Table VI.

Frequencies of tetramer⁺ CD4⁺ cells in PBMC, spleen, LN, and liver at euthanasia

	Frequency (%) of tetramer+ CD4+ cells from the following groupa
	Immunized				Control
Cell sourceb	3892	3937	3943	3959	3962	3989
PBMC (pre-immunization)	0.0009	0.0003	0.0020	0.0005
PBMC (challenge)	0.0361	0.0090	0.0324	0.0206	0.0015	0.0001
PBMC (death)	0.0003	0.0002	0.0003	0.0003	0.0006	0.0002
Spleen (death)	0.0004	0.0018	0.0048	0.0003	0.0006	NDc
LN (death)	0.0013	0.0001	0.0026	0.0003	0.0018	0.0007
Liver (death)	0.0019	0.0027	0.0032	0.0021	NDc	0.0009

^aCryopreserved lymphocytes were thawed, and viable cells stained with the *1101-F2-5B tetramer. The percentage of tetramer⁺ CD4⁺ cells of total CD4⁺ T cells was calculated. Numbers in bold represent significantly higher mean frequencies of tetramer⁺ CD4⁺ T cells in compared with those in PBMC pre-immunization using a one-tailed paired t-test (P= 0.008 for liver and P= 0.014 for PBMC at the time of challenge).

^bCryopreserved PBMC were obtained before immunization, on the day of challenge (day 321 post immunization; animals 3892, 3937, 3989, 3962), 5 days post-challenge (animal 3943), 12 days post-challenge (animal 3959), and at the time of death (day 63, animals 3892 and 3962; day 69, animal 3937; day 75, animal 3943; day 84, animal 3959, and day 89 post-challenge, animal 3989).

^cNot determined because of insufficient cell numbers.