Department of Biological and Environmental Sciences, University of Gothenburg, Gothenburg, Sweden.
Front Immunol. 2018 Dec 11;9:2816. doi: 10.3389/fimmu.2018.02816. eCollection 2018.
In seed plants, pollen grains carry the male gametes to female structures. They are frequent in the ambient air, and cause airway inflammation in one out of four persons in the population. This was traditionally attributed to soluble glycoproteins, leaking into the nasal mucosa or the conjunctiva, and able to bind antibodies. It is now more and more recognized that also other immunomodulating compounds are present. Lipids bind to Toll-like and PPARγ receptors belonging to antigen-presenting cells in the mammal immune system, activate invariant Natural Killer T-cells, and are able to induce a Type 2 reaction in effector cells. They may also mimic lipid mediators from mammal mast cells. Pollen grains have a rich lipodome of their own. Among the lipids that have been associated with an atopic reaction are saturated and unsaturated fatty acids, glycophospholipids, sphingolipids, sterols, and oxylipids, as well as lipopolysaccharides from the microbiome on the pollen surface. Lipids can be ligands to allergenic proteins.
在种子植物中，花粉粒携带雄性配子到雌性结构。它们在环境空气中很常见，在人群中每四个人中就有一个会引起气道炎症。这传统上归因于可溶性糖蛋白，它们渗透到鼻黏膜或结膜中，能够结合抗体。现在越来越多的人认识到，也存在其他免疫调节化合物。脂质与哺乳动物免疫系统中的抗原呈递细胞上的 Toll 样受体和 PPARγ 受体结合，激活不变自然杀伤 T 细胞，并能够在效应细胞中诱导 2 型反应。它们还可以模拟哺乳动物肥大细胞中的脂质介质。花粉粒本身有丰富的脂类组。与过敏反应相关的脂质包括饱和脂肪酸和不饱和脂肪酸、糖磷脂、鞘脂、甾醇和氧化脂质，以及花粉表面微生物组的脂多糖。脂质可以作为过敏原蛋白的配体。
