Fig 1.

Immunization with the YopE_69-77 peptide induces YopE_69-77-specific CD8 T cell responses. C57BL/6 mice were immunized intranasally with 10 μg YopE_69-77 peptide mixed with cholera toxin (CT) as an adjuvant on days 0, 7, and 21. Control mice received CT alone at the same times. The presence of total and YopE_69-77-specific CD8 T cells in the indicated organs was determined by flow cytometry and tetramer staining 16 days after the last immunization. (A) Representative images of the analysis of the single-cell suspension prepared from mouse lung, spleen (SPL), and mesenteric lymph nodes (MLN) obtained from either control mice (CT; left) or peptide-immunized mice (YopE_69-77 plus CT; right). The percentage of total cells contained in each quadrant is shown. (B) Summary of the percentage of YopE_69-77-specific CD8 T cells within total CD8 T cell populations in the indicated organs from either CT-immunized mice (triangle) or YopE_69-77 peptide-plus-CT-immunized mice (square). Each symbol represents the value obtained from one mouse. The data shown are the summary of two independent experiments with cohorts of 2 to 3 mice. By Mann-Whitney test, “**” indicates P values of less than 0.01 compared to treatment with CT alone.