Abstract:

o observe the changes in the secretion of IL-12,IL-18 and the expressions of TLR4 in J774A.1 cells after ionizing irradiation,and explore the mechanism of Toll signaling pathway.Methods J774A.1 cells were divided into low dose (0.075 Gy)and high dose (2.00 Gy) irradiation groups,each group included sham irradiation,4,8,16,24,48 h  after irradiation subgroups. Flow cytometry and ELISA were used to detect the expression of TLR4 and the protein levels of IL-12 and IL-18, respectively. Results
At early stage,both of IL-12（4 h） and IL-18（4 h） expressed more than sha
m irradiation after low dose ionizing radiation,and then gradually returned to the   level in sham irradiation group. After high dose ionizing radiation,the expression of IL-12 kept higher level compared with  sham irradiation group at 4 -24 h（P<0.05 or P<0.01）,and then returned to the  normal level at 48 h;while the expression of IL-18 was similar with that in low dose  irradiation group,it was up-regulated at 4 h after irradiation（P<0.05）,and then gradually returned to the control level. Conclusion Ionizing radiation  can　increase the expression of TLR4 and the protein levels of IL-12,IL-18 and promote the immune response and start innate immunity.

Key words: X-rays;J774A.1 cells;Toll-like receptor;interleukin-12;interleukin-18