March 16th 2007

Dr. Catherine Derry introduced and chaired this meeting which was held at Hertfordshire Biopark. Its aim was to provide evolving knowledge facilitate their T cell subset characterisation. Professor Adrian Hayday (King’s College London, UK) identified critical roles for gamma-delta T cells in protection, regulation, pathogenesis and therapy. Immunoregulation mediated by CD4+CD25+Foxp3+ regulatory T cells (Treg) was the focus of Dr Jian-Guo Chai’s (Imperial College, UK) talk. He presented key findings on tracking the interplay between antigen-specific naïve and regulatory T cells in vivo. Exploitation of Treg-mediated immunosuppression to control organ rejection in transplantation was proposed by Dr Giovanni Lombardi (King’s College London, UK). She suggested the use of adoptive cell therapy with “customised” antigen-specific Treg to do this. A failure of immunoregulation in pre-eclampsia during pregnancy was discussed by Professor Ian Sargent (University of Oxford, UK) who challenged the normal view of reproductive immunology. Professor Sargent suggested that normal pregnancy is more likely to be a controlled state of inflammation and the predominant immune interactions in the deciduas are between placental trophoblast and maternal NK rather than T cells. He described novel ways in which trophoblast and NK cell interactions could stimulate the systemic inflammatory response and lead to the maternal syndrome of pre-eclampsia. Analogous to the state of controlled inflammation described above, IL-10 regulated pathology in Tricuris muris (T. muris) infections was suggested by Mr Neil Humphreys (University of Manchester, UK). Gut infections can remotely alter immune responses to skin allergens, suggesting their influence on Langerhans cell migration. The role that epidermal Langerhans cell migration plays in elicitation and regulation in the context of parasite infestation is currently being investigated. The clear clinical potential of Treg cell function in the development of new cell-based immunotherapies requires an ability to characterise their function in vitro. Dr Oliver Garden (Imperial College London, UK) and his team have developed a quantitative assay for Treg function in vitro. He discussed the functional characterisation of CD4⁺CD25⁺ Treg cells and its implications for the pathogenesis of autoimmune conditions such as systemic lupus erythematosus (SLE). The flow cytometric detection, quantificaton, separation and characterization of live antigen-specific lymphocytes via their capture of membrane fragments from antigen-presenting cells (trogocytosis) was described by Dr Denis Hudrisier (IPBS, CNRS & Paul Sabatier University, France). He has called this the Trogocytosis Analysis Protocol (TRAP) assay [Hudrisier 2006; Paux et al. 2006], which can be used to detect lymphocytes specifically reacting with antigens and identify them from complex mixtures. The TRAP assay is simple, inexpensive and requires no specialist knowledge about the antigen or its restriction element. Dr Dawn Farrar (Miltenyi Biotec, UK) pointed out the advantages of using magnetic separation for T cell subset sorting and identification, while Dr Joost Schuitemaker (IQ Products, The Netherlands) presented several flow cytometric techniques that are used in fundamental immunological research.

Author: Dr. Kamal Ivory. Gastrointestinal Biology and Health, Institute of Food Research, Norwich, UK.  kamal.ivory@BBSRC.AC.UK

Posted by: Dr. Claire Morgan, EuroSciCon, claire.morgan@euroscicon.com