Mast Cell-Derived Exosomes Promote Th2 Cell Differentiation via OX40L-OX40 Ligation

Abstract EN

Exosomes are nanovesicles released by different cell types, such as dendritic cells (DCs), mast cells (MCs), and tumor cells.

Exosomes of different origin play a role in antigen presentation and modulation of immune response to infectious disease.

In this study, we demonstrate that mast cells and CD4+ T cells colocated in peritoneal lymph nodes from BALB/c mouse.

Further, bone marrow-derived mast cells (BMMCs) constitutively release exosomes, which express CD63 and OX40L.

BMMC-exosomes partially promoted the proliferation of CD4+ T cells.

BMMC-exosomes significantly enhanced the differentiation of naive CD4+ T cells to Th2 cells in a surface contact method, and this ability was partly inhibited by the addition of anti-OX40L Ab.

In conclusion, BMMC-exosomes promoted the proliferation and differentiation of Th2 cells via ligation of OX40L and OX40 between exosomes and T cells.

This method represents a novel mechanism, in addition to direct cell surface contacts, soluble mediators, and synapses, to regulate T cell actions by BMMC-exosomes.