Library
Home/Health & Medicine/The coevolution of ido1 and ahr in the emergence of regulatory t-cells in mammals
1,922
8
Essay, 9 pages (2000 words)

The coevolution of ido1 and ahr in the emergence of regulatory t-cells in mammals

Subject: Health & Medicine
Info
  • Published: December 28, 2021
  • Updated: December 28, 2021
  • University / College: The University of Warwick
  • Language: English
  • Downloads: 6

The aryl hydrocarbon receptor (AhR) is a ligand-operated transcription factor originally recognized as the mediator of the toxicity of dioxins. AhR is presumed to have evolved from invertebrates, where it served a ligand-independent role in normal development processes. Evolution of the receptor in vertebrates resulted in the ability to bind structurally different ligands, including xenobiotics, such as dioxin, and catabolites derived from the host’s own metabolism, or from the microbiota. It is now clear that AhR contributes to immune homeostasis by promoting immunomodulatory and host-protective effects ( 1 , 2 ). It is likewise clear that the nature of the ligand as well as the tissue specificity [e. g., gut ( 3 ), skin ( 4 ), and lymphoid tissue] in which AhR engagement occurs largely dictate the outcome of AhR activation.

Indoleamine 2, 3-dioxygenase 1 (IDO1) catalyzes the initial rate-limiting step in degrading tryptophan along the kynurenine pathway ( 5 – 7 ). Initially confined to regulation of tryptophan availability in local tissue microenvironments, IDO1 is now considered to play a wider role that extends to homeostasis and plasticity of the immune system. Its effects involve not only tryptophan deprivation but also the production of immunoactive kynurenines, which may act as AhR ligands ( 8 – 12 ). Although two additional enzymes, i. e., IDO2 and tryptophan 2, 3-dioxigenase (TDO2), catalyze the same reaction along the kynurenine pathway ( 13 ), IDO1 is apparently unique in promoting immunoregulatory effects over the long term, owing to its ability to function as a signaling molecule ( 14 – 16 ). IDO1 first appeared in placental animals by duplication of the IDO2 gene ( 17 ), suggesting that the coexistence of two allogeneic individuals (i. e., mother and fetus) in the same organism would require advanced strategies of immune regulation capable of maintaining T-cell tolerance for prolonged periods of time.

The appearance of higher vertebrates, and specifically mammals, was, in fact, marked by the emergence of regulatory T (Treg) cells ( 18 , 19 ). Thus, an entirely new paradigm in immunology, and more specifically in immune tolerance, may be the coevolution of three systems, namely, the IDO1 mechanism, kynurenine-driven gene transcription, and T-cell regulatory activity, which, originating from the initial need of protecting the fetus in mammals, have later turned into a pivotal mechanism of peripheral tolerance in autoimmunity, transplantation, and neoplasia.

The present Research Topic brings together 11 articles covering evolutionary aspects of tryptophan catabolic enzymes and AhR, their role in physiology and pathogenesis. In their Review Article, Ball et al. pointed out two interesting features emerging from studies of the dynamic evolution of TDO2, IDO1, and IDO2 ( 20 ). The three enzymes, which belong in two distinct superfamilies (TDO and IDO), have converged into the same catalytic activity, thus underlining the critical importance of tryptophan metabolism in all organisms. Yet, the IDO superfamily underwent divergent evolution, which occurred by gene duplication and led to the expression of an eclectic protein, IDO1, in placental animals. Because Ido1 −/− mice are mosaic deficient for the IDO2 function possibly owing to an altered mRNA splicing, distinct IDO genes may also influence the expression of each other by a still unclarified mechanism, as suggested by Prendergast et al. ( 21 ).

Zelante et al. dealt with the adaptive properties of IDO1 and AhR from a different perspective, i. e., taking into consideration the possibility that tryptophan metabolism by human microbiome has been playing a major role in shaping the coevolution of the AhR/IDO1 axis in immune regulation ( 22 ). Interestingly, they recently discovered a tryptophan catabolite selectively produced by certain Lactobacilli of the human microbiome (i. e., indole-3-aldehyde) capable of activating AhR and thus inducing the expression of IDO1 and anti-inflammatory responses ( 3 ). Tryptophan catabolic enzymes may, however, represent a double-edged sword in the interaction between mammals and pathogenic microbes, as outlined by Schulze et al. ( 23 ), because tryptophan depletion exerts bactericidal activity in tryptophan auxotrophs. Microorganisms such as E. coli and HIV are known to highjack the immunosuppressive effects of IDO1, though. Intriguingly, Kishimoto et al. discussed the possibility that microRNAs (miRNAs) may regulate the transcriptional expression of IDO-encoding genes, mainly in autoimmunity ( 24 ). Because miRNAs have been suggested to be instrumental in the evolution of organismal complexity ( 25 ) and AhR has been shown to induce the expression of several miRNAs ( 26 ), these observations further underline the critical interdependence of AhR and IDO enzymes in coping with mammalian challenges.

In their Perspective, Orabona et al. proposed an additional level of cross-regulation between the two systems ( 27 ), which may occur via AhR non-genomic effects that imply recruitment of a ubiquitin ligase complex and consequent proteasomal degradation of target proteins, a mechanism also considered by Quintana et al. ( 28 ). Because IDO1 is known to be subjected to regulatory proteolysis, AhR may not only induce but also switch off the IDO1 mechanism. Thus, depending on the specific pathologic conditions and timing of events, AhR may represent a friend or foe, and pollutants may play a major role in this regard, as suggested by the Perspective Article by Mezrich et al. ( 29 ).

Neoplasia represents a condition where drug targeting of the AhR/tryptophan metabolism axis has made the greatest progress. Already considered as a mechanism of immune escape in tumor progression, the data by Hanks et al. indicate that IDO1, modulated by several factors, is also involved in creating the permissive conditions for early carcinogenetic events ( 30 ). Most of these AhR/IDO1 modulating factors were examined by Platten et al. as potentially indirect, yet innovative, drug targets ( 31 ). Van den Eynde et al., thanks to the use of a highly specific anti-human IDO1 antibody, elegantly revisited the expression of this immunoregulatory enzyme in almost one thousand tumor specimens, finding that IDO1 is not upregulated in tumor-draining lymph nodes as previously reported, but it is restricted to tumor cells, stroma, and endothelium ( 32 ).

The reviews presented in this e-book of Frontiers are meant to provide readers with an overview of the intricacies of AhR functioning in both physiology and pathology, and of the combined effects of AhR ligand – intrinsic and – extrinsic factors, including the local tissue, which may provide a specific set of coactivators and functions bridging the basic transcriptional machinery to the target genes.

Conflict of Interest Statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

References

1. Bessede A, Gargaro M, Pallotta MT, Matino D, Macchiarulo A, Vacca C, et al. Aryl hydrocarbon receptor control of a disease tolerance defence pathway. Nature (2014)511 : 184–90. doi: 10. 1038/nature13323

|||

2. Moura-Alves P, Fae K, Houthuys E, Dorhoi A, Kreuchwig A, Furkert J, et al. AhR sensing of bacterial pigments regulates antibacterial defence. Nature (2014)512 : 387–92. doi: 10. 1038/nature13684

|||

3. Zelante T, Iannitti RG, Cunha C, De Luca A, Giovannini G, Fallarino F, et al. Tryptophan catabolites from microbiota engage aryl hydrocarbon receptor and balance mucosal reactivity via interleukin-22. Immunity (2013)39 : 372–85. doi: 10. 1016/j. immuni. 2013. 08. 003

|||

4. Di Meglio P, Duarte JH, Ahlfors H, Owens ND, Li Y, Villanova F, et al. Activation of the aryl hydrocarbon receptor dampens the severity of inflammatory skin conditions. Immunity (2014)40 : 989–1001. doi: 10. 1016/j. immuni. 2014. 04. 019

|||

5. Grohmann U, Fallarino F, Puccetti P. Tolerance, DCs and tryptophan: much ado about IDO. Trends Immunol (2003)24 : 242–8. doi: 10. 1016/S1471-4906(03)00072-3

|

6. Mellor AL, Munn DH. IDO expression by dendritic cells: tolerance and tryptophan catabolism. Nat Rev Immunol (2004)4 : 762–74. doi: 10. 1038/nri1457

|||

7. Puccetti P, Grohmann U. IDO and regulatory T cells: a role for reverse signalling and non-canonical NF-kappaB activation. Nat Rev Immunol (2007)7 : 817–23. doi: 10. 1038/nri2163

|||

8. Belladonna ML, Grohmann U, Guidetti P, Volpi C, Bianchi R, Fioretti MC, et al. Kynurenine pathway enzymes in dendritic cells initiate tolerogenesis in the absence of functional IDO. J Immunol (2006)177 : 130–7. doi: 10. 4049/jimmunol. 177. 1. 130

|||

9. Fallarino F, Grohmann U, Vacca C, Orabona C, Bianchi R, Belladonna ML, et al. The combined effects of tryptophan starvation and tryptophan catabolites down-regulate T cell receptor zeta-chain and induce a regulatory phenotype in naive T cells. J Immunol (2006)176 : 6752–61. doi: 10. 4049/jimmunol. 176. 11. 6752

|||

10. Fallarino F, Grohmann U, Orabona C, Bianchi R, Belladonna ML, Puccetti P, et al. Modulation of tryptophan catabolism by regulatory T cells. Nat Immunol (2003)4 : 1206–12. doi: 10. 1038/ni1003

|||

11. Fallarino F, Grohmann U, Vacca C, Bianchi R, Orabona C, Puccetti P, et al. T cell apoptosis by tryptophan catabolism. Cell Death Differ (2002)9 : 1069–77. doi: 10. 1038/sj. cdd. 4401073

|||

12. Munn DH, Sharma MD, Baban B, Harding HP, Zhang Y, Ron D, et al. GCN2 kinase in T cells mediates proliferative arrest and anergy induction in response to indoleamine 2, 3-dioxygenase. Immunity (2005)22 : 633–42. doi: 10. 1016/j. immuni. 2005. 03. 013

|||

13. Austin CJ, Rendina LM. Targeting key dioxygenases in tryptophan-kynurenine metabolism for immunomodulation and cancer chemotherapy. Drug Discov Today (2014). doi: 10. 1016/j. drudis. 2014. 11. 007

|||

14. Pallotta MT, Orabona C, Volpi C, Vacca C, Belladonna ML, Bianchi R, et al. Indoleamine 2, 3-dioxygenase is a signaling protein in long-term tolerance by dendritic cells. Nat Immunol (2011)12 : 870–8. doi: 10. 1038/ni. 2077

|||

15. Orabona C, Pallotta MT, Grohmann U. Different partners, opposite outcomes: a new perspective of the immunobiology of indoleamine 2, 3-dioxygenase. Mol Med (2012)18 : 834–42. doi: 10. 2119/molmed. 2012. 00029

|||

16. Pallotta MT, Orabona C, Bianchi R, Vacca C, Fallarino F, Belladonna ML, et al. Forced IDO1 expression in dendritic cells restores immunoregulatory signalling in autoimmune diabetes. J Cell Mol Med (2014)18 (10): 2082–91. doi: 10. 1111/jcmm. 12360

|||

17. Ball HJ, Yuasa HJ, Austin CJ, Weiser S, Hunt NH. Indoleamine 2, 3-dioxygenase-2; a new enzyme in the kynurenine pathway. Int J Biochem Cell Biol (2009)41 : 467–71. doi: 10. 1016/j. biocel. 2008. 01. 005

|||

18. Gobert M, Lafaille JJ. Maternal-fetal immune tolerance, block by block. Cell (2012)150 : 7–9. doi: 10. 1016/j. cell. 2012. 06. 020

|||

19. Williams Z. Inducing tolerance to pregnancy. N Engl J Med (2012)367 : 1159–61. doi: 10. 1056/NEJMcibr1207279

|

20. Ball HJ, Jusof FF, Bakmiwewa SM, Hunt NH, Yuasa HJ. Tryptophan catabolizing enzymes – party of three. Front Immunol (2014)5 : 485. doi: 10. 3389/fimmu. 2014. 00485

|||

21. Prendergast GC, Metz R, Muller AJ, Merlo LM, Mandik-Nayak L. IDO2 in immunomodulation and autoimmune disease. Front Immunol (2014)5 : 585. doi: 10. 3389/fimmu. 2014. 00585

|||

22. Zelante T, Iannitti RG, Fallarino F, Gargaro M, De Luca A, Moretti S, et al. Tryptophan feeding of the IDO1-AhR axis in host-microbial symbiosis. Front Immunol (2014)5 : 640. doi: 10. 3389/fimmu. 2014. 00640

|

23. Schmidt SV, Schultze JL. New insights into IDO biology in bacterial and viral infections. Front Immunol (2014)5 : 384. doi: 10. 3389/fimmu. 2014. 00384

|||

24. Nguyen NT, Nakahama T, Le DH, Van Son L, Chu HH, Kishimoto T. Aryl hydrocarbon receptor and kynurenine: recent advances in autoimmune disease research. Front Immunol (2014)5 : 551. doi: 10. 3389/fimmu. 2014. 00551

|||

25. Berezikov E. Evolution of microRNA diversity and regulation in animals. Nat Rev Genet (2011)12 : 846–60. doi: 10. 1038/nrg3079

|||

26. Nakahama T, Hanieh H, Nguyen NT, Chinen I, Ripley B, Millrine D, et al. Aryl hydrocarbon receptor-mediated induction of the microRNA-132/212 cluster promotes interleukin-17-producing T-helper cell differentiation. Proc Natl Acad Sci U S A (2013)110 : 11964–9. doi: 10. 1073/pnas. 1311087110

|||

27. Pallotta MT, Fallarino F, Matino D, Macchiarulo A, Orabona C. AhR-mediated, non-genomic modulation of IDO1 function. Front Immunol (2014)5 : 497. doi: 10. 3389/fimmu. 2014. 00497

|||

28. Jaronen M, Quintana FJ. Immunological relevance of the coevolution of IDO1 and AHR. Front Immunol (2014)5 : 521. doi: 10. 3389/fimmu. 2014. 00521

|||

29. Julliard W, Fechner JH, Mezrich JD. The aryl hydrocarbon receptor meets immunology: friend or foe? A little of both. Front Immunol (2014)5 : 458. doi: 10. 3389/fimmu. 2014. 00458

|||

30. Holtzhausen A, Zhao F, Evans KS, Hanks BA. Early carcinogenesis involves the establishment of immune privilege via intrinsic and extrinsic regulation of indoleamine 2, 3-dioxygenase-1: translational implications in cancer immunotherapy. Front Immunol (2014)5 : 438. doi: 10. 3389/fimmu. 2014. 00438

|

31. Platten M, von Knebel-Döberitz N, Oezen I, Wick W, Ochs K. Cancer immunotherapy by targeting IDO1/TDO and their downstream effectors. Front Immunol (2015)5 : 673. doi: 10. 3389/fimmu. 2014. 00673

|||

32. van Baren N, Van den Eynde B. Tryptophan-degrading enzymes in tumoral immune resistance. Front Immunol (2015)6 : 34. doi: 10. 3389/fimmu. 2015. 00034

|

Thank's for Your Vote!
The coevolution of ido1 and ahr in the emergence of regulatory t-cells in mammals. Page 1
The coevolution of ido1 and ahr in the emergence of regulatory t-cells in mammals. Page 2
The coevolution of ido1 and ahr in the emergence of regulatory t-cells in mammals. Page 3
The coevolution of ido1 and ahr in the emergence of regulatory t-cells in mammals. Page 4
The coevolution of ido1 and ahr in the emergence of regulatory t-cells in mammals. Page 5
The coevolution of ido1 and ahr in the emergence of regulatory t-cells in mammals. Page 6
The coevolution of ido1 and ahr in the emergence of regulatory t-cells in mammals. Page 7
The coevolution of ido1 and ahr in the emergence of regulatory t-cells in mammals. Page 8
The coevolution of ido1 and ahr in the emergence of regulatory t-cells in mammals. Page 9

This work, titled "The coevolution of ido1 and ahr in the emergence of regulatory t-cells in mammals" was written and willingly shared by a fellow student. This sample can be utilized as a research and reference resource to aid in the writing of your own work. Any use of the work that does not include an appropriate citation is banned.

If you are the owner of this work and don’t want it to be published on AssignBuster, request its removal.

Request Removal
Cite this Essay

References

AssignBuster. (2021) 'The coevolution of ido1 and ahr in the emergence of regulatory t-cells in mammals'. 28 December.

Reference

AssignBuster. (2021, December 28). The coevolution of ido1 and ahr in the emergence of regulatory t-cells in mammals. Retrieved from https://assignbuster.com/the-coevolution-of-ido1-and-ahr-in-the-emergence-of-regulatory-t-cells-in-mammals/

References

AssignBuster. 2021. "The coevolution of ido1 and ahr in the emergence of regulatory t-cells in mammals." December 28, 2021. https://assignbuster.com/the-coevolution-of-ido1-and-ahr-in-the-emergence-of-regulatory-t-cells-in-mammals/.

1. AssignBuster. "The coevolution of ido1 and ahr in the emergence of regulatory t-cells in mammals." December 28, 2021. https://assignbuster.com/the-coevolution-of-ido1-and-ahr-in-the-emergence-of-regulatory-t-cells-in-mammals/.


Bibliography


AssignBuster. "The coevolution of ido1 and ahr in the emergence of regulatory t-cells in mammals." December 28, 2021. https://assignbuster.com/the-coevolution-of-ido1-and-ahr-in-the-emergence-of-regulatory-t-cells-in-mammals/.

Work Cited

"The coevolution of ido1 and ahr in the emergence of regulatory t-cells in mammals." AssignBuster, 28 Dec. 2021, assignbuster.com/the-coevolution-of-ido1-and-ahr-in-the-emergence-of-regulatory-t-cells-in-mammals/.

More Related Papers
Editorial: contemporary perspective on 5-ht 2c receptor function and its pharmacological targeting
Reconceptualizing second-person interaction
Authentic leadership: application to women leaders
Neural correlates for apathy: frontal-prefrontal and parietal cortical- subcortical circuits
A remark on the fractional integral operators and the image formulas of generalized lommel–wright function
Get in Touch

Please, let us know if you have any ideas on improving The coevolution of ido1 and ahr in the emergence of regulatory t-cells in mammals, or our service. We will be happy to hear what you think: [email protected]