A backpack-based myeloid cell therapy for multiple sclerosis

Area of Science:

• Immunology
• Neuroscience
• Biomaterials Science

Background:

• Multiple sclerosis (MS) is an autoimmune disease with no cure, currently managed with immunosuppressants causing side effects.
• Myeloid cell dysfunction is implicated in MS, yet their therapeutic potential remains largely unexplored.

Purpose of the Study:

• To investigate a novel myeloid cell-based therapeutic strategy for MS using engineered microparticles.
• To assess the efficacy of modulating myeloid cell phenotype for treating experimental autoimmune encephalomyelitis (EAE), an MS model.

Main Methods:

• Developed monocyte-adhered microparticles ("backpacks") delivering interleukin-4 and dexamethasone to activate anti-inflammatory myeloid phenotypes.
• Administered backpack-laden monocytes to EAE mice and evaluated their infiltration into the central nervous system (CNS).
• Assessed the impact of backpack-monocytes on myeloid cell function, immune cell populations (T helper 1/17), cytokine levels, and motor function.

Main Results:

• Backpack-laden monocytes successfully infiltrated the inflamed CNS and modulated both local and systemic immune responses.
• Treated monocytes altered myeloid cell compartments within the CNS, impacting antigen presentation and reactive species production.
• Significant reduction in systemic pro-inflammatory cytokines and modulation of T_H1/T_H17 populations were observed.
• Therapeutic intervention led to improved motor function in EAE mice.

Conclusions:

• Myeloid cells can be therapeutically reprogrammed using biomaterial-based "backpacks" to combat MS-like pathology.
• This approach offers an antigen-free method to precisely tune cell phenotype in vivo, highlighting myeloid cells as a viable therapeutic target.