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

<bold>Purpose: </bold>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.<bold>Methods: </bold>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.<bold>Results: </bold>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).<bold>Conclusion: </bold>Mild hypothermia inhibited the production and accumulation of MDSCs induced by LPS administration in septic mice. [ABSTRACT FROM AUTHOR]