Distinct microRNA signatures in human lymphocyte subsets and enforcement of the naive state in CD4+ T cells by the microRNA miR-125b.

MicroRNAs are small noncoding RNAs that regulate gene expression post-transcriptionally. Here we applied microRNA profiling to 17 human lymphocyte subsets to identify microRNA signatures that were distinct among various subsets and different from those of mouse lymphocytes. One of the signature microRNAs of naive CD4+ T cells, miR-125b, regulated the expression of genes encoding molecules involved in T cell differentiation, including IFNG, IL2RB, IL10RA and PRDM1.

Molecular purging of multiple myeloma cells by ex-vivo culture and retroviral transduction of mobilized-blood CD34+ cells.

Background: Tumor cell contamination of the apheresis in multiple myeloma is likely to affect disease-free and overall survival after autografting.

Objective: To purge myeloma aphereses from tumor contaminants with a novel culture-based purging method.

Methods: We cultured myeloma-positive CD34+ PB samples in conditions that retained multipotency of hematopoietic stem cells, but were unfavourable to survival of plasma cells.

Mobilized blood CD34+ cells transduced and selected with a clinically applicable protocol reconstitute lymphopoiesis in SCID-Hu mice.

We developed a clinically applicable gene transfer procedure into mobilized peripheral blood (MPB) CD34(+) hematopoietic progenitor cells, based on single viral exposure and selection of engineered cells. CD34(+) cells were transduced with a retroviral vector carrying the truncated form of the nerve growth factor receptor (Delta NGFR) marker gene, and immunoselected for Delta NGFR expression. Optimal time and procedure for viral exposure, length of culture, and transgene expression of MPB CD34(+) cells were determined using in vitro assays.