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Christopher CoatesPhD Research Student
BSc (Honours) Biological (& Biomedical) Sciences National University of Ireland, Maynooth (2005-2009)
Supervisors: Dr. Timothy Whalley
Start Date: 1st October 2009 tel: +(44) 1786 466550 fax: +(44) 1786 467840 |
Current research project PhD
Hemocyanin - an essential component of arthropod immunity?
Hemocyanin is the most abundant protein present in hemolymph (present at concentrations of up to a staggering 120 mg/ml). While hemocyanin has been well characterised as an oxygen carrier, several studies have indicated that it is possible to convert oxygen-binding hemocyanin to a functionally active phenoloxidase.
We have recently characterised the structural changes associated with the induction of phenoloxidase activity in hemocyanin (Baird et al., 2007). This functional change was induced by the presence of the artificial activator SDS. To date, the natural inducer of phenoloxidase activity in hemocyanin has not been investigated. The aim of this project is to identify and fully characterise the natural inducer of phenoloxidase activity in hemocyanin.
The micellar form of SDS induces maximal phenoloxidase activity in hemocyanin, and so our search for natural inducers will focus on natural lipids in the form of liposomes, which will mirror the micellar state of SDS. One naturally occurring lipid which has been shown to activate prophenoloxidase (an enzyme which is phylogenetically related to hemocyanin) in Drosphila melanogaster is phosphatidylserine (Bidla et al., 2008). The appearance of phosphatidylserine on the external surface of eukaryotic cells entering apoptotic pathways has been well documented and we aim to explore the display of phosphatidylserine on the surface of hemocytes following septic infection.
Objectives:
- to screen marine and terrestrial arthropods for a suitable model organnism/system to work with
- to isolate infected and non-infected hemocytes
- to monitor the appearance of phosphatidylserine on the surface of infected and non-infected hemocytes using commercially available apoptosis detection kits
- to test the ability of natural lipids, including phosphatidylserine, to induce phenoloxidase activity in hemocyanin
- to investigate the physiological circumstances in which hemocyanin is converted to a phenoloxidase
- to characterise the structural changes associated with the induction of phenoloxidase activity by natural activator(s).
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Pictured above are the most widely know arthropods, arachnids, crustaceans and insects. The Phylum Arthropoda is the most organism rich phylum, consisting of an estimated one million species inhabiting both terrestrial and aquatic environments.
Research Interests
Evaluating the cellular and humoral innate immune response of Arthropods particularly insects. Using cytological, molecular, biochemical and proteomic experimentation to elucidate the activation of the cellular immune response and observe cross communication with the humoral immune response.
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Fig.1 Hemocyanin and Arthropod Immunity, this figure details the many roles hemocyanin displays: carrying molecular oxygen, ROS production, Phenoloxidase activity and release of AMP as well as clot formation.
Society Membership
- Society of Biology
- International Endotoxin and Innate Immunity Society (IEIIS)
- International Society for Developmental and Comparative Immunology ( ISDCI)
Conference(s)
Society for General Microbiology (April 2009, University College Cork) ''Innovative models and systems to explore microbial pathogenesis''
Poster Presentations
*Christopher Coates*, Peter Mowlds & Kevin Kavanagh ( April 2009). 'Oral administraion of beta-glucan and latex enhances the immune response of Galleria mellonella larvae to Candida albicans'. Society for General Microbiology ,Irish Division.
John Fallon, Linda Williams,*Christopher Coates* & Kevin Kavanagh (November 2008). 'Utilising Galleria mellonella larvae for assessing the disease causing potential of environmental isolates of Aspergillus fumigatus': Annual Environmental Protection Agency Strive conference.
Previous Research Projects
4th year Research Project
*Christopher Coates* (2009) 'Analysis of the immune response induced by Galleria mellonella larvae upon oral administration of microbial cell wall components'. Supervised by Dr. Kevin Kavanagh, Medical Mycology Unit, N.U.I Maynooth, Co, Kildare, Ireland.
Science Foundation Ireland PURE-UREKA Scholarship in Chemical Biology
*Christopher Coates* & Kevin Kavanagh. (2008) 'Immuno-stimulation of Galleria mellonella larvae using beta-glucan and analysis of a dose dependent response' Scholarship was awarded for a summer bursary as a Research Assisstant in the Medical Mycology Unit, N.U.I Maynooth.
Publication(s)
Peter Mowlds, *Christopher Coates*, Julie Renwick and Kevin Kavanagh. 2010. Dose dependent cellular and humoral responses in Galleria mellonella larvae after beta-glucan inoculation. Microbes and Infection. 12, 146-153. Glucan paper.
Interests/Honorary Posts
- PhD(postgraduate) Respresentative (SBES)
- Chair of the staff - student committee (SBES)
- Member of the Stirling graduate research steering councill (SGRS)
- Associate member of the Stirling students union association (SUSA)
