Pentraxin 3 Facilitates Shrimp-Allergic Responses in IgE-Activated Mast Cells

Figure 5

CEBPD is upregulated upon PTX3 treatment and contributes to degranulation and production of inflammatory mediators in mast cells. (a, b) Three-to-four-week-old female C57BL/6 mice ( per group) were intraperitoneally sensitized and challenged with PBS or shrimp extract. Using Al(OH)3 as an adjuvant, shrimp allergy mice received shrimp extract plus Al(OH)3 in PBS i.p. on days 1, 4, 7, 10, 13, 16, 19, and 22. Blood was collected after the challenge on day 30 for the determination of IgE and PTX3 levels. Levels of serological total IgE and PTX3 were determined by ELISA. (c) Effects of PTX3 (300 ng/ml) for 30 and 60 min on the mRNA levels of CEBPD in RBL-2H3 cells. (d) RBL-2H3 cells were stimulated with PTX3 (300 ng/ml) for 30 and 60 min. Total lysates were harvested for western blot analysis using antibodies as indicated. (e) IgE-sensitized RBL-2H3 cells were stimulated with DNP-BSA plus PTX3 (300 ng/ml) or not for 30 min. Total lysates were harvested for western blot analysis using antibodies as indicated. (f) Serum-sensitized RBL-2H3 cells were stimulated with shrimp extract for 15 min. Total lysates were harvested for western blot analysis using antibodies as indicated. (g) RBL-2H3 cells were infected with lentiviruses bearing shVoid or shCEBPD and treated with or without PTX3. Total RNA was harvested for qPCR assays. (h) β-hexosaminidase activity was determined as described in the Materials and Methods.

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