Related Experiment Videos
A perspective on clonal phenotypic (antigenic) variation in protozoan parasites
1Division of Infection and Immunity, Institute of Biomedical and Life Sciences, Joseph Black Building, University of Glasgow, Glasgow, G12 8QQ. m.turner@bio.gla.ac.uk
Parasitology
|March 8, 2003
Summary
Pathogens use intra-clonal antigenic variation, a genotype-不变 mechanism, to evade host immunity. This strategy promotes transmission and leads to chronic infections via hierarchical antigen switching.
Area of Science:
- Microbiology
- Immunology
- Evolutionary Biology
Background:
- Pathogens employ intra-clonal phenotypic variation to evade host immune responses.
- Antigenic variation is a key strategy for pathogen survival and transmission.
Purpose of the Study:
- To theoretically analyze the functional constraints and implications of antigenic variation.
- To elucidate the role of antigenic variation in promoting pathogen transmission and chronic infections.
Main Methods:
- Theoretical analysis of antigenic variation mechanisms.
- Examination of the functional requirements for effective antigenic variation.
Main Results:
- Antigenic variation (sensu stricto) does not involve genotypic changes.
- Five conditions must be met for effective antigenic variation: multi-antigen expression, environmental interaction, mutually exclusive expression within cells and populations, and population growth.
- Meeting these conditions results in chronic infections and hierarchical, reversible antigen switching.
Conclusions:
- Antigenic variation is a polyphyletic trait crucial for pathogen persistence.
- Hierarchical expression and reversible switching of antigens are key features of this evasion strategy.
- Understanding these mechanisms is vital for developing effective anti-pathogen therapies.