Multiple vaccinations with tumor cells secreting gp96-Ig expanded tumor-reactive CD8+ T lymphocytes and increased survival in T cell-replete syngeneic HSCT recipients with lymphoma. Transplants were performed as in Figure 3, and recipients were inoculated intraperitoneally with 1.0 × 105 E.G7 lymphoma cells the following day to simulate tumor relapse after HSCT. (A) Equivalent survival of HSCT recipients with lymphoma receiving T cells from tumor-bearing or tumor-naive donors or no T cells; n = 4 to 5 from 3 independent experiments; x, no vaccine (tumor); +, no vaccine (naive); −, no T cells. (B) Multiple vaccinations with gp96-Ig-secreting tumor cells efficiently expanded tumor-reactive CD8+ T cells in lymphoma-bearing HSCT recipients. Two days following tumor inoculation, recipients were vaccinated intraperitoneally with irradiated (40 Gy) E.G7 lymphoma cells secreting gp96-Ig and repeated every 3 days for a total of 5 vaccinations; n = 20 from pool of 4 experiments; x, no vaccine; ♦, E.G7; ●, E.G7-gp96-Ig. (C) Vaccination with tumor cells secreting gp96-Ig led to increased MST and overall survival of lymphoma-bearing HSCT recipients; n = 4 to 5; x, no vaccine; ♦, E.G7; ●, E.G7-gp96-Ig; ○, E.G7-gp96-Ig (no T cells). The no vaccine group illustrated here is shown in A with other nonvaccinated groups. (D) Equivalent survival of vaccinated HSCT recipients receiving T cells from tumor-bearing or tumor-naive donors; n = 6; ●, E.G7-gp96-Ig (tumor); ○, E.G7-gp96-Ig (naive).
