The C. elegans CHP1 homolog, pbo-1, functions in innate immunity by regulating the pH of the intestinal lumen

English version

Autoři: Saida Benomar ^aff001; Patrick Lansdon ^aff001; Aaron M. Bender ^aff002; Blake R. Peterson ^aff002; Josephine R. Chandler ^aff001; Brian D. Ackley ^aff001
Působiště autorů: Department of Molecular Biosciences, The University of Kansas, Lawrence, KS, United States of America ^aff001; Department of Medicinal Chemistry, The University of Kansas, Lawrence, KS, United States of America ^aff002
Vyšlo v časopise: The C. elegans CHP1 homolog, pbo-1, functions in innate immunity by regulating the pH of the intestinal lumen. PLoS Pathog 16(1): e32767. doi:10.1371/journal.ppat.1008134
Kategorie: Research Article
doi: https://doi.org/10.1371/journal.ppat.1008134

Souhrn

Caenorhabditis elegans are soil-dwelling nematodes and models for understanding innate immunity and infection. Previously, we developed a novel fluorescent dye (KR35) that accumulates in the intestine of C. elegans and reports a dynamic wave in intestinal pH associated with the defecation motor program. Here, we use KR35 to show that mutations in the Ca²⁺-binding protein, PBO-1, abrogate the pH wave, causing the anterior intestine to be constantly acidic. Surprisingly, pbo-1 mutants were also more susceptible to infection by several bacterial pathogens. We could suppress pathogen susceptibility in pbo-1 mutants by treating the animals with pH-buffering bicarbonate, suggesting the pathogen susceptibility is a function of the acidity of the intestinal pH. Furthermore, we use KR35 to show that upon infection by pathogens, the intestinal pH becomes neutral in a wild type, but less so in pbo-1 mutants. C. elegans is known to increase production of reactive oxygen species (ROS), such as H₂O_2, in response to pathogens, which is an important component of pathogen defense. We show that pbo-1 mutants exhibited decreased H₂O₂ in response to pathogens, which could also be partially restored in pbo-1 animals treated with bicarbonate. Ultimately, our results support a model whereby PBO-1 functions during infection to facilitate pH changes in the intestine that are protective to the host.

Klíčová slova:

Animal pathogens – Bacterial pathogens – Bicarbonates – Caenorhabditis elegans – Enterococcus faecalis – Gastrointestinal tract – Pathogens – Pseudomonas aeruginosa

Zdroje

1. Zou CG, Tu Q, Niu J, Ji XL, Zhang KQ. The DAF-16/FOXO transcription factor functions as a regulator of epidermal innate immunity. PLoS Pathog. 2013;9(10):e1003660. doi: 10.1371/journal.ppat.1003660 24146615; PubMed Central PMCID: PMC3798571.

2. Clifford DP, Repine JE. Hydrogen peroxide mediated killing of bacteria. Mol Cell Biochem. 1982;49(3):143–9. doi: 10.1007/bf00231175 6298593.

3. Knoops B, Argyropoulou V, Becker S, Ferte L, Kuznetsova O. Multiple roles of peroxiredoxins in inflammation. Mol Cells. 2016;39(1):60–4. doi: 10.14348/molcells.2016.2341 26813661; PubMed Central PMCID: PMC4749876.

4. Sorhagen K, Laxa M, Peterhansel C, Reumann S. The emerging role of photorespiration and non-photorespiratory peroxisomal metabolism in pathogen defence. Plant biology. 2013;15(4):723–36. doi: 10.1111/j.1438-8677.2012.00723.x 23506300.

5. Buettner GR. Superoxide dismutase in redox biology: the roles of superoxide and hydrogen peroxide. Anti-cancer agents in medicinal chemistry. 2011;11(4):341–6. doi: 10.2174/187152011795677544 21453242; PubMed Central PMCID: PMC3131414.

6. Perez S, Talens-Visconti R, Rius-Perez S, Finamor I, Sastre J. Redox signaling in the gastrointestinal tract. Free radical biology & medicine. 2017;104:75–103. doi: 10.1016/j.freeradbiomed.2016.12.048 28062361.

7. McCallum KC, Garsin DA. The role of reactive oxygen species in modulating the Caenorhabditis elegans immune response. PLoS pathogens. 2016;12(11):e1005923. Epub 2016/11/11. doi: 10.1371/journal.ppat.1005923 27832190; PubMed Central PMCID: PMC5104326.

8. Irazoqui JE, Urbach JM, Ausubel FM. Evolution of host innate defence: insights from Caenorhabditis elegans and primitive invertebrates. Nat Rev Immunol. 2010;10(1):47–58. Epub 2009/12/24. doi: 10.1038/nri2689 20029447; PubMed Central PMCID: PMC2965059.

9. Bhavsar AP, Brown ED. The worm turns for antimicrobial discovery. Nat Biotechnol. 2006;24(9):1098–100. Epub 2006/09/12. doi: 10.1038/nbt0906-1098 16964218.

10. Moy TI, Conery AL, Larkins-Ford J, Wu G, Mazitschek R, Casadei G, et al. High-throughput screen for novel antimicrobials using a whole animal infection model. ACS Chem Biol. 2009;4(7):527–33. Epub 2009/07/04. doi: 10.1021/cb900084v 19572548; PubMed Central PMCID: PMC2745594.

11. Singh V, Aballay A. Regulation of DAF-16-mediated innate immunity in Caenorhabditis elegans. J Biol Chem. 2009;284(51):35580–7. Epub 2009/10/28. M109.060905 [pii] doi: 10.1074/jbc.M109.060905 19858203; PubMed Central PMCID: PMC2790988.

12. Chavez V, Mohri-Shiomi A, Garsin DA. Ce-Duox1/BLI-3 generates reactive oxygen species as a protective innate immune mechanism in Caenorhabditis elegans. Infection and immunity. 2009;77(11):4983–9. Epub 2009/08/19. doi: 10.1128/IAI.00627-09 19687201; PubMed Central PMCID: PMC2772517.

13. Tiller GR, Garsin DA. The SKPO-1 peroxidase functions in the hypodermis to protect Caenorhabditis elegans from bacterial infection. Genetics. 2014;197(2):515–26. Epub 2014/03/14. doi: 10.1534/genetics.113.160606 24621828; PubMed Central PMCID: PMC4063911.

14. Thomas JH. Genetic analysis of defecation in Caenorhabditis elegans. Genetics. 1990;124(4):855–72. Epub 1990/04/01. 2323555; PubMed Central PMCID: PMC1203977.

15. Wagner J, Allman E, Taylor A, Ulmschneider K, Kovanda T, Ulmschneider B, et al. A calcineurin homologous protein is required for sodium-proton exchange events in the C. elegans intestine. Am J Physiol Cell Physiol. 2011;301(6):C1389–403. Epub 2011/08/26. doi: 10.1152/ajpcell.00139.2011 21865588; PubMed Central PMCID: PMC3273995.

16. Pfeiffer J, Johnson D, Nehrke K. Oscillatory transepithelial H(+) flux regulates a rhythmic behavior in C. elegans. Current biology: CB. 2008;18(4):297–302. Epub 2008/02/23. doi: 10.1016/j.cub.2008.01.054 18291648; PubMed Central PMCID: PMC2350219.

17. Beg AA, Ernstrom GG, Nix P, Davis MW, Jorgensen EM. Protons act as a transmitter for muscle contraction in C. elegans. Cell. 2008;132(1):149–60. Epub 2008/01/15. doi: 10.1016/j.cell.2007.10.058 18191228; PubMed Central PMCID: PMC2258244.

18. Bender A, Woydziak ZR, Fu L, Branden M, Zhou Z, Ackley BD, et al. Novel acid-activated fluorophores reveal a dynamic wave of protons in the intestine of Caenorhabditis elegans. ACS Chem Biol. 2013;8(3):636–42. Epub 2012/12/22. doi: 10.1021/cb300396j 23256594; PubMed Central PMCID: PMC3600105.

19. Chauhan VM, Orsi G, Brown A, Pritchard DI, Aylott JW. Mapping the pharyngeal and intestinal pH of Caenorhabditis elegans and real-time luminal pH oscillations using extended dynamic range pH-sensitive nanosensors. ACS Nano. 2013;7(6):5577–87. Epub 2013/05/15. doi: 10.1021/nn401856u 23668893.

20. Allman E, Wang Q, Walker RL, Austen M, Peters MA, Nehrke K. Calcineurin homologous proteins regulate the membrane localization and activity of sodium/proton exchangers in C. elegans. Am J Physiol Cell Physiol. 2016;310(3):C233–42. Epub 2015/11/13. doi: 10.1152/ajpcell.00291.2015 26561640.

21. Matsushita M, Tanaka H, Mitsui K, Kanazawa H. Dual functional significance of calcineurin homologous protein 1 binding to Na(+)/H(+) exchanger isoform 1. Am J Physiol Cell Physiol. 2011;301(2):C280–8. Epub 2011/05/06. doi: 10.1152/ajpcell.00404.2010 21543739.

22. Garsin DA, Sifri CD, Mylonakis E, Qin X, Singh KV, Murray BE, et al. A simple model host for identifying Gram-positive virulence factors. Proceedings of the National Academy of Sciences of the United States of America. 2001;98(19):10892–7. Epub 2001/09/06. doi: 10.1073/pnas.191378698 11535834; PubMed Central PMCID: PMC58570.

23. Tenor JL, McCormick BA, Ausubel FM, Aballay A. Caenorhabditis elegans-based screen identifies Salmonella virulence factors required for conserved host-pathogen interactions. Current biology: CB. 2004;14(11):1018–24. Epub 2004/06/09. doi: 10.1016/j.cub.2004.05.050 15182677.

24. Chavez V, Mohri-Shiomi A, Maadani A, Vega LA, Garsin DA. Oxidative stress enzymes are required for DAF-16-mediated immunity due to generation of reactive oxygen species by Caenorhabditis elegans. Genetics. 2007;176(3):1567–77. Epub 2007/05/08. doi: 10.1534/genetics.107.072587 17483415; PubMed Central PMCID: PMC1931534.

25. Ammar YB, Takeda S, Hisamitsu T, Mori H, Wakabayashi S. Crystal structure of CHP2 complexed with NHE1-cytosolic region and an implication for pH regulation. The EMBO journal. 2006;25(11):2315–25. Epub 2006/05/20. doi: 10.1038/sj.emboj.7601145 16710297; PubMed Central PMCID: PMC1478177.

26. Di Sole F, Vadnagara K, Moe OW, Babich V. Calcineurin homologous protein: a multifunctional Ca2+-binding protein family. Am J Physiol Renal Physiol. 2012;303(2):F165–79. Epub 2011/12/23. doi: 10.1152/ajprenal.00628.2011 22189947; PubMed Central PMCID: PMC3404583.

27. Kootstra PR, Wever R, de Vijlder JJ. Thyroid peroxidase: kinetics, pH optima and substrate dependency. Acta Endocrinol (Copenh). 1993;129(4):328–31. Epub 1993/10/01. doi: 10.1530/acta.0.1290328 8237251.

28. Vatsyayan P, Goswami P. Acidic pH conditions induce dissociation of the haem from the protein and destabilise the catalase isolated from Aspergillus terreus. Biotechnol Lett. 2011;33(2):347–51. Epub 2010/10/26. doi: 10.1007/s10529-010-0442-2 20972700.

29. Cruz MR, Graham CE, Gagliano BC, Lorenz MC, Garsin DA. Enterococcus faecalis inhibits hyphal morphogenesis and virulence of Candida albicans. Infection and immunity. 2013;81(1):189–200. Epub 2012/11/02. doi: 10.1128/IAI.00914-12 23115035; PubMed Central PMCID: PMC3536143.

30. Aballay A, Yorgey P, Ausubel FM. Salmonella typhimurium proliferates and establishes a persistent infection in the intestine of Caenorhabditis elegans. Current biology: CB. 2000;10(23):1539–42. Epub 2000/12/15. doi: 10.1016/s0960-9822(00)00830-7 11114525.

31. Cezairliyan B, Vinayavekhin N, Grenfell-Lee D, Yuen GJ, Saghatelian A, Ausubel FM. Identification of Pseudomonas aeruginosa phenazines that kill Caenorhabditis elegans. PLoS pathogens. 2013;9(1):e1003101. Epub 2013/01/10. doi: 10.1371/journal.ppat.1003101 23300454; PubMed Central PMCID: PMC3536714.

32. Shah VS, Meyerholz DK, Tang XX, Reznikov L, Abou Alaiwa M, Ernst SE, et al. Airway acidification initiates host defense abnormalities in cystic fibrosis mice. Science. 2016;351(6272):503–7. Epub 2016/01/30. doi: 10.1126/science.aad5589 26823428; PubMed Central PMCID: PMC4852973.

33. Shah VS, Ernst S, Tang XX, Karp PH, Parker CP, Ostedgaard LS, et al. Relationships among CFTR expression, HCO3- secretion, and host defense may inform gene- and cell-based cystic fibrosis therapies. Proceedings of the National Academy of Sciences of the United States of America. 2016;113(19):5382–7. Epub 2016/04/27. doi: 10.1073/pnas.1604905113 27114540; PubMed Central PMCID: PMC4868420.

34. Martinez D, Vermeulen M, von Euw E, Sabatte J, Maggini J, Ceballos A, et al. Extracellular acidosis triggers the maturation of human dendritic cells and the production of IL-12. Journal of immunology. 2007;179(3):1950–9. Epub 2007/07/21. doi: 10.4049/jimmunol.179.3.1950 17641062.

35. Rotstein OD. Interactions between leukocytes and anaerobic bacteria in polymicrobial surgical infections. Clin Infect Dis. 1993;16 Suppl 4:S190–4. Epub 1993/06/01. doi: 10.1093/clinids/16.supplement_4.s190 8324117.

36. Coakley RJ, Taggart C, McElvaney NG, O'Neill SJ. Cytosolic pH and the inflammatory microenvironment modulate cell death in human neutrophils after phagocytosis. Blood. 2002;100(9):3383–91. Epub 2002/10/18. doi: 10.1182/blood.V100.9.3383 12384441.

37. Hackam DJ, Grinstein S, Nathens A, Watson WG, Marshall JC, Rotstein OD. Exudative neutrophils show impaired pH regulation compared with circulating neutrophils. Arch Surg. 1996;131(12):1296–301. Epub 1996/12/01. doi: 10.1001/archsurg.1996.01430240050006 8956771.

38. Fishelson Z, Horstmann RD, Muller-Eberhard HJ. Regulation of the alternative pathway of complement by pH. Journal of immunology. 1987;138(10):3392–5. Epub 1987/05/15. 2952717.

39. Lardner A. The effects of extracellular pH on immune function. J Leukoc Biol. 2001;69(4):522–30. Epub 2001/04/20. 11310837.

40. Farwell WR, Taylor EN. Serum anion gap, bicarbonate and biomarkers of inflammation in healthy individuals in a national survey. CMAJ. 2010;182(2):137–41. Epub 2009/12/17. doi: 10.1503/cmaj.090329 20008503; PubMed Central PMCID: PMC2817320.

41. Brenner S. The genetics of Caenorhabditis elegans. Genetics. 1974;77(1):71–94. 4366476; PubMed Central PMCID: PMC1213120.