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Role of cell surface mannose residues in host cell invasion by Trypanosoma cruzi
Abstract:
The role of mannose residues on the membranes of Trypanosoma cruzi and its host cells in their association (surface binding plus internalization of the parasite) leading to infection was studied. Used in this work were the bloodstream (trypomastigote), intracellular (amastigote) and insect-transmissible (metacyclic trypomastigote) forms of the parasite; mouse macrophages and rat heart myoblasts were used as the host cells. Removal of mannose residues from the surface of all forms of the parasite by treatment with alpha-mannosidase produced a marked increase in their respective abilities to associate with either host cell. The increase was more pronounced with the bloodstream and insect-derived trypomastigotes (which can penetrate cell membranes) than with the amastigotes (which can not do so). By contrast, mannosidase treatment of the macrophages and the myoblasts caused a significant decrease in the ability of these cells to associate with either bloodstream or insect-derived trypomastigote forms. The capacity of mannosidase-treated macrophages to take up the non-invasive amastigotes was also reduced. These results, as a whole, suggest that mannose residues on the surface of the parasite modulate their binding to macrophages and myoblasts and that mannose residues on the surface of these host cells play a role in cell association with the parasite.
Insights
Mannose residues on Trypanosoma cruzi parasites and host cells influence infection. Removing mannose from parasites increased host cell association, while removing it from host cells decreased parasite binding.
Area of Science:
- Parasitology
- Cell Biology
- Infectious Diseases
Background:
- Trypanosoma cruzi infection involves parasite-host cell interactions.
- Mannose residues on cell surfaces are implicated in biological recognition events.
Purpose of the Study:
- To investigate the role of mannose residues in Trypanosoma cruzi and host cell association.
- To understand how mannose influences parasite binding and internalization, leading to infection.
Main Methods:
- Used bloodstream (trypomastigote), intracellular (amastigote), and metacyclic trypomastigote forms of T. cruzi.
- Employed mouse macrophages and rat heart myoblasts as host cells.
- Treated parasites and host cells with alpha-mannosidase to remove mannose residues.
Main Results:
- Removing mannose from T. cruzi increased its association with host cells, particularly trypomastigotes.
- Removing mannose from host cells decreased their association with trypomastigotes.
- Mannosidase treatment reduced host cell uptake of amastigotes.
Conclusions:
- Parasite surface mannose residues modulate binding to host cells.
- Host cell surface mannose residues play a role in parasite association.
- Mannose-mediated interactions are critical for T. cruzi infection dynamics.