Clonal expansion and decreased occurrence of peripheral blood gamma delta T cells of the V delta 2J delta 3 lineage in multiple sclerosis patients

Unconventional T cells in brain homeostasis, injury and neurodegeneration

The interaction between peripheral immune cells and the brain is an important component of the neuroimmune axis. Unconventional T cells, which include natural killer T (NKT) cells, mucosal-associated invariant T (MAIT) cells, γδ T cells, and other poorly defined subsets, are a special group of T lymphocytes that recognize a wide range of nonpolymorphic ligands and are the connection between adaptive and innate immunity. Recently, an increasing number of complex functions of these unconventional T cells in brain homeostasis and various brain disorders have been revealed. In this review, we describe the classification and effector function of unconventional T cells, review the evidence for the involvement of unconventional T cells in the regulation of brain homeostasis, summarize the roles and mechanisms of unconventional T cells in the regulation of brain injury and neurodegeneration, and discuss immunotherapeutic potential as well as future research goals. Insight of these processes can shed light on the regulation of T cell immunity on brain homeostasis and diseases and provide new clues for therapeutic approaches targeting brain injury and neurodegeneration.

γδ T Cells Participating in Nervous Systems: A Story of Jekyll and Hyde

γδ T cells are distributed in various lymphoid and nonlymphoid tissues, and act as early responders in many conditions. Previous studies have proven their significant roles in infection, cancer, autoimmune diseases and tissue maintenance. Recently, accumulating researches have highlighted the crosstalk between γδ T cells and nervous systems. In these reports, γδ T cells maintain some physiological functions of central nervous system by secreting interleukin (IL) 17, and neurons like nociceptors can in turn regulate the activity of γδ T cells. Moreover, γδ T cells are involved in neuroinflammation such as stroke and multiple sclerosis. This review illustrates the relationship between γδ T cells and nervous systems in physiological and pathological conditions.

γδ T lymphocytes in the pathogenesis of multiple sclerosis and experimental autoimmune encephalomyelitis

The aim of the current review is to summarize the results of studies on the role of γδ T cells in the pathogenesis of multiple sclerosis and its animal model - the experimental autoimmune encephalomyelitis. Despite the fact that numerous studies have been performed, the role of γδ T is still not fully understood. It seems that there are two distinct subpopulations - one exacerbating the disease (IL-17-producing) and the other playing a protective role (IFN-γ-secreting). Nevertheless, future studies are required for an understanding of γδ T cells role in multiple sclerosis.

Role of apolipoproteins in gammadelta and NKT cell-mediated innate immunity

Recent findings reveal unanticipated connections between the fields of lipid metabolism and immunology. They concern gammadelta and NKT cells, nonconventional T cell populations that do not recognize protein antigens and are involved in immunity against cancer, defense against infections, or in regulation of classical immune responses. In this review, we summarize data linking perturbations of apolipoprotein levels and nonconventional T cells with inflammatory processes such as autoimmune diseases or atherosclerosis. We integrate and discuss recent findings on the implication of apolipoproteins in antigen recognition by gammadelta and NKT cells, with emphasis on apolipoproteins A-I and E. These findings also provide indications that apolipoproteins influence antitumor immunosurveillance.

Immunopathogenesis of multiple sclerosis: the role of T cells

Multiple sclerosis is considered to be an autoimmune disease that results from aberrant immune responses to central nervous system antigens. T cells are considered to be crucial in orchestrating an immunopathological cascade that culminates in damage to the myelin sheath, oligodendrocytes and axons.