Intrathymic inoculation of the radiation leukemia virus (RadLV) into C57BL/6 mice induces thymic lymphomas after 4-6 months. During premalignant latency, a population of RadLV-infected prelymphoma (PL) cells (whose survival is dependent on autostimulation with IL-4) persists in the thymus. PL cells explanted from RadLV-inoculated mice can be propagated in cultures containing IL-4, and in vitro growth of PL cells is effectively inhibited by anti-IL-4 antibodies. We subjected RadLV-inoculated mice to prophylactic treatment with anti-IL-4 antibodies and a virus-specific immunotoxin (IT). Administration of IT delayed the onset of lymphoma but was not curative. Anti-IL-4 antibodies had a similar effect when administered at low doses. High doses of anti-IL-4, given 3-5 weeks after virus inoculation, provided complete protection against lymphoma. These results demonstrate the effectiveness of prophylactic intervention during premalignancy by using antagonists that restrain the growth of PL cells.
ASJC Scopus subject areas
- Cancer Research