Gemfibrozil Inhibits Legionella pneumophila and Mycobacterium tuberculosis Enoyl Coenzyme A Reductases and Blocks Intracellular Growth of These Bacteria in Macrophages

We report here that gemfibrozil (GFZ) inhibits axenic and intracellular growth of Legionella pneumophila and of 27 strains of wild-type and multidrug-resistant Mycobacterium tuberculosis in bacteriological medium and in human and mouse macrophages, respectively. At a concentration of 0.4 mM, GFZ completely inhibited L. pneumophila fatty acid synthesis, while at 0.12 mM it promoted cytoplasmic accumulation of polyhydroxybutyrate. To assess the mechanism(s) of these effects, we cloned an L. pneumophila FabI enoyl reductase homolog that complemented for growth an Escherichia coli strain carrying a temperature-sensitive enoyl reductase and rendered the complemented E. coli strain sensitive to GFZ at the nonpermissive temperature. GFZ noncompetitively inhibited this L. pneumophila FabI homolog, as well as M. tuberculosis InhA and E. coli FabI

Engraftment for CD34 selected stem cell products is not compromised by cryopreservation.

BACKGROUND: The coinfusion of haploidentical CD34+ selected peripheral blood stem cell products with umbilical cord blood (UCB) provides early neutrophil recovery, long-term UCB engraftment, and a lower incidence of graft-versus-host disease; however, this complex transplant presents a scheduling challenge for both the cellular therapy laboratory and the clinical team. Cryopreservation of the haploidentical product can facilitate scheduling, but has been previously shown to be associated with infusion reactions and delayed platelet (PLT) engraftment in allogeneic hematopoietic progenitor cell transplant. STUDY DESIGN AND METHODS: To test whether cryopreservation of the CD34+ selected product compromises the graft, we compared neutrophil and PLT engraftment kinetics for patients receiving freshly infused or cryopreserved products. Seventy-two products collected from haploidentical related donors were CD34+ selected and infused in a combined transplant with UCB: 32 were cryopreserved before infusion and 40 were infused fresh. RESULTS: No adverse infusion events were reported in either group and there was no difference in neutrophil and PLT engraftment time between fresh and cryopreserved products. CONCLUSION: Cryopreservation of a CD34+-selected product can be safely used in a combined transplant with UCB and does not affect engraftment time