1.Immunomodulatory activity of macrophage trained induced by Streptococcus plur-animalium
Xinyi DU ; Yu GAO ; Xueyue LUO ; Yongjun YANG ; Zhenzhen LIU
Chinese Journal of Veterinary Science 2024;44(8):1645-1650
This experiment aims to screen and isolate bacteria for the domestication of macrophages and to identify their domestication effector molecules.Bacteria were isolated and purified from cow and sheep feces.The procedures included preparing fermentation supernatant and conducting ex-periments with a mouse peritoneal macrophage model.Nitric oxide(NO)levels were measured,tumor necrosis factor-alpha(TNF-α)was analyzed using ELISA,the domestication activity was e-valuated by mouse peritoneal macrophage model.The activated bacteria were subjected to 16S rRNA gene sequences identification,growth curves determination,and saturated ammonium sul-fate precipitation for NO assay and ELISA analysis of TNF-α to assess the phagocytic capability of domesticated macrophages against Staphylococcus aureus.One strain,ED-8,with immunomodula-tory polarizing properties was successfully isolated.Alignment of its 16S rRNA gene sequence showed 99.86%similarity with Streptococcus zooepidemicus,classifying it as such species.The fermentation supernatant significantly stimulated NO and TNF-a secretion in macrophages.The phagocytic capability against Staphylococcus aureus of macrophages polarized by ED-8 also en-hanced.This effect was retained after crude extraction,indicating the presence of immunomodula-tory activity.In this study,multiple animal chain streptococcus ED-8 was successfully isolated.Its secreted products were shown to induce the trained immunity of macrophages,enhancing their phagocytic activity.