Research paperLeukotriene receptor expression in mast cells is affected by their agonists

- Tissue mast cells express CYSLTR1, CYSLTR2, GPR17, BLTR1, and BLTR2.
- cysLTs and LTB4 modulate LT receptor expression in tissue mast cells.
- Leukotrienes induce LT receptor translocation in tissue mast cells.

The effects of LTs are mediated by GPCRs: cysLTs interact with CYSLTR1, CYSLTR2, or GPR17, and LTB4 acts via BLT1R or BLT2R. Data relating to the presence of these receptors in mature tissue mast cells are not entirely known. By confocal microscopy with image analyses and flow cytometry, we established that native rat mast cells isolated from peritoneal cavity constitutively express all studied receptors. Moreover, we clearly documented that LTs by themselves can influence their own receptor expression. Low concentrations of LTs induce translocation of LT receptors from cell interior to plasma membrane, which can lead to increased mast cell responsiveness to LT stimulation. High concentrations of LTs cause internalization and, in consequence, reduction in the number of receptors on the cell surface, and it may result in desensitization of mast cells to subsequent LT stimulation. These observations may imply a physiological feedback mechanism regulating mast cell sensitivity to LT activation within tissues.