The Preliminary Study Of Correlation Between Toxoplasma Gondii Infection And NLRP3Inflammasome

ObjectiveToxoplasma gondii is a worldwide spread opportunities pathogenic parasite. Although estimated that one third of the world’s population are infected with Toxoplasma gondii, but the most common form of the disease is latent or asymptomatic. The pregnants infected Toxoplasma gondii are apparent. The congenital toxoplasmosis is often with abortion, fetal death and congenital deformity.However, its pathogenic mechanism is unclear.This study is aim to illustrate the correlation between innate immune change after Toxoplasma gondii infection and pathogenic mechanism of toxoplasmosis. We try to search the activity of NLRP3inflammasome and the mechanism of NLRP3inflammation activity after infected Toxoplasma gondii. The results of the study will provide a new strategy for therapy of toxoplasmosis.Methods1, The study of association between Toxoplasma gondii infection and NLRP3activation:Toxoplasma gondii tachyzoites infected the THP-1cells in a1:2(tachyzoites:cells) ratio and control group was joined the same volume PBS buffer.The expression of NLRP3and caspase-1was analysed by Semiquantitative PCR and Western blot in THP-1cells. The IL-1β and IL-18were tested by ELISA in THP-1cells supernatant. Subsequently, Kunming mice were randomly divided into the experimental group and control group.2×107Toxoplasma gondii tachyzoites were injected into the experimental group mice peritoneal cavity and control group with the same volume of PBS buffer. The level of NLRP3and caspase-1was analysed by Semiquantitative PCR in the spleens of mouse. The IL-1β and IL-18were tested by ELISA in mouse peripheral blood serum.2, The mechanism of Toxoplasma gondii infection activates the NLRP3inflammasome:Toxoplasma gondii tachyzoites infected the THP-1cells in the control group and the experimental group with a1:2(tachyzoites:cells) ratio. The blank group not infected with Toxoplasma gondii tachyzoites. At the same time, the experimental group was added70Mm K+,25Mm N-acetyl-L-cysteine (NAC) and10μm CA-074Me respectively. The IL-1β and IL-18were tested by ELISA in THP-1cells supernatant. Results1, The study of association between Toxoplasma gondii infection and NLRP3activation:The mRNA and protein expression of NLRP3and caspase-1increased after the Toxoplasma gondii infected THP-1cells. IL-1β and IL-18showed the same change with NLRP3and caspase-1in THP-1cells supernatant. The same results were also shown in the Toxoplasma gondii infected mice.2, The mechanism of Toxoplasma gondii infection activates the NLRP3inflammasome:The content of IL-1β and IL-18in the experimental group increased compared with the blank group, but no significant change compared with the control group after added K+. Its activation may be independent of K+efflux. The content of IL-1β and IL-18in the experimental group significantly reduced compared with the blank group and also significantly reduced compared with the control group after added NAC. Its activation may be related to ROS. The content of IL-1β and IL-18in the experimental group increased compared with the blank group, but no significant change compared with the control group after added CA-074Me. Its activation may be independent of cathepsin.ConclusionToxoplasma gondii can activate the NLRP3inflammasome and led to IL-1β and IL-18increased. The mechanism of NLRP3inflammasome activation by Toxoplasma gondii infection may be related to ROS.