Humoral and cellular immune responses in mice after airway administration of Bacillus thuringiensis Cry1Ab and MON810 cry1Ab-transgenic maize

Figures & data

Figure 1. Experimental protocol. Mice were intranasally (i.n.) immunised with Cry1Ab protoxin, MON810 pollen and non-GM pollen (Experiment 1) and trypsinised Cry1Ab (trypCry1Ab), MON810 leaf extract and non-GM leaf extract (Experiment 2) on days 0, 1 and 2, and boostered i.n. with the equivalent test materials on days 21, 22 and 23. Blood samples were collected on days 0 and 21, and blood, BALFs and mediastinal lymph nodes (MLN) were collected at termination on day 26.

Table 1. Total exposure doses of Cry1Ab in MON810 pollen and leaves per mouse.

Source	Cry1Ab (µg/mg)	Plant material (mg) per mouse	Total dose Cry1Ab (µg) per mouse
MON810 pollen	0.00692	3^a	0.02
MON810 leaf	0.61251	21^b	12.86

^a Exposure for 6 days of 500 µg pollen each day.

^b Exposure for 6 days of 3.5 mg leaves (in extract form) each day.

Figure 2. Cry1Ab-specific IgG1 (a), IgE (b) and IgG2a (c) in serum after intranasal immunisation and booster of mice to Cry1Ab protoxin and fresh MON810 maize pollen and non-GM pollen on days 0, 1, 2, 3, 21, 22 and 23. Cry1Ab-specific IgG1 (d), IgE (e) and IgG2a (d) in serum after intranasal immunisation and booster of mice to trypsinised Cry1Ab and MON810 leaf extract and non-GM leaf extracts on days 0, 1, 2, 3, 21, 22 and 23.

Note: Asterisks (*) denote groups that are significantly different (p < 0.05) from control group exposed to physiological buffer only.

Figure 3. Cytokine IL-5 (a), MCP-1 (b), IL-17 (c), TNFα (d) and IFN (e) levels in BALFs collected on day 26 after intranasal exposure of mice to Cry1Ab protoxin and fresh maize pollen on days 0, 1, 2, 21, 22 and 23. Each circle represents one individual animal and bars represent group medians. The dotted lines indicate the lower quantitative detection limit of the assays.

Note: Asterisks (*) denote groups that are significantly different (p < 0.05) from the control group (CTRL) exposed to physiological buffer only.

Figure 4. Percentages (%) of macrophages (a), neutrophils (b), lymphocytes (c) and eosinophils (d) in the BALFs collected on day 26 after intranasal exposure of mice to trypsinised Cry1Ab (trypCry1Ab), or leaf extracts from the genetically modified maize event MON810 and its conventional counterpart (non-GM) on days 0, 1, 2, 21, 22 and 23. Bars represent group medians and circles represent one individual animal.

Note: Asterisks (*) denote groups that are significantly different (p < 0.05) from the control group exposed to physiological buffer only.

Figure 5. Cytokine IL-10 (a), IFNγ (b), IL-4 (c), IL-13 (d) and IL-17 (e) secretion (pg/mL) from mediastinal lymph node (MLN) cells collected on day 26 after intranasal exposure of mice to trypsinised Cry1Ab (trypCry1Ab), or leaf extracts from the genetically modified maize event MON810 or its conventional counterpart (non-GM) on days 0, 1, 2, 21, 22 and 23. Each circle represents one individual animal and bars represent group medians. The dotted lines indicate the lower quantitative detection limit of the assays.

Note: Asterisks (*) denote groups that are significantly different (p < 0.05) from the control group exposed to physiological buffer only.