Effects of a reduced oxygen tension culture system on human T cell clones as a function of in vitro age.

Oxidative DNA damage has been suggested to contribute to the decline in T cell clone (TCC) function with increased age in vitro. To test this hypothesis the effect of a reduced oxygen tension culture system (6% O2) on TCCs was examined. Specifically, the effects of the altered culture conditions on DNA damage levels, in vitro lifespan and proliferative capacity were assessed in five independently derived human CD4+ TCCs. DNA damage levels over the entire lifespan were significantly lowered by reducing oxygen tension. Lifespan (total population doublings (PDs) achieved) and proliferative capacity (PDs/week) were reduced for all clones under reduced oxygen tension when compared to standard culture conditions. This observed tendency warrants further investigation using a greater number of clones from donors of all age groups before definitive conclusions regarding the effect of low oxygen tension on the lifespan and proliferative capacity of TCC can be made. However, these results may suggest that the reduced oxygen tension culture system has interfered with some aspect of T cell biology not yet examined within the remit of this study.