Limits...
Differential effects of the Toll-like receptor 2 agonists, PGN and Pam3CSK4 on anti-IgE induced human mast cell activation.

Yu Y, Yip KH, Tam IY, Sam SW, Ng CW, Zhang W, Lau HY - PLoS ONE (2014)

Bottom Line: Pretreatment of PGN and Pam3CSK4 inhibited anti-IgE induced calcium mobilization and degranulation without down-regulation of FcεRI expression.Pam3CSK4 but not PGN acted in synergy with anti-IgE for IL-8 release when the TLR2 agonist was added simultaneously with anti-IgE.Studies with inhibitors of key enzymes implicated in mast cell signaling revealed that the synergistic release of IL-8 induced by Pam3CSK4 and anti-IgE involved ERK and calcineurin signaling cascades.

View Article: PubMed Central - PubMed

Affiliation: Shenzhen Key Laboratory for Translational Medicine of Dermatology, Biomedical Research Institute, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, Guangdong Province, China; School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, China.

ABSTRACT
Mast cells are pivotal in the pathogenesis of allergy and inflammation. In addition to the classical IgE-dependent mechanism involving crosslinking of the high-affinity receptor for IgE (FcεRI), mast cells are also activated by Toll-like receptors (TLRs) which are at the center of innate immunity. In this study, we demonstrated that the response of LAD2 cells (a human mast cell line) to anti-IgE was altered in the presence of the TLR2 agonists peptidoglycan (PGN) and tripalmitoyl-S-glycero-Cys-(Lys)4 (Pam3CSK4). Pretreatment of PGN and Pam3CSK4 inhibited anti-IgE induced calcium mobilization and degranulation without down-regulation of FcεRI expression. Pam3CSK4 but not PGN acted in synergy with anti-IgE for IL-8 release when the TLR2 agonist was added simultaneously with anti-IgE. Studies with inhibitors of key enzymes implicated in mast cell signaling revealed that the synergistic release of IL-8 induced by Pam3CSK4 and anti-IgE involved ERK and calcineurin signaling cascades. The differential modulations of anti-IgE induced mast cell activation by PGN and Pam3CSK4 suggest that dimerization of TLR2 with TLR1 or TLR6 produced different modulating actions on FcεRI mediated human mast cell activation.

Show MeSH

Related in: MedlinePlus

Effects of PGN and Pam3CSK4 on the expression of FcεRI on LAD2 cells.LAD2 cells (without IgE sensitization) were incubated with PGN (50 µg/ml) (A) and Pam3CSK4 (20 µg/ml) (B) for 24 h and FcεRI surface expression was analyzed by flow cytometry after cells were incubated with FITC-conjugated anti-human FcεRI antibody, FITC-conjugated mouse IgG2b isotype control or FACS buffer for specific labelling of FcεRI, isotype and blank control respectively. The FcεRI expression of cells that were not treated (grey curve) or treated (blank curve) with the TLR2 ligands was not different as shown. Results were representative of four independent experiments.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4232580&req=5

pone-0112989-g002: Effects of PGN and Pam3CSK4 on the expression of FcεRI on LAD2 cells.LAD2 cells (without IgE sensitization) were incubated with PGN (50 µg/ml) (A) and Pam3CSK4 (20 µg/ml) (B) for 24 h and FcεRI surface expression was analyzed by flow cytometry after cells were incubated with FITC-conjugated anti-human FcεRI antibody, FITC-conjugated mouse IgG2b isotype control or FACS buffer for specific labelling of FcεRI, isotype and blank control respectively. The FcεRI expression of cells that were not treated (grey curve) or treated (blank curve) with the TLR2 ligands was not different as shown. Results were representative of four independent experiments.

Mentions: We examined the effect of the TLR2 ligands PGN and Pam3CSK4 on the surface expression of FcεRI on LAD2 cells. Our results showed that comparing with the non-treated cells (grey line), pre-treatment of PGN or Pam3CSK4 for 24 h did not reduce the expression of FcεRI on LAD2 cells (black line) (Fig. 2A, B).


Differential effects of the Toll-like receptor 2 agonists, PGN and Pam3CSK4 on anti-IgE induced human mast cell activation.

Yu Y, Yip KH, Tam IY, Sam SW, Ng CW, Zhang W, Lau HY - PLoS ONE (2014)

Effects of PGN and Pam3CSK4 on the expression of FcεRI on LAD2 cells.LAD2 cells (without IgE sensitization) were incubated with PGN (50 µg/ml) (A) and Pam3CSK4 (20 µg/ml) (B) for 24 h and FcεRI surface expression was analyzed by flow cytometry after cells were incubated with FITC-conjugated anti-human FcεRI antibody, FITC-conjugated mouse IgG2b isotype control or FACS buffer for specific labelling of FcεRI, isotype and blank control respectively. The FcεRI expression of cells that were not treated (grey curve) or treated (blank curve) with the TLR2 ligands was not different as shown. Results were representative of four independent experiments.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4232580&req=5

pone-0112989-g002: Effects of PGN and Pam3CSK4 on the expression of FcεRI on LAD2 cells.LAD2 cells (without IgE sensitization) were incubated with PGN (50 µg/ml) (A) and Pam3CSK4 (20 µg/ml) (B) for 24 h and FcεRI surface expression was analyzed by flow cytometry after cells were incubated with FITC-conjugated anti-human FcεRI antibody, FITC-conjugated mouse IgG2b isotype control or FACS buffer for specific labelling of FcεRI, isotype and blank control respectively. The FcεRI expression of cells that were not treated (grey curve) or treated (blank curve) with the TLR2 ligands was not different as shown. Results were representative of four independent experiments.
Mentions: We examined the effect of the TLR2 ligands PGN and Pam3CSK4 on the surface expression of FcεRI on LAD2 cells. Our results showed that comparing with the non-treated cells (grey line), pre-treatment of PGN or Pam3CSK4 for 24 h did not reduce the expression of FcεRI on LAD2 cells (black line) (Fig. 2A, B).

Bottom Line: Pretreatment of PGN and Pam3CSK4 inhibited anti-IgE induced calcium mobilization and degranulation without down-regulation of FcεRI expression.Pam3CSK4 but not PGN acted in synergy with anti-IgE for IL-8 release when the TLR2 agonist was added simultaneously with anti-IgE.Studies with inhibitors of key enzymes implicated in mast cell signaling revealed that the synergistic release of IL-8 induced by Pam3CSK4 and anti-IgE involved ERK and calcineurin signaling cascades.

View Article: PubMed Central - PubMed

Affiliation: Shenzhen Key Laboratory for Translational Medicine of Dermatology, Biomedical Research Institute, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, Guangdong Province, China; School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, SAR, China.

ABSTRACT
Mast cells are pivotal in the pathogenesis of allergy and inflammation. In addition to the classical IgE-dependent mechanism involving crosslinking of the high-affinity receptor for IgE (FcεRI), mast cells are also activated by Toll-like receptors (TLRs) which are at the center of innate immunity. In this study, we demonstrated that the response of LAD2 cells (a human mast cell line) to anti-IgE was altered in the presence of the TLR2 agonists peptidoglycan (PGN) and tripalmitoyl-S-glycero-Cys-(Lys)4 (Pam3CSK4). Pretreatment of PGN and Pam3CSK4 inhibited anti-IgE induced calcium mobilization and degranulation without down-regulation of FcεRI expression. Pam3CSK4 but not PGN acted in synergy with anti-IgE for IL-8 release when the TLR2 agonist was added simultaneously with anti-IgE. Studies with inhibitors of key enzymes implicated in mast cell signaling revealed that the synergistic release of IL-8 induced by Pam3CSK4 and anti-IgE involved ERK and calcineurin signaling cascades. The differential modulations of anti-IgE induced mast cell activation by PGN and Pam3CSK4 suggest that dimerization of TLR2 with TLR1 or TLR6 produced different modulating actions on FcεRI mediated human mast cell activation.

Show MeSH
Related in: MedlinePlus