Transcriptome analysis of the effect of C-C chemokine receptor 5 deficiency on cell response to Toxoplasma gondii in brain cells

Abstract

Background Infection with Toxoplasma gondii is thought to damage the brain and be a risk factor for neurological and psychotic disorders. The immune response-participating chemokine system has recently been considered vital for brain cell signaling and neural functioning. Here, we investigated the effect of the deficiency of C-C chemokine receptor 5 (CCR5), which is previously reported to be associated with T. gondii infection, on gene expression in the brain during T. gondii infection and the relationship between CCR5 and the inflammatory response against T. gondii infection in the brain. Results We performed a genome-wide comprehensive analysis of brain cells from wild-type and CCR5-deficient mice. Mouse primary brain cells infected with T. gondii were subjected to RNA sequencing. The expression levels of some genes, especially in astrocytes and microglia, were altered by CCR5-deficiency during T. gondii infection, and the gene ontology and Kyoto Encyclopedia of Genes and Genomes analysis revealed an enhanced immune response in the brain cells. The expression levels of genes which were highly differentially expressed in vitro were also investigated in the mouse brains during the T. gondii infections. Among the genes tested, only Saa3 (serum amyloid A3) showed partly CCR5-dependent upregulation during the acute infection phase. However, analysis of the subacute phase showed that in addition to Saa3, Hmox1 may also contribute to the protection and/or pathology partly via the CCR5 pathway. Conclusions Our results indicate that CCR5 is involved in T. gondii infection in the brain where it contributes to inflammatory responses and parasite elimination. We suggest that the inflammatory response by glial cells through CCR5 might be associated with neurological injury during T. gondii infection to some extent.

Transcriptomic Analysis of the Effects of Chemokine Receptor CXCR3 Deficiency on Immune Responses in the Mouse Brain during Toxoplasma gondii Infection

“…Total RNA was extracted with TRI Reagent ® (Sigma-Aldrich), according to the manufacturer's protocol. The extracted RNA was individually subjected to RNA-seq, according to the protocol used in our previous study [20,35,37]. Briefly, 1 µg of total RNA was subjected to poly-A selection.…”

“…All treatments and subsequent analyses were performed on individual transcripts. The data of WT samples has been used in our previously published articles [35,37] because all the samples in these articles and the present study were prepared simultaneously. Raw sequence reads were subjected to quality control, and the cleaned reads were mapped to the reference mouse genome (mm10) with CLC Genomics Workbench version 10 (CLC bio, Aarhus, Denmark) (read mapping parameters: minimum fraction length of read overlap = 0.95, minimum sequence similarity = 0.95).…”

“…Primers used were listed in Table S2. The cycle threshold (C t ) values were normalized to the expression levels using the 2 −∆∆Ct method [37,46]. Gapdh was used as the internal control gene after comparison with Actb using RefFinder [47].…”

CCR5 and CCR5Δ32 in bacterial and parasitic infections: Thinking chemokine receptors outside the HIV box

“…Also, CCR5 absence can increase susceptibility to T. gondii (Bonfá et al, 2014; Khan et al, 2006). Finally, a recent study suggested that CCR5 participates in the regulation of inflammatory response, tissue injury and elimination of T. gondii infection in the brain (Kobayashi et al, 2019).…”

Functional characterization of acyl-CoA binding protein in Neospora caninum

“…Raw counts were normalized using the Benjamini and Hochberg's approach for controlling the false discovery rate (FDR) [38]. A corrected P-value of 0.005 and log 2 (Fold change) of 1.2 were set as the threshold for significantly differential expression [39,40].…”