Diverse effects of bacterial cell wall components on mast cell degranulation, cysteinyl leukotriene generation and migration

Abstract

Nowadays there is more and more evidence that mast cells take part in antibacterial defence. Mast cells have the ability to kill bacteria via phagocytose-dependent or phagocytose-independent ways and express antimicrobial peptides that can directly kill pathogens at their site of entry. What is more, mast cells are capable of processing bacterial antigens for presentation through class I and II MHC molecules. Some data indicate that these cells can release various proinflammatory mediators in response to activation with bacteria and/or their products, however this information is still far from complete. Therefore, in this study we examined the ability of PGN from Staphylococcus aureus, LPS from Eschericha coli and LAM from Mycobacterium smegmatis to stimulate mature rat mast cell degranulation as well as cysteinyl LT generation. We also studied the influence of these bacterial components on mast cell migration. We found that PGN, LPS and LAM all failed to induce mast cell degranulation and histamine release. At the same time, activation of mast cells with these bacterial antigens resulted in generation and release of significant amounts of LT. Moreover, we documented that, even in the presence of laminin, none of the bacterial antigens used stimulated mast cell migration. However, PGN did induce migration of RANTES-primed mast cells, and LPS did stimulate mast cell migratory response after priming with IL-6. Our results show that PGN, LPS and LAM might be among the important bacterial antigens involved in mast cell activation during bacterial infection. Key words bacterial cell wall components, leukotrienes, mast cells.Mast cells are distributed throughout connective tissues and are particularly numerous beneath the subepithelial surface of the skin, in the respiratory system, in the gastrointestinal and genitourinary tracts, and adjacent to blood vessels and nerves. These cells are a potent source List of Abbreviations: BMMC, bone marrow-derived mast cells; BSA, bovine serum albumin; CBMC, cord blood-derived mast cells; cDMM, DMEM supplemented with 10% FCS, 10 μg/mL gentamicin and 2 mM

Surface TLR2 and TLR4 Expression on Mature Rat Mast Cells Can Be Affected by Some Bacterial Components and Proinflammatory Cytokines

“…It should be stressed that we stated that TLR4 level is higher than TLR2 expression. Moreover, we established that mast cells respond to stimulation with both PGN and LAM, that is, TLR2 ligands, as well as to LPS, that is, TLR4 ligand, by generation and release of cysLTs, according to previous reports [33–35], and this effect is partially, but significantly, decreased by anti-TLR2 or anti-TLR4 antibodies. What is more, by the use of flow cytometry technique, we also stated that rat peritoneal mast cells do not express CD14 molecules.…”

IgE by Itself Affects Mature Rat Mast Cell Preformed and De Novo-Synthesized Mediator Release and Amplifies Mast Cell Migratory Response

“…For time-course experiments mast cells were incubated with IgE at final concentrations of 5 µg/mL for 0, 5, 10, 30, or 60 min. After incubation the reaction was stopped by adding 1.9 mL of cold medium for rat mast cells and the release of histamine was measured using spectrofluorometric method, as described previously [39]. Briefly, after centrifugation (1200 rpm, 5 min, 4°C), supernatants were decanted into separate tubes whereas 2 mL of distilled water was added to each tube with cell pellet.…”

Possible Involvement of TLRs and Hemichannels in Stress-Induced CNS Dysfunction via Mastocytes, and Glia Activation

“…Poly (I:C) treatment also decreases degranulation in an in vitro allergic model, affecting mastocyte adhesion to fibronectin and vitronectin through conformational inactivation of CD29, the receptor of fibronectin [44]. Moreover, LPS and PGN induce mastocytes migration in vitro after brief treatment with IL-6 and CCL5/RANTES, respectively [45]. …”