Lipoteichoic acid downregulates FcεRI expression on human mast cells through Toll-like receptor 2

Human Cathelicidin CAP18/LL-37 Changes Mast Cell Function toward Innate Immunity

“…Amplification was carried out for the following number of cycles: 48 for formylpeptide receptor like 1 (FPRL1) and P2X 7 , and 25 for b-actin. Each cycle included denaturation for 30 s at 94°C, annealing for 30 s (63°C for FPRL1, 57°C for P2X 7 , or 61°C for b-actin), and extension for 1 min at 68°C. After the final cycle, the samples were incubated for 10 min at 68°C.…”

“…TLR1, TLR2, TLR4, TLR5, and TLR9 are especially important for host defense against bacteria because these TLRs recognize bacterial components and then promote cytokine secretion. 6) Mast cells express functional TLRs [7][8][9][10] and contribute to host defense or the initiation of an innate immune response by releasing cytokines and chemokines following TLR stimulation. [11][12][13][14] For example, the W/W v mouse, a mast cell-deficient mouse, has an increased incidence of mortality from cecal ligation and puncture; however, the increased mortality is reduced in mast cell-reconstituted W/W v mice.…”

Experimental immunology FcεRI-mediated mast cell response is modulated by TLR2 and TLR4 ligation

“…It has been established that TLR2 ligands, i.e. peptidoglycan (PGN) and lipoteichoic acid (LTA), reduced FcεRI-mediated degranulation of human mast cell line LAD2, and only LTA-priming significantly inhibited FcεRI-dependent degranulation of human pulmonary mast cells, as assessed by β-hexosaminidase release [22]. It was also stated that there was no significant change in degranulation of bone marrow-derived mast cells (BMMCs) following stimulation through TLR4 with LPS and FcεRI cross-linking [23].…”

“…The underlying mechanisms by which TLR ligands in combination with FcεRI-mediated activation influence mast cell response remain unclear. TLR2 and TLR4 agonists may modulate the surface expression of FcεRI and in consequence can alter mast cell FcεRI-dependent response [17,22,29]. Since it is well documented that TLR ligation stimulates mast cell to various cytokine secretion [5,7,[14][15][16][17] it may be assumed that these secreted cytokines indirectly affect FcεRI-dependent mast cell activity by autocrine feedback loop mechanism [22,23,25].…”

Toll-like receptors 3 ligation directly and indirectly affects mast cell cysteinyl leukotriene generation

“…Among the TLR family members, TLR3, TLR7/8 and TLR9 are the receptors specific to virus-associated molecular patterns [11,16]. Although previously these receptors have been reported in mast cells, the data are scarce and mainly refer to mRNA transcript expression in cultured cell lines [17][18][19][20][21][22]. Thus, it could be assumed that mast cells are capable of being activated by viral ligands, and thereby involved in antiviral immune response and/or development of virus-induced diseases.…”