Differential structure and immunomodulatory functions of lipophosphoglycan between Leishmania spp

Leishmaniasis is a collective term for several tropical, neglected diseases caused by protozoans of the species Leishmania, 20 of which causing disease in humans ranging from localised self-healing lesions to chronic manifestations which affect the skin or inner organs. Although millions of infections are accounted for annually, treatment options are scarce and limited to medication associated with heavy side-effects and increasing antibiotic resistance. Case studies point towards immunotherapy as effective alternative treatment relying on immunomodulatory properties of e.g., the Bacillus Calmette-Guérin vaccine. Leishmania parasites are also known to modulate the immune system, yet the underlying macromolecules and surface molecules remain widely under characterised. With this short review, we aim to provide a complete summary of the existing literature describing one of the most expressed surface molecule on Leishmania spp, lipophosphoglycan (LPG), which shows great variability between different lifecycle stages and different Leishmania spp. Complete characterisation of LPG may aid to improve treatment and aid the development of vaccination strategies, and open new avenues to exploit the immunomodulatory properties of LPG in unrelated conditions.