Tick salivary glycans – a sugar-coated tick bite.

Red meat allergy is linked to exposure to alpha-Gal epitopes found in the saliva of ticks and hence known as the alpha-Gal syndrome. Alpha-Gal epitopes are found in the saliva of the Lone star tick, Amblyomma americanum , and the alpha-Gal syndrome is predominantly associated with exposure to A. americanum tick bites in the USA. Alpha-Gal epitopes are also presumably present in the saliva of the blacklegged tick, Ixodes scapularis, but exposure to these ticks is not predominantly linked to the alpha-Gal syndrome. Salivary glycans of I. scapularis have also been shown to play a role in the development of acquired tick resistance to tick infestations on non-natural host species. Deciphering the mechanistic basis of alpha-Gal syndrome and acquired tick resistance will enhance our understanding of glycans in the context of glycoimmunology and tick–host interactions. Ticks are hematophagous arthropods that transmit disease-causing pathogens worldwide. Tick saliva deposited into the tick-bite site is composed of an array of immunomodulatory proteins that ensure successful feeding and pathogen transmission. These salivary proteins are often glycosylated, and glycosylation is potentially critical for the function of these proteins. Some salivary glycans are linked to the phenomenon of red meat allergy – an allergic response to red meat consumption in humans exposed to certain tick species. Tick salivary glycans are also invoked in the phenomenon of acquired tick resistance wherein non-natural host species exposed to tick bites develop an immune response that thwarts subsequent tick feeding. This review dwells on our current knowledge of these two phenomena, thematically linked by salivary glycans. [ABSTRACT FROM AUTHOR]