A sub-group of the members of the ECF Consortium held a two-day meeting in Oxford to discuss one of the Consortium objectives, “To induce T-cell mediated immunity by targeting the schizont stage of the parasite.”
My thanks to David Kiereini in Nairobi and Nicola Ternette, Simon Draper and Sharon Harrison in Oxford for help in the logistics of the meeting. And thanks to members of the Consortium for making the effort to attend – Nicola/Simon probably had the shortest travel time while Don Knowles (Pullman, WA) and Morten Nielsen (Buenos Aires) can argue over the longest! Others came from Edinburgh (Ivan Morrison, Tim Connelley, Lotte Bell and Niall MacHugh), London (Dirk Werling), Copenhagen (Soren Buus) and Nairobi (Lucilla Steinaa, Nick Svitek and me). Nick Juleff from the Bill and Melinda Gates Foundation (Seattle) was also present.
We met at the Nuffield Department of Medicine Research Building, University of Oxford. The first day, 2nd December, was spent providing updates on progress made in various activities under the objective: investigation of immune correlates with protection; evaluation of the Ad5/MVA prime-boost antigen delivery system; evaluation of BHV4 as an antigen delivery system; expression of candidate vaccine antigens in yeast; development of reagents to map peptide-specific T cell responses; immunoscreening of synthetic peptide libraries; a proteomics approach to identify MHC class-I associated peptides; use of bioinformatics tools to support antigen detection.
Day two, 3rd December, was spent making presentations to Seph Borrow and Tomas Hanke from the University of Oxford. Both Seph and Tomas are global leaders in the area of HIV/AIDS vaccine research. They kindly agreed to participate in our meeting to provide us with the benefit of their expertise in vaccinology, their knowledge on the topic of CD8 T cells and to critically assess our research activities and results. It was a very lively day with robust discussions following many penetrating questions. To summarize the day the experts were pleasantly surprised by how much is known about ECF, were encouraged by our progress and made the general observation that we were on the right track!
For me some of the take away lessons / highlights were the following: for CD8 T cell priming an antigen delivery system that provides persistence of antigen may work better than one that provides an antigen burst; the proteomics approach is highly promising and will become a go-to method but the loop on candidate antigens identified by this method needs to be closed; we lack a method to fast-track testing of candidate CD8 antigens and still need to identify immunization methods that prime CD8 T cells to kill schizont-infected cell; we need to develop additional assays, e.g., growth inhibition and poly-functionality of cells when assessing immune responses. Herein lies one of rubs: the large repertoire of immunological reagents that researchers in human and mouse studies take for granted are simply not available for the bovine. No wonder livestock vaccine development is handicapped. Nevertheless, the day and meeting ended on a very optimistic note.