Role of Phospholipid Scramblase in Interferon Action

磷脂扰乱酶在干扰素作用中的作用

• 批准号: 6403133
• 负责人: Robert H. Silverman
• 金额: $ 34.65万
• 依托单位: CLEVELAND CLINIC FOUNDATION
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-07-10 至 2006-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6403133
• 关键词: RNA biosynthesis; Vesiculovirus; antiviral agents; apoptosis; cell cycle; cell membrane; cell proliferation; endopeptidases; fatty acylation; gag protein; guanine nucleotide exchange factors; interferons; intracellular; laboratory mouse; leukocyte activation /transformation; macrophage; membrane proteins; natural killer cells; neoplastic cell; neoplastic growth; phosphatidylserines; phospholipids; reticuloendothelial system; virus diseases; virus envelope; virus replication

Interferons (IFN) are pleiotropic cytokines with diverse immune regulatory, anti-tumor, and anti-viral activities. Whereas several IFN-regulated genes with distinct anti- proliferative and anti-viral activities have been identified, many of the cellular mechanisms underlying these biologically- important effects of IFN remain unknown. Recently, we identified phospholipid scramblase-1 (PLSCR1) a plasma membrane protein implicated in Ca2+-dependent reorganization of plasma membrane phospholipids as a markedly IFN-upregulated gene. Our preliminary data also suggest that PLSCR1 itself exhibits anti- tumor and anti-viral activities that mimic effects normally associated with the response to IFN. In this proposal we aim to elucidate the specific role of IFN-regulated members of the PLSCR gene family in the overall biologic response to IFN. Our Specific Aims include: (1) to identify other members of the PLSCR gene family that may be regulated by IFN, and to identify cellular changes induced by IFN that are directly mediated by PLSCR1 or homologous proteins. Changes in topology of plasma membrane phospholipids in response to IFN will be evaluated and related to potential changes in the fatty acylation and intracellular distribution of newly synthesized PLSCR1 polypeptide. The possibility that PLSCR1 co-localizes with viral envelope proteins in detergent-resistant membrane "rafts" will be explored, and the functional significance of conserved PPxY motifs common to PLSCR1 and many enveloped virus matrix and gag proteins will be determined; (2) to elucidate the specific contribution of PLSCR1 to IFN's anti-tumor activity. Tumor incidence in PLSCR1-null/p53-null mice will be determined and effects of IFN-alpha on the growth of PLSCR1-null and wild type tumors will be compared. Potential effects of PLSCR1 on cell proliferation and macrophage activation/recruitment will be examined; and (3) to determine the contribution of PLSCR1 to IFN's anti-viral activity. Vesicular stomatitis virus (VSV) replication in wild type and PLSCR1-null cells will be compared, both in presence and absence of IFN. Specific effects of cellular PLSCR1 on each stage of the viral life cycle will be identified. Potential anti-viral activity of PLSCR1 in vivo will be explored in wild type and PLSCR1-null mice. It is proposed that detailed understanding of the role of the PLSCR gene family in IFN biology may suggest novel anti-viral and anti-tumor strategies based on selective induction, activation, or mimicry of the PLSCR proteins.

干扰素（IFN）是一种具有多种免疫调节、抗肿瘤和抗病毒活性的多效性细胞因子。尽管已经鉴定了几种具有不同抗增殖和抗病毒活性的IFN调节基因，但IFN的这些生物学重要作用的许多细胞机制仍然未知。 最近，我们确定了磷脂scramblase-1（PLSCR 1）的一个质膜蛋白牵连在Ca 2+依赖性重组的质膜磷脂作为一个显着的IFN-上调基因。 我们的初步数据还表明，PLSCR 1本身表现出抗肿瘤和抗病毒活性，其模拟通常与对IFN的应答相关的作用。 在这项提案中，我们的目标是阐明的具体作用，IFN-调节的PLSCR基因家族的成员在整体生物反应IFN。 我们的具体目标包括：（1）鉴定可能受IFN调节的PLSCR基因家族的其他成员，并鉴定由IFN诱导的由PLSCR 1或同源蛋白直接介导的细胞变化。 将评估响应于IFN的质膜磷脂的拓扑结构的变化，并将其与新合成的PLSCR 1多肽的脂肪酰化和细胞内分布的潜在变化相关。 PLSCR 1与病毒包膜蛋白共定位在抗洗涤剂膜“筏”中的可能性将被探索，PLSCR 1和许多包膜病毒基质和gag蛋白共有的保守PPxY基序的功能意义将被确定;（2）阐明PLSCR 1对IFN抗肿瘤活性的特异性贡献。 将测定PLSCR 1-null/p53-null小鼠中的肿瘤发生率，并将比较IFN-α对PLSCR 1-null和野生型肿瘤生长的影响。 将检查PLSCR 1对细胞增殖和巨噬细胞活化/募集的潜在作用;和（3）确定PLSCR 1对IFN的抗病毒活性的贡献。 将在存在和不存在IFN的情况下比较野生型和PLSCR 1-null细胞中的水泡性口炎病毒（VSV）复制。 将鉴定细胞PLSCR 1对病毒生命周期每个阶段的特异性作用。 将在野生型和PLSCR 1缺失小鼠中探索PLSCR 1的体内潜在抗病毒活性。 有人建议，详细了解的PLSCR基因家族在IFN生物学中的作用，可能会建议新的抗病毒和抗肿瘤策略的基础上选择性诱导，激活，或模仿的PLSCR蛋白。