Effects Of TLR2,TLR4,NLRP3 And PGE₂ On Mouse Macrophages Against Staphylococcus Aureus Invading Intracellular

Staphylococcus aureus is a common gram-positive pathogen that can cause animal pneumonia,endocarditis,sepsis,dairy cow mastitis,dairy cow endometritis,etc.The occurrence of infectious diseases,serious illness can cause sick animal death.Streptococcus aureus invades the body through Toll-like receptor(TLR)and NOD-like receptor(NOD-like receptor),which is mainly activated by pattern recognition receptor(PRRs)(NLR and pyrin domains-containing protein 3,NLRP3)is the most common factor in the proinflammatory cytokines,antiinflammatory cytokines and chemokines.Representative NLRP receptors.TLR2,TLR4 and NALP3 are an integral part of the innate immune system capable of recognizing the pathogen recognition receptor(PRR)of pathogen-associated molecular patterns(PAMP).Many studies have demonstrated that these receptors recognize pathogen and hazard associated molecular patterns(DAMP),thereby initiating host defense.Therefore,in this study,the peritoneal macrophages of TLR2,TLR4 and NLRP3 knockout mice were used to study the expression of SA113(ATCC 35556)wild-type(WT),SA113 lgt::erm B(?lgt)lipoprotein The peritoneal macrophages were transfected into mouse peritoneal macrophages by colony counting and ELISA.The results showed that the peritoneal macrophages And to investigate the expression of cytokines in PGE2 on macrophages of mice infected with S.aureus.(1)The survival rate of the bacteria into the cells was significantly lower than that of the lipoprotein deletion group and the infection group of the lipophilic strain and the wild type strain.PGE2 pretreatment of wild type,lipoprotein deletion and lipoprotein recovery strain infection group compared with wild type,lipoprotein deletion and lipoprotein recovery strain infection group,the survival rate of bacteria into the cells were significantly reduced.PGE2 pretreatment of lipoprotein-deficient strains of infected bacteria into the cell viability was almost zero.(2)There was no significant difference in the survival rate of TLR2-/-,TLR4-/-mouse macrophage group compared with Staphylococcus aureus infection in C57BL/6 mice macrophage group.The survival rate of bacteria in the NLRP3-/-mouse macrophage group was significantly higher than that in the C57BL/6 mouse macrophage group.(3)There was no significant difference in the levels of RANTES and TNF-a between PGE2 pretreatment group and control group.Compared with the control group,the levels of RANTES and TNF-a were significantly increased in Staphylococcus aureus infection group and PGE2 pretreatment group.There was no significant difference in RANTES and TNF-a between PGE2 pretreatment group and Staphylococcus aureus infection group.There was no significant difference in IL-10 and IL-1? between PGE2 pretreatment group and control group.Compared with the control group,the levels of IL-10 and IL-1?were significantly increased in Staphylococcus aureus infection group and PGE2 pretreatment group.The levels of IL-10 and IL-1? in PGE2 pretreatment group were significantly higher than those in Staphylococcus aureus infection group.This experiment confirms that lipoproteins are the major immunologically active components that Staphylococcus aureus can normally invade cells and parasite in mouse macrophage cytoplasm.NLRP3 cell cytoplasmic receptors have a significant effect on S.aureus invading mouse macrophages,and IL-1? can activate cytokines as NLRP3.IL-1? secretion is significant when Staphylococcus aureus invades mouse macrophages Rise.