T cell receptor transgenic lymphocytes infiltrating murine tumors are not induced to express foxp3

Table 2 Adoptive transfer of CD4 T cells populations into B16-OVA tumor-bearing mice.

Percent Foxp3^EGFP Positive Cells Received From Spleen and Tumor
T Cell Subsets Adoptively Transferred	Spleen day 5	Tumor day 5	Spleen day 10	Tumor day 10	Spleen day 15	Tumor day 15
Bone marrow control (0%)	0.0, 0.0		0.0, 0.0		0.0, 0.0
C57BL/6 CD4 (0%)	0.0, 0.0		0.3, 0.5	0.0,0.0	0.0, 0.0
C57BL/6 nTreg CD4 (100%)	1.4, 1.9		11.7, 15.2		14.8, 20.8
C57BL/6 iTreg CD4 (26%)	0.4, 0.3		4.5, 3.8		0.4, 2.0
OTII CD4 (0%)	0.0, 0.1		0.0, 0.0		0.0, 0.0	0.0, 0.0
OTII iTreg CD4 (10.4%)	0.2, 0.0	0.0, 0.0	0.9, 1.4	0.1, 0.1	0.3, 0.4
	SPLEEN day 7	TUMOR day 7	SPLEEN day 14	TUMOR day 14	SPLEEN day 25	TUMOR day 25
Pmel CD8 (<1%)	0.0, 0.0	0.1, 0.1	0.0, 0.0	0.1, 0.1	0.0, 0.0	0.0,0.0

C57BL/6 (CD45.2) mice bearing (five-day) B16-OVA tumors were irradiated with 900 cGy. The following day, all mice received bone marrow, from syngenic CD45.1 mice. Several different populations of cells were adoptively transferred into B16-OVA tumor-bearing mice. These cells were activated for 72 hours with αCD3/αCD28/IL-2, and in some cases flow-purified to yield a homogenous population of Foxp3^EGFP-positive or negative cells. These cell populations included: (1) 10⁵ C57BL/6 CD4 T cells (0% Foxp3^EGFP); (2) 10⁵ C57BL/6 CD4 nTreg (100% Foxp3^EGFP); (3) 10⁵ C57BL/6 CD4 TGFβ-induced iTreg (flow purified Foxp3^EGFP-negative CD4 T cells, activated in the presence of TGFβ for 72 hours to yield ~26% Foxp3^EGFP iTreg); (4) 10⁵ OTII CD4 T cells (0% Foxp3^EGFP); (5) 10⁵ OTII CD4 iTreg (10.4% Foxp3^EGFP); and 10⁶ Pmel CD8 (<1% Foxp3^EGFP). When sufficient numbers of TIL could be isolated for flow (at least 10³), these were also surface phenotyped.

ISSN: 1756-8722