T-bet-regulated myeloid innate defense against Toxoplasma gondii

T-bet 调节的骨髓对弓形虫的先天防御

• 批准号: 10660458
• 负责人: AMERICO HARRY LOPEZ-YGLESIAS
• 金额: $ 31.5万
• 依托单位: INDIANA UNIV-PURDUE UNIV AT INDIANAPOLIS
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-01 至 2028-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10660458
• 关键词: Acute; Adoptive Transfer; Animals; Antiparasitic Agents; B-Lymphocytes; CD4 Positive T Lymphocytes; Cells; Cessation of life; Clinical; Congenital Toxoplasmosis; Cyst; Cytometry; Defense Mechanisms; Development; Fetus; Flow Cytometry; Host Defense; Host resistance; Human; ITGAX gene; Immune; Immune response; Immune system; Immunity; Immunocompromised Host; Immunofluorescence Immunologic; Individual; Infection; Interferon Type II; Interleukin-12; Invaded; Kinetics; Lymphocyte; Lymphoid Cell; Maps; Mediating; Medicine; Molecular; Molecular Biology Techniques; Morbidity - disease rate; Mus; Mutant Strains Mice; Myelogenous; Myeloid Cells; Parasites; Parasitic infection; Population; Production; Regimen; Reporter; Reporting; Research; Role; Sorting; Splenocyte; T cell response; T-Lymphocyte; T-bet protein; Testing; Therapeutic Intervention; Time; Toxic effect; Toxoplasma gondii; Toxoplasmosis; United States; Up-Regulation; acute infection; adaptive immune response; antimicrobial; cell type; conditional knockout; cytokine; experimental study; foodborne; in vivo; mortality; mouse model; myeloid cell development; novel; pathogen; reconstitution; response; side effect; single-cell RNA sequencing; targeted treatment; therapeutic target

Abstract Toxoplasma gondii is the causative agent of toxoplasmosis, and it is estimated to infect a third of the human population globally. T. gondii infection can result in serious complications including congenital toxoplasmosis of the fetus and death among immunocompromised individuals. Unfortunately, current regimens for T. gondii treatment show high rates of toxicity, and are only able to treat the acute stage of the parasitic infection. Therefore, there is an urgent need develop new medicines with specific efficacy against T. gondii. Host immunity against T. gondii is defined by a MyD88-dependent IL-12 response, which generates a CD4+ Th1- derived IFN-γ response necessary for host survival. The transcription factor T-bet is considered essential for the development and function of innate lymphoid cells (ILCs) and TH1s during T. gondii infection. T-bet is traditionally considered the master regulator of lymphocyte-derived interferon-gamma (IFN-γ) production. Yet, T-bet-independent ILC- and TH1-derived IFN-γ is insufficient for host immunity, demonstrating that IFN-γ alone is insufficient for host defense and that T-bet must be inducing an IFN-γ-independent anti-parasitic response. For instance, despite robust IFN-γ production, T-bet-deficient mice succumb to infection significantly faster than animals lacking lymphocytes, suggesting T-bet-expressing myeloid cells are required for host survival. Our objective is to define T-bet’s role in regulating myeloid cell-dependent immunity against T. gondii. Our preliminary findings have identified a unique T-bet expressing CD11c+MHCII- myeloid cell population that are critical for eliminating T. gondii. Based on these results, we hypothesize that T-bet expression in myeloid cells regulates pathogen clearance and host survival during T. gondii infection. To test our hypothesis, we will (i) determine the underlying mechanism(s) of T-bet in regulating myeloid cell-mediated defense against T. gondii (AIM 1) and (ii) define the molecular functions of T-bet-expressing myeloid cells in mediating host resistance against T. gondii (AIM 2). We will utilize unbiased T-bet reporter mice and cell-type-specific T-bet-deficient mice established in our lab, in combination with various molecular biology techniques, spectral cytometry, immunofluorescence, and single-cell RNA-sequencing. Together, these experiments will for the first time establish T-bet’s role in mediating myeloid cell-dependent host defense against T. gondii, thereby providing novel specific targets for therapeutic intervention.

摘要 弓形虫是弓形虫病的病原体，据估计感染了三分之一的人类。 全球人口。T.弓形虫感染可导致严重的并发症，包括先天性弓形虫病， 胎儿和死亡的免疫功能低下的人。不幸的是，目前的T.弓形虫 治疗显示出高毒性，并且仅能够治疗寄生虫感染的急性期。 因此，迫切需要开发新的抗T.刚地。主机 抗T.弓形虫是由MyD 88依赖性IL-12应答定义的，其产生CD 4 + Th 1- 来源于宿主存活所必需的IFN-γ应答。转录因子T-bet被认为是必不可少的， T.弓形虫感染T-bet是 传统上被认为是淋巴细胞衍生的干扰素-γ（IFN-γ）产生的主要调节剂。然而， 非T-bet依赖性ILC和TH 1衍生的IFN-γ不足以产生宿主免疫，这表明单独的IFN-γ 不足以进行宿主防御，T-bet必须诱导IFN-γ非依赖性抗寄生虫应答。 例如，尽管IFN-γ产生旺盛，但T-bet缺陷小鼠感染的速度明显更快， 与缺乏淋巴细胞的动物相比，这表明表达T-bet的骨髓细胞是宿主生存所必需的。 我们的目的是确定T-bet在调节髓系细胞依赖的抗T细胞免疫中的作用。刚地。我们 初步研究结果已经确定了一个独特的表达T-bet的CD 11 c +MHCII-髓样细胞群， 关键在于消除T。刚地。基于这些结果，我们假设T-bet在髓系细胞中的表达， 调节T.弓形虫感染为了验证我们的假设，我们将（i） 确定T-bet在调节骨髓细胞介导的针对T.弓形虫 (AIM 1）和（ii）定义了表达T-bet的骨髓细胞在介导宿主抗性中的分子功能 抗犬弓弓形虫（AIM 2）。我们将利用无偏倚的T-bet报告小鼠和细胞类型特异性T-bet缺陷型小鼠。 在我们实验室建立的小鼠，结合各种分子生物学技术，光谱细胞术， 免疫荧光和单细胞RNA测序。这些实验将首次 确定T-bet在介导骨髓细胞依赖性宿主防御T.弓形虫，从而提供 治疗干预的新的特异性靶点。