Fig. 4.

Effect of mast cell supernatants and selective antagonists on cytokine mRNA levels in T helper type 2 (Th2) cells. Th2 cells were incubated with X-VIVO 15 medium alone or medium containing prostaglandin D₂ (PGD₂) (black bars) or mast cell supernatants (1:2 dilution) (open bars) in the presence or absence of ramatroban or SQ29548 as indicated for 3 h. The total RNA from the cell pellets was extracted. Semi-quantitative reverse transcription–polymerase chain reaction was conducted to measure the change on gene expression of interleukin (IL)-4, IL-5 and IL-13. Results are presented mean ± standard error of the mean of % mean response induced by PGD₂ alone (n = 6). P < 0·0001 by analysis of variance. P > 0·05 by Newman–Keuls test for no additive versus unactivated mast cells (UMS)/diclofenac-treated mast cells activated with IgE/anti-IgE (DAMS)/mast cells activated with IgE/anti-IgE (AMS) + 1 µM ramatroban, UMS versus DAMS/AMS + 1 µM ramatroban, DAMS versus AMS + 1 µM ramatroban, 100 nM PGD₂versus AMS/AMS + 1 µM SQ29548, AMS versus AMS + 1 µM SQ29548, n = 6.