Effects of 10-T static magnetic field on human peripheral blood immune cells

The exposure of peripheral blood mononuclear cells (PBMCs) was performed in a 10-T static magnetic field. Without lymphocyte stimulation, there were no significant differences in the viability of the exposed and unexposed CD4(+) T cells, CD8(+) T cells, B cells, and natural killer (NK) cells. The expression of Th1 type chemokine receptor, CXCR3, and Th2 type receptor, CCR3, was unaltered after magnetic-field exposure. No differences were observed in the naive T cells and memory T-cell subclasses in either CD4(+) or CD8(+) T cells. In contrast to the unstimulated condition, the magnetic-field exposure reduced the viability of phytohemagglutinin (PHA)-activated T cells in both the CD4(+) and CD8(+) subclasses. In particular, the number of PHA-treated naive CD8(+) T cells (CD45RA(+)CD4(-)CD8(+)) was markedly decreased after the magnetic-field exposure, while PHA-treated memory CD8(+) cells (CD45RA(-)CD4(-)CD8(+)) were resistant to the exposure. The number of PHA-treated naive CD4(+) T cells (CD45RA(+)CD4(+)CD8(-)) and memory cells (CD45RA(-)CD4(+)CD8(-)) was markedly decreased to a similar degree. Thus the susceptibility of lymphocytes to the magnetic-field exposure differed among activated T-cell subtypes. The magnetic-field exposure significantly increased the death of PHA-stimulated lymphocytes by apoptosis. These results suggest that a strong static magnetic field has acute effects on immune cells during cell division, while the field exposure has a minimal effect on immune cells in a nondividing phase.