Toxoplasma gondii Manipulates Expression of Host Long Noncoding RNA during Intracellular Infection

Abstract

Long noncoding RNA (lncRNA) are non-protein-coding transcripts greater than 200 nucleotides that regulate gene expression. The field of transcriptomics is only beginning to understand the role of lncRNA in host defense. Little is known about the role of lncRNA in the response to infection by intracellular pathogens such as Toxoplasma gondii. Using a microarray, we examined the differential expression of 35,923 lncRNAs and 24,881 mRNAs in mouse bone-marrow-derived macrophages during infection with high- and low-virulence T. gondii strains. We found that 1,522 lncRNA molecules were differentially regulated during infection with the high-virulence Type I strain, versus 528 with the less-virulent Type II strain. Of these lncRNAs, 282 were co-regulated with a nearby or overlapping mRNA–including approximately 60 mRNAs with immune-related functions. We validated the microarray for 4 lncRNAs and 4 mRNAs using qRT-PCR. Using deletion strains of T. gondii, we found that the secretory kinase ROP16 controls upregulation of lncRNAs Csf1-lnc and Socs2-lnc, demonstrating that the parasite directly manipulates host lncRNA expression. Given the number of regulated lncRNAs and the magnitude of the expression changes, we hypothesize that these molecules constitute both an additional regulatory layer in the host response to infection and a target for manipulation by T. gondii.

Expression of Long Non-Coding RNAs by Human Retinal Müller Glial Cells Infected with Clonal and Exotic Virulent Toxoplasma gondii

“…It is also clear that infectious pathogens may influence the expression of host lncRNA [28]. Using a microarray-based profiling approach, Liu et al [37] and Menard et al [38] independently evaluated the global lncRNA transcriptome in cells infected with T. gondii tachyzoites. There are many methodological differences between our investigation and these two studies, including molecular biological methods, strains of parasite, and host species and host cell population, all of which may impact experimental results.…”

“…Liu et al [37] used an array that covered 40,173 human lncRNAs to study infection of human neonatal fibroblasts by the type II avirulent strain ME49 strain-4525 lncRNAs were up-regulated, and 1519 lncRNAs were down-regulated, and coding-non-coding co-expression network analyses showed lncRNAs were involved in the expression of multiple immune-related proteins. Menard et al [38] examined differential expression of lncRNAs in mouse bone marrow-derived macrophages infected with the type I virulent RH strain or the type II avirulent PTG strain-893 lncRNAs were up-regulated, and 875 lncRNAs were down-regulated, and gene ontology analyses demonstrated that these lncRNAs participated in many immune-related biological processes [38]. This second study highlighted a difference in the cellular response to the virulent and avirulent T. gondii strains, which was explained in part by a direct effect of the parasite ROP16 protein on host cell lncRNA expression [38].…”

“…The involvement of lncRNAs in T. gondii infection of Müller cells is unstudied. Indeed, there is little published literature on the role of Müller cells during a T. gondii infection [18,19,36], or during intracellular pathogen infection in general [37,38]. Here, we were interested in the lncRNA response of Müller cells to infection with virulent strains of T. gondii, with a focus on the acute immune response.…”

Invisible Designers: Brain Evolution Through the Lens of Parasite Manipulation

“…Some of these RNA molecules may interfere with the messenger and noncoding RNAs injected by the parasite, initiate epigenetic changes that counteract their activity, or even regulate the expression of the parasite's own genes. The fact that some noncoding RNAs in the host are strongly induced by parasite-derived molecules is usually interpreted as evidence of parasite manipulation (for a recent example involving toxoplasma see Menard et al 2018). However, it is also possible that certain host RNAs function as components of molecular mechanisms that detect and adaptively respond to manipulative attacks.…”

A long non-coding RNA controls parasite differentiation in African trypanosomes

“…While ANCR suppresses epidermal differentiation pathway and maintains the 55 stem cell compartment, TINCR promotes epidermal terminal differentiation (Kretz et al, 2013(Kretz et al, , 56 2012. LncRNAs are also important players in parasite infections, regulating antigenic 57 variation of Plasmodium falciparum (Amit-Avraham et al, 2015; Guizetti et al, 2016) and 58 associated to the host cell response in Toxoplasma gondii infection (Menard et al, 2018). 59…”