Enhanced protective immunity in DBA/2 mice that receive sublethal irradiation and immune reconstitution

Objective: To observe the general status and the immunity of DBA/2 mice injected with leukemia vaccine during the immune reconstitution, and to observe the survival rate of these injected mice that were then challenged by L1210 cells. Methods: Normal mice and reconstituted lymphopenic mice (RLM; DBA/2 mice rendered lymphopenic with sublethal irradiation and reconstituted with naive splenocytes) were used in the vaccination and challenge experiments with L1210 cells. Results: Following vaccination, a significant increase of the IFN- γ was detected in the blood of vaccinated RLM compared with that of vaccinated normal mice, as assessed by ELISA. Significantly, greater protection was induced in vaccinated RLM, which led to a stronger protection from death. Conclusion: The vaccination of reconstituted lymphopenic hosts could elicit superior anti-tumor immunity compared with normal hosts, highlighting the potential clinical benefit of performing tumor vaccination during immune reconstitution.