Anti-Lipopolysaccharide egg yolk antibody enhance the phagocytosis of mammalian phagocytes

Abstract

Macrophages play crucial roles in combatting infectious disease by promoting inflammation and phagocytosis. The decline of macrophage phagocytic function will bring many serious consequence，include weakened pathogen clearance. As an avain antibody, IgY has been widely used in preventing and treating infectious diseases,but,whether it can enhance the phagocytic ability of mammalian macrophage in order to clear phathogens is still unknown. In this study, mouse peritoneal macrophages and THP-1 cells were cultured with anti-LPS IgY in vivo or in vitro respectively. Morphological observation, ELISA, fluorescence immunoassays and flow cytometry were used to study whether IgY could enhance phagocytosis of mammalian macrophages. It was found that without anti-LPS IgY, mouse peritoneal macrophages showed adherent growth with no differentiation and few pseudopod extension; but with effect of anti-LPS IgY, peritoneal macrophages presented more significant characteristics in adherent growth, extension deformation and protruding pseudopods. By flow cytometry, the macrophages from anti-LPS IgY injectioned group mice exhibited increased phagocytosis percentage(90.83±2.59%) and index(4.45±0.13) significantly compared to PBS groups(64.32±1.5%, and 2.36±0.11) and non-immunized IgY groups(65.94%±1.4%, and 2.4±0.15); to PMA-induced THP-1 cells, the similar results could be found. The percentage and index were significantly increased with much larger body and more pseudopods for THP-1 cells co-incubated with anti-LPS IgY(79.83±0.38% and 2.64±0.03), compared to cells co-incubated with PBS (68.07±0.52%, and 1.88±0.03) or non-immunized IgY(74.89±1.14% and 2.30±0.02). The results showed that anti-LPS IgY was effective in promoting growth of macrophages, the pseudopod extension and stronger phagocytic capacity. Our study indicated that anti-lps IgY could enhance phagocytic capacity of mammalian macrophages to internalize phathegens more effectively by larger body and more pseudopods. This may be important for IgY to prevent and treat infectious diseases.