EpiToolKit--a web server for computational immunomics.

Predicting the T-cell-mediated immune response is an important task in vaccine design and thus one of the key problems in computational immunomics. Various methods have been developed during the last decade and are available online. We present EpiToolKit, a web server that has been specifically designed to offer a problem-solving environment for computational immunomics. EpiToolKit offers a variety of different prediction methods for major histocompatibility complex class I and II ligands as well as minor histocompatibility antigens. These predictions are embedded in a user-friendly interface allowing refining, editing and constraining the searches conveniently. We illustrate the value of the approach with a set of novel tumor-associated peptides. EpiToolKit is available online at www.epitoolkit.org.

HLA ligand profiles of primary renal cell carcinoma maintained in metastases.

In recent years, several approaches have been taken in the peptide-based immunotherapy of metastatic renal cell carcinoma (RCC), although little is known about HLA presentation on metastases compared to primary tumor and normal tissue of RCC. In this study we compared primary tumor, normal tissue and metastases with the aim of identifying similarities and differences between these tissues. We performed this comparison for two RCC patients on the level of the HLA ligandome using mass spectrometry and for three patients on the level of the transcriptome using oligonucleotide microarrays. The quantitative results show that primary tumor is more similar to metastasis than to normal tissue, both on the level of HLA ligand presentation and mRNA. We were able to characterize a total of 142 peptides in the qualitative analysis of HLA-presented peptides. Six of them were significantly overpresented on metastasis, among them a peptide derived from CD151; fourteen were overpresented on both primary tumor and metastasis compared to normal tissue, among them an HLA ligand derived from tumor protein p53. Thus, we could demonstrate that peptide-based immunotherapy might affect tumor as well as metastasis of RCC, but not healthy kidney tissue. Furthermore we were able to identify several peptides derived from tumor-associated antigens that are suitable for vaccination of metastatic RCC.

Repeat expansion in spinocerebellar ataxia type 17 alleles of the TATA-box binding protein gene: an evolutionary approach.

The variability and mutational changes of the CAG microsatellite in the TATA-box binding protein gene (TBP) were studied. We sequenced the microsatellite of the TBP gene of 25 unrelated individuals from northern Germany (10 SCA17 patients and 15 unaffected control individuals). In addition, the microsatellites were sequenced from individuals of 10 northern German families with at least one family member affected by SCA17. To study also the evolutionary history of this CAG/CAA microsatellite in nonhuman primates, the homologous regions were analysed from Pan troglodytes, Gorilla gorilla, Pongo pygmaeus, P. abellii, Hylobates lar, Nomascus leucogenys, Symphalangus syndactylus, Macaca mulatta, Papio hamadryas, Colobus polykomos and Callithrix jacchus. Three major conclusions were drawn: (i) Patterns of synonymous CAA interruptions in the microsatellite are characteristic and likely to result from selection for stabilizing the repetitive region; (ii) Interspecific comparisons indicate that SCA17 is likely to be a human trait. The most common allele in humans (37 repeats) is close to the threshold value upon which neurodegenerative changes can occur and may act as a repository for expanded, pathogenic alleles; (iii) The cassette-like structure of five out of 17 expanded alleles can be attributed to unequal crossing over. This can explain the rare and sporadic de novo generation of SCA17 alleles.

SYFPEITHI: database for searching and T-cell epitope prediction.

Reverse immunology has been used for about 12 years in order to identify T-cell epitopes from pathogens or tumor-associated antigens. In this chapter, we discuss the advantages and pitfalls of T-cell epitope prediction compared to classical experimental procedures such as epitope mapping and cloning experiments. We introduce our three established programs, SYFPEITHI, PAProc, and SNEP, which are freely accessible at no cost in the World Wide Web for the prediction of either HLA-peptide binding or proteasomal processing of antigens. We demonstrate the performance of our epitope prediction programs with several examples and in comparison to other epitope prediction programs available. We also reflect the actual possibilities and limitations of such computer-aided work.

SNEP: SNP-derived epitope prediction program for minor H antigens.

The single nucleotide polymorphism (SNP)-derived Epitope Prediction program (SNEP) is now available to the public. It predicts minor histocompatibility antigens (miHAgs), which are T-cell epitopes containing polymorphic spots, from proteins listed in the SWISS-PROT database. SNEP recognizes polymorphisms (termed VARIANT or CONFLICT in SWISS-PROT) and predicts potential T-cell epitopes within a chosen distance around the polymorphic residue. The prediction algorithm is based on the SYFPEITHI T-cell epitope prediction program. SNEP is able to search for proteins according to their accession numbers, sequence stretches or gene names, for example. The predictions are available for several human leucocyte antigen class I and class II allelic products, which allow for a rapid and precise evaluation of potential miHAgs within polymorphic antigens.