Cell host & microbe
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Cell host & microbe · Oct 2014
CommentPortrait of a killer: genome of the 2014 EBOV outbreak strain.
A recent study by Gire et al. (2014) identifies differences that make the 2014 West Africa Ebola virus unique and details how the virus spread from Guinea to Sierra Leone. This work highlights the power of new genomic technologies to facilitate rapid public health and scientific responses to the crisis.
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The continuing emergence of arboviruses such as chikungunya virus requires thoughtful attention and approaches for risk management. Incorporating experimental evolutionary studies, as described in this issue by Stapleford et al. (2014), has the potential to move public health toward a more proactive agenda for predicting and responding to disease emergence.
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Cell host & microbe · Nov 2012
Defining a healthy human gut microbiome: current concepts, future directions, and clinical applications.
Indigenous microbiota are an essential component in the modern concept of human health, but the composition and functional characteristics of a healthy microbiome remain to be precisely defined. Patterns of microbial colonization associated with disease states have been documented, but the health-associated microbial patterns and their functional characteristics are less clear. A healthy microbiome, considered in the context of body habitat or body site, could be described in terms of ecologic stability (i.e., ability to resist community structure change under stress or to rapidly return to baseline following a stress-related change), by an idealized (presumably health-associated) composition or by a desirable functional profile (including metabolic and trophic provisions to the host). Elucidation of the properties of healthy microbiota would provide a target for dietary interventions and/or microbial modifications aimed at sustaining health in generally healthy populations and improving the health of individuals exhibiting disrupted microbiota and associated diseases.
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Cell host & microbe · Sep 2012
Intravascular neutrophil extracellular traps capture bacteria from the bloodstream during sepsis.
During the systemic inflammatory response of severe sepsis, neutrophils accumulate in the liver microcirculation, but their functional significance is largely unknown. We show that neutrophils migrate to liver sinusoids during endotoxemia and sepsis where they exert protective effects by releasing neutrophil extracellular traps (NETs), which are DNA-based structures that capture and eliminate microbes. NETs released into the vasculature ensnare bacteria from the bloodstream and prevent dissemination. ⋯ During sepsis, NET release increases bacterial trapping by 4-fold (beyond the basal level provided by resident intravascular macrophages). Blocking NET formation reduces the capture of circulating bacteria during sepsis, resulting in increased dissemination to distant organs. Thus, NETs ensnare circulating bacteria and provide intravascular immunity that protects against bacterial dissemination during septic infections.
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Cell host & microbe · Aug 2012
Candida albicans infection affords protection against reinfection via functional reprogramming of monocytes.
Immunological memory in vertebrates is often exclusively attributed to T and B cell function. Recently it was proposed that the enhanced and sustained innate immune responses following initial infectious exposure may also afford protection against reinfection. Testing this concept of "trained immunity," we show that mice lacking functional T and B lymphocytes are protected against reinfection with Candida albicans in a monocyte-dependent manner. ⋯ The training required the β-glucan receptor dectin-1 and the noncanonical Raf-1 pathway. Monocyte training by β-glucans was associated with stable changes in histone trimethylation at H3K4, which suggests the involvement of epigenetic mechanisms in this phenomenon. The functional reprogramming of monocytes, reminiscent of similar NK cell properties, supports the concept of "trained immunity" and may be employed for the design of improved vaccination strategies.