a fluorometric assay and found a significant increase in NOX activity in macrophages in WT cells in the presence of IL-17, compared to untreated cells (Δil-17ra). Further, using CellROX Green, they measured ROS levels in mock, WT and ΔdotA mutant-infected cells and found a significant increase in ROS in the mutated cells and not the WT. This suggests that Coxiella burnetii employs the T4BSS to block IL-17 mediated ROS.

Conclusion:

This study shows that Coxiella burnetii targets the IL-17R-ACT1-TRAF6 pathway to inhibit transcription of IL-17 target genes and block the activity of NOX enzymes to prevent ROS, ultimately to protect themselves during immune invasion. 

Why we chose this preprint:

Q fever is a zoonotic disease caused by Coxiella burnetii that causes severe chronic illness and is transmitted through inhaling contaminated aerosols. The diagnosis and treatment of Q fever has been met with difficulty, as there is no licensed vaccine or therapy available. As researchers interested in health and medicine, this is very concerning, and this is what made this preprint so intriguing.

Essentially, Coxiella burnetii  is able to combat oxidative stress and survive in the host body. This study is vital to the understanding of the physiological relevance of how these pathogens interact with the host immune system. The authors paint a well put together picture of how this bacterium targets the IL-17R-ACT1-TRAF6 pathway. The research on how this bacterium combats oxidative stress to promote survival adds to the knowledge of how reactive oxygen stress works in the host-microbe relationship and could potentially lead to novel therapeutics. This aspect of the paper attracted us personally, as we have a great interest in understanding cell signaling mechanisms, which would enable us to better comprehend the disease prognosis and the drug mechanisms used in treating this disease. 


Questions for the Authors:

Q1. It is stated that C. burnetii has been found to use one or more T4BSS effector proteins, do you think that C. burnetii evolved to use varying numbers of T4BSS effectors to adapt to different host environments, such as when the host has an elevated or decreased immune system?

Q2. Could this process of ROS combatants be utilized for a potential therapy in battling ROS synthetically in the human body in relation to combating ROS-elevating disorders, such as cancers and chronic diseases?

Q3. What approach would be taken to discern the virulence determinants excreted by the C. burnetii T4BSS system that effectively impede the IL-17 pathway?

Q4. Do you intend to perform Real-time quantitative PCR assay for the purpose of ascertaining the quantitative levels of NFkB p65, MAPK, and SAPK/JNK subsequent to the induction of IL-17?

Q5. How might the ability of Coxiella burnetii to inhibit IL-17-mediated oxidative stress impact the development of Q fever?

References:
1. Million, M., et al., Evolution from acute Q fever to endocarditis is associated with underlying valvulopathy and age and can be prevented by prolonged antibiotic treatment. Clin Infect Dis, 2013. 57(6): p. 836-44.
2. Kampschreur, L.M., et al., Chronic Q fever diagnosis— consensus guideline versus expert opinion. Emerg Infect Dis, 2015. 21(7): p. 1183-8.
3. Raoult, D., Treatment of Q fever. Antimicrob Agents Chemother, 1993. 37(9): p. 1733- 474 6.
4. Dahlgren, F.S., D.L. Haberling, and J.H. McQuiston, Q fever is underestimated in the United States: a comparison of fatal Q fever cases from two national reporting systems. Am J Trop Med Hyg, 2015. 92(2): p. 244-6.
5. Maor, Y., et al., Coxiella burnetii Endocarditis and Aortic Vascular Graft Infection: An Underrecognized Disease. Ann Thorac Surg, 2016. 101(1): p. 141-5.
6. Keijmel, S.P., et al., A fatal case of disseminated chronic Q fever: a case report and brief review of the literature. Infection, 2016. 44(5): p. 677-82.
7. Botelho-Nevers, E., et al., Coxiella burnetii infection of aortic aneurysms or vascular grafts: report of 30 new cases and evaluation of outcome. Eur J Clin Microbiol Infect Dis, 2007. 26(9): p. 635-40.
8. Voth, D.E., D. Howe, and R.A. Heinzen, Coxiella burnetii inhibits apoptosis in human THP-1 cells and monkey primary alveolar macrophages. Infect Immun, 2007. 75(9): p. 4263-71.
9. Cunha, L.D., et al., Inhibition of inflammasome activation by Coxiella burnetii type IV secretion system effector IcaA. Nat Commun, 2015. 6: p. 10205.
10. Curtis, M.M. and S.S. Way, Interleukin-17 in host defence against bacterial, mycobacterial and fungal pathogens. Immunology, 2009. 126(2): p. 177-85.
11. Khader, S.A. and R. Gopal, IL-17 in protective immunity to intracellular pathogens. Virulence, 2010. 1(5): p. 423-7.
12. Onishi, R.M. and S.L. Gaffen, Interleukin-17 and its target genes: mechanisms of interleukin-17 function in disease. Immunology, 2010. 129(3): p. 311-21.
13. Amatya, N., A.V. Garg, and S.L. Gaffen, IL-17 Signaling: The Yin and the Yang. Trends Immunol, 2017. 38(5): p. 310-322.
14. McGeachy, M.J., D.J. Cua, and S.L. Gaffen, The IL-17 Family of Cytokines in Health and Disease. Immunity, 2019. 50(4): p. 892-906.
15. Barin, J.G., et al., Macrophages participate in IL-17-mediated inflammation. Eur J Immunol, 2012. 42(3): p. 726-36.
16. Lin, Y., et al., Interleukin-17 is required for T helper 1 cell immunity and host resistance to the intracellular pathogen Francisella tularensis. Immunity, 2009. 31(5): p. 799-810.
17. Kimizuka, Y., et al., Roles of interleukin-17 in an experimental Legionella pneumophila pneumonia model. Infect Immun, 2012. 80(3): p. 1121-7.
18. Chen, J., et al., IL-17A induces pro-inflammatory cytokines production in macrophages via MAPKinases, NF-κB and AP-1. Cell Physiol Biochem, 2013. 32(5): p. 1265-74.
19. Gu, C., L. Wu, and X. Li, IL-17 family: cytokines, receptors and signaling. Cytokine, 2013. 64(2): p. 477-85.
20. Leonardi, A., et al., CIKS, a connection to Ikappa B kinase and stress-activated protein kinase. Proc Natl Acad Sci U S A, 2000. 97(19): p. 10494-9.
21. Mahapatra, S., et al., Coxiella burnetii Employs the Dot/Icm Type IV Secretion System to Modulate Host NF-κB/RelA Activation. Front Cell Infect Microbiol, 2016. 6: p. 188.
22. Burette, M., et al., Modulation of innate immune signaling by a Coxiella burnetii eukaryotic-like effector protein. Proc Natl Acad Sci U S A, 2020. 117(24): p. 13708- 13718.
23. Voth, D.E. and R.A. Heinzen, Sustained activation of Akt and Erk1/2 is required for Coxiella burnetii antiapoptotic activity. Infect Immun, 2009. 77(1): p. 205-13.
24. Jansen, A.F.M., et al., Viable Coxiella burnetii Induces Differential Cytokine Responses in Chronic Q Fever Patients Compared to Heat-Killed Coxiella burnetii. Infect Immun, 2018. 86(10).
25. Ammerdorffer, A., et al., Coxiella burnetii isolates originating from infected cattle induce a more pronounced proinflammatory cytokine response compared to isolates from infected goats and sheep. Pathog Dis, 2017. 75(4)

  1. Shembade, N., Harhaj, E. IKKi: a novel regulator of Act1, IL-17 signaling and pulmonary inflammation. Cell Mol Immunol8, 447–449 (2011). https://doi.org/10.1038/cmi.2011.4

 

doi: Pending

Read preprint (3 votes)

Have your say

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

Sign up to customise the site to your preferences and to receive alerts

Register here

Also in the cell biology category:

Notch3 is a genetic modifier of NODAL signalling for patterning asymmetry during mouse heart looping

Tobias Holm Bønnelykke, Marie-Amandine Chabry, Emeline Perthame, et al.

Selected by 06 June 2024

Bhaval Parmar

Developmental Biology

LINC complex alterations are a hallmark of sporadic and familial ALS/FTD

Riccardo Sirtori, Michelle Gregoire, Emily Potts, et al.

Selected by 03 June 2024

Megane Rayer et al.

Cell Biology

G6b-B antibody-based cis-acting platelet receptor inhibitors (CAPRIs) as a new family of anti-thrombotic therapeutics

Alexandra Mazharian, Ophélie Bertin, Amrita Sarkar, et al.

Selected by 03 June 2024

Simon Cleary

Pharmacology and Toxicology

Also in the immunology category:

Feedback loop regulation between viperin and viral hemorrhagic septicemia virus through competing protein degradation pathways

Xiaobing Lu, Meisheng Yi, Zhe Hu, et al.

Selected by 21 May 2024

UofA IMB565 et al.

Immunology

Fetal brain response to maternal inflammation requires microglia

Bridget Elaine LaMonica Ostrem, Nuria Dominguez Iturza, Jeffrey Stogsdill, et al.

Selected by 24 April 2024

Manuel Lessi

Neuroscience

Alteration of long and short-term hematopoietic stem cell ratio causes myeloid-biased hematopoiesis

Katsuyuki Nishi, Taro Sakamaki, Akiomi Nagasaka, et al.

Selected by 24 April 2024

Manuel Vicente, Anaisa Ferreira

Immunology

Also in the microbiology category:

Characterization of natural product inhibitors of quorum sensing in Pseudomonas aeruginosa reveals competitive inhibition of RhlR by ortho-vanillin

Kathryn E. Woods, Sana Akhter, Blanca Rodriguez, et al.

Selected by 22 May 2024

UofA IMB565 et al.

Microbiology

Feedback loop regulation between viperin and viral hemorrhagic septicemia virus through competing protein degradation pathways

Xiaobing Lu, Meisheng Yi, Zhe Hu, et al.

Selected by 21 May 2024

UofA IMB565 et al.

Immunology

Lytic bacteriophages interact with respiratory epithelial cells and induce the secretion of antiviral and proinflammatory cytokines

Paula F. Zamora, Thomas G. Reidy, Catherine R. Armbruster, et al.

Selected by 20 May 2024

UofA IMB565 et al.

Microbiology

preLists in the cell biology category:

BSCB-Biochemical Society 2024 Cell Migration meeting

This preList features preprints that were discussed and presented during the BSCB-Biochemical Society 2024 Cell Migration meeting in Birmingham, UK in April 2024. Kindly put together by Sara Morais da Silva, Reviews Editor at Journal of Cell Science.

 



List by Reinier Prosee

‘In preprints’ from Development 2022-2023

A list of the preprints featured in Development's 'In preprints' articles between 2022-2023

 



List by Alex Eve, Katherine Brown

preLights peer support – preprints of interest

This is a preprint repository to organise the preprints and preLights covered through the 'preLights peer support' initiative.

 



List by preLights peer support

The Society for Developmental Biology 82nd Annual Meeting

This preList is made up of the preprints discussed during the Society for Developmental Biology 82nd Annual Meeting that took place in Chicago in July 2023.

 



List by Joyce Yu, Katherine Brown

CSHL 87th Symposium: Stem Cells

Preprints mentioned by speakers at the #CSHLsymp23

 



List by Alex Eve

Journal of Cell Science meeting ‘Imaging Cell Dynamics’

This preList highlights the preprints discussed at the JCS meeting 'Imaging Cell Dynamics'. The meeting was held from 14 - 17 May 2023 in Lisbon, Portugal and was organised by Erika Holzbaur, Jennifer Lippincott-Schwartz, Rob Parton and Michael Way.

 



List by Helen Zenner

9th International Symposium on the Biology of Vertebrate Sex Determination

This preList contains preprints discussed during the 9th International Symposium on the Biology of Vertebrate Sex Determination. This conference was held in Kona, Hawaii from April 17th to 21st 2023.

 



List by Martin Estermann

Alumni picks – preLights 5th Birthday

This preList contains preprints that were picked and highlighted by preLights Alumni - an initiative that was set up to mark preLights 5th birthday. More entries will follow throughout February and March 2023.

 



List by Sergio Menchero et al.

CellBio 2022 – An ASCB/EMBO Meeting

This preLists features preprints that were discussed and presented during the CellBio 2022 meeting in Washington, DC in December 2022.

 



List by Nadja Hümpfer et al.

Fibroblasts

The advances in fibroblast biology preList explores the recent discoveries and preprints of the fibroblast world. Get ready to immerse yourself with this list created for fibroblasts aficionados and lovers, and beyond. Here, my goal is to include preprints of fibroblast biology, heterogeneity, fate, extracellular matrix, behavior, topography, single-cell atlases, spatial transcriptomics, and their matrix!

 



List by Osvaldo Contreras

EMBL Synthetic Morphogenesis: From Gene Circuits to Tissue Architecture (2021)

A list of preprints mentioned at the #EESmorphoG virtual meeting in 2021.

 



List by Alex Eve

FENS 2020

A collection of preprints presented during the virtual meeting of the Federation of European Neuroscience Societies (FENS) in 2020

 



List by Ana Dorrego-Rivas

Planar Cell Polarity – PCP

This preList contains preprints about the latest findings on Planar Cell Polarity (PCP) in various model organisms at the molecular, cellular and tissue levels.

 



List by Ana Dorrego-Rivas

BioMalPar XVI: Biology and Pathology of the Malaria Parasite

[under construction] Preprints presented at the (fully virtual) EMBL BioMalPar XVI, 17-18 May 2020 #emblmalaria

 



List by Dey Lab, Samantha Seah

1

Cell Polarity

Recent research from the field of cell polarity is summarized in this list of preprints. It comprises of studies focusing on various forms of cell polarity ranging from epithelial polarity, planar cell polarity to front-to-rear polarity.

 



List by Yamini Ravichandran

TAGC 2020

Preprints recently presented at the virtual Allied Genetics Conference, April 22-26, 2020. #TAGC20

 



List by Maiko Kitaoka et al.

3D Gastruloids

A curated list of preprints related to Gastruloids (in vitro models of early development obtained by 3D aggregation of embryonic cells). Updated until July 2021.

 



List by Paul Gerald L. Sanchez and Stefano Vianello

ECFG15 – Fungal biology

Preprints presented at 15th European Conference on Fungal Genetics 17-20 February 2020 Rome

 



List by Hiral Shah

ASCB EMBO Annual Meeting 2019

A collection of preprints presented at the 2019 ASCB EMBO Meeting in Washington, DC (December 7-11)

 



List by Madhuja Samaddar et al.

EMBL Seeing is Believing – Imaging the Molecular Processes of Life

Preprints discussed at the 2019 edition of Seeing is Believing, at EMBL Heidelberg from the 9th-12th October 2019

 



List by Dey Lab

Autophagy

Preprints on autophagy and lysosomal degradation and its role in neurodegeneration and disease. Includes molecular mechanisms, upstream signalling and regulation as well as studies on pharmaceutical interventions to upregulate the process.

 



List by Sandra Malmgren Hill

Lung Disease and Regeneration

This preprint list compiles highlights from the field of lung biology.

 



List by Rob Hynds

Cellular metabolism

A curated list of preprints related to cellular metabolism at Biorxiv by Pablo Ranea Robles from the Prelights community. Special interest on lipid metabolism, peroxisomes and mitochondria.

 



List by Pablo Ranea Robles

BSCB/BSDB Annual Meeting 2019

Preprints presented at the BSCB/BSDB Annual Meeting 2019

 



List by Dey Lab

MitoList

This list of preprints is focused on work expanding our knowledge on mitochondria in any organism, tissue or cell type, from the normal biology to the pathology.

 



List by Sandra Franco Iborra

Biophysical Society Annual Meeting 2019

Few of the preprints that were discussed in the recent BPS annual meeting at Baltimore, USA

 



List by Joseph Jose Thottacherry

ASCB/EMBO Annual Meeting 2018

This list relates to preprints that were discussed at the recent ASCB conference.

 



List by Dey Lab, Amanda Haage

Also in the immunology category:

Journal of Cell Science meeting ‘Imaging Cell Dynamics’

This preList highlights the preprints discussed at the JCS meeting 'Imaging Cell Dynamics'. The meeting was held from 14 - 17 May 2023 in Lisbon, Portugal and was organised by Erika Holzbaur, Jennifer Lippincott-Schwartz, Rob Parton and Michael Way.

 



List by Helen Zenner

Fibroblasts

The advances in fibroblast biology preList explores the recent discoveries and preprints of the fibroblast world. Get ready to immerse yourself with this list created for fibroblasts aficionados and lovers, and beyond. Here, my goal is to include preprints of fibroblast biology, heterogeneity, fate, extracellular matrix, behavior, topography, single-cell atlases, spatial transcriptomics, and their matrix!

 



List by Osvaldo Contreras

Single Cell Biology 2020

A list of preprints mentioned at the Wellcome Genome Campus Single Cell Biology 2020 meeting.

 



List by Alex Eve

Autophagy

Preprints on autophagy and lysosomal degradation and its role in neurodegeneration and disease. Includes molecular mechanisms, upstream signalling and regulation as well as studies on pharmaceutical interventions to upregulate the process.

 



List by Sandra Malmgren Hill

Antimicrobials: Discovery, clinical use, and development of resistance

Preprints that describe the discovery of new antimicrobials and any improvements made regarding their clinical use. Includes preprints that detail the factors affecting antimicrobial selection and the development of antimicrobial resistance.

 



List by Zhang-He Goh

Zebrafish immunology

A compilation of cutting-edge research that uses the zebrafish as a model system to elucidate novel immunological mechanisms in health and disease.

 



List by Shikha Nayar
Close