T helper cell 22
 | This article may be too technical for most readers to understand. (July 2022) |
T helper cell 22, also known as the Th22 cell, are a type of immune cell. Th22 are a derivative of naïve CD4+ T cells induced by the ligand activation of the transcription factor aryl hydrocarbon receptor (AhR),[1] which uses environmental, metabolic, microbial, and dietary cues to control complex transcriptional programmes.[2] Th22 cell’s function is mediated by its ligand specific cytokine interleukin-22 (IL-22).[3]
Differentiation and cytokine expression[edit]
Th22 were distinguished as their own class of helper cells due to the stimulation and production of IL-22 independent of IFN- γ , IL-4, or IL-17 stimulation that are associated with Th1, Th2, and Th17 respectively.[1][4] Th22 cell differentiation is stimulated by IL-6 and TNF-α, but others have found Th22 can be stimulated using Langerhans cells and dermal DCs.[3] Th22 cells are known to secrete IL-22, IL-13, IL-26, TNF-α, and granzyme B.[5]
In the immune response[edit]
Th22 cells express the chemokine receptors CCR4, CCR6, and CCR10 which direct the cells to barrier surfaces such as the skin and tissue.[3][5][6] Similarly, IL-22, the characteristic cytokine produced by Th22 cells has little effect on immune cells and instead acts on mucosal barriers.[5] Due to mucosal barrier interactions Th22 and subsequently IL-22 play a significant role in a variety of skin diseases, intestinal diseases, autoimmune diseases, and allergy conditions. Many of these diseases are characterized by increased circulation of Th22 cells and concomitant increased IL-22 expression.[3]
In psoriasis, there is a positive feedback loop between Th22 and IL-22 expression.[3] Increased expression of IL-22 is observed during lesion formation that augments the expression of anti-microbials and induces chemokine ligand (CCL)-20 recruiting CCR6 , which is expressed on Th22 cells increasing their concentration in the lesion.[3] Similarly, Th22 cells are found throughout the intestinal wall in irritable bowel diseases, facilitating IL-22 secretion and subsequent induction of tissue specific genes.[3][7] Interestingly, Th22 cells induced expression of IL-22 in allergic asthma has been seen to have a protective effect against lung hypertension and tissue damage in murine models.[3]
References[edit]
- ^ a b Trifari S, Kaplan CD, Tran EH, Crellin NK, Spits H (August 2009). "Identification of a human helper T cell population that has abundant production of interleukin 22 and is distinct from T(H)-17, T(H)1 and T(H)2 cells". Nature Immunology. 10 (8): 864–871. doi:10.1038/ni.1770. PMID 19578368. S2CID 30507460.
- ^ Rothhammer V, Quintana FJ (March 2019). "The aryl hydrocarbon receptor: an environmental sensor integrating immune responses in health and disease". Nature Reviews. Immunology. 19 (3): 184–197. doi:10.1038/s41577-019-0125-8. PMID 30718831. S2CID 59603271.
- ^ a b c d e f g h Jia L, Wu C (2014). "The Biology and Functions of Th22 Cells". In Sun B (ed.). T Helper Cell Differentiation and Their Function. Advances in Experimental Medicine and Biology. Vol. 841. Dordrecht: Springer Netherlands. pp. 209–230. doi:10.1007/978-94-017-9487-9_8. ISBN 978-94-017-9487-9. PMID 25261209.
- ^ Duhen T, Geiger R, Jarrossay D, Lanzavecchia A, Sallusto F (August 2009). "Production of interleukin 22 but not interleukin 17 by a subset of human skin-homing memory T cells". Nature Immunology. 10 (8): 857–863. doi:10.1038/ni.1767. PMID 19578369. S2CID 205362675.
- ^ a b c Jiang Q, Yang G, Xiao F, Xie J, Wang S, Lu L, Cui D (2021). "Role of Th22 Cells in the Pathogenesis of Autoimmune Diseases". Frontiers in Immunology. 12: 688066. doi:10.3389/fimmu.2021.688066. PMC 8290841. PMID 34295334.
- ^ Fard NA, Azizi G, Mirshafiey A (July 2016). "The Potential Role of T Helper Cell 22 and IL-22 in Immunopathogenesis of Multiple Sclerosis". Innovations in Clinical Neuroscience. 13 (7–8): 30–36. PMC 5022987. PMID 27672486.
- ^ Li LJ, Gong C, Zhao MH, Feng BS (December 2014). "Role of interleukin-22 in inflammatory bowel disease". World Journal of Gastroenterology. 20 (48): 18177–18188. doi:10.3748/wjg.v20.i48.18177. PMC 4277955. PMID 25561785.