Multi-modal antigen specific therapy for autoimmunity

Area of Science:

• Immunology
• Neuroimmunology
• Autoimmune Disease Research

Background:

• Peripheral tolerance is a key strategy to control T cell responses and manage ongoing diseases.
• Experimental Allergic Encephalomyelitis (EAE) serves as a model for studying autoimmune conditions affecting the central nervous system.

Purpose of the Study:

• To investigate the use of immunoglobulins (Igs) engineered to present self and altered self peptides for modulating T cell responses.
• To evaluate the efficacy of Ig-conjugated peptides in suppressing ongoing EAE.

Main Methods:

• Genetically engineered immunoglobulins (Ig-PLP1 and Ig-PLP-LR) were created to present specific encephalitogenic peptides (PLP1 and PLP-LR).
• These engineered Igs were administered to mice with active EAE to assess their therapeutic potential.
• Mechanisms involving Fcgamma receptor (FcgammaR) crosslinking, IL-10 production by antigen-presenting cells (APCs), and T cell modulation were analyzed.

Main Results:

• Both Ig-PLP1 and Ig-PLP-LR demonstrated suppression of subsequent relapses in mice with ongoing EAE.
• Aggregation of Ig constructs led to FcgammaR crosslinking and IL-10 induction by APCs without upregulating costimulatory molecules.
• IL-10 mediated bystander suppression, synergizing with peptide presentation to effectively modulate EAE.

Conclusions:

• Peptide presentation without costimulation, combined with IL-10-induced bystander suppression, offers an effective multi-modal strategy for T cell modulation in EAE.
• Higher potency of Ig-PLP1 compared to Ig-PLP-LR suggests that peptide affinity is crucial for successful T cell modulation in this therapeutic approach.