Antibody-secreting Cells in the Outcome of Trypanosoma cruzi Infection

克氏锥虫感染结果中的抗体分泌细胞

• 批准号: 10449154
• 负责人: ADRIANA GRUPPI
• 金额: $ 13.3万
• 依托单位: NATIONAL RESEARCH COUNCIL OF ARGENTINA
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-05-01 至 2027-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10449154
• 关键词: Acute; Adenosine; Adjuvant; Affect; Affinity; Anatomy; Antibodies; Antibody Affinity; Antibody Formation; Antibody-mediated protection; Antigen Presentation; Antigen-Presenting Cells; Antigens; Appearance; Autoantibodies; B-Cell Activation; B-Lymphocyte Subsets; B-Lymphocytes; Bacterial Infections; Biological Assay; Bone Marrow; CD8-Positive T-Lymphocytes; CD80 gene; CD86 gene; COVID-19; Cells; Chagas Disease; Characteristics; Chimera organism; Chronic; Clinic; Clinical; Coculture Techniques; Comprehension; Cues; Cytometry; Data; Detection; Development; Disease; Disease Outcome; Disease Progression; Enzyme-Linked Immunosorbent Assay; Evaluation; Exhibits; Experimental Models; Flow Cytometry; Frequencies; Functional disorder; Generations; Helper-Inducer T-Lymphocyte; Heterogeneity; Humoral Immunities; IgG1; IgG2; Image; Immune; Immune response; Immunity; Immunofluorescence Immunologic; Immunoglobulin Class Switching; Immunoglobulin G; Immunoglobulin M; Immunoglobulin Somatic Hypermutation; Immunoglobulin Switch Recombination; Immunoglobulin-Secreting Cells; Immunology; Immunosuppression; In Vitro; Infection; Inflammatory; Interferons; Interleukin-17; Interleukin-6; Knowledge; Latin America; Link; Lymphocyte Activation; Lymphocytic choriomeningitis virus; Measures; Microbe; Modeling; Mus; Mutant Strains Mice; Nucleosides; Outcome; Parasite Control; Parasitemia; Parasites; Parasitic infection; Pathogenesis; Pathogenicity; Pathway interactions; Persons; Phase; Plasmablast; Plasmodium; Play; Population; Public Health; Publishing; Reaction; Regulation; Reporting; Role; Salmonella; Side; Signal Transduction; Source; Specificity; Structure of germinal center of lymph node; T cell response; T-Lymphocyte; TNF gene; Testing; Time; Trypanosoma cruzi; Vaccines; Virus Diseases; adaptive immunity; antimicrobial; base; chronic infection; conditioning; cytokine; design; economic impact; experimental study; extracellular; immunoregulation; improved; in vivo; influenzavirus; innovation; migration; mortality; novel; novel therapeutics; pathogen; physically handicapped; programmed cell death ligand 1; response; single-cell RNA sequencing; therapeutic target

PROJECT SUMMARY/ABSTRACT Chagas disease, caused by the parasite Trypanosoma cruzi, affects 6 million people and has a major economic impact due to early mortality and physical disabilities. It is endemic in Latin America but has become a global public health concern following the migration of infected people. Disease progression that varies from symptomless to severe, has been linked to both parasite heterogeneity and host-related immunity. Parasite persistence as well as the intensity of the inflammatory immune response are determinants of the clinical manifestations of the disease. Understanding components of host immunity will be crucial to the comprehension of pathogenesis and will allow design of novel therapeutics. The acute phase of Chagas disease results in polyclonal B cell activation that may be related to the important early extrafollicular plasmablast (EF-PB) response that precedes germinal center (GC) reactions. In this direction, the source of polyreactive antibodies (Abs) was not clearly identified. We initially considered that this polyclonal B cell response would restrict anti-parasite responses. However, we observed that EF-PB produce parasite-specific Abs of different isotypes and that signals via BCR, in some way, condition PB generation which requires the participation of T follicular helper (Tfh) cells. Also, the EF-PB are the main source of IL-17 in T. cruzi infected mice and a fraction of them produce IL-6 and other cytokines and express molecules related to antigen presentation. Of note, IL-17 produced by B cells/PB was shown to be key to sustain CD8+T cell activity and survival. Finally, we determined that PB from T. cruzi infected mice express high levels of the ectoenzyme CD39, higher than T cells, which combined with CD73 hydrolyze exogenous ATP to adenosine which plays immunomodulatory functions. The absence of PB in early T. cruzi infection significantly increases the parasitemia, but on the other side, favors the earlier appearance of GC and increases the frequency of TNF+IFN+ T cells suggesting a controversial role of PB. Our findings are particularly timely given reports describing poor clinical outcomes in Covid19 associated with high PB responses. Altogether, the results support our hypothesis that early EF-PB from T. cruzi infected mice have parasite control capacity and can condition disease outcome. We are focused at further characterizing these EF-PB cell population/s to determine their heterogeneity as well as its contribution to protection or pathogenicity. Using different strategies such as single-cell RNAseq, analysis of somatic hypermutation, identification of antigen-specificity and affinity we will perform detailed characterizations of EF-PB in T. cruzi infected mice. By using genetically modified mice, co- culture experiments and mixed bone marrow chimeras we will be able to delineate the role of EF-PB and CD39 in conditioning humoral as well as cellular responses in experimental Chagas disease. The identification of the EF-PB characteristics and roles will be of great significance for the development of new strategies aiming at the therapeutic targeting of B cells in the clinic. For instance, this innovative approach could provide information required to develop an effective vaccine against T. cruzi.

项目总结/摘要 查加斯病由寄生虫克氏锥虫引起，影响600万人，并对经济产生重大影响 因为过早死亡和身体残疾。它在拉丁美洲流行，但已成为全球公共卫生问题。 关注感染者的迁移。从轻微到严重的疾病进展， 与寄生虫异质性和宿主相关免疫有关。寄生虫的持久性以及 炎性免疫应答是疾病临床表现的决定因素。理解 宿主免疫的组分对于理解发病机理是至关重要的，并且将允许设计新的免疫调节剂。 治疗学 恰加斯病的急性期导致多克隆B细胞活化，这可能与重要的早期炎症反应有关。 滤泡外浆母细胞（EF-PB）反应先于生发中心（GC）反应。在这个方向上， 多反应性抗体（Abs）的来源未明确确定。我们最初认为这种多克隆B细胞 反应将限制抗寄生虫反应。然而，我们观察到EF-PB产生寄生虫特异性Abs， 不同的同种型，并通过BCR信号，以某种方式，条件PB的产生，需要参与 滤泡辅助性T细胞（Tfh）此外，EF-PB是T细胞IL-17的主要来源。克鲁兹感染的小鼠和一小部分 它们中的大多数产生IL-6和其它细胞因子，并表达与抗原呈递相关的分子。值得注意的是，IL-17 显示由B细胞/PB产生的CD 8 +T细胞是维持CD 8 +T细胞活性和存活的关键。最后，我们确定， PB从T。克氏病毒感染的小鼠表达高水平的胞外酶CD 39，高于T细胞， 与CD 73一起水解外源性ATP生成腺苷，发挥免疫调节功能。PB的缺失 在早期T。Cruzi感染显著增加寄生虫血症，但另一方面，有利于早期出现 的GC和增加的TNF+IFN γ + T细胞的频率表明PB的有争议的作用。我们的研究结果是 特别是考虑到描述Covid 19中与高PB缓解相关的不良临床结局的报告。 总之，这些结果支持了我们的假设，即T.克氏病毒感染的小鼠有寄生虫控制 能力，并能控制疾病的结果。我们专注于进一步表征这些EF-PB细胞群体/s 以确定它们的异质性以及其对保护或致病性的贡献。使用不同策略 例如单细胞RNAseq、体细胞超突变分析、抗原特异性和亲和性翼的鉴定 将在T.克鲁兹感染了小鼠。通过使用转基因小鼠， 通过培养实验和混合骨髓嵌合体，我们将能够描述EF-PB和CD 39在 调节实验性恰加斯病的体液和细胞反应。EF-PB的鉴定 的特点和作用，对于制定新的战略， 在临床上对B细胞的治疗靶向。例如，这种创新方法可以提供信息， 需要开发有效的T.克鲁兹