Catálogo de publicaciones - revistas

<jats:title>Intestinal organoids as an infection model</jats:title> <jats:p> Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes an influenza-like disease with a respiratory transmission route; however, patients often present with gastrointestinal symptoms such as diarrhea, vomiting, and abdominal pain. Moreover, the virus has been detected in anal swabs, and cells in the inner-gut lining express the receptor that SARS-CoV-2 uses to gain entry to cells. Lamers <jats:italic>et al.</jats:italic> used human intestinal organoids, a “mini-gut” cultured in a dish, to demonstrate that SARS-CoV-2 readily replicates in an abundant cell type in the gut lining—the enterocyte—resulting in the production of large amounts of infective virus particles in the intestine. This work demonstrates that intestinal organoids can serve as a model to understand SARS-CoV-2 biology and infectivity in the gut. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6499" page="50" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abc1669">50</jats:related-article> </jats:p>

<jats:title>An infallible inhibitor of Cas13</jats:title> <jats:p> CRISPR-Cas13 protects bacterial populations from viral infections by indiscriminately destroying the RNA of the cell and its invader, simultaneously arresting the growth of infected hosts and the spread of the virus. This response is mediated by the Cas13 nuclease, which unleashes massive RNA degradation after recognition of viral transcripts that are complementary to its guide RNA. Meeske <jats:italic>et al.</jats:italic> discovered AcrVIA1, a viral-encoded inhibitor that binds to Cas13 to occlude the RNA guide and prevent the activation of the nuclease (see the Perspective by Barrangou and Sontheimer). As opposed to inhibitors of DNA-cleaving CRISPR-Cas systems, which require multiple infections to neutralize all Cas nucleases of the host, production of AcrVIA1 by a single virus is sufficient to overcome the CRISPR-Cas13 response. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6499" page="54" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abb6151">54</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6499" page="31" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abc8243">31</jats:related-article> </jats:p>

<jats:title>Enzymatic activity of histones</jats:title> <jats:p> Eukaryotic histones serve as structural elements to package DNA. However, they contain a copper-binding site for which the biological relevance is unknown. Copper homeostasis is critical for several fundamental eukaryotic processes, including mitochondrial respiration. Attar <jats:italic>et al.</jats:italic> hypothesized that histones may play a critical role in cellular copper utilization (see the Perspective by Rudolph and Luger). Using a multifaceted approach ranging from in vitro biochemistry to in vivo genetic and molecular analyses, they found that the histone H3-H4 tetramer is an oxidoreductase enzyme that catalyzes reduction of cupric ions, thereby providing biologically usable cuprous ions for various cellular processes. This work opens a new front for chromatin biology, with implications for eukaryotic evolution and human biology and disease. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6499" page="59" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aba8740">59</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6499" page="33" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abc8242">33</jats:related-article> </jats:p>

<jats:title>Some cope better than others</jats:title> <jats:p> Increasingly, research is revealing how organisms may, or may not, adapt to a changing climate. Understanding the limitations placed by a species's physiology can help to determine whether it has an immediate potential to deal with rapid change. Many studies have looked at physiological tolerance to climate change in fishes, with results indicating a range of responses. Dahlke <jats:italic>et al.</jats:italic> conducted a meta-analysis to explore how life stage may influence a species's ability to tolerate temperature change (see the Perspective by Sunday). They found that embryos and breeding adult fishes are much more susceptible to temperature change than those in other life stages and that this factor must therefore be considered in evaluations of susceptibility. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6499" page="65" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.aaz3658">65</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6499" page="35" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abd1272">35</jats:related-article> </jats:p>

<jats:title>Biofilm formation from cell fountains</jats:title> <jats:p> Bacteria form three-dimensional communities called biofilms that are ubiquitous in nature and underlie human infections. Medically, biofilms are problematic because they protect resident cells from antibiotics. Although biofilms have been intensively studied, we do not understand how they develop cell by cell. Micron-sized bacteria are densely packed within biofilms, making it exceptionally challenging to track their movements. Qin <jats:italic>et al.</jats:italic> studied biofilm formation in the pathogen and model biofilm former <jats:italic>Vibrio cholerae</jats:italic> (see the Perspective by Dal Co and Brenner). The authors combined light-sheet microscopy with cell labeling to map the trajectories of a biofilm founder cell and its descendants in space and time as they built a biofilm. The findings revealed that as the bacteria reproduce, a bacterial “fountain” drives biofilm expansion and dictates the final positions of the offspring. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6499" page="71" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abb8501">71</jats:related-article> ; see also p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6499" page="30" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abd1225">30</jats:related-article> </jats:p>

<jats:title>Vaccine candidate tested in monkeys</jats:title> <jats:p> Global spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to an urgent race to develop a vaccine. Gao <jats:italic>et al.</jats:italic> report preclinical results of an early vaccine candidate called PiCoVacc, which protected rhesus macaque monkeys against SARS-CoV-2 infection when analyzed in short-term studies. The researchers obtained multiple SARS-CoV-2 strains from 11 hospitalized patients across the world and then chemically inactivated the harmful properties of the virus. Animals were immunized with one of two vaccine doses and then inoculated with SARS-CoV-2. Those that received the lowest dose showed signs of controlling the infection, and those receiving the highest dose appeared more protected and did not have detectable viral loads in the pharynx or lungs at 7 days after infection. The next steps will be testing for safety and efficacy in humans. </jats:p> <jats:p> <jats:italic>Science</jats:italic> , this issue p. <jats:related-article xmlns:xlink="http://www.w3.org/1999/xlink" ext-link-type="doi" issue="6499" page="77" related-article-type="in-this-issue" vol="369" xlink:href="10.1126/science.abc1932">77</jats:related-article> </jats:p>