Parasite Carbohydrate Vaccines

Abstract

Vaccination is an efficient means of combating infectious disease burden globally. However, routine vaccines for the world's major human parasitic diseases do not yet exist. Vaccines based on carbohydrate antigens are a viable option for parasite vaccine development, given the proven success of carbohydrate vaccines to combat bacterial infections. We will review the key components of carbohydrate vaccines that have remained largely consistent since their inception, and the success of bacterial carbohydrate vaccines. We will then explore the latest developments for both traditional and non-traditional carbohydrate vaccine approaches for three of the world's major protozoan parasitic diseases—malaria, toxoplasmosis, and leishmaniasis. The traditional prophylactic carbohydrate vaccine strategy is being explored for malaria. However, given that parasite disease biology is complex and often arises from host immune responses to parasite antigens, carbohydrate vaccines against deleterious immune responses in host-parasite interactions are also being explored. In particular, the highly abundant glycosylphosphatidylinositol molecules specific for Plasmodium, Toxoplasma, and Leishmania spp. are considered exploitable antigens for this non-traditional vaccine approach. Discussion will revolve around the application of these protozoan carbohydrate antigens for vaccines currently in preclinical development.

An α-Gal-containing neoglycoprotein-based vaccine partially protects against murine cutaneous leishmaniasis caused by Leishmania major

“…Carbohydrates have been proposed as potential targets for vaccines against Leishmania spp. [ 32 , 67 ]. Vaccination with Leishmania lipophosphoglycan (LPG), one of the major components of the glycocalyx of the parasite, revealed contradictory results [ 68 – 70 ].…”

“…Although the levels of anti-α-Gal antibodies are very high in Leishmania infections [ 21 , 23 , 24 , 26 ], it has not yet been demonstrated whether these antibodies have any protective role. More recently, Jaurigue and Seeberger [ 32 ] have proposed α-Gal epitopes as vaccine candidates against Leishmania spp. and other major protozoan parasites.…”

Potential targets for next generation antimicrobial glycoconjugate vaccines

“…Furthermore, glycosylphosphatidylinositol molecules, which are present on the surface of virtually all eukaryotic cells serving as surface protein anchors, occur at relatively high levels and with specific structures in parasitic protozoa, such as Plasmodium falciparum (Gowda, Gupta and Davidson 1997 ). The use of parasite carbohydrates as potential vaccine antigens has been recently reviewed and will not be in the scope of the present work (Jaurigue and Seeberger 2017 ).…”

Vaccine Types

“…At present, there are human trials underway with several different DNA vaccines, including those for malaria, AIDS, influenza, and herpesvirus. Researchers hope that DNA vaccines can produce immunity against parasitic diseases such as malaria; however, there is currently no human vaccine in use for fighting parasites [24].…”