Molecular mechanism responsible for the priming of macrophage activation.

Host macrophages can be preprogrammed into opposing primed or tolerant states depending upon the nature and quantities of external stimulants. The paradigm of priming and tolerance has significant implications in the pathogenesis and resolution of both acute and chronic inflammatory diseases. However, the responsible mechanisms are not well understood. Here, we report that super low dose bacterial endotoxin lipopolysaccharide (LPS), as low as 5 pg/ml, primes the expression of proinflammatory mediators in macrophages upon a second high dose LPS challenge (100 ng/ml), although 5 pg/ml LPS itself does not trigger noticeable macrophage activation. Mice primed with super low dose LPS (0.5 µg/kg body weight) in vivo experience significantly elevated mortality following a second hit of high dose LPS as compared with saline-primed control mice. Mechanistically, we demonstrate that LPS primes macrophages by removing transcriptional suppressive RelB through interleukin receptor-associated kinase 1 and Tollip (Toll-interacting protein)-dependent mechanisms. This is in sharp contrast to the well documented RelB stabilization and induction by high dose LPS, potentially through the phosphoinositide 3-kinase (PI3K) pathway. Super low dose and high dose LPS cause opposing modulation of interleukin receptor-associated kinase 1 and PI3K pathways and lead to opposing regulation of RelB. The pathway switching induced by super low versus high dose LPS underscores the importance of competing intracellular circuitry during the establishment of macrophage priming and tolerance.

Bacterial Retention During Filtration of a Live Attenuated Virus Vaccine Through the Sartobran P Sterile Filter.

Recent studies of sterile filtration of a Live Attenuated Virus (LAV) demonstrated that the Sartobran P sterile filter provided 80% yield of a LAV that was 100 - 400 nm in size, raising questions about the effectiveness of this filter in retaining the standard challenge bacterium, Brevundimonas diminuta. This study evaluated the retention of B. diminuta by the Sartobran P over a range of conditions appropriate for LAV filtration. The B. diminuta were characterized by dynamic light scattering (DLS), nanoparticle tracking analysis (NTA), and scanning electron microscopy. The Sartobran P showed complete retention of B. diminuta under all conditions, even in the presence of additives like sucrose, surfactants, and high salt that have previously been hypothesized to increase the risk of bacterial breakthrough. The size of B. diminuta decreased when incubated in the nutrient poor media required by the ASTM challenge test. The addition of sucrose caused a further reduction in size as measured by NTA, although this was due to an increase in cell motility. There was no evidence of bacterial breakthrough at high loadings of either the LAV or B. diminuta, further demonstrating the effectiveness of the Sartobran P for sterile filtration of large viral vaccines.

It was the best of times, it was the worst of times: doctoral students' experiences of family therapy research training through alternative forms of data representation.

In this study, we interviewed 14 doctoral students from 10 COAMFTE-accredited doctoral programs to learn more about how they experienced their research training and what they might suggest to strengthen the research culture in their training programs. We solicited somewhat unconventional data--metaphors, poetry, free associations, critical experiences--to (a) tap into our participants' underlying thought processes, (b) capture the multifaceted nature of their doctoral research training, and (c) represent the richness of our participants' subjective experiences. The themes we identified reflect both positive and negative research training experiences and suggest several ways that family therapy program faculty might improve their programs' research training and culture.