Dr Lanzavecchia's research has focussed on the role played by inflammation in helping the body to fight disease, showing that it is far more than an inconvenient side-effect.
Dendritic cells are the body's blood hounds, travelling all over the body sniffing out foreign proteins. They digest these proteins and then display small fragments (peptides) on their surfaces using special molecules called MHC II. The dendritic cells then travel back to the lymph nodes where T cells recognise the peptide-MHC II complex and rev into action.
The research carried out by Dr Lanzavecchia and his team shows that in order to do their job effectively the dendritic cells need to encounter inflammation. In response to molecules found at the site of inflammation, dendritic cells mature and produce more MHC II molecules. In addition, the peptide-MHC II complexes are displayed on the surface of the mature cells for ten times longer than on immature cells. Dr Lanzavecchia believes that this increased display time is important since it gives the dendritic cells time to return to the lymph nodes and launch at T cell attack.
Further research by the Swiss team indicates that inflammation is also important in guiding activated T cells to the site of infection. Tissues which are inflamed as a result of an allergic response produces a molecule called eotaxin. One class of T cells, Th2, carry a receptor for eotaxin which enables them to home in on the site of this inflammation. Th2 cells initiate and maintain the allergic response, so Dr Lanzavecchia envisages a new type of anti-allergy drug, which interferes with eotaxin or its receptor and so distracts the Th2 cells from reaching their target. Such drugs could also help us in the fight against HIV since this virus uses the eotaxin receptor to help it get inside white blood cells.
Dr Lanzavecchia will show that other types of immune cell are also guided to sites of inflammation by chemical messengers.
By understanding how dendritic cells stimulate an immune response and how chemical messengers direct the immune cells to the target site, Dr Lanzavecchia thinks that we can learn to deliver vaccines in more effective ways. Improved delivery should stimulate a protective immune response in the right region of the body, leading to longer lasting immunity and fewer side-effects.
Notes:
1. Dr Lanzavecchia is speaking in the Vaccines session on Thursday 4 December.
The BSI 5th Annual Congress will be held at the Brighton Centre, Brighton, UK
from 2-5 December.
2. Dr Lanzavecchia can be contacted at the Basel Institute for Immunology, Grenzacherstrasse 487, Postfach, CH-4005 Basel, Switzerland. Tel: +41 61 605 1326 Fax: +41 61 605 1222 Lanzavecchia@bii.ch
3. There will be a press office at the meeting from 9am on Tuesday 2 December, tel. +44 1 273 724 320 / 0378 406 416. Journalists are welcome to attend but are asked to contact Kirstie Urquhart in advance to register.
4. Before the meeting Kirstie can be contacted on +44 181 875 2402 / kirstie@immunology.org