Exercise and tissue-resident memory T cells: from circulating numbers to spatial immune remodeling.

Area of Science:

• Immunology
• Exercise Physiology
• Cell Biology

Background:

• Tissue-resident memory T (T_RM) cells provide localized immune surveillance in non-lymphoid organs.
• Conventional exercise immunology focuses on circulating lymphocytes, overlooking T_RM cells.
• A spatial immune remodeling framework is needed to understand exercise's impact on tissue immunity.

Purpose of the Study:

• To review T_RM cell biology and its relevance to exercise immunology.
• To investigate if endurance training enhances T_RM cell density and function in non-lymphoid tissues.
• To explore mechanisms by which exercise influences T_RM cell establishment and function.

Main Methods:

• Review of current literature on T_RM cell biology and exercise immunology.
• Analysis of molecular basis, differentiation, and tissue-specific diversity of T_RM cells.
• Exploration of exercise-induced factors (adrenergic signaling, thermoregulation, hemodynamics) affecting T_RM cells.

Main Results:

• Endurance training may increase T_RM cell density and function, akin to vaccination.
• Exercise intensity exhibits a biphasic J-shaped relationship with immunoprotection.
• Optimal training at lower intensities enhances T_RM cell immunity, while higher intensities may be detrimental.

Conclusions:

• Exercise can modulate T_RM cell immunity, shifting focus from circulating cells to tissue-level responses.
• Further research is needed on adrenergic signaling, tissue-specific exercise prescriptions, and clinical translation.
• Findings suggest a paradigm shift in exercise immunology towards understanding spatial immune remodeling.