Enhancement of Th1 immune response by CD8alpha(+) dendritic cells loaded with heat shock proteins enriched tumor extract in tumor-bearing mice.

The discovery of dendritic cells (DCs) as professional antigen presenting cells has opened up new possibilities for their use in the development of tumor vaccines. We investigated the effect of the CD8alpha(+) DCs loaded with heat-treated tumor lysate (HTL) as a vaccine in tumor immunotherapy. The HTL loaded CD8alpha(+) DCs, TL loaded CD8alpha(+) DCs and unloaded CD8alpha(+) DCs were subcutaneously injected in the fibrosarcoma-bearing mice. The splenocyte proliferation and the shifting of Th1/Th2 response were measured. The results indicated a significant increase in the lymphocytes proliferation and the IFN-gamma production in the test group of mouse splenocytes. According to the results, HTL loaded CD8alpha(+) DCs vaccine significantly decreased tumor growth and longer survival than the other immunized animals. These findings show that anti-tumor immune response against the fibrosarcoma can be induced by HTL loaded CD8alpha(+) DCs and may provide a useful therapeutic model for development of approaches to tumor treatments.