| 研究実績の概要 |
Understanding the molecular defense mechanism of phagocytes and identifying their effector molecules against malarial parasites may provide important clues for the discovery of new therapies. In the current proposed study, gene profile of macrophages and neutrophils phagocytizing Plasmodium falciparum-parasitized erythrocytes (iRBC) was studied using DNA microarray in an attempt to define the molecular defense mechanism against infection. The transcriptional gene profile of macrophages in response to iRBCs represented 168 down-regulated genes, which were mainly involved in the cellular immune response, and 216 upregulated genes, which were involved in cellular proteolysis, growth, and adhesion. Importantly, β-defensin 130 (DEFB130) was characterized as anti-malarial agent in vitro and in vivo (The manuscript has been submitted to the Scientific Report).
The gene profiling of the neutrophils in response to iRBCs revealed a broad and vigorous set of gene expression represented in 384 downregulated and 148 genes upregulated genes. Importantly, the upregulated genes were involved in multiple cellular function including cellular signaling, development, proteolysis, immune suppression and adhesion. Next, the results generated by DNA microarray analysis was confirmed by quantitative real-time PCR (qPCR) for the randomly upregulated genes.
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
This is the first study showing the involvement of macrophage defensin in killing of malarial parasites. DEFB130 was one of the top upregulated genes in macrophages and differentiated macrophages phagocytizing iRBCs exhibited an increase in intracellular DEFB130 levels accumulate at the site of iRBC engulfment. Both in vitro and in vivo experiments using DEFB130 synthetic peptide revealed a modest toxic effect of this molecule on the parasites.
Genes including CTSL, SOC3, CISH2, CXCL10 and CD64 were the highly upregulated in neutrophils phagocytizing iRBCs and they are involved in multiple functions such as cellular proteolysis, immune response and adhesion.
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| 今後の研究の推進方策 |
Based on DNA microarray data, five genes including CTSL, SOC3, CISH2, CXCL10 and CD64 are selected for further characterization. Manipulation of gene expression using gene overexpression and knockdown techniques using human HL60 cell line and primary neutrophils is to be perform to understand the role of the targeted genes in malarial infection.
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