Bioeffects And Molecular Mechanisms Of EMP On T Lymphocytes

Electromagnetic pulse(EMP), which is a kind of highpower electromagnetic wave, is widely applied in many fields, and has attracted much attention on its bioeffects and molecule mechanisms. The immune system is a primary mechanism of defending the foreign aggression and damage. It has been found that electromagnetic radiation has all kinds of effects on the immune system. But the effects of the EMP, as a special electromagnetic radiation, on T lymphocytes has few report.AIM:To investigate effects and mechanisms of EMP on T lymphocytesMETHODS:Part one:the four weeks old male BALB/c mice were exposed to the EMP, the parameters of which is that the field density is200kV/m, Tr is3.5ns, pulse width is14ns, repetitive frequency is1Hz,400pulses per day and for a week. The following parameters were observed after EMP exposure.1. The thymus and the spleen were HE stained to show the morphological changes; 2. The weight of the body was obtained before killed, The weight of the spleen and the thymus was measured after killed, then to calculate the thymus and spleen index; To count the number of lymphocytes in the spleen and the thymus by extracting;3. To examine the percentage of T cells and B cells in the spleen by FCM (Flow Cytometry);4. The apoptosis and the cell cycle of the lymphocytes in the spleen were measured by FCM;5. The migration ability of the lymphocytes in the spleen was examined by Migration assay after exposure with different times groups (control,100pulses,200pulses,400pulses) and different time groups (1d,3d,7d,14d,28d);6. To check the level of SDF-1excreted in the spleen by ELISA;7. To show the expression of the p-AKT of the lymphocytes in the spleen by Western blotting;Part two:the Jurkat T cell was exposed to the same EMP, and the following parameters were checked:1. To observe the migration ability of the Jurkat cell by Migration assay after exposure with different times groups(sham,100pulses,200pulses,400pulses) and different time groups(sham,1h,3h,6h,12h,24h);2. To examine the surface expression of CXCR4on the Jurkat cell membrane by the FCM;3. To check the changes of PI3K、p-AKT、PAK1、Racl of the Jurkat cell by Western blotting;4. The expression of IL-4and IFN-y of the Jurkat cell was detected by ELISA assay. RESULTS:Part one:The male BALB/c mice was exposed to EMP,(1) the structure of the thymus has no significant changes after exposure; the blood sinus of the spleen is expanded, prominent hyperemic, the structure of the splenic corpuscle is not clear;(2) the changes of thymus index has no stastical meaning, the spleen index of the exposure group is higher than the control group on the3rd and7th day after the exposure; the number of the thymus lymphocytes has no remarkable changes, the number of the spleen lymphocytes of the exposure group is more than the sham on the3rd and7th day after exposure;(3) the percentage of T cell in the spleen is increasing comparing to the sham group, the B cell has no significant changes;(4) EMP exposure has no effects on the cycle and apoptosis of the lymphocytes;(5) the migration ability of the400pulses group is stronger than the control group, and the migration ability of the lymphocytes in the spleen is more faster on the1st,3rd and7th day after the exposure;(6) the level of SDF-1in the spleen is increasing;(7) the expression of p-AKTis increasing according to the time of the migration.Part two:After exposed to EMP, the Jurkat T cell shows that,(1) the migration ability of the200times group is significantly increasing than other groups; and faster at1h,3h,6h after exposure than the sham;(2) the expression of CXCR4is more than the sham at6h after exposure;(3) the changes of the expression of PI3K, p-AKT, PAK-1and Racl has a link with the time of migration ability changes;(4) the expression of IL-4is higher at3h and6h after exposure, and IFN-y is increasing at1h,3h and6h after exposure. CONCLUSIONS:Under this experimental conditions:EMP exposure has no significant effect on the thymus. The structure of the spleen is damaged; the weight of the spleen is increasing, and the number of the lymphocytes in the spleen is mounting up; there is no effects on cell cycle and apoptosis of lymphocytes; Furthermore, with the EMP exposure, the migration ability of the lymphocytes in the spleen is more faster and the migration ability of the Jurkat cell is stronger.