The dynamic changes of anti-Gr-1 to deplete myeloid-derived suppressor cells in newborn mice

Abstract

Objective To analyze the dynamic changes of myeloid-derived suppressor cells(MDSCs)in newborn mice after the inoculation of anti-Gr-1 antibody and to discuss the efficiency and reaction time of depleting MDSCs. Methods Neonatal BALB/c mice(n=50) were randomly separated into 5 groups and were intraperitoneally inoculated with anti-Gr-1(15 μg). All mice were sacrificed at day 9 after birth.liver and spleen were collected to centrifuge for the mononuclear cells respectively and MDSCs(CD11b+ Gr-1+ ) were analyzed through flow cytometry. Results ①Compared with the normal mice, MDSCs in the spleen of the experimental mice, which were inoculated with anti-Gr-1 for 4 hours, were significantly reduced[(9.19±1.40)%vs.(26.01±2.26)%, t=20.266, P<0.05]and still remained for 24~48 hours.The ratio of depleting MDSCs reached at 64.6% but after 48 hours the ratio declined to 35.1%.②Compared with the normal mice, MDSCs in liver of the experimental mice which were inoculated with anti-Gr-1 for 24 hours, were significantly reduced[(8.98±1.03)%vs.(15.75±1.10)%, t=11.12, P<0.05]. The ratio of depleting MDSCs reached 42.9%.After 48 hours the ratio increased to 70.9%.③Compared with the same experimental gourp, the ratio of MDSCs subsets(M-MDSCs/G-MDSCs) in murine liver and spleen were obviously different. Conclusion The efficient and reacted time of depleting MDSCs with anti-Gr-1 are different in murine liver and spleen.After inoculating with anti-Gr-1, it will retain the levels of 35.1%~64.6% MDSCs in murine spleen between 4 and 48 hours, but it will retain the levels of 42.9%~70.9% MDSCs in murine liver between 24 and 48 hours. Key words: Myeloid-derived suppressor cells; Innate immunity; Anti-Gr-1; Neonatal mice; Flow cytometry