Amnion-derived multipotent progenitor cells support allograft tolerance induction.

Donor-specific immunological tolerance using high doses of bone marrow cells (BMCs) has been demonstrated in mixed chimerism-based tolerance induction protocols; however, the development of graft versus host disease remains a risk. Here, we demonstrate that the co-infusion of limited numbers of donor unfractionated BMCs with human amnion-derived multipotent progenitor cells (AMPs) 7 days post-allograft transplantation facilitates macrochimerism induction and graft tolerance in a mouse skin transplantation model. AMPs + BMCs co-infusion with minimal conditioning led to stable, mixed, multilineage lymphoid and myeloid macrochimerism, deletion of donor-reactive T cells, expansion of CD4(+)CD25(+)Foxp3(+) regulatory T cells (T(regs)) and long-term allograft survival (>300 days). Based on these findings, we speculate that AMPs maybe a pro-tolerogenic cellular therapeutic that could have clinical efficacy for both solid organ and hematopoietic stem cell transplant applications.

DNA microarray technology for neonatal screening.

Modern molecular biology, owing much to the Human Genome Initiative, has elucidated many of the genetic mechanisms underlying heritable metabolic disease. While the use of molecular methods has flourished in research laboratories, complexity and cost have limited their utility in newborn screening. Newborn blood cards provide high quality DNA samples able to provide reliable support to highly multiplexed polymerase chain reactions (PCR). New manufacturing processes have reduced the cost of DNA microarray technology to the point where it is a practical tool for population screening. In a single assay, a DNA microarray facilitates the co-detection of amplification products diagnostic for several genetic diseases. High throughput is achieved with automation at every step, from DNA extraction to detection of hybrids. We suggest that it is both feasible and practical to develop a first-tier newborn screening protocol based upon multiplex PCR and analysis of amplification products using DNA microarrays. Initial data utilizing the model systems of sickle cell disease, alpha-1-antitrypsin deficiency and Factor V Leiden will be reported.

TGF-beta 1 pretreatment impairs the allostimulatory function of human bone marrow-derived antigen-presenting cells for both naive and primed T cells.

Transforming growth factor-beta (TGF-beta) exhibits strong antiproliferative effects upon lymphocytes and inhibits many of the effector functions of activated immune cells. However, its influence on the inductive phase of immune responses, and in particular its effect on antigen-presenting cells (APC), has not been well studied. In this investigation, we examined the influence of human TGF-beta 1 on the antigen-presenting function of human bone marrow (BM)-derived APC propagated in liquid culture for 11-17 days in response to granulocyte/macrophage colony-stimulating factor (GM-CSF). These cells were predominantly macrophages, accompanied by a minor population of dendritic cells. TGF-beta 1 had no effect upon the allostimulatory function of vertebral body whole BM cells cultured for 3-5 days in GM-CSF. However, it markedly reduced the allostimulatory capacity of BM-derived APC exposed to the cytokine for the last 3 days of culture. This inhibitory action could not be ascribed to cytokine 'carry-over', or to any consistent changes in the expression of cell surface molecules implicated in antigen presentation (HLA-DR), intercellular adhesion (ICAM-1; CD54), or costimulatory activity (B7-1; CD80). Mechanisms that may underlie the inhibitory action of TGF-beta on APC function and the immunologic and possible clinical implications of the findings are discussed.