Is lipophosphoglycan a virulence factor? A surprising diversity between Leishmania species

Lipophosphoglycan is a prominent member of the phosphoglycan-containing sur face glycoconjugates of Leishmania. Genetic tests enable confirmation of it s role in parasite virulence and permit discrimination between the roles of lipophosphoglycan and related glycoconjugates, When two different lipophos phoglycan biosynthetic genes from Leishmania major were knocked out, there was a clear loss of virulence in several steps of the infectious cycle but, with Leishmania mexicana, no effect on virulence was found. This points to an unexpected diversity in the reliance of Leishmania species on virulence factors, a finding underscored by recent studies showing great diversity i n the host response to Leishmania species.