The Immunobiology Working Party (IWP) established the influence of HLA antigens on the outcome of bone marrow transplantation (BMT) under the initial chairmanship and guidance of Professor Jon van Rood. Under his co-ordination, several groups made important contributions to this topic, as well as to our overall understanding of the alloresponse and frequencies of responses to individual HLA antigens. This successful era was continued under chairmanship of Professor Eliane Gluckman, who focussed the IWP towards understanding the principles underlying successful cord blood transplantation. Professor Gluckman created EUROCORD and established this as one of the most important co-operative organisations in the area of stem cell transplantation in Europe. Under her direction, many of the immunological aspects of cord blood transplantation were revealed.

There is no doubt that during the lifetime of the IWP, there have been tremendous developments in the area of immunology and in our understanding of the immunological aspects of BMT. We are now in a position where immunotherapies directed against viral antigens such as CMV and EBV, and against minor antigens have been applied to the patient and this can be extended to unique tumour specific antigens. In addition, we are now in a position to modulate the immune response by specific T-cell depletion, either antigen specific or, in the context of transplantation, allospecific depletion. Finally, the deeper understanding of the different aspects of histocompatibility gained by achieving high resolution typing and matching, is clarifying the contribution of HLA class I and class II antigens in the overall outcome for the patient.

Future Plans
Over the coming years, I foresee the IWP as playing a key role in integrating immune intervention to improve the outcome of transplantation. Our activities will focus on three main areas: first, on the analysis of different aspects of immune reconstitution; second, on dissecting the role of the thymus in peripheral T-cell differentiation and its role in generating different sub-populations of T-cells and third, on the mechanisms that might drive the different components of the T-cell repertoire to more effective anti-tumour activity. In particular, this will require spectratyping and phenotyping of the cellular immune reconstitution and an improvement in the understanding of the role of NK cells in graft versus leukaemic responses.

Another important component is the co-operative action to implement immunotherapy against viral and tumour-specific antigens. Several members of the IWP are working in this area, developing T-cells against CMV, minor antigens and leukaemic specific antigens. Together, we will co-operate to make this a successful European Union effort.

We will continue to dissect the role of multiple immunogenetic factors in affecting the global outcome of transplantation by using high resolution typing for polymorphisms in non-HLA molecules for other potential regulatory genes. By performing a multi-centric analysis, we hope to achieve sufficient numbers to arrive at a clear understanding of how best to prevent rejection, GvHD, and improve long-term survival.

It is the aim of the IWP to collaborate with other groups and to have interactions with all the EBMT working parties. In addition, we will continue to have strong interactions with EUROCORD and again, we hope to improve our understanding of the immunological aspects of stem cell transplantation.