Immune Responses to Paramyxoviruses and Human Pneumoviru

呼吸道合胞病毒保护性免疫反应的特征。目的：鉴定参与RSV感染后产生保护性免疫的RSV F和G蛋白表位。 呼吸道合胞病毒是全球幼儿下呼吸道疾病的最常见原因。这种病毒的F和G糖蛋白是已知的保护性免疫反应的目标。然而，免疫是不完全的，尽管出现了抗F和抗G抗体，但仍会反复感染同源或异种亚型的病毒。此外，中和胞外病毒的抗体可能无法抑制融合或细胞间传播。这些发现表明，自然感染后引发的人类B细胞反应可能缺乏阻止病毒与受体相互作用的抗体。 为了了解病毒感染性所需的病毒-细胞相互作用，开始了识别呼吸道合胞病毒使用的受体(S)的研究。用肝素琼脂糖亲和层析法检测RSV F和G病毒包膜糖蛋白与细胞表面糖胺聚糖的结合情况。细胞结合实验检测细胞与Vero、Hep-2和A549细胞的结合，通过细胞与Gag裂解酶的竞争结合和流动处理来评价相互作用的特异性。进一步对多肽进行评估，以确定它们是否代表人类感染期间识别的表位。 在过去的一年中，对RSV-F1和F2中的线性肝素结合区进行了定位。不连续的氯化钠梯度也被用来比较强毒株和减毒株B亚群RSV包膜糖蛋白的肝素结合亲和力。这些研究表明，B亚群弱毒株对肝素的亲和力高于强毒亲本株。同样，在体外，可溶性肝素对减毒病毒的抑制作用比低传代的亲本病毒更有效。这一发现表明，组织培养适应可以增加肝素亲和力，这有助于体内肝素的衰减。 麻疹病毒疫苗株的免疫原性和安全性。目的：确定麻疹免疫的最佳年龄和计划，并确定与自身免疫反应相关的麻疹疫苗成分。 USPHS的主要目标之一是到2000年在区域内消灭麻疹，这一目标是由于提高了免疫接种率和实施了两剂时间表而实现的。然而，在最佳使用麻疹疫苗以实现全球根除方面，仍然存在一些悬而未决的问题。例如，需要进行研究，以确定最安全和最有效的麻疹疫苗，用于免疫功能低下的儿童，例如感染艾滋病毒的儿童。如果感染麻疹病毒，这些免疫功能受损的儿童可能会患上严重疾病，或成为麻疹病毒持续脱落和传播的来源，并阻碍根除工作。此外，接种疫苗的母亲所生的健康婴儿在很小的时候就会失去被动获得的麻疹抗体，并在一岁生日之前变得容易感染。目前尚不清楚目前的麻疹疫苗能否常规有效地为幼儿接种疫苗。 进步。该实验室为下列主要调查人员进行的临床研究提供支持： 1.Rosa Wong-Chew博士与Jose Valdesino、Hayley Gans、Yvonne、Maldonado和Anne Arvin一起，斯坦福大学：对墨西哥12个月大的婴儿使用标准滴度埃德蒙斯顿-萨格勒布疫苗皮下和鼻内接种麻疹疫苗进行了评估。这项研究表明，无论给药途径如何，大多数婴儿都能激发B和/或T细胞免疫。一份基于这些发现的手稿已被接受出版 2.NIBSC的Afzal博士邀请该实验室参与一项合作研究，以评估RT-PCR在检测炎症性肠病患者组织中的麻疹病毒序列方面的使用。这些研究表明，不同实验室的聚合酶链式反应敏感性差异很大。经RT-PCR检测，炎症性肠病患者的所有组织均不含麻疹病毒基因组。这些结果发表在《医学病毒学杂志》上。 本项目包含2002财年项目1Z01BK002019-10和1Z01BK002020-10。

Characterization of the Protective Immune Response to Respiratory Syncytial Virus. Goal: To identify RSV F and G protein epitopes involved in producing protective immunity following RSV infection. Respiratory syncytial virus is the most common cause of lower respiratory tract disease in young children worldwide. The F and G glycoproteins of this virus are known targets of a protective immune response. However, immunity is incomplete and repeated infections with viruses of the homologous or heterologous subtype occur despite development of anti-F and anti-G antibodies. In addition, antibodies that neutralize extracellular virus may not be able to inhibit fusion or cell-to-cell spread. These findings suggest that human B cell responses elicited after natural infection may be deficient in antibodies that prevent virus-receptor interactions. In order to understand virus-cell interactions required for virus infectivity, studies were initiated to identify the receptor(s) used by RSV. The binding of RSV F and G viral envelope glycoproteins to cell surface glycosaminoglycans was evaluated using heparin agarose affinity chromatography. Cell binding assays were used to evaluate binding to Vero, Hep-2 and A549 cells and the specificity of the interaction was evaluated by competitive binding and flowing treatment of cells with GAG lyases. Peptides were further evaluated to see if they represented epitopes recognized during human infection. During the last year linear heparin binding domain within RSV-F1 and F2 were mapped. Discontinuous sodium chloride gradients were also used to compare heparin-binding affinities of the envelope glycoproteins of virulent and attenuated RSV subgroup B strains. These studies showed that an attenuated subgroup B strain had higher affinity for heparin than did the virulent parental strain. Likewise, the attenuated virus was inhibited in vitro more efficiently by soluble heparin than the low passage virulent parent virus. The findings suggest that tissue culture adaptation can increase heparin affinity and this contributes to attenuation in vivo. Immunogenicity and Safety of Measles Virus Vaccine Strains. Goal: To identify the preferred age and schedule for measles immunization and to identify measles vaccine components associated with autoimmune responses. One of the major goals of the USPHS was the regional elimination of measles by the year 2000, a goal that was achieved due to an increase in immunization rates and implementation of a two-dose schedule. However, there are still some unanswered questions regarding optimal use of measles vaccines so that worldwide eradication is achieved. For example, research is needed in order to identify the safest and most effective measles vaccine for immunization of immunocompromised children, e.g., with HIV infection. If infected with measles virus, these immunocompromised children could suffer serious disease or be a source of persistent shedding and spread of measles virus and impede the eradication effort. In addition, healthy infants born to immunized mothers lose passively acquired measles antibody at an early age, and become vulnerable to infection before their first birthday. It is not known if young infants can be routinely and effectively immunized with current measles vaccines. Progress. This laboratory provided support for clinical studies conducted by the following primary investigators: 1. Drs. Rosa Wong-Chew with Jose Valdespino, Hayley Gans, Yvonne, Maldonado, and Anne Arvin, Stanford: Evaluated subcutaneous vs. intranasal measles vaccination using standard titer Edmonston-Zagreb vaccine in 12 month old infants in Mexico. This study demonstrated that B and/or T cell immunity was elicited in a majority of infants irrespective of route of administration. A manuscript based on these findings has been accepted for publication 2. Dr. Afzal, NIBSC, invited this laboratory to participate in a collaborative study to evaluate the use of RT-PCR in the detection of measles virus sequences in tissues from individuals with inflammatory bowel disease. These studies showed that PCR sensitivity varied widely by laboratory. All tissues from individuals with inflammatory bowel disease were found to be free of measles virus genome when tested by RT-PCR. These results were published in Journal of Medical Virology. This project incorporates FY2002 projects 1Z01BK002019-10 and 1Z01BK002020-10.