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CHARACTERIZATION OF THE HEMOCYTES OF SUSCEPTIBLE AND RESISTANT BIOMPHALARIA ALEXANDRINA SNAIL
Journal of the Egyptian Society of Parasitology
|September 20, 2018
Summary
The study reveals differences in snail hemocytes, the cells of the internal defense system, between susceptible and resistant snails infected with S. mansoni. Resistant snails showed decreased hemocyte counts and activated cell morphology post-infection.
Area of Science:
- Immunology
- Malacology
- Cell Biology
Background:
- The internal defense system of molluscs relies on hemolymph soluble components and circulating hemocytes.
- Hemocytes are crucial for innate immunity in invertebrates like the snail Biomphalaria alexandrina.
- Understanding hemocyte responses is key to deciphering host-parasite interactions, particularly in Schistosoma mansoni infections.
Purpose of the Study:
- To investigate and compare hemocyte characteristics in susceptible and resistant B. alexandrina snails infected with S. mansoni.
- To analyze hemocyte counts and morphological changes using light and electron microscopy.
Main Methods:
- Comparative analysis of hemocyte counts in susceptible and resistant B. alexandrina snails before and after S. mansoni infection.
- Morphological characterization of circulating and tissue hemocytes using light microscopy (LM) and scanning electron microscopy (SEM).
- Evaluation of cellular activation signs in hemocytes via LM and transmission electron microscopy (TEM).
Main Results:
- No significant difference in hemocyte counts between groups before infection.
- A significant decrease in circulating hemocytes observed in the resistant group post-infection.
- LM identified five circulating hemocyte types in both groups.
- SEM revealed rounded, smooth-surfaced hemocytes in susceptible snails versus irregular, corrugated-surfaced hemocytes in resistant snails.
- LM and TEM indicated heightened cell activation in hemocytes of resistant snails.
Conclusions:
- Hemocyte morphology and activation states differ between susceptible and resistant B. alexandrina snails following S. mansoni infection.
- While hemocyte types are conserved, resistant snails exhibit more pronounced signs of immune cell activation.
- Further research into hemocyte functional activities is essential for understanding mollusc susceptibility to pathogens and their immune responses.
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