Microbial Metabolism Modulates Antibiotic Susceptibility within the Murine Gut Microbiome
Although antibiotics disturb the structure of the gut microbiota, factors that modulate these perturbations are poorly understood. Bacterial metabolism is an important regulator of susceptibility in vitro and likely plays a large role within the host. We applied a metagenomic and metatranscriptomic approach to link antibiotic-induced taxonomic and transcriptional responses within the murine microbiome. We found that antibiotics significantly alter the expression of key metabolic pathways at the whole-community and single-species levels.
Defining the Distinct Skin and Gut Microbiomes of the Northern Pike (Esox lucius)
The microbiome of freshwater fish has important implications for both commercial and recreational fishing because it can have significant impacts on host health, spoilage rates, and susceptibility to disease. The aqueous environment serves as a possible avenue for continuous introduction of microbes to an animal host, but little is known about how the surrounding microbiota contribute to piscine microbiomes. To better understand the composition of the fish microbiome exposed to the natural environment, we profiled the microbial composition of the gut and the skin mucosal surface (SMS) of northern pike (Esox lucius) and the surrounding river water.
Congratulations to Swathi Penumutchu who has received an NSF Fellowship Award for her work in the Belenky Lab!
Qa-1-Restricted CD8+ T Cells Can Compensate for the Absence of Conventional T Cells during Viral Infection
Anderson et al. describe a heterogenous population of non-classical CD8+ T cells responding to MCMV. Importantly, this population can protect mice from MCMVinduced lethality in the absence of other adaptive immune cells. Among the MHC class Ib-restricted CD8+ T cells responding, Qa-1-specific cells are required for protection.
Shp-2 is critical for ERK and metabolic engagementdownstream of IL-15 receptor in NK cells
The phosphatase Shp-2 was implicated in NK cell development and functions due to itsinteraction with NK inhibitory receptors, but its exact role in NK cells is still unclear. Here weshow, using mice conditionally deficient for Shp-2 in the NK lineage, that NK cell develop-ment and responsiveness are largely unaffected. Instead, wefind that Shp-2 serves mainly toenforce NK cell responses to activation by IL-15 and IL-2. Shp-2-deficient NK cells havereduced proliferation and survival when treated with high dose IL-15 or IL-2. Mechanistically,Shp-2 deficiency hampers acute IL-15 stimulation-induced raise in glycolytic and respirationrates, and causes a dramatic defect in ERK activation. Moreover, inhibition of the ERK andmTOR cascades largely phenocopies the defect observed in the absence of Shp-2. Together,our data reveal a critical function of Shp-2 as a molecular nexus bridging acute IL-15 signalingwith downstream metabolic burst and NK cell expansion.
Cross-Domain and Viral Interactions in the Microbiome
The importance of the microbiome to human health is increasingly recognized and has become a major focus of recent research. However, much of the work has focused on a few aspects, particularly the bacterial component of the microbiome, most frequently in the gastrointestinal tract. Yet humans and other animals can be colonized by a wide array of organisms spanning all domains of life, including bacteria and archaea, unicellular eukaryotes such as fungi, multicellular eukaryotes such as helminths, and viruses. As they share the same host niches, they can compete with, synergize with, and antagonize each other, with potential impacts on their host. Here, we discuss these major groups making up the human microbiome, with a focus on how they interact with each other and their multicellular host.