The Role of Heparan Sulfate in the B cell response

硫酸乙酰肝素在 B 细胞反应中的作用

• 批准号: 8205263
• 负责人: Damian Luis Trujillo
• 金额: $ 3.36万
• 依托单位: UNIVERSITY OF CALIFORNIA BERKELEY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-07-01 至 2012-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8205263
• 关键词: Accounting; Address; Adhesions; Affect; Affinity; Antibodies; Antibody Affinity; Antibody Formation; B-Cell Development; B-Lymphocyte Subsets; B-Lymphocytes; Binding; Cell Communication; Cell physiology; Cells; Communicable Diseases; Data; Dose; EXT1 gene; Enhancing Antibodies; Environment; Exhibits; Growth Factor; Health; Heparitin Sulfate; IgG1; Immune; Immune response; Immune system; Infection; Influenza; Interferon Receptor; Interferons; Invaded; Ligands; Lung; Maintenance; Measures; Mediating; Microscopy; Modeling; Monitor; Morbidity - disease rate; Mus; Nature; Pathology; Phenotype; Photons; Play; Poly I-C; Population; Process; Regulation; Relative (related person); Role; Series; Serum; Signal Transduction; Specificity; Structure of germinal center of lymph node; Testing; Thymus Gland; Vaccines; Viral; Viral Load result; Virus; Virus Diseases; Work; base; cell motility; chemokine; cytokine; in vivo; influenzavirus; migration; mortality; novel; pathogen; protective effect; receptor; research study; response; vaccine development

DESCRIPTION (provided by applicant): Heparan sulfate influences many cellular processes including adhesion, motility, ligand-receptor interaction, and proliferation. B cells account for a major component of the adaptive immune system, in which they aid in the elimination of, and protection against, invading pathogens. Crucial to the initiation and maintenance of a B cell response is B cell localization, cytokine/chemokine responsiveness, and cell-to-cell interaction. We have recently observed that heparan sulfate is drastically upregulated on B-cells. Indeed, whereas naive B-cells do not express heparan sulfate, B-cells isolated from mice infected with viruses, or mice injected with poly I:C, express heparan sulfate. Importantly this phenotype is abolished when interferon receptor deficient mice are used, indicating a requirement for interferon in this process. Accordingly, B-cells treated ex-vivo with interferon alone express high levels of heparan sulfate. Interestingly, we have shown that interferon treated B-cells are more responsive to the B cell-specific cytokine APRIL, a phenotype associated with increased heparan sulfate-expression. Altogether, these experiments suggest that upon viral infection, interferon induces heparan sulfate expression on B-cells, rendering these cells more responsive to their environment, and potentially affecting the B-cell antibody response. To test this hypothesis, we have generated mice that are deficient for heparan sulfate expression on B-cells (EXT1-/- mice) and have shown that their B- cell development is not altered. Interestingly, preliminary data generated using 2-photon microscopy indicates that B-cell motility was affected in the presence of interferon in a heparan sulfate-dependent manner. Using influenza as an infectious model, we have demonstrated that both the thymus -dependent and - independent antibody responses are increased in EXT1-/- mice. Despite generating this increased response, viral restriction in EXT1-/- mice is unaffected. This proposal aims to further characterize the role of heparan sulfate expression on B cells during a humoral response. Due to the preliminary nature of our in vivo infection data, we aim to confirm and further our initial findings. To this end, we will infect mice with a range of infectious doses of influenza virus and assess the quality of the antibody response by monitoring host health, viral restriction, responding B cell subsets, and the antibodies produced. This will be accomplished by measuring viral titers, antibody titers, responding B cell populations, and host morbidity and mortality. To address the observations that EXT1-/- mice generate an expanded antibody response, yet are unable to more efficiently restrict influenza, we will assess the specificity and efficiency of the humoral response. This will be done by determining the affinity and the virus-neutralizing capabilities of EXT1-/- antibodies. Finally, we will assess the protective effect of serum antibodies isolated from influenza- immune EXT1-/- mice. We hope to reveal additional alterations in the EXT1-/- antibody response that will further support our hypothesis that IFN-mediated induction of HS on B cells serves as a novel form of immune regulation. Based on this, we believe that this work may aid in the development of vaccines in which an effective B cell response is necessary. PUBLIC HEALTH RELEVANCE: The work we prose here may help in understanding of the antibody response against infectious disease. Furthermore, understanding of the topic may enhance vaccine development.

描述(由申请人提供)：硫酸乙酰肝素影响许多细胞过程，包括黏附、运动、配体-受体相互作用和增殖。B细胞是适应性免疫系统的主要组成部分，在适应性免疫系统中，它们帮助消除和保护入侵的病原体。B细胞的定位、细胞因子/趋化因子的反应性以及细胞间的相互作用是启动和维持B细胞反应的关键。我们最近观察到，硫酸乙酰肝素在B细胞上显著上调。事实上，虽然幼稚的B细胞不表达硫酸乙酰肝素，但从感染病毒的小鼠或注射聚I：C的小鼠分离出来的B细胞表达硫酸乙酰肝素。重要的是，当使用干扰素受体缺陷小鼠时，这种表型被取消，这表明在这一过程中需要干扰素。因此，单独使用干扰素体外处理的B细胞表达高水平的硫酸乙酰肝素。有趣的是，我们已经证明，干扰素处理的B细胞对B细胞特异性细胞因子APRIL的反应更强，这是一种与硫酸肝素表达增加相关的表型。总之，这些实验表明，在病毒感染后，干扰素诱导B细胞上硫酸肝素的表达，使这些细胞对环境更敏感，并可能影响B细胞抗体反应。为了验证这一假设，我们培育了B细胞上硫酸肝素表达不足的小鼠(EXT1-/-小鼠)，并表明它们的B细胞发育没有改变。有趣的是，使用双光子显微镜产生的初步数据表明，在干扰素存在的情况下，B细胞的运动受到硫酸乙酰肝素依赖的影响。使用流感作为感染模型，我们已经证明了EXT1-/-小鼠的胸腺依赖和非依赖抗体反应都增加了。尽管产生了这种增加的反应，但EXT1-/-小鼠的病毒限制不受影响。这项建议旨在进一步表征B细胞上硫酸肝素表达在体液反应中的作用。由于我们体内感染数据的初步性质，我们的目标是确认并进一步推进我们的初步发现。为此，我们将用一系列传染性剂量的流感病毒感染小鼠，并通过监测宿主健康、病毒限制、反应B细胞亚群和产生的抗体来评估抗体反应的质量。这将通过测量病毒滴度、抗体滴度、反应的B细胞群以及宿主发病率和死亡率来实现。为了解决EXT1-/-小鼠产生扩大的抗体反应，但不能更有效地限制流感的观察，我们将评估体液反应的特异性和有效性。这将通过确定EXT1-/-抗体的亲和力和病毒中和能力来完成。最后，我们将评估从流感免疫EXT1-/-小鼠分离的血清抗体的保护作用。我们希望揭示EXT1-/-抗体反应的其他变化，这将进一步支持我们的假设，即通过干扰素诱导B细胞上的HS是一种新的免疫调节形式。基于此，我们认为这项工作可能有助于疫苗的开发，在疫苗中，有效的B细胞反应是必要的。 公共卫生相关性：我们在这里发表的工作可能有助于理解对传染病的抗体反应。此外，对这一主题的理解可能会促进疫苗的开发。