Methods: Mast cell migration was examined using the Boyden chamber technique. The MC/9 mouse mast cell clone sensitized with anti-dinitrophenyl (DNP) IgE was placed in the upper wells, and DNP-conjugated human serum albumin (DNP-HAS) was added to the lower wells. Mast cells in the lower wells were counted using a Fuchus Rosenthal calculator. DNP-IgE-sensitized MC/9 cells or bone-marrow derived mast cells (BMMCs) were incubated with DNP in pH-changed medium, and tumor necrosis factor (TNF)-α, interleukin (IL)-6, and IL-13 levels in the supernatant were measured using enzyme-linked immunosorbent assays. The data were compared by using the Student’s t-test with the Bonferroni correction for multiple comparisons.
Results: Acidic pH significantly inhibited migration of MC/9 cells toward DNP-HAS. In addition, extracellular acidification clearly induced IL-6 and IL-13 production. The viability of MC/9 cells was not affected by alterations in pH.
Conclusions: Acidic pH inhibits MC/9 cell migration. Furthermore, extracellular acidification enhances DNP-IgE–induced IL-6 and IL-13 production in MC/9 cells and BMMCs.