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Phenotypic and functional characterisation of canine monocytes: towards a novel therapeutic target for inflammatory and autoimmune disease?

Supervisors:  Professor Oliver Garden (ogarden@rvc.ac.uk), Dr Michelle Goulart (mgoulart@rvc.ac.uk), Dr Balazs Szladovits (bszladovits@rvc.ac.uk) 

 Recent years have seen exciting developments in our knowledge of monocyte biology. For many years the prevailing paradigm has been that monocytes are developmental precursors of macrophages: constant recruitment of monocytes into tissues was thought to be required to maintain the homeostasis of tissue-resident macrophages. Insights that have come to light in the past two years have dramatically altered this view, with the recognition of at least two subsets of monocytes that have immune functions distinct from those of tissue-resident macrophages. ‘Inflammatory’ monocytes, identified by the phenotype CD14highCD16-CCR2+CX3CR1lowCD62LhighMHC IIlow, are rapidly recruited to sites of inflammation or remodelling where they differentiate to monocyte-derived DCs or macrophages, the latter distinct from the tissue-resident population. In contrast, the CD14lowCD16+CCR2-CCR5+CX3CR1highCD62L-MHC IIhigh cells, which are thought to be derived from the CD14high monocytes, may represent terminally-differentiated blood-resident macrophages whose primary function is to survey endothelial integrity. Nothing is known about the heterogeneity of monocytes in dogs and whether similar subsets exist. We hypothesise that monocytes with equivalent phenotype exist in dogs and propose a project that builds on exciting preliminary data from the Immune Regulation Laboratory that support this notion.

 Multicolour flow cytometry will be used to characterise monocytes in the blood of healthy dogs and dogs with inflammatory and autoimmune disease. CD14high and CD14low monocytes will be isolated by flow-assisted cell sorting, prior to reverse-transcriptase-PCR for known monocyte markers as well as appropriate reference genes identified by GeNORM analysis. Functional properties of the sorted cells will be interrogated in vitro by their co-culture with pre-activated T cells in the presence of low concentrations of lipopolysaccharide. T cell proliferation, assessed by the dilution of an intracellular dye, will be measured as a read-out, as well as concentrations of pro-inflammatory cytokines in culture supernatants. The ultrastructure of the CD14high and CD14low monocytes will be defined by transmission electron microscopy.   

We would welcome informal approaches by students interested in this exciting project, which builds upon very promising preliminary data accrued to date that will be extended in this project. We aim to publish. Please direct enquiries to ogarden@rvc.ac.uk in the first instance.  

References

1.  Gordon S and Taylor, PR (2005) Monocyte and macrophage heterogeneity. Nature Reviews Immunology 5: 953-964

2.  Ginhoux F and Jung S (2014) Monocytes and macrophages: developmental pathways and tissue homeostasis. Nature Reviews Immunology 14: 392-404

If you would like to apply for this studentship please contact the supervisors in the first instance and then apply via. See also the How to Apply box

The deadline for applications is 3rd April 2016