Sp. Bhattacharyya et al., ACTIVATED T-LYMPHOCYTES INDUCE DEGRANULATION AND CYTOKINE PRODUCTION BY HUMAN MAST-CELLS FOLLOWING CELL-TO-CELL CONTACT, Journal of leukocyte biology, 63(3), 1998, pp. 337-341
Activated mast cells reside in close apposition to T cells in some inf
lammatory processes, In this study, we analyzed whether this close phy
sical proximity affects human mast cell degranulation and cytokine rel
ease, Thus HMC-1 human mast cells or primary bone marrow-derived human
mast cells were cocultured with activated and with resting T cells, M
ast cells cocultured with activated T cells released histamine and bet
a-hexosaminidase and produced tumor necrosis factor alpha (TNF-alpha),
an effect that peaked at 20 h, Kinetics of histamine release parallel
ed the formation of heterotypic aggregates, Separation of the two cell
populations with a porous membrane prevented mediator release and TNF
-alpha production, Addition of the PI3-kinase inhibitor, wortmannin, i
nhibited the heterotypic adhesion-associated degranulation but not TNF
-alpha production. These data thus indicate a novel pathway through wh
ich human mast cells are activated to both release granule-associated
mediators and to produce cytokines in association with heterotypic adh
esion to activated human T cells.