Public T cell receptor beta-chains are not advantaged during positive selection.

Studies of human and murine T cells have shown that public TCR beta-chain rearrangements can dominate the Ag-specific and naive repertoires of distinct individuals. We show that mouse T cells responding to the minor histocompatibility Ag HYDbSmcy share an invariant Vbeta8.2-Jbeta2.

Natural regulation of immunity to minor histocompatibility antigens.

MHC-matched hemopoietic stem cell transplantation is commonly used for the treatment of some forms of leukemia. Conditioning regimens before transplant act to reduce the burden of leukemic cells and the graft-vs-leukemia (GvL) effect can eliminate residual disease. The GvL effect results largely from the recognition of minor histocompatibility Ags by donor T cells on recipient tissues.

Expansion of CD8+ cytotoxic T cells in vitro and in vivo using MHC class I tetramers.

Background: The expansion of cytotoxic CD8+ T lymphocytes (CTLs) which recognize peptide epitopes of tumour or viral origin has been a major aim of immunotherapy research for the past decade. Alongside the established dendritic cell-based methods, more recent approaches using recombinant MHC class I peptide complexes have been developed.

Methods: In this study we have explored the potential of a simplified system using soluble streptavidin-linked MHC class I tetramers to expand antigen-specific CTLs in vitro and in vivo.

TCR-alpha CDR3 loop audition regulates positive selection.

How positive selection molds the T cell repertoire has been difficult to examine. In this study, we use TCR-beta-transgenic mice in which MHC shapes TCR-alpha use. Differential AV segment use is directly related to the constraints placed on the composition of the CDR3 loops.

Role of immunoproteasomes in cross-presentation.

The evidence that proteasomes are involved in the processing of cross-presented proteins is indirect and based on the in vitro use of proteasome inhibitors. It remains, therefore, unclear whether cross-presentation of MHC class I peptide epitopes can occur entirely within phagolysosomes or whether it requires proteasome degradation. To address this question, we studied in vivo cross-presentation of an immunoproteasome-dependent epitope.