CD8(+) T-Cells as Immune Regulators of Multiple Sclerosis

Area of Science:

• Neuroimmunology
• T-cell immunology
• Autoimmune diseases

Background:

• Multiple sclerosis (MS) research predominantly focuses on CD4(+) T-cells.
• CD8(+) T-cells are abundant in MS lesions, yet their role remains debated.
• Evidence suggests both pathogenic and regulatory functions for CD8(+) T-cells in MS and EAE.

Purpose of the Study:

• To review the multifaceted roles of CD8(+) T-cells in MS and its animal model, experimental autoimmune encephalomyelitis (EAE).
• To present evidence supporting both pathogenic and regulatory functions of CD8(+) T-cells.
• To explore the therapeutic potential of CD8(+) T-cells in MS treatment.

Main Methods:

• Review of existing literature on CD8(+) T-cell involvement in MS and EAE.
• Analysis of studies investigating CNS-specific CD8(+) T-cell functions.
• Examination of glatiramer acetate (GA) effects on CD8(+) T-cells in MS patients.

Main Results:

• CD8(+) T-cells can exhibit cytotoxic/suppressor functions, inhibiting disease via IFNγ and perforin.
• These regulatory CD8(+) T-cells are CNS antigen-specific and MHC class I-restricted.
• GA treatment induces immunosuppressive CD8(+) T-cells in MS patients, distinct from CNS-specific ones (HLA-E restricted).

Conclusions:

• CD8(+) T-cells possess both pathogenic and regulatory capabilities in MS.
• Loss of CD8(+) T-cell suppressive function correlates with MS relapse, restored during quiescence.
• Harnessing regulatory CD8(+) T-cells offers a promising avenue for MS immunotherapy.