Bcl6 is essential for the generation of long-term memory CD4+ T cells. Int Immunol 19

Bcl6 plays a role in the generation and maintenance of memory CD81 T cells. We analyzed here a role for Bcl6 in the generation of long-term memory CD41 T cells. Naive CD45RB1 CD41 T cells from Bcl6-deficient DO11.10 (KJ1.261) transgenic mice were transferred into BALB/c mice and immunized with ovalbumin peptide and LPS. Long-term memory KJ1.261 CD41 T cells from wild-type mice were detected in the spleen, lungs and liver during 10 weeks after immunization; however, Bcl6-deficient KJ1.261 CD41 T cells were vanished completely in those organs 4 weeks after immunization. Since memory CD41 T cells can be generated from effector CD41 T cells, properties of Bcl6-deficient effector CD41 T cells were compared with those wild-type effector CD41 T cells 10 days after immunization. Numbers of IFN-g-non-producing CD45RB2, CD62L1 or IL-7Ra1 effector CD41 T cells in the spleen, lungs and liver were similar between Bcl6-deficient and wild-type CD41 T cells. However, the percentage of apoptotic cells in Bcl6-deficient effector CD41 T cells was higher than that in wild-type effector CD41 T cells. At the late effector phase, the number of IFN-g-non-producing cells and the percentage of apoptotic cells in Bcl6-deficient CD41 T cells were smaller and higher than those in wild-type CD41 T cells, respectively. These data suggest that Bcl6 in CD41 T cells plays a rol