Study On RNA Modification Signatures Of Different Toxoplasma Gondii Genotypes And Mice Acutely Infected With Toxoplasma Gondii

Background:Toxoplasma Gondii was a widespread obligate intracellular parasite.As an important zoonotic pathogen,studies have shown that about one-third of the world’s population has positive serum antibody test results.Toxoplasmosis poses a serious threat to immunocompromised people,such as HIV/AIDS patients,and can lead to death in severe cases.RNA modification was one of the important contents of epigenetic research.Changes in the level of modification can affect RNA processing,degradation and translation,thereby affecting gene expression and key cellular processes.At present,it has been reported to play an important role in the infection of various human diseases.In contrast,little is known about the parasite RNA modification characteristics,and there are few reports on the changes of T.gondii and host RNA modification.In order to reveal the RNA modification characteristics of different genotypes of T.gondii and acutely infected mice with T.gondii,a mouse model of PRU cyst infection was constructed in this experiment.Modification levels of total RNA,t RNA and snc RNA in liver,spleen and serum of different virulent parasite strains and acutely infected mice.The RNA modification characteristics of different virulent parasite strains and acutely infected mice were described,and the mechanism of RNA modification regulating host resistance to T.gondii was preliminarily analyzed and discussed by Northern blot and other techniques.Results:1.Quantitatively detected 18 kinds of RNA modifications in different genotypes of T.gondii tachyzoites,analyzed the proportions and described the maps of different types of RNA modifications.The same modification was expressed in different abundances in different genotypes of T.gondii,but both I andΨmodifications were relatively high.The total RNA modification levels of different genotypes of T.gondii vary greatly,and the levels of various RNA modifications in RH strains are higher.The expression levels of these 14 modifications of m₂²⁷G were positively correlated with virulence.In addition,many modifications in the total RNA of T.gondii showed a strong linear relationship,and most of the modifications showed a linear positive correlation,such as m¹A,m⁶A,m⁵U and m³U,while a small number of RNA modifications showed a linear negative correlation.2.Quantitatively detected 20 RNA modifications in liver and spleen of mice during acute infection of T.gondii PRU strain,and 19 modifications in serum.Compared with normal mice,modified changes occurred in liver,spleen,and serum total RNA.The modification levels of m⁷G,m²G,m₂²G,m¹G,m⁵U,m⁵Um and m⁵C in liver total RNA decreased significantly,while m₂²⁷G and m³U increased significantly;onlyΨdecreased significantly in t RNA;m¹I,m⁶A,m⁷G,m²G,m₂²G,m¹G,m⁵C and m³C were significantly increased,while I,Am,Gm,Um and Cm were significantly decreased.In spleen total RNA,the modification levels of m¹A,m⁷G,m²G,m¹G,m⁵C,m³C and ac⁴C were significantly increased,while m₂²⁷G and Cm were significantly decreased;in t RNA,the modification levels of m¹A,m⁶A and m⁵C were significantly decreased,and the levels of Am,m₂²G and Um were significantly increased;snc RNA Significant increases in upper Am,Gm,m⁷G,m²G,m₂²G,Um,m⁵C and m³C.The levels of most modifications(m¹A,Am,m¹I,m⁶A,m⁷G,m²G,m₂²G,m¹G,m₂²⁷G,m⁵U,m⁵Um,Ψ,m⁵C,m³C,ac⁴C)in total RNA in serum were significantly decreased,and only the I modification level was significantly increased.By real-time quantitative PCR detection,it was found that the expression level of RNA methylase was consistent with the expression level of its corresponding modification.3.Compared with normal mice,the expression levels of spleen cytokines in acute infection mice were all up-regulated,among which IL-5,IL-12,IFN-γ,and TNF-βwere significantly different.m¹A,m⁵C,m³C,ac⁴C,m⁷G,m₂²G,m¹G were highly positively correlated with the cytokines detected except IL-5,and Um,Ψ,m⁵Um,Cm,Gm and m₂²⁷G were negatively correlated with most cytokines.The levels of ts RNA^Val,ts RNA^Ala and ts RNA^Gly in the liver of acutely infected mice were up-regulated by Northern blot,and the expressions of translation initiation factor complex-related proteins e IF4A and e IF4E were down-regulated by Western blot.Conclusion:Different genotypes of T.gondii have different RNA modification characteristics,and the RNA modification level of T.gondii may have a certain correlation with virulence.During the acute infection of T.gondii,the liver,spleen and serum of mice underwent a large number of changes in RNA modification levels.RNA modification may be involved in regulating the body’s resistance to T.gondii infection.The up-regulated ts RNA may affect protein translation by binding to the translation initiation factor complex,thereby regulating the body’s resistance to T.gondii infection.This study is the first to describe the changes of RNA modifications in the liver,spleen and serum of T.gondii and Toxoplasma-infected mice,and screen out a large number of differential modifications,which provides a new direction for the development of new treatments and new targets for toxoplasmosis.Data information and theoretical references are provided for subsequent in-depth research.