Reversible effect of magnetic fields on human lymphocyte activation patterns: different sensitivity of naive and memory lymphocyte subsets.

The aim of this study was to investigate the influence of 50 Hzmagnetic or static magnetic fields of 0.5 mT on subsets of humanCD4+ T cells in terms of cytokine release/content, cellproliferation and intracellular free calcium concentration.CD4+ T cells can be divided into different subsets on the basisof surface marker expression, such as CD45, and T cells can bedivided into naive (CD45RA+) and memory (CD45RA2) cells. Inthis study, the effects of magnetic fields after 24 and 48 h of cellculture were analyzed. We found that the CD4+CD45RA2 Tsubset were more sensitive after 2 h of exposure. Decreases inthe release/content of IFN-c, in cell proliferation and inintracellular free calcium concentrations were observed inexposed CD4+CD45RA2 T cells compared to CD4+CD45RA+T cells. The results suggest that exposure to the magnetic fieldsinduces a delay in the response to stimulants and thatmodifications are rapidly reversible, at least after a shortexposure.