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: 6915019
• 负责人: Robert H. Silverman
• 金额: $ 40.9万
• 依托单位: CLEVELAND CLINIC LERNER COM-CWRU
• 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 2008-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6915019
• 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。尽管已鉴定出几种具有独特抗增殖和抗病毒活性的IFN调节基因，但IFN的这些重要生物学作用背后的许多细胞机制仍然未知。 最近，我们发现磷脂扰乱酶-1 (PLSCR1) 是一种质膜蛋白，与 Ca2+ 依赖性质膜磷脂重组有关，是一种明显 IFN 上调的基因。 我们的初步数据还表明，PLSCR1 本身表现出抗肿瘤和抗病毒活性，模拟通常与 IFN 反应相关的效应。 在本提案中，我们旨在阐明 PLSCR 基因家族中受 IFN 调节的成员在 IFN 的整体生物反应中的具体作用。 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 PLSCR1 或同源蛋白直接介导的 IFN 诱导的细胞变化。 将评估响应 IFN 的质膜磷脂拓扑结构的变化，并将其与新合成的 PLSCR1 多肽的脂肪酰化和细胞内分布的潜在变化相关。 将探索 PLSCR1 与病毒包膜蛋白在耐去垢剂膜“筏”中共定位的可能性，并将确定 PLSCR1 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； (2)阐明PLSCR1对IFN抗肿瘤活性的具体贡献。 将测定 PLSCR1-null/p53-null 小鼠中的肿瘤发生率，并比较 IFN-α 对 PLSCR1-null 和野生型肿瘤生长的影响。 将检查 PLSCR1 对细胞增殖和巨噬细胞激活/招募的潜在影响； (3)确定PLSCR1对IFN抗病毒活性的贡献。 将比较水泡性口炎病毒 (VSV) 在野生型和 PLSCR1 缺失细胞中的复制，无论是否存在 IFN。 细胞 PLSCR1 对病毒生命周期每个阶段的具体影响将被确定。 将在野生型和 PLSCR1 缺失小鼠中探索 PLSCR1 体内潜在的抗病毒活性。 有人提出，详细了解 PLSCR 基因家族在 IFN 生物学中的作用可能会提出基于选择性诱导、激活或模拟 PLSCR 蛋白的新型抗病毒和抗肿瘤策略。