AML tumor cell growth suppression is dependent on affinity to CD3ε
| AML cell lines . | MFI ratio CLL-1 . | FAB subtype . | CLL1/CD3H EC50 (ng/mL) . | CLL1/CD3H % depletion . | CLL1/CD3L EC50 (ng/mL) . | CLL1/CD3L % depletion . |
|---|---|---|---|---|---|---|
| Molm-13 | 1.1 | M5 | 19.9 | 51 | 147 | 57 |
| ML-2 | 2.4 | M4 | 2.8 | 100 | 304 | 81 |
| THP-1 | 4 | M5 | 2.5 | 92 | 131 | 90 |
| EOL-1 | 4.7 | M4-EOS | 2 | 82 | 172 | 78 |
| Nomo-1 | 4.9 | M5 | 11.8 | 76 | 263 | 84 |
| HL-60 | 12.7 | M5 | 2.2 | 100 | 119 | 47 |
| U937 | 21 | M2 | 2.7 | 100 | 70 | 89 |
| PL-21 | 21.4 | M3 | 5.8 | 99 | 129 | 98 |
| AML cell lines . | MFI ratio CLL-1 . | FAB subtype . | CLL1/CD3H EC50 (ng/mL) . | CLL1/CD3H % depletion . | CLL1/CD3L EC50 (ng/mL) . | CLL1/CD3L % depletion . |
|---|---|---|---|---|---|---|
| Molm-13 | 1.1 | M5 | 19.9 | 51 | 147 | 57 |
| ML-2 | 2.4 | M4 | 2.8 | 100 | 304 | 81 |
| THP-1 | 4 | M5 | 2.5 | 92 | 131 | 90 |
| EOL-1 | 4.7 | M4-EOS | 2 | 82 | 172 | 78 |
| Nomo-1 | 4.9 | M5 | 11.8 | 76 | 263 | 84 |
| HL-60 | 12.7 | M5 | 2.2 | 100 | 119 | 47 |
| U937 | 21 | M2 | 2.7 | 100 | 70 | 89 |
| PL-21 | 21.4 | M3 | 5.8 | 99 | 129 | 98 |
CLL-1 expression for each AML cell line is expressed as the MFI Ratio between CLL-1 MFI divided by Isotype MFI; (Burkitt lymphoma cell line, Namalwa, was used as a negative control and had a MFI ratio of 0.9). EC50 is the concentration of TDB, CLL1/CD3H, or CLL1/CD3L, which was required to inhibit cell growth of AML tumor cell lines in the presence of purified effector human CD8+ T cells and TDB. Nonspecific targeting by CLL1/CD3H was performed on two B cell lines, WSU (non-Hodgkin lymphoma) and BJAB (Burkitt lymphoma), and were shown to have no effect on cell growth compared with a positive control anti-CD20/CD3H TDB and a negative control nontargeting (NT)/CD3H TDB (data not shown). Percent depletion measures the depth of the response or amount of tumor cell lyses as determined by fluorescence-activated cell sorting.