T-cell surveillance of the human brain in health and multiple sclerosis

• Published in: Seminars in immunopathology Vol. 44; no. 6; pp. 855 - 867
• Main Authors: Smolders, Joost, van Luijn, Marvin M., Hsiao, Cheng-Chih, Hamann, Jörg
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.11.2022; Springer Nature B.V
• Subjects: Biomedical and Life Sciences; Biomedicine; Brain; Central Nervous System; Cerebrospinal fluid; Drug delivery; Humans; Immunology; Internal Medicine; Lymphocytes; Lymphocytes T; Meninges; Multiple sclerosis; Multiple Sclerosis - pathology; Parenchyma; Pathology; Review; Surveillance; T-Lymphocytes; perivascular space; cells; T; multiple sclerosis; cerebrospinal fluid; CNS; meninges; TRM cells
• ISSN: 1863-2297; 1863-2300
• DOI: 10.1007/s00281-022-00926-8

Circulating and tissue-resident T cells collaborate in the protection of tissues against harmful infections and malignant transformation but also can instigate autoimmune reactions. Similar roles for T cells in the brain have been less evident due to the compartmentized organization of the central nervous system (CNS). In recent years, beneficial as well as occasional, detrimental effects of T-cell-targeting drugs in people with early multiple sclerosis (MS) have increased interest in T cells patrolling the CNS. Next to studies focusing on T cells in the cerebrospinal fluid, phenotypic characteristics of T cells located in the perivascular space and the meninges as well as in the parenchyma in MS lesions have been reported. We here summarize the current knowledge about T cells infiltrating the healthy and MS brain and argue that understanding the dynamics of physiological CNS surveillance by T cells is likely to improve the understanding of pathological conditions, such as MS.