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Consequences of immunopathology for pathogen virulence evolution and public health: malaria as a case study
Evolutionary theories explaining virulence—the fitness damage incurred by infected hosts—often focus on parasite strategies for within-host exploitation. However, much virulence can be caused by the host's own immune response: for example, pro-inflammatory cytokines, although essential for kill...
Autores principales: | , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Blackwell Publishing Ltd
2011
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3352548/ https://www.ncbi.nlm.nih.gov/pubmed/25567973 http://dx.doi.org/10.1111/j.1752-4571.2010.00178.x |
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author | Long, Gráinne H Graham, Andrea L |
author_facet | Long, Gráinne H Graham, Andrea L |
author_sort | Long, Gráinne H |
collection | PubMed |
description | Evolutionary theories explaining virulence—the fitness damage incurred by infected hosts—often focus on parasite strategies for within-host exploitation. However, much virulence can be caused by the host's own immune response: for example, pro-inflammatory cytokines, although essential for killing malaria parasites, also damage host tissue. Here we argue that immune-mediated virulence, or ‘immunopathology,’ may affect malaria virulence evolution and should be considered in the design of medical interventions. Our argument is based on the ability of immunopathology to disrupt positive virulence-transmission relationships assumed under the trade-off theory of virulence evolution. During rodent malaria infections, experimental reduction of inflammation using reagents approved for field use decreases virulence but increases parasite transmission potential. Importantly, rodent malaria parasites exhibit genetic diversity in the propensity to induce inflammation and invest in transmission-stage parasites in the presence of pro-inflammatory cytokines. If immunopathology positively correlates with malaria parasite density, theory suggests it could select for relatively low malaria virulence. Medical interventions which decrease immunopathology may therefore inadvertently select for increased malaria virulence. The fitness consequences to parasites of variations in immunopathology must be better understood in order to predict trajectories of parasite virulence evolution in heterogeneous host populations and in response to medical interventions. |
format | Online Article Text |
id | pubmed-3352548 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2011 |
publisher | Blackwell Publishing Ltd |
record_format | MEDLINE/PubMed |
spelling | pubmed-33525482012-05-24 Consequences of immunopathology for pathogen virulence evolution and public health: malaria as a case study Long, Gráinne H Graham, Andrea L Evol Appl Perspective Evolutionary theories explaining virulence—the fitness damage incurred by infected hosts—often focus on parasite strategies for within-host exploitation. However, much virulence can be caused by the host's own immune response: for example, pro-inflammatory cytokines, although essential for killing malaria parasites, also damage host tissue. Here we argue that immune-mediated virulence, or ‘immunopathology,’ may affect malaria virulence evolution and should be considered in the design of medical interventions. Our argument is based on the ability of immunopathology to disrupt positive virulence-transmission relationships assumed under the trade-off theory of virulence evolution. During rodent malaria infections, experimental reduction of inflammation using reagents approved for field use decreases virulence but increases parasite transmission potential. Importantly, rodent malaria parasites exhibit genetic diversity in the propensity to induce inflammation and invest in transmission-stage parasites in the presence of pro-inflammatory cytokines. If immunopathology positively correlates with malaria parasite density, theory suggests it could select for relatively low malaria virulence. Medical interventions which decrease immunopathology may therefore inadvertently select for increased malaria virulence. The fitness consequences to parasites of variations in immunopathology must be better understood in order to predict trajectories of parasite virulence evolution in heterogeneous host populations and in response to medical interventions. Blackwell Publishing Ltd 2011-03 /pmc/articles/PMC3352548/ /pubmed/25567973 http://dx.doi.org/10.1111/j.1752-4571.2010.00178.x Text en © 2011 Blackwell Publishing Ltd |
spellingShingle | Perspective Long, Gráinne H Graham, Andrea L Consequences of immunopathology for pathogen virulence evolution and public health: malaria as a case study |
title | Consequences of immunopathology for pathogen virulence evolution and public health: malaria as a case study |
title_full | Consequences of immunopathology for pathogen virulence evolution and public health: malaria as a case study |
title_fullStr | Consequences of immunopathology for pathogen virulence evolution and public health: malaria as a case study |
title_full_unstemmed | Consequences of immunopathology for pathogen virulence evolution and public health: malaria as a case study |
title_short | Consequences of immunopathology for pathogen virulence evolution and public health: malaria as a case study |
title_sort | consequences of immunopathology for pathogen virulence evolution and public health: malaria as a case study |
topic | Perspective |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3352548/ https://www.ncbi.nlm.nih.gov/pubmed/25567973 http://dx.doi.org/10.1111/j.1752-4571.2010.00178.x |
work_keys_str_mv | AT longgrainneh consequencesofimmunopathologyforpathogenvirulenceevolutionandpublichealthmalariaasacasestudy AT grahamandreal consequencesofimmunopathologyforpathogenvirulenceevolutionandpublichealthmalariaasacasestudy |