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Updated: Aug 28, 2026
07:16
In Vivo Assessment of Rodent Plasmodium Parasitemia and Merozoite Invasion by Flow Cytometry
Published on: April 5, 2015
Influence of erythrocyte membrane components on malaria merozoite invasion
The Journal of Experimental Medicine
|December 1, 1973
Abstract:
Chymotrypsin- and Pronase-treated human erythrocytes were refractory to invasion by P. knowlesi merozoites; invasion was not inhibited by trypsin or neurammidase treatment. These data implicate a surface protein other than sialoglycoprotein as the receptor site for merozoites. Invasion of rhesus erythrocytes was unaffected by pretreatment with these enzymes. Differences in membrane structure of erythrocytes from various species may explain the absence of an enzyme effect on rhesus erythrocytes.
Insights
Human erythrocyte invasion by Plasmodium knowlesi merozoites is blocked by chymotrypsin and pronase treatments. This suggests a non-sialoglycoprotein surface protein acts as the merozoite receptor, unlike in rhesus erythrocytes.
Area of Science:
- Parasitology
- Cell Biology
- Biochemistry
Background:
- Plasmodium knowlesi merozoites infect erythrocytes, causing malaria.
- Erythrocyte surface proteins are crucial for merozoite invasion.
- The specific receptor for P. knowlesi merozoites on human erythrocytes remains unclear.
Purpose of the Study:
- To identify the specific erythrocyte surface protein involved in P. knowlesi merozoite invasion.
- To investigate the role of erythrocyte membrane proteins in host specificity.
Main Methods:
- Human and rhesus erythrocytes were treated with various enzymes (chymotrypsin, pronase, trypsin, neuraminidase).
- The susceptibility of treated erythrocytes to P. knowlesi merozoite invasion was assessed.
- Comparative analysis of enzyme effects across different erythrocyte species was performed.
Main Results:
- Chymotrypsin and pronase treatment rendered human erythrocytes resistant to P. knowlesi merozoite invasion.
- Trypsin and neuraminidase treatments did not inhibit invasion of human erythrocytes.
- Rhesus erythrocyte invasion was unaffected by any enzyme pretreatment.
- These findings implicate a non-sialoglycoprotein surface protein as the merozoite receptor on human erythrocytes.
Conclusions:
- A specific surface protein, distinct from sialoglycoproteins, serves as the receptor for P. knowlesi merozoites on human erythrocytes.
- Differences in erythrocyte membrane structure between human and rhesus species likely explain the differential enzyme effects and host specificity.
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