FIG. 3.

Clonal expansion of OT-I CD8⁺ and OT-II CD4⁺ T cells following intranasal immunization with S. gordonii. CFSE-labeled OT-I CD8⁺ and OT-II CD4⁺ T cells were adoptively cotransferred into C57BL/6 mice, and then the mice were intranasally immunized with 10⁹ CFU of the recombinant vaccine strain GP1456 or control strain GP1295. OVA-specific proliferation of OT-I CD8⁺ and OT-II CD4⁺ T cells was assessed in cervical lymph nodes (CLN), lung, and spleen collected 5 days after immunization and analyzed as CFSE dilution (x axis) on the gated CFSE-positive CD8⁺ or CFSE-positive CD4⁺ populations with light scatter properties of lymphocytes. The percentage of proliferating cells is reported above peaks.