Abstract:

Objective  To study the effects of immune complexes on proliferation, cytokine secretion and phagocytosis of monocyte macrophages in vitro. Methods  The immune complexes group：necrosis supernatant + Systemic lupus erythematosus(SLE) serum;  five control groups: the (necrosis supernatant + normal human serum) group, the necrosis supernatant group, the SLE serum group, the normal serum group and the medium group, all groups were applied to U937 cells and macrophages induced from U937 cells. 24 hours later, U937 cell proliferation was detected by CCK-8 assay, Tumor necrosis factor-a (TNF-α) and B cell activating factor (BAFF) were determined by RT-PCR, neutral red colorimetric assay phagocytosis of macrophages. Results  Compared with the control groups, immune complexes could significantly promote the proliferation of U937 cells (P<0.05), TNF-a and BAFF mRNA expression levels were significantly increased (P<0.05), and immune complexes could significantly inhibit the phagocytosis of macrophages (P<0.05). Conclusion  Immune complexes can cause abnormal activation of the mononuclear phygocyte system (MPS), which leads to increased production and decreased removal of immune complexes. Thus, immune complexes are involved in the occurrence and development of SLE.

Key words: Systemic lupus erythematosus; Immune complexes; Monocyte macrophage; Proliferation; Secretion; Phagocytosis