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Surface sialic acids taken from the host allow trypanosome survival in tsetse fly vectors.

Nagamune K, Acosta-Serrano A, Uemura H, Brun R, Kunz-Renggli C, Maeda Y, Ferguson MA, Kinoshita T - J. Exp. Med. (2004)

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Dept. of Immunoregulation, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan.

ABSTRACT
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.

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Related in: MedlinePlus

Complementation of sialylation deficiency of TbGPI8-KO mutant by soluble form trans-sialidase. (A) Partial restoration of sialic acids on the surface of GPI8KO by expressing soluble form trans-sialidase. The amount of sialic acids on wild-type (WT), GPI8KO transfected with an empty vector (mock), and GPI8KO-expressing soluble form trans-sialidase (sTS) were determined. Standard deviation of three independent measurements is indicated. (B) Restoration of the surface sialic acids rescued infectivity to Tsetse flies. Infectivity was scored in a similar way as described in Fig. 1 A. The number of flies in each group is indicated above each bar. (C) Different infectivities of sTS-transfected trypanosomes in male and female flies.
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fig3: Complementation of sialylation deficiency of TbGPI8-KO mutant by soluble form trans-sialidase. (A) Partial restoration of sialic acids on the surface of GPI8KO by expressing soluble form trans-sialidase. The amount of sialic acids on wild-type (WT), GPI8KO transfected with an empty vector (mock), and GPI8KO-expressing soluble form trans-sialidase (sTS) were determined. Standard deviation of three independent measurements is indicated. (B) Restoration of the surface sialic acids rescued infectivity to Tsetse flies. Infectivity was scored in a similar way as described in Fig. 1 A. The number of flies in each group is indicated above each bar. (C) Different infectivities of sTS-transfected trypanosomes in male and female flies.

Mentions: The procyclic form of T. brucei grown in SDM-79 with 10% (vol/vol) heat-inactivated FCS were mixed 1:1 with washed horse red blood cells in the medium at 107 cells/ml. Tsetse flies were infected with each clone through an artificial membrane (12). On day 24 (see Fig. 1 A) or 27 (see Fig. 3, B and C) after infection, flies were dissected and scored for the infection.


Surface sialic acids taken from the host allow trypanosome survival in tsetse fly vectors.

Nagamune K, Acosta-Serrano A, Uemura H, Brun R, Kunz-Renggli C, Maeda Y, Ferguson MA, Kinoshita T - J. Exp. Med. (2004)

Complementation of sialylation deficiency of TbGPI8-KO mutant by soluble form trans-sialidase. (A) Partial restoration of sialic acids on the surface of GPI8KO by expressing soluble form trans-sialidase. The amount of sialic acids on wild-type (WT), GPI8KO transfected with an empty vector (mock), and GPI8KO-expressing soluble form trans-sialidase (sTS) were determined. Standard deviation of three independent measurements is indicated. (B) Restoration of the surface sialic acids rescued infectivity to Tsetse flies. Infectivity was scored in a similar way as described in Fig. 1 A. The number of flies in each group is indicated above each bar. (C) Different infectivities of sTS-transfected trypanosomes in male and female flies.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2211819&req=5

fig3: Complementation of sialylation deficiency of TbGPI8-KO mutant by soluble form trans-sialidase. (A) Partial restoration of sialic acids on the surface of GPI8KO by expressing soluble form trans-sialidase. The amount of sialic acids on wild-type (WT), GPI8KO transfected with an empty vector (mock), and GPI8KO-expressing soluble form trans-sialidase (sTS) were determined. Standard deviation of three independent measurements is indicated. (B) Restoration of the surface sialic acids rescued infectivity to Tsetse flies. Infectivity was scored in a similar way as described in Fig. 1 A. The number of flies in each group is indicated above each bar. (C) Different infectivities of sTS-transfected trypanosomes in male and female flies.
Mentions: The procyclic form of T. brucei grown in SDM-79 with 10% (vol/vol) heat-inactivated FCS were mixed 1:1 with washed horse red blood cells in the medium at 107 cells/ml. Tsetse flies were infected with each clone through an artificial membrane (12). On day 24 (see Fig. 1 A) or 27 (see Fig. 3, B and C) after infection, flies were dissected and scored for the infection.

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Dept. of Immunoregulation, Research Institute for Microbial Diseases, Osaka University, 3-1 Yamada-oka, Suita, Osaka 565-0871, Japan.

ABSTRACT
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.

Show MeSH
Related in: MedlinePlus