Toxoplasma gondii is a globally-distributed intracellular parasitic protozoon with wide host range. Chronic infection is the most prevalent form of T. gondii infection, which can lead to significant damage. CD44 plays an important role in body's immune response, however, little is known about the function and mechanism of CD44 in T. gondii infection until now. In the present study, total RNA isolated from four groups including C57BL/6 mouse (C57), C57BL/6△CD44 mouse(C57△CD44), C57BL/6 mouse infected with T. gondii (C57-TG) and C57BL/6△CD44 infected with T. gondii (C57△CD44-TG)were subjected to comparative transcriptome analyses using RNA-seq techniques to explore the possible function of CD44 in mouse brain during chronic Toxoplasma infection. The results indicated a total of 35,908, 54,428, 51,473 and 22,387 unigenes were annotated in KOG, Swissprot, GO and KEGG databases by transcriptome analysis, respectively, and all the databases shared 9,833 unigenes. Subsequently, differentially expressed GO terms and enriched KEGG Pathways showed 20,303 unigenes were annotated belonging to three main GO categories (namely biological process, cellular component and molecular function) and six main KEGG categories (cellular processes, environmental information processing, genetic information processing, human diseases, metabolism and organismal systems) between normal C57 and C57△CD44 mice, as well as for C57-TG and C57△CD44-TG mice. For up-regulated genes, Mid1, Ttr and Cd4 were significantly up-regulated in the C57△CD44 mouse compared with the C57 mouse, and Pcp2, Ppp1r17 and Nrk were significantly up-regulated in the C57△CD44-TG mouse compared with the C57-TG mouse. As to down-regulated genes, AC114588.1, Cbln3 and Pmch were significantly down-regulated in the C57△CD44 the mouse compared with the C57 mouse, and down-regulated genes were enriched for immunoglobulins, major histocompatibility complex (MHC) class II antigens, chemokines ligands and interferon (IFN)-inducible GTPase families in the C57△CD44-TG mouse compared with the C57-TG mouse. The present study is the first trial for exploring the function of CD44 in the mouse brain during chronic infection with T. gondii at the transcriptional level, which can provide a basis for the study of the host immune defense mechanism against T. gondii infection.

弓形虫是一种宿主范围广泛的细胞内寄生的原生动物。慢性感染是弓形虫感染的最普遍形式，它可能导致重大损害。CD44在机体的免疫反应中起着重要的作用，然而，到目前为止，关于CD44在弓形虫感染中的功能和机制还知之甚少。本研究从感染弓形虫（C57-TG）和C57BL / 6的C57BL / 6小鼠（C57），C57BL / 6△CD44小鼠（C57△CD44），C57BL / 6小鼠四个组中分离出总RNA △CD44感染弓形虫使用RNA-seq技术对（C57△CD44-TG）进行了比较转录组分析，以探索CD44在慢性弓形虫中在小鼠脑中的可能功能感染。结果表明，通过转录组分析分别在KOG，Swissprot，GO和KEGG数据库中分别注释了35,908、54,428、51,473和22,387个单基因，所有数据库共享9,833个单基因。随后，差异表达的GO术语和丰富的KEGG Pathways显示注释了20,303个单基因，属于三个主要的GO类别（即生物过程，细胞成分和分子功能）和六个主要的KEGG类别（细胞过程，环境信息处理，遗传信息处理，人类）正常C57和C57△CD44小鼠之间以及C57-TG和C57△CD44-TG小鼠之间的疾病，代谢和生物系统）。对于上调的基因，与C57小鼠和Pcp2相比，C57△CD44小鼠的Mid1，Ttr和Cd4明显上调。与C57-TG小鼠相比，C57△CD44-TG小鼠中Ppp1r17和Nrk明显上调。关于下调基因，与C57小鼠相比，C57△CD44小鼠中AC114588.1，Cbln3和Pmch显着下调，并且下调基因富含免疫球蛋白，II类主要组织相容性复合体。与C57-TG小鼠相比，C57△CD44-TG小鼠体内的抗原，趋化因子配体和干扰素（IFN）诱导型GTPase家族。本研究是探索CD44在慢性感染小鼠大脑中功能的第一个试验。与C57-TG小鼠相比，C57△CD44-TG小鼠的免疫球蛋白，主要组织相容性复合物（MHC）II类抗原，趋化因子配体和干扰素（IFN）诱导的GTPase家族富集和下调的基因。本研究是探索CD44在慢性感染小鼠大脑中功能的第一个试验。与C57-TG小鼠相比，C57△CD44-TG小鼠的免疫球蛋白，主要组织相容性复合物（MHC）II类抗原，趋化因子配体和干扰素（IFN）诱导的GTPase家族富集和下调的基因。本研究是探索CD44在慢性感染小鼠大脑中功能的第一个试验。弓形虫在转录水平上，可以为研究宿主对弓形虫感染的免疫防御机制提供基础。