Continuous and interval training attenuate encephalomyelitis by separate immunomodulatory mechanisms

Area of Science:

• Immunology
• Neuroscience
• Exercise Physiology

Background:

• Exercise training demonstrates beneficial effects on autoimmune diseases like multiple sclerosis (MS) and experimental autoimmune encephalomyelitis (EAE).
• The specific mechanisms by which different exercise training paradigms modulate autoimmune disease remain unclear.

Purpose of the Study:

• To compare the immune-modulating effects and mechanisms of high-intensity continuous training (HICT) and high-intensity interval training (HIIT) on systemic autoimmunity in a mouse model of EAE.
• To elucidate whether HICT and HIIT utilize shared or distinct pathways to influence disease course.

Main Methods:

• The proteolipid protein (PLP)-induced EAE mouse model was used to assess training effects on systemic autoimmune responses.
• Mice underwent either HICT or HIIT on a treadmill, and their lymph-node (LN) T cells were transferred to naive recipients to evaluate EAE development.
• In vitro analyses examined T-cell activation, proliferation, immune cell profiling, and cytokine production in LN cells from trained and sedentary donor mice.

Main Results:

• Both HICT and HIIT significantly reduced the encephalitogenicity of PLP-reactive T cells, leading to decreased EAE clinical severity and central nervous system pathology.
• HICT markedly inhibited PLP-induced T-cell proliferation without altering the T-cell profile.
• HIIT did not affect T-cell proliferation but inhibited the differentiation of T cells into pro-inflammatory T-helper 1 and T-helper 17 autoreactive populations.

Conclusions:

• High-intensity continuous training and high-intensity interval training attenuate systemic autoimmunity and T cell-mediated neuroinflammation through distinct immunomodulatory mechanisms.
• HICT primarily acts by suppressing T-cell proliferation, while HIIT functions by inhibiting the polarization of autoreactive T cells.