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Clinical and Developmental Immunology
Volume 2013, Article ID 923107, 5 pages
Research Article

Tumor Protective Activity of CD4+ but Not of CD8+ T Cells in DNA-Vaccinated Mice Challenged with bcr-abl-Transformed Cells

Institute of Hematology and Blood Transfusion, Department of Experimental Virology, U Nemocnice 1, 12820 Prague 2, Czech Republic

Received 21 August 2013; Revised 31 October 2013; Accepted 2 November 2013

Academic Editor: Shigeo Koido

Copyright © 2013 Martina Petráčková et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


In the recent past, it has repeatedly been reported that CD4 cells play an important role in the immunology of chronic myeloid leukaemia. It was therefore of interest to test their activity in an animal model using bcr-abl-transformed cells. BALB/c mice were four times immunized with a DNA vaccine carrying the bcr-abl fusion gene. Two weeks after the last vaccine dose, the animals were challenged with syngeneic bcr-abl-transformed 12B1 cells which form solid tumors after subcutaneous administration. At the time of challenge, animals were treated with antibodies against the CD8+ T cells or CD4+ T cells. The efficacy of the depletion was monitored and found highly effective. All nonimmunized animals developed tumors. All animals untreated with the antibodies as well as those in which CD8+ T cells had been depleted, were fully protected against the challenge. On the other hand, almost all mice treated with anti-CD4+ antibody developed tumors. These results strongly suggested that the CD4+ T cells acted as effectors in the present system.