Marker gene transfer into leukapheresis preparations containing hematopoietic progenitor cells: application in high-dose therapy rescued by reinfusion of peripheral blood hematopoietic progenitors in patients with multiple myeloma

Strategies for Zinc Uptake in Pseudomonas aeruginosa at the Host-Pathogen Interface

As a structural, catalytic, and signaling component, zinc is necessary for the growth and development of plants, animals, and microorganisms. Zinc is also essential for the growth of pathogenic microorganisms and is involved in their metabolism as well as the regulation of various virulence factors. Additionally, zinc is necessary for infection and colonization of pathogenic microorganisms in the host. Upon infection in healthy organisms, the host sequesters zinc both intracellularly and extracellularly to enhance the immune response and prevent the proliferation and infection of the pathogen. Intracellularly, the host manipulates zinc levels through Zrt/Irt-like protein (ZIP)/ZnT family proteins and various zinc storage proteins. Extracellularly, members of the S100 protein family, such as calgranulin C, sequester zinc to inhibit microbial growth. In the face of these nutritional limitations, bacteria rely on an efficient zinc transport system to maintain zinc supplementation for proliferation and disruption of the host defense system to establish infection. Here, we summarize the strategies for zinc uptake in conditional pathogenic Pseudomonas aeruginosa, including known zinc uptake systems (ZnuABC, HmtA, and ZrmABCD) and the zinc uptake regulator (Zur). In addition, other potential zinc uptake pathways were analyzed. This review systematically summarizes the process of zinc uptake by P. aeruginosa to provide guidance for the development of new drug targets.

Long-term follow-up of gene-marked CD34+ cells after autologous stem cell transplantation for multiple myeloma

Gene marking can be used to investigate if progenitor cells harvested from patients are contaminated with tumorigenic cells. It can also provide information about the contribution of hematopoietic stem cells to long-term engraftment and about long-term transgene expression from integrated retroviral vectors. In order to study autologous-infused cell contribution to relapse as well as the long-term persistence of the transgene in hematopoietic cells following autologous bone marrow (BM) transplantation for multiple myeloma, we genetically marked autologous CD34+ enriched BM or peripheral blood cell grafts of eight myeloma patients using retroviral vectors. Six patients were subsequently transplanted with the marked graft and followed with regular time points of analysis. Briefly, mononuclear cells were harvested by leukapheresis during 2-4 consecutive days following priming with granulocyte-macrophage colony-stimulating factor (GM-CSF) or G-CSF. The CD34+ cells separated on Cellpro ceprate avidin-biotin columns were exposed to the G1Na vector coding for neomycin resistance gene at a ratio of five vector particles per cell at three consecutive time points achieving an average transduction efficacy of 2% (0.43-5.1%). The patients were transplanted with a mixture of transduced cells and un-manipulated graft. Vector integration and transgene expression were analyzed by colony assays and polymerase chain reaction. The transgene could be detected for up to 5 years post-transplant in normal BM cells, even in remission following relapse and no side effects related to retroviral gene transfer were observed. There were no marked myeloma cells observed in the patients either in remission or in relapsing disease, which indicates that contribution of infused cells to relapse is unlikely.