Donor Treg expansion by liposomal α-galactosylceramide modulates Tfh cells and prevents sclerodermatous chronic...

Area of Science:

• Immunology
• Transplantation Science
• Cellular Biology

Background:

• Chronic graft-versus-host disease (cGVHD) is a significant cause of morbidity and mortality after hematopoietic stem cell transplantation (HSCT).
• α-Galactosylceramide (α-GC) is a synthetic glycolipid that activates invariant natural killer T (iNKT) cells.
• iNKT cell activation by α-GC can lead to both immune-stimulatory and immune-regulatory cytokine production, promoting regulatory T-cell (Treg) expansion.

Purpose of the Study:

• To investigate the impact of iNKT cell stimulation with liposomal α-GC immediately post-transplant.
• To assess the effects on immune reconstitution and the development of sclerodermatous cGVHD.

Main Methods:

• Administration of liposomal α-GC post-hematopoietic stem cell transplantation.
• Monitoring of iNKT cell homeostasis in both host and donor.
• Analysis of regulatory T-cell (Treg) expansion.
• Measurement of plasma CXCL13 levels and lymph node follicular helper T cells.

Main Results:

• Multiple liposomal α-GC administrations modulated host and donor iNKT cell populations.
• Early expansion of donor Tregs was observed.
• Immune modulation led to decreased CXCL13 and follicular helper T cells, inhibiting germinal center formation.
• Efficient prevention of sclerodermatous cGVHD was achieved.

Conclusions:

• iNKT cell stimulation with liposomal α-GC effectively prevents sclerodermatous cGVHD post-HSCT.
• The study highlights the coordination of T- and B-cell immunity in cGVHD pathogenesis.
• This approach presents a novel strategy for inducing immune tolerance after allogeneic HSCT.