Tc17 cells in autoimmune diseases

Abstract

Multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE), a pathologically similar disease used to model MS in rodents, are typical CD4+ T cell-dominated autoimmune diseases. CD4+ interleukin (IL)17+ T cells (Th17 cells) have been well studied and have shown that they play a critical role in the pathogenesis of MS/EAE. However, studies have suggested that CD8+IL17+ T cells (Tc17 cells) have a similar phenotype and cytokine and transcription factor profiles to those of Th17 cells and have been found to be crucial in the pathogenesis of autoimmune diseases, including MS/EAE, psoriasis, type I diabetes, rheumatoid arthritis, and systemic lupus erythematosus. However, the evidence for this is indirect and insufficient. Therefore, we searched for related publications and attempted to summarize the current knowledge on the role of Tc17 cells in the pathogenesis of MS/EAE, as well as in the pathogenesis of other autoimmune diseases, and to find out whether Tc17 cells or Th17 cells play a more critical role in autoimmune disease, especially in MS and EAE pathogenesis, or whether the interaction between these two cell types plays a critical role in the development of the disease.

Role of autoreactive Tc17 cells in the pathogenesis of experimental autoimmune encephalomyelitis

“…Tc17 and Th17 cells may have different protein kinase B/mammalian target of rapamycin signaling requirements, as well as divergent metabolic requirements 77 . Finally, the plasticity and related functions of Tc17 and Th17 cells are different 25 . Th17 cells can switch to a Th1‐like phenotype, resulting in a more pathogenic profile, which has been confirmed by studies on pathological inflammation in the CNS 78 and intestine during bacterial infection or colitis 79 .…”

“…However, the CD8 + T cell subtype that plays a critical role in the pathogenesis of EAE remains unclear. Currently, the major subsets of CD8 + T cells are Tc1, Tc2, Tc9, Tc17, and Treg cells 24,25 . Among these subsets, Tc17 cells are strongly associated with autoimmune diseases in both human and animal models 29–35 …”

“…Currently, the major subsets of CD8 + T cells are Tc1, Tc2, Tc9, Tc17, and Treg cells. 24,25 Among these subsets, Tc17 cells are strongly associated with autoimmune diseases in both human and animal models. [29][30][31][32][33][34][35] In the present study, we used our alreadyestablished strategy for preparing the EAE model to study the role of MOG 35-55 -specific Tc17 cells in the pathogenesis of EAE and MS. 51,53,54,56 Here, we focused on Tc17 cells in EAE and used Th17 cells (CD4 + counterparts of Tc17) and Tc1 cells (different subsets of CD8 + ) as controls.…”

“…Although Tc17 cells have similar cytokine profiles to Th17 cells, the two cell types exhibit some differences 25 . In the skin, Tc17 and Th17 cells coexpress retinoic acid receptor‐related orphan nuclear receptor gamma (RORγt) and GATA‐3 only under antigen stimulation 73 .…”

Exploring the immune‐modulating properties of boswellic acid in experimental autoimmune encephalomyelitis

“…In many diseases, such as rheumatoid arthritis, systemic lupus erythematosus, Type 1 diabetes, and MS, that involve the immune system attacking the body, adaptive immunity plays a key role. This is especially true for the inflammation caused by Th1/Th17 cells [42,43]. The immune-inflammatory process involves certain cytokines that are essential for its function.…”