A, Antigen-activated pmel (CD45.2+ CD90.1−) or MyD88−/− pmel (CD45.2+ CD90.1+) T cells were injected into C57BL6 mice. Blood samples were analyzed 45 days after transfer by flow cytometric staining for specific congenic markers. B, The number of transferred cells in the spleen, lymph nodes, bone marrow, liver and lung were analyzed by flow cytometry at the indicated time points after transfer. C, 20 days after adoptive transfer of pmel or MyD88−/− pmel T cells, mice were vaccinated with gp100, CpG-ODN in IFA and the number of pmel and MyD88−/− pmel CD8+ T cells in the blood were measured by flow cytometric analysis at the indicated time points after vaccination. Statistics were generated by student T test comparing pmel and MyD88−/−pmel T cells, *P <0.05, **P <0.01.