Table I.
EXO-targeted CD4+ T cell vaccine protects against lung tumor metastases
| Vaccinesa | Tumor Growth Incidence (%) | Median Number of Lung Tumor Colonies |
|---|---|---|
| Expt. 1 | ||
| DCOVA | 2/8 (25) | 17 ± 6 |
| aTEXO | 0/8 (0) | 0 |
| aT | 8/8 (100) | >100 |
| PBS | 8/8 (100) | >100 |
| Expt. 2 | ||
| aTEXO(IL-2−/−) | 7/8 (88) | 78 ± 20 |
| aTEXO(IFN-γ −/−) | 0/8 (0) | 0 |
| aTEXO (TNF-α −/−) | 0/8 (0) | 0 |
| aTEXO (CD40−/−) | 0/8 (0) | 0 |
| aTEXO (CD54−/−) | 3/8 (38) | 26 ± 8 |
| aTEXO (CD80−/−) | 5/8 (63) | 47 ± 23 |
| aTEXO (K b−/−) | 7/8 (88) | 84 ± 17 |
| PBS | 8/8 (100) | >100 |
| Expt. 3 | ||
| DCOVA | 4/8 (50) | 14 ± 9 |
| aTEXO | 0/8 (0) | 0 |
| PBS | 8/8 (100) | >100 |
| Expt. 4 | ||
| DCOVA | 2/8 (25) | 17 ± 6 |
| DCOVA plus Tr cells | 8/8 (100) | >100 |
| aTEXO | 0/8 (0) | 0 |
| aTEXO plus Tr cells | 0/8 (0) | 0 |
| PBS | 8/8 (100) | >100 |
In experiment 1, the wild-type C57BL/6 (B6) mice (n = 8) were i.v. immunized with DCOVA, aT and aTEXO cells, or PBS. In experiment 2, the wild-type C57BL/6 mice (n = 8) were i.v. immunized with either aTEXO cells or aTEXO cells with various gene KO. Six days after the immunization, each mouse was challenged i.v. with OVA-expressing (BL6–10OVA) tumor cells (0.5 × 106 cells/mouse). In experiment 3, the wild-type C57BL/6 mice (n = 8) were i.v. immunized with DCOVA, aTEXO, or PBS. Three months after the immunization, each mouse was challenged i.v. with BL6–10OVA tumor cells (2 × 106 cells/mouse). In experiment 4, the wild-type C57BL/6 mice (n = 8) were i.v. immunized with DCOVA, aTEXO cells alone or together with CD4+25+ Tr cells. Six days after the immunization, each mouse was challenged i.v. with OVA-expressing (BL6–10OVA) tumor cells (0.5 × 106 cells/ mouse). All the mice were sacrificed 4 wk after tumor cell challenge and the numbers of lung metastatic tumor colonies were counted. One representative experiment of three is shown.