Mucosal B cells are activated by Nm OMVs to induce T-cell proliferation. Purified tonsil B cells (106/mL) were stimulated with Pansorbin, 50 μg/mL; H44/76, 25 μg/mL; and LpxA−, 25 μg/mL OMVs. After 48 hours, the expression of CD25, CD40, and CD86 was evaluated on CD19+ B cells with the use of flow cytometry. The histogram black line represents antigen stimulated cells, gray shaded area is media only, and black fill is unstained cells. Data shown are normalized to the number of events (A). In parallel, purified CD3 T cells (106/mL) were added to unstimulated, H44/76 (15 μg/mL)- and H44/76 (25 μg/mL)-stimulated B cells (106/mL) at a 1:1 ratio. Proliferation was assessed by tritiated-thymidine (3HTdR) incorporation during days 4 to 9 of culture (B). Results are representative of at least 3 separate experiments.
