Effect of mild hypothermia on the increase of CD11b+ Gr-1+ myeloid-derived suppressor cells induced by lipopolysaccharide in a mouse model of sepsis

This study aimed to investigate the influence of mild hypothermia on the number of CD11b+ Gr-1+ myeloid-derived suppressor cells (MDSCs) induced by lipopolysaccharide (LPS) injection in mice with sepsis. BALB/c mice were administered LPS to establish a mouse model of sepsis. Then, these mice were randomly divided into 3 groups: the mild hypothermia plus LPS group, the normothermia plus LPS group, and the LPS group. The normal control group was injected the same amount of 0.9% sodium chloride solution. The ratio of CD11b+ Gr-1+ MDSCs in the mouse spleen and bone marrow was determined at 6, 12, 24, 48, and 72 hours after LPS injection and after injected 0.9% sodium chloride solution. Compared with the control group, the number of MDSCs in the spleen in the sepsis group increased gradually, and the difference was significant at 12 hours after injection (P < .01). Moreover, the number of MDSCs was the lowest in the mild hypothermia group, and there was a significant difference than the other 2 groups at 48 hours (P < .01). The number of MDSCs in the bone marrow increased gradually, and the difference between the sepsis and control groups was significant at 24 hours (P < .01). The number of MDSCs in the mild hypothermia group was the lowest, and there was a statistically significant difference than the other 2 groups (P < .05). Mild hypothermia inhibited the production and accumulation of MDSCs induced by LPS administration in septic mice.