Surface sialic acids taken from the host allow trypanosome survival in tsetse fly vectors.
The African trypanosome Trypanosoma brucei, which causes sleeping sickness in humans and Nagana disease in livestock, is spread via blood-sucking Tsetse flies. In the fly's intestine, the trypanosomes survive digestive and trypanocidal environments, proliferate, and translocate into the salivary gland, where they become infectious to the next mammalian host. Here, we show that for successful survival in Tsetse flies, the trypanosomes use trans-sialidase to transfer sialic acids that they cannot synthesize from host's glycoconjugates to the glycosylphosphatidylinositols (GPIs), which are abundantly expressed on their surface. Trypanosomes lacking sialic acids due to a defective generation of GPI-anchored trans-sialidase could not survive in the intestine, but regained the ability to survive when sialylated by means of soluble trans-sialidase. Thus, surface sialic acids appear to protect the parasites from the digestive and trypanocidal environments in the midgut of Tsetse flies.
Nagamune
Kisaburo
K
Dept. of Immunoregulation, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan.
Acosta-Serrano
Alvaro
A
Uemura
Haruki
H
Brun
Reto
R
Kunz-Renggli
Christina
C
Maeda
Yusuke
Y
Ferguson
Michael A J
MA
Kinoshita
Taroh
T
D000818:Animals; D006001:Glycoconjugates / Q000037:antagonists & inhibitors / Q000096:biosynthesis; D017261:Glycosylphosphatidylinositols / Q000276:immunology; D006801:Humans; D007303:Insect Vectors / Q000469:parasitology; D009439:Neuraminidase / Q000276:immunology*; D012469:Salivary Glands / Q000469:parasitology; D012794:Sialic Acids / Q000032:analysis*; D014346:Trypanosoma brucei brucei / Q000254:growth & development*; D014353:Trypanosomiasis, African / Q000635:transmission; D014370:Tsetse Flies / Q000469:parasitology*
D006001:Glycoconjugates; D017261:Glycosylphosphatidylinositols; D012794:Sialic Acids; D009439:Neuraminidase