These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Age-associated mortality in immune challenged mosquitoes (Aedes aegypti) correlates with a decrease in haemocyte numbers.
    Author: Hillyer JF, Schmidt SL, Fuchs JF, Boyle JP, Christensen BM.
    Journal: Cell Microbiol; 2005 Jan; 7(1):39-51. PubMed ID: 15617522.
    Abstract:
    Mosquitoes vector pathogens. One aspect that has been overlooked in mosquito-pathogen relationships is the effect of host age on immune competence. Here, we show that there is age-associated mortality following immune challenge with Escherichia coli. This mortality correlates with a decrease in haemocyte numbers (blood cells) and a decreased ability to kill E. coli. Although the number of haemocytes decreases, the available haemocytes retain their phagocytic ability regardless of age, and we estimate that individual granulocytes can phagocytose approximately 1500 E. coli. Moreover, transcription profiles for cecropin, defensin and gambicin in E. coli challenged mosquitoes do not change with age, indicating that the increased susceptibility is not attributed to fewer humoral antimicrobial peptides. These results suggest that a contributing factor for the age-associated mortality is the decrease in circulating haemocytes, which reduces the overall phagocytic capacity of mosquitoes. To our knowledge, this is the first report detailing an age-associated decline in the immunological capabilities of mosquitoes following challenge with an infectious agent. These data also call for caution in the analysis and interpretation of experimental results when mosquito age has not been closely monitored. Lastly, a model for haemocyte function is presented.
    [Abstract] [Full Text] [Related] [New Search]