Interleukin‐17 producing mucosal associated invariant T cells ‐ emerging players in chronic inflammatory diseases?

Abstract

Mucosal associated invariant T (MAIT) cells are a population of evolutionarily conserved T cells, which express an invariant T cell receptor (TCR) and represent a significant subset of innate-like T cells in humans, yet their role in immunity is still emerging. Unlike conventional αβ T cells, MAIT cells are not restricted by MHC molecules, but instead uniquely recognize microbially derived vitamin metabolites presented by the MHC-I like molecule MR1. MAIT cells are enriched in mucosal sites and tissues including liver andadipose tissue where they are thought to play an important role in immunosurveillance and immunity against microbial infection. In addition to their putative role in antimicrobial immunity, recent research on MAIT cells, in particular IL-17 producing MAIT cells, has demonstrated their involvement in numerous chronic inflammatory conditions. In this review, we give an overview of the work to date on the function and subsets of MAIT cells. We also examine the role of IL-17 producing MAIT cells in chronic inflammatory diseases ranging from autoimmune conditions, metabolic diseases to cancer. Furthermore, we discuss the most recent findings from the clinic that might help deepen our understanding about the biology of MAIT cells.

Anti-Inflammatory Effects of Lagerstroemia ovalifolia Teijsm. & Binn. in TNFα/IFNγ-Stimulated Keratinocytes

“…These chemokines have an important role in the pathogenesis of AD [ 26 , 27 ]. For example, chemokines differentiate T lymphocytes and recruit leukocytes to sites of inflammation [ 28 , 29 ]. In this study, TARC and MDC were increased by TNF α /IFN γ but significantly decreased by LOC ( Figure 4 ).…”

Mucosal Associated Invariant T Cells in Cancer-Friend or Foe?

“…In addition to IFNγ, Ling and colleagues also reported elevated IL-17A production by MAIT cells in both the periphery and tumours of patients with CRC [ 30 ]. IL-17 producing MAIT cells have been implicated in numerous chronic inflammatory diseases [ 14 ], with one study demonstrating a negative role for IL-17 producing MAIT cells in murine models of melanoma, driven by IL-17 inhibition of natural killer (NK) cell responses [ 34 ]. Whether MAIT cells have a positive or negative role in anti-tumour immunity in CRC remains a point of debate and will require further work to elucidate the mechanisms underpinning the reported alterations.…”

“…MAIT cells can also be activated independent of TCR engagement, via pro-inflammatory cytokines such as IL-18 [ 11 , 12 , 13 ]. Upon activation, MAIT cells can rapidly respond, producing a milieu of cytokines including interferon-gamma (IFNγ), tumour necrosis factor alpha (TNFα) and interleukin-17 (IL-17) [ 12 , 14 ]. MAIT cell cytokine profiles can vary depending on their tissue localization [ 15 ].…”

Значение Т-Клеток Врожденной Иммунной Системы В Развитии Метавоспаления Жировой Ткани При Ожирении

“…Дані активуючі MAIT-клітини рибофлавінові антигени генеруються патогенними і коменсальними бактеріями. TCR-незалежним способом MAIT-клітини активуються за допомогою цитокінів IL-7, IL-12 і IL-18 [22,31,52].…”

“…Т-клітинні натуральні кілери становлять собою Т-клітини, які розпізнають ліпідні антигени, що пре-Рисунок 1. Активація MAIT-клітин [52] зентуються молекулою CD1d. На відміну від традиційних αβT-клітин, які розпізнають антигенні пептиди в контексті молекул MHC I або II класу й активуються стимулюючими сигналами CD3/CD28 або інших корецепторів, NKT-клітини розпізнають гліколіпідні антигени, пов'язані з виключно некласичною молекулою MHC CD1d.…”