The ex vivo induction of human CD103⁺ CD25hi Foxp3⁺ CD4⁺ and CD8⁺ Tregs is IL-2 and TGF-β1 dependent.

The expression of the integrin αE (CD103), may enhance the retention of regulatory T cells to peripheral inflammatory sites and possibly contribute to their suppressive potential. The aim of this study was to define the regulatory role of IL-2 and TGF-β1 on the CD103 expression and the optimal in vitro conditions for the induction/expansion of human CD4(+) and CD8(+) Tregs. Cord blood mononuclear cells (CBMC) were stimulated under various culture conditions, including anti-CD3, anti-CD28, IL-2 and TGF-β1.

Vbeta usage and T regulatory cells in children following partial or total thymectomy after open heart surgery in infancy.

During open heart surgery in infants the thymus was usually removed, partly or completely. Our previous studies on 16 such children indicated reduced T-cell output later in life with signs of extrathymic maturation of the T cells, but no reduction in T regulatory cells (CD4+CD25+). The diversity of the T-cell repertoire in these children was examined to test if the extrathymic microenvironment could alter Vbeta usage.

Naive human T-cells become non-responsive towards anti-TNFalpha (infliximab) treatment in vitro if co-stimulated through CD28.

Tumour necrosis factor alpha (TNFalpha) inhibitors are widely used successfully as immunomodulatory agents in various autoimmune diseases. They primarily target the direct pro-inflammatory effect of TNFalpha. They have also been found to be critical for T-cell viability and activation.

Evidence for extrathymic T cell maturation after thymectomy in infancy.

Our previous study showed that children who had been partially or completely thymectomized during heart surgery as infants had lower proportions and numbers of total lymphocytes and reduced proportions of T cells (CD3(+)), helper T cells (CD4(+)) and naive T cells (CD3(+) CD4(+) CD45RA(+)), but normal proportion of cytotoxic T cells (CD8(+)). In this study T lymphocytes from a selected group of eight of these children and age- and gender-matched controls were characterized further using flow cytometry to determine phenotypes of T cells and T cell subsets related to T cell regulation and phenotypes suggestive of extrathymic maturation. Immune function was assessed by measuring autoantibodies and antibodies against vaccines.

The influence of partial or total thymectomy during open heart surgery in infants on the immune function later in life.

Infants undergoing open heart surgery often have all or part of their thymus removed. The activity of the immune system has not been investigated thoroughly in these children, and only shortly after the operation. Therefore, it was decided to investigate the activity of the immune system in more detail in children several years after their operation.