Figure 4.

Development of CD4⁺ memory T cell populations in LdCen^−/−2W immunized mice. (A) Flow cytometric analysis of 2W⁺ and LLO⁺ CD4⁺ T cell populations enriched from spleen and lymph nodes of immunized animals 21 days after LdCen^−/−2W immunization. CD62L^hi, IL7-R⁺, CCR7⁺ CD4⁺ T cells are identified as central memory T cell populations. (B) Flow cytometric analysis of 2W⁺ and LLO⁺ CD4 T cell populations enriched from spleen and lymph nodes of immunized animals 21 days after LdCen^−/−2W immunization with asymptomatic infection (LdWT^LLO + LdCen^−/−2W). (C) CD62L^hi, IL7-R⁺ CCR7⁺ CD4⁺ T cell populations in different groups of animals at 21 days postimmunization. (D) CD62L^hi, IL7-R⁺ CCR7⁺ CD4⁺ T cell populations 57 days postimmunization with LdCen^−/−2Win various groups. Data from a representative experiment are shown with three to four mice per group per time point.