Table 1.
Multiple transfers of memory cells
| Experimental group | ADI performed with | nu/nu host | Duration of PEC within host | Deaths: day and frequency* | Untreated control: death day and frequency* | ||
|---|---|---|---|---|---|---|---|
| I | 1 × 107 DBA/2 iPEC | 1° | 33 days | – | 0/21 | d9 | 5/5 |
| II | 1 × 107 group I mPEC | 2° | 43 days | – | 0/19 | d8 | 2/2 |
| III | 5 × 106 group II mPEC | 3° | 41 days | d40 | 1/10 | d9 | 2/2 |
| IV | 5 × 106 group III mPEC | 4° | 145 days | d39 | 1/3 | d10 | 2/2 |
| d78 | 1/3 | ||||||
| d145 | 1/3 | ||||||
All animals received 4·5 Gy whole-body irradiation before being inoculated intravenously with 1 × 105 ESbL-Gal. Group I animals were treated with 1 × 107 day 3 (d3) immune peritoneal exudate cells (iPEC) obtained from ESbL-Gal-immunized DBA/2 mice. Memory peritoneal exudate cells (mPEC) were obtained from adoptive immunotherapy (ADI)-treated BALB/c nu/nu mice by injecting 1 × 107 irradiated (100 Gy) ESbL-Gal cells intraperitoneally 3 days before isolation of mPEC. These were used to confer tumour protection to ESbL-Gal-inoculated BALB/c nu/nu mice (group II) following the standard ADI protocol. This procedure was repeated three times, leaving the immune cells within each host for a minimum of 1 month (time spans indicated) before reisolation and transfer to the next host.
Total duration of the experiment: 8 months.
Frequency indicates the number of dead animals in relation to the total number of animals per group.