Plant virus infection as a determinant of pollen allergenicity

花粉引起的鼻炎和结膜炎是一个主要的健康问题，多达四分之一的英国人口现在受到影响。病毒侵染植物很常见，并有可能引起花粉粒组成的深刻变化。为了研究在草中感染病毒可以增强花粉刺激过敏反应的能力这一概念，建议在两个具有互补专业知识的机构之间开展合作：牛津大学生态和水文学中心(CEH)和南安普顿大学感染、炎症和修复处。我们将把重点放在草本植物的花粉上，这些花粉是英国过敏性鼻结膜炎的主要诱因。CEH的工作人员将向南安普顿小组提供分别受到特定病毒(花椒潜伏白化病毒、鸡冠花条纹马铃薯Y病毒或鸡冠花斑驳病毒)入侵的温室种植的金雀花(甜美春草)或鸡尾草(鸡尾草)的花粉。霍代伊病毒可以通过花粉传播，而马铃薯Y病毒则表达丰富的蛋白酶。这三种病毒都能产生丰富的衣壳蛋白，它们的感染应该会触发宿主表达广泛的防御蛋白。所有这些变化都可能发生在花器官中，因此来自受感染植物的花粉可能会被额外的过敏原污染。将在南安普敦使用适当的体外和体内模型来研究病毒诱导的致敏效力变化的可能性。将仔细比较脱病毒植物和受病毒感染植物的标准化花粉提取物的蛋白质成分，并调查不同花粉提取物成分与IgE结合的模式。我们将研究在体外刺激肥大细胞和嗜碱性细胞激活的可能性，并探索蛋白水解酶或其他花粉成分改变上皮单分子层的能力。我们将寻求在草花粉过敏受试者的皮肤和上呼吸道中引发过敏反应，并将其与来自无病毒和受病毒感染的草的花粉引起的反应进行比较。这项研究应该提供关于植物病毒可能在多大程度上改变花粉诱导敏化或引起过敏反应的潜力的信息。这将首次对这些病毒作为花粉过敏的环境决定因素进行评估，并可能为减少社区疾病负担的新方法开辟道路。

Pollen-induced rhinitis and conjunctivitis represents a major health problem, with up to one in four of the UK population now affected. Virus infection of plants is common and has the potential to induce profound changes in the composition of pollen grains. In order to investigate the concept that virus-infection in grasses can enhance the ability of pollen to stimulate allergic reactions, a collaboration is proposed between two institutions with complementary expertise: the Centre for Ecology and Hydrology (CEH) in Oxford and the Infection, Inflammation and Repair Division of the University of Southampton. We will focus on pollens from grass species implicated as major triggers of allergic rhinoconjunctivitis in the UK. Staff of CEH will supply the Southampton team with pollen from glasshouse-grown Anthoxanthum odoratum (sweet vernal grass) or Dactylis glomerata (cocksfoot) separately invaded by specific viruses (Anthoxanthum latent blanching hordeivirus, Cocksfoot streak potyvirus or Cocksfoot mottle sobemovirus). The hordeivirus can be pollen-borne, while the potyvirus expresses abundant proteases. All of the three viruses produce abundant capsid proteins and their infections should trigger host expression of a wide range of defensive proteins. All these alterations can occur in flower organs so pollens from infected plants could become contaminated with additional allergens. The potential for virus-induced alterations in allergenic potency will be investigated in Southampton using appropriate in vitro and in vivo models. The protein components of standardised extracts of pollens from virus free and virus infected plants will be carefully compared, and patterns of IgE binding by components of the different pollen extracts investigated. The potential to stimulate mast cell and basophil activation in vitro will be examined, and the ability of proteases or other pollen constituents to alter epithelial monolayers explored. We shall seek to provoke allergic reactions in the skin and upper airways of grass pollen allergic subjects, and compare responses elicited with pollen from virus free and virus infected grasses. This study should provide information on the extent to which plant viruses may alter the potential of pollens to induce sensitisation or to elicit allergic reactions. This will allow for the first time an assessment of these viruses as environmental determinants of pollen allergy, and could open the way for new approaches to reduce the burden of disease in the community.