Abstract: Objective　To investigate the effects of SETD4 (SET-domain containing protein 4) knockout on the differentiation, maturity and function of pMφ (peritoneal macrophages), differentiation of immune cells in peripheral blood and spleen, and development of thymus and spleen in mice.　Methods　The expression of CD31 on pMφ was detected by flow cytometry. The release of both TNF- α and IL-6 from LPS-treated pMφ in SETD4-/- and SETD4+/+ mice were examined and compared by liquid chip technology. The phagocytosis of pMφ was detected by flow cytometry and the migration of pMφ was measured by Transwell system. The number and proportion of immune cells in blood and spleen from SETD4-/- and SETD4+/+ mice were detected by flow cytometry. Difference on the structure of thymus and spleen from SETD4-/- and SETD4+/+ mice was compared by HE staining.　Results　(1)Compared with SETD4+/+ cells, the release of TNF- α and IL-6 decreased in SETD4-/- pMφ in response to LPS stimulation, while there were no significant difference in  ratio, differentiation and maturity of pMφ. (2)There were no significant difference in phagocytosis and migration between SETD4-/- and SETD4+/+ pMφ. (3)There were no significant difference in number and proportion of immune cells in peripheral blood and spleen from SETD4-/- and SETD4+/+ mice. (4)SETD4 knockout had no significant effect on the structure of thymus and spleen from SETD4-/- and SETD4+/+ mice.　Conclusions　(1)SETD4 has a positive role in the production of TNF- α and IL-6 from LPS stimulated pMφ, while no significant effect on the differentiation, maturity, phagocytosis and migration of pMφ. (2)SETD4 knockout has no obvious effect on the differentiation of immune cells in peripheral blood and spleen, and the development of thymus and spleen.

Key words: SETD4, 　Immune cells, 　Peritoneal macrophages, 　Inflammatory cytokines