• Treg;
  • FoxP3;
  • DNA damage;
  • apoptosis;
  • flow cytometry


A number of apoptotic stimuli produce a different response by CD4+ regulatory and effector lymphocytes. So far, little is known concerning the sensitivity of CD4+ regulatory T cells (Treg) to genotoxic agents. Observations from a mouse model suggest that Treg are more resistant to DNA damage compared to CD4+ T effector cells (Teff). By flow cytometry we analysed the apoptotic response to genotoxic stimuli in culture, comparing Treg and Teff. CD4+ regulatory lymphocytes appeared to be more resistant than CD4+ effector lymphocytes. Results of costaining experiments for CD45RA suggest that this dissimilarity is not related to the differentiation to a CD45RA negative phenotype. Further, neither the antiapoptotic protein Bcl-2 nor Bcl-xL were found to be expressed in greater amounts by Treg compared to Teff. The differential sensitivity of Treg and Teff to DNA-damage inducing agents may be of clinical relevance in cancer therapy. © 2011 International Society for Advancement of Cytometry