The purpose of this review was to go through the impact of pollen components on innate immune responses. Pollens include a variety of components that might elicit an innate immune response. Each component activates the innate immune response in a unique way. Pollen nicotinamide adenine dinucleotide phosphate oxidases generate reactive oxygen species and attract neutrophils, which cause allergic inflammation. Pollen proteases disrupt the function of the epithelial barrier and enhance antigen absorption. Pollen proteins and pollen lipids influence dendritic cell activity and cause Th2 polarisation in aqueous pollen extracts. Clinical studies have shown that modulating the innate immune response to pollens with toll-like receptor 9- and toll-like receptor 4-stimulating conjugates are well tolerated and produce clear immunological effects, but it is ineffective in suppressing primary clinical endpoints of allergic inflammation.

More study on the innate immune mechanisms activated by pollen components is needed to develop innovative methods to prevent allergic inflammation.