IFNgamma ELISPOT of peptide pulsed, leukapheresis derived PBMC Tumor antigen specific activation of CD8 and CD4 DTH infiltrating T cells (CD137, CD107a, CD154, cytokines TNFalpha and IFNgamma)

In ongoing trials with peptide loaded DC (> 60 pat.) routine immunomonitoring at frequent intervals showed a high correlation between different assays (IFN gamma ELISPOT; modified MLPC = combination of limiting dilution, multiple peptide restimulation, tetramer detection). Both assays demonstrated declining responses upon extension of vaccination intervals. We suggest: IFN gamma ELISPOT as basic assay (costs, workload) that can be frequently performed in every patient for routine monitoring Modified MLPC (combination of limiting dilution, multiple peptide resti...

We are progressing steadily towards the delivery of a standardized method for the immuno-monitoring of DC vaccination trials using a finite number of defined tumor antigens. Our starting point was the method that we had developed previously to estimate blood frequencies of CD8 T lymphocytes against one defined antigenic peptide. It was based on an in vitro restimulation of blood lymphocytes with the peptide and growth factors over two weeks followed by detection with the appropriate HLA class I tetramer. In order to estimate frequencies of responding cells, these ...

For immuno-monitoring we established methods and protocols for detection of antigen-specific T cell populations in human and mice. Particularly we have identified CD40L as a unifying marker for all antigen-reactive T cells. This will significantly improve the possibilities to characterize specific immune responses, e.g. following vaccinations with dendritic cells.