| Mast cells secrete a wide spectrum of stored or
newly synthesized pro-inflammatory, anti-inflammatory,
and/or immunosuppressive mediators and express several
costimulatory and inhibitory surface molecules. Mast cells
finely tune activities of T cells, B cells, and regulatory cells
and effectively contribute to the development of different T
cell-associated responses by influencing their recruitment, activation, proliferation, and differentiation. The interaction between mast cells and T cells, with regard to cellular functionality and immune responses, can be assessed in both activating
and inhibitory regulations. While Th2 cytokines, including IL-
5 and IL-9, stimulate stem cell factor (SCF)-dependent proliferation of mast cells, Th1 cytokine IFN-γ suppresses SCFmediated differentiation of mast cell progenitors. Mast cell
mediators such as CCL5 have a role in the recruitment of
CD8+ T cells to viral infection sites where their ability in
clearance of viral reservoirs is needed. The capacity of mast
cells in presenting antigens by classes I and II MHC molecules
to CD4+ and CD8+ T cells respectively is considered one of
the main antigen-dependent interactions of mast cells with T
cells. Interestingly, Tregs recruit mast cells to different sites
through secretion of IL-9, while the OX40L (expressed on
mast cell)-OX40(expressed on T cell) interaction inhibits the
extent of the mast cell degranulation. Recently, the capability
of exosomes to carry regulatory receptors of the mast cell
surface and their role in T cell activation has been investigated.
Functional interplay between mast cells and T cell subsets has
been suggested primarily by investigating their co-localization
in inflamed tissues and involvement of mast cells in autoimmune diseases. In this review, the interactions of mast cells
with T cells are reviewed in cell-to-cell, cytokine, and
exosome categories. |