Is there an adaptive response in spleen lymphocytes of C57B1/6 mice as assessed by chromosomal aberrations?

In previous publications we have shown that no adaptive response could be induced in preimplantation embryos and spleen lymphocytes of Heiligenberger mice, a strain inbred at our institute (Wojcik et al., Int. J. Radiat. Biol. 62, 177-186, 1992; Müller et al., Int. J. Radiat. Biol. 62, 169-175, 1992). Because of data indicating that some humans may be genetically deficient in the ability to express an adaptive response, we have speculated that the cells of the Heiligenberger strain may lack an adaptive response. To check this, experiments have been done with spleen lymphocytes of the C57B1/6 mice. Initial results indicated the presence of an adaptive response in some individual C57B1/6 mice. However, an analysis of aberration scores of parallel lymphocyte cultures revealed a high intraindividual variability, indicating that the adaptive response observed initially was a reflection of this variability rather than of induced radiation resistance. This conclusion is confirmed further by the lack of such variability in parallel cultures of lymphocytes from Heiligenberger mice.