Galectin-1 inhibits oral-intestinal allergy syndrome

Abstract

Background and aims: The pathogenesis of oral-intestinal allergy syndrome (OIAS) has not been well understood. Published data indicate that galectin (Gal) 1 has immune regulatory functions. This study tests a hypothesis that Gal1 inhibits oral-intestinal allergy syndrome.

Methods: Mice were sensitized to peanut extracts (PE) via the buccal mucosa with or without using Gal1 together.

Results: Upon re-exposure to specific antigen, the OIAS mice showed the systemic allergic response, the oral allergic reactions, and intestinal allergic inflammation, including increases in serum histamine, drop of the core temperature, higher levels of PE-specific IgE and interleukin (IL)-4. Increases in mast cell and eosinophil in the oral mucosa and intestinal mucosa were also observed. The OIAS was inhibited by co-administration with Gal1 via a mechanism of suppressing micro RNA (miR)-98 and reversing the expression of IL-10 in CD14+ cells in the intestine.

Conclusions: The OIAS can be induced by applying specific antigens to the oral mucosa, which can be inhibited by co-administration with Gal1.

Keywords: galectin-1; micro RNA-98; oral allergy; oral mucosa; peanut.

Figure 1. Allergic response in allergic mice

The bars indicate the serum histamine A., drop of the core temperature B., counts of mast cell/eosinophil in the oral and intestinal mucosa C-D., serum specific IgE (sIgE) E. and serum IL-4 F. in mice. The treatment of mice is denoted on the X axis. Each dot represents an individual datum. Saline: Mice were treated with saline used as controls. PE: Mice were sensitized to PE. Gal1: Mice received Gal1 via intraperitoneal injection. Each group consists of 6 mice. The data were summarized from 6 independent experiments.

Figure 2. Gal1 facilitates the generation of IL-10+ CD14+ cells

A-D. the gated dot plots indicate the frequency of IL-10+ CD14+ cells in the mouse intestine. The treatment of mice is denoted above each panel. E. the summarized data of (A-D). Saline: Mice were treated with saline used as controls. PE: Mice were sensitized to PE. Gal1: Mice received Gal1 via intraperitoneal injection. Each group consists of 6 mice. The data represent 6 independent experiments.

Figure 3. miR-98 and IL-10 levels in CD14+ cells

The levels of miR-98 A. IL-10 mRNA B. and IL-10 protein C. in CD14+ cells; the cells were isolated from LPMCs of mice treated with the reagents denoted on the X axis. D., the negative correlation between IL-10 mRNA and miR-98 in CD14+ cells of the allergic mouse intestine. Each group consists of 6 mice.

Figure 4. Gal1 suppresses miR-98 and reverses IL-10 expression in CD14+ cells

A. positive correlation between serum IL-4 levels and miR-98 in intestinal CD14+ cells of allergic mice. B. the levels of miR-98 in CD14+ cells. The CD14+ cells were isolated from the naive mouse spleen after exposure to IL-4 in the culture for 48 h. #, Gal1 in the culture (15 ng/ml). C. the levels of miR-98 in CD14+ cells isolated from the OIAS mouse intestine after exposure to Gal1 in the culture for 48 h. D. the levels of IL-10 mRNA in CD14+ cells isolated from the allergic mouse intestine after exposure to Gal1 and LPS in the culture for 48 h. E. the CD45 RNAi results; (a) CD14+ cells were treated with CD45 RNAi; (b) CD14+ cells were treated with control RNAi. *, p <0.01, compared with the 0 group. The data were summarized from 3 independent experiments.

Figure 5. IL-10+ CD14+ cells inhibit oral-intestinal syndrome

A. the gated flow cytometry histograms show the frequency of IL-10+ CD14+ cells after treating with the reagents denoted above each histogram. B-G. the bars show the results of serum histamine (B), changes of the core temperature (C), counts of mast cell (D) and eosinophil (E) in the buccal mucosa and the intestinal mucosa, serum specific IgE (F) and serum IL-4 (G) of mice (with the oral-intestinal syndrome) after the treatment denoted on the X axis. Each group consists of 6 mice. Data of the bars were summarized from 6 independent experiments.