Figure 3. A role of MLN but not the thymus in cross-differentiation from the CD8 T-cell lineage to CD4⁺Foxp3⁺ CI-T_reg cells.

(A–C) Analyses of OT1⁺Rag^o mice 2 wks post MLN removal: (A) success of MLN removal; (B) representative flow cytometry plots (the numbers in the flow cytometry plots represent percentages of gated populations); (C) Summary of CD4⁺ and CD4⁺Foxp3⁺ cell counts (n=4, mean±SEM). (D) Conversion of purified peripheral OT1⁺CD8⁺CD4⁻CD25⁻Foxp3⁻ cells after transfer into athymic hosts. MHCII⁺ or MHCII^o OT1⁺Rag^o donors were used to purify the peripheral CD8 T cells to examine whether presence of MHCII during maturation of the CD8 T cells enables a lasting potential for their conversion to CD4⁺ cells in a new host. (E) MHCII⁺ or MHCII^o Rag^o recipients were used to examine the requirements of MHCII during conversion of adoptively transferred OT1⁺Rag^o CD8 T cells. Representative flow cytometry plots are followed by a summary of CD4⁺ and CD4⁺Foxp3⁺ cell counts. Each data point represents one animal (n=5–7, mean±SEM).*, p<0.05.