Teicoplanin versus ß-lactam for febrile patients with Staphylococcus-like bacteremia: focus on methicillin-susceptible Staphylococcus aureus bacteremia.

BACKGROUND: Many studies have shown that vancomycin is inferior to ß-lactam antibiotics in terms of effectiveness in the treatment of methicillin-susceptible Staphylococcus aureus (MSSA) bacteremia. However, limited data are available regarding the comparison of clinical outcomes between patients receiving initial teicoplanin and those receiving ß-lactam antibiotics for MSSA bacteremia. METHODS: Eighty-four adults with MSSA bacteremia were included: initial teicoplanin treatment group (n = 28) and ß-lactam treatment group (n = 56). The two groups were further stratified based on propensity score matching according to the outcome analysis using a logistic regression model. We investigated the clinical outcomes between the groups before and after propensity score matching after treatment completion. RESULTS: Pittsburgh bacteremia score ≥ 4 (odds ratio, 60.6; 95%CI, 7.4-496.8) was an independent risk factor for unfavorable outcome. After propensity score matching, the initial teicoplanin treatment group and the ß-lactam treatment group consisted of 28 patients each. No statistically significant differences were observed in the proportions of patients with favorable outcomes and 30-day overall mortality rates between the groups before and after propensity score matching after the completion of teicoplanin or ß-lactam treatment. The Kaplan-Meier 30-day survival curve also showed no significant difference between the patients receiving initial teicoplanin treatment and those receiving ß-lactam treatment before and after matching (hazard ratio, 1.84, 95%CI, 0.60-5.64; and 3.12, 95%CI, 0.98-9.99, respectively). CONCLUSIONS: There were no significant difference in clinical outcomes between initial teicoplanin treatment and ß-lactam treatment among patients with MSSA bacteremia. Pittsburgh bacteremia score ≥ 4 was a significant risk factor for mortality.

Association of dysfunctional synapse defective 1 (SYDE1) with restricted fetal growth - SYDE1 regulates placental cell migration and invasion.

The transcription factor glial cells missing 1 (GCM1) regulates trophoblast differentiation and function during placentation. Decreased GCM1 expression is associated with pre-eclampsia, suggesting that abnormal expression of GCM1 target genes may contribute to the pathogenesis of pregnancy complications. Here we identified a novel GCM1 target gene, synapse defective 1 (SYDE1), which encodes a RhoGAP that is highly expressed in human placenta, and demonstrated that SYDE1 promotes cytoskeletal remodelling and cell migration and invasion. Importantly, genetic ablation of murine Syde1 results in small fetuses and placentas with aberrant phenotypes in the placental-yolk sac barrier, maternal-trophoblast interface, and placental vascularization. Microarray analysis revealed altered expression of renin-1, angiotensin I converting enzyme 2, angiotensin II type 1a receptor, and membrane metalloendopeptidase of the renin-angiotensin system in Syde1-knockout placenta, which may compensate for the vascular defects to maintain normal blood pressure. As pregnancy proceeds, growth restriction of the Syde1-/- fetuses and placentas continues, with elevated expression of the Syde1 homologue Syde2 in placenta. Syde2 may compensate for the loss of Syde1 function because SYDE2, but not the GAP-dead SYDE2 mutant, reverses migration and invasion activities of SYDE1-knockdown JAR trophoblast cells. Clinically, we further detected decreased SYDE1 expression in preterm and term IUGR placentas compared with gestational age-matched controls. Our study suggests a novel mechanism for GCM1 and SYDE1 in regulation of trophoblast cell migration and invasion during placental development and that decreased SYDE1 expression is associated with IUGR. Copyright © 2016 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Cisd2 deficiency drives premature aging and causes mitochondria-mediated defects in mice.

CISD2, the causative gene for Wolfram syndrome 2 (WFS2), is a previously uncharacterized novel gene. Significantly, the CISD2 gene is located on human chromosome 4q, where a genetic component for longevity maps. Here we show for the first time that CISD2 is involved in mammalian life-span control. Cisd2 deficiency in mice causes mitochondrial breakdown and dysfunction accompanied by autophagic cell death, and these events precede the two earliest manifestations of nerve and muscle degeneration; together, they lead to a panel of phenotypic features suggestive of premature aging. Our study also reveals that Cisd2 is primarily localized in the mitochondria and that mitochondrial degeneration appears to have a direct phenotypic consequence that triggers the accelerated aging process in Cisd2 knockout mice; furthermore, mitochondrial degeneration exacerbates with age, and the autophagy increases in parallel to the development of the premature aging phenotype. Additionally, our Cisd2 knockout mouse work provides strong evidence supporting an earlier clinical hypothesis that WFS is in part a mitochondria-mediated disorder; specifically, we propose that mutation of CISD2 causes the mitochondria-mediated disorder WFS2 in humans. Thus, this mutant mouse provides an animal model for mechanistic investigation of Cisd2 protein function and help with a pathophysiological understanding of WFS2.

Adipocyte IL-15 regulates local and systemic NK cell development.

NK cell development and homeostasis require IL-15 produced by both hematopoietic and parenchymal cells. Certain hematopoietic IL-15 sources, such as macrophages and dendritic cells, are known, whereas the source of parenchymal IL-15 remains elusive. Using two types of adipocyte-specific Il15(-/-) mice, we identified adipocytes as a parenchymal IL-15 source that supported NK cell development nonredundantly. Both adipocyte-specific Il15(-/-) mice showed reduced IL-15 production specifically in the adipose tissue but impaired NK cell development in the spleen and liver in addition to the adipose tissue. We also found that the adipose tissue harbored NK progenitors as other niches (e.g. spleen) for NK cell development, and that NK cells derived from transplanted adipose tissue populated the recipient's spleen and liver. These findings suggest that adipocyte IL-15 contributes to systemic NK cell development by supporting NK cell development in the adipose tissue, which serves as a source of NK cells for other organs.

Teicoplanin therapy for MRSA bacteraemia: a retrospective study emphasizing the importance of maintenance dosing in improving clinical outcomes.

OBJECTIVES: To study the relationship between teicoplanin maintenance dosing and clinical outcomes in adults with MRSA bacteraemia. METHODS: MRSA bacteraemic patients who received three teicoplanin loading doses (6 mg/kg/12 h) followed by maintenance doses of 6 mg/kg/24 h (Group 1) or 6 mg/kg/12 h (Group 2) were retrospectively analysed. Evaluated on day 7, an unfavourable early clinical response referred to the presence of septic shock, persistent fever, persistent leucocytosis and/or persistent bacteraemia. Assessed at completion of teicoplanin therapy, an unfavourable final clinical response referred to clinical treatment failure. RESULTS: Compared with those in Group 1 (n = 122), patients in Group 2 (n = 82) had significantly higher rates of favourable early clinical response (P = 0.040) and final clinical response (P < 0.001) and a lower bloodstream-infection-related mortality rate (P = 0.018). Based on estimated ORs for favourable final clinical response in multivariate analysis, endocarditis (P < 0.001; OR 0.109, 95% CI 0.032-0.368), pneumonia (P < 0.001; OR 0.172, 95% CI 0.069-0.433), ICU admission (P < 0.001; OR 0.132, 95% CI 0.054-0.325) and high Pittsburgh bacteraemia score (P = 0.042; OR 0.187, 95% CI 0.021-0.457) were each a risk factor for an unfavourable final clinical response. Higher teicoplanin maintenance dosing contributed to a favourable final clinical response (P < 0.001; OR 8.800, 95% CI 3.602-21.502). Significantly higher favourable final clinical response rates were also found in patients with endocarditis (P = 0.007) and pneumonia (P < 0.001) in Group 2 compared with their counterparts in Group 1. CONCLUSIONS: These data highlight the importance of higher teicoplanin maintenance dosing, especially for severe infections due to MRSA.

Reduced uterine receptivity for mouse embryos developed from in-vitro matured oocytes.

PURPOSE: The outcomes of in-vitro maturation (IVM) are inferior compared to those of IVF. The purpose of the study was to compare the implantation rates of IVM- and in-vivo maturation (IVO)- derived embryos, and to evaluate their effects on uterine receptivity. METHODS: The IVM- and IVO- oocytes were obtained from female mice, fertilized and transferred to separate oviducts of the same pseudo-pregnant mice. After 5 days, the implanted blastocysts were dissected out of the uterine horns, and the uterine horns were analyzed for the expression of mRNAs encoding leukemia inhibitory factor, heparin-binding epidermal growth factor, insulin-like growth factor binding protein-4, progesterone receptor, and Hoxa-10. RESULTS: The maturation rate of the IVM- oocytes was 81.2%. The fertilization rate of the IVM oocytes was lower than that of the IVO oocytes (50.5% vs. 78.0%, p = 0.038), as was their implantation rate (14.5% vs. 74.7%, p < 0.001). All 5 mRNAs examined were expressed at significantly lower levels in the uterine horns that received the IVM-derived embryos than in those that received the IVO-derived embryos. CONCLUSIONS: The IVM-derived embryos are less competent in inducing expression of implantation-related mRNAs in the uterine horn.

Anaerobic and aerobic cleavage of the steroid core ring structure by Steroidobacter denitrificans.

The aerobic degradation of steroids by bacteria has been studied in some detail. In contrast, only little is known about the anaerobic steroid catabolism. Steroidobacter denitrificans can utilize testosterone under both oxic and anoxic conditions. By conducting metabolomic investigations, we demonstrated that S. denitrificans adopts the 9,10-seco-pathway to degrade testosterone under oxic conditions. This pathway depends on the use of oxygenases for oxygenolytic ring fission. Conversely, the detected degradation intermediates under anoxic conditions suggest a novel, oxygenase-independent testosterone catabolic pathway, the 2,3-seco-pathway, which differs significantly from the aerobic route. In this anaerobic pathway, testosterone is first transformed to 1-dehydrotestosterone, which is then reduced to produce 1-testosterone followed by water addition to the C-1/C-2 double bond of 1-testosterone. Subsequently, the C-1 hydroxyl group is oxidized to produce 17-hydroxy-androstan-1,3-dione. The A-ring of this compound is cleaved by hydrolysis as evidenced by H2(18)O-incorporation experiments. Regardless of the growth conditions, testosterone is initially transformed to 1-dehydrotestosterone. This intermediate is a divergence point at which the downstream degradation pathway is governed by oxygen availability. Our results shed light into the previously unknown cleavage of the sterane ring structure without oxygen. We show that, under anoxic conditions, the microbial cleavage of steroidal core ring system begins at the A-ring.

Sildenafil improves long-term effect of endothelial progenitor cell-based treatment for monocrotaline-induced rat pulmonary arterial hypertension.

BACKGROUND AIMS: We hypothesized that the long-term therapeutic effect of combined sildenafil and bone marrow-derived endothelial progenitor cells (BMDEPCs) on monocrotaline (MCT)-induced rat pulmonary arterial hypertension (PAH) is superior to either treatment alone. METHODS: Male Sprague-Dawley rats (n = 40) were equally divided into normal controls, MCT (65 mg/kg, subcutaneously) only, MCT + sildenafil (25 mg/kg/day, orally), MCT + BMDEPCs (2.0 × 10(6) autologous cells, intravenously) and MCT + sildenafil+ BMDEPCs. BMDEPCs and sildenafil were given on day 21 after MCT administration. Animals were sacrificed by day 90 after MCT administration. RESULTS: The apoptotic (caspase 3, Bax) and inflammatory (tumor necrosis factor-α, matrix metalloproteinase-9) biomarkers in right ventricle and lung and pulmonary expressions of fibrotic biomarkers (transforming growth factor-ß, p-Smad3) and connexin 43 protein were lower in monotherapy groups (i.e., MCT + sildenafil and MCT + BMDEPCs) and further decreased in normal controls and combined treatment groups (i.e., MCT + sildenafil + BMDEPCs) compared with untreated animals (i.e., MCT only) (all P < 0.01). Expressions of anti-fibrotic biomarkers (bone morphogenetic protein-2, p-Smad1/5) and numbers of alveolar sacs and arterioles in lung were higher in monotherapy groups and further increased in normal controls and combined treatment groups compared with untreated animals (all P < 0.005). In right ventricle, connexin 43 and α-myosin heavy chain (MHC) expressions were higher in the monotherapy groups and further elevated in normal controls and combined treatment groups compared with untreated animals, whereas ß-MHC exhibited the opposite pattern (all P < 0.01). Right ventricular systolic pressure and weight were lower in the monotherapy animals and further reduced in normal controls and combined treatment groups compared with untreated animals (all P < 0.0001). CONCLUSIONS: Combined therapy with BMDEPCs and sildenafil was superior to either treatment alone in attenuating rodent MCT-induced PAH.

Melatonin treatment improves adipose-derived mesenchymal stem cell therapy for acute lung ischemia-reperfusion injury.

This study investigated whether melatonin-treated adipose-derived mesenchymal stem cells (ADMSC) offered superior protection against acute lung ischemia-reperfusion (IR) injury. Adult male Sprague-Dawley rats (n = 30) were randomized equally into five groups: sham controls, lung IR-saline, lung IR-melatonin, lung IR-melatonin-normal ADMSC, and lung IR-melatonin-apoptotic ADMSC. Arterial oxygen saturation was lowest in lung IR-saline; lower in lung IR-melatonin than sham controls, lung IR-melatonin-normal ADMSC, and lung IR-melatonin-apoptotic ADMSC; lower in lung IR-melatonin-normal ADMSC than sham controls and lung IR-melatonin-apoptotic ADMSC; lower in lung IR-melatonin-apoptotic ADMSC than sham controls (P < 0.0001 in each case). Right ventricular systolic blood pressure (RVSBP) showed a reversed pattern among all groups (all P < 0.0001). Changes in histological scoring of lung parenchymal damage and CD68+ cells showed a similar pattern compared with RVSBP in all groups (all P < 0.001). Changes in inflammatory protein expressions such as VCAM-1, ICAM-1, oxidative stress, TNF-α, NF-κB, PDGF, and angiotensin II receptor, and changes in apoptotic protein expressions of cleaved caspase 3 and PARP, and mitochondrial Bax, displayed identical patterns compared with RVSBP in all groups (all P < 0.001). Numbers of antioxidant (GR+, GPx+, NQO-1+) and endothelial cell biomarkers (CD31+ and vWF+) were lower in sham controls, lung IR-saline, and lung IR-melatonin than lung IR-melatonin-normal ADMSC and lung IR-melatonin-apoptotic ADMSC, and lower in lung IR-melatonin-normal ADMSC than lung IR-melatonin-apoptotic ADMSC (P < 0.001 in each case). In conclusion, when the animals were treated with melatonin, the apoptotic ADMSC were superior to normal ADMSC for protection of lung from acute IR injury.

Activation of TrkB signaling mitigates cerebellar anomalies caused by Rbm4-Bdnf deficiency.

A molecular and functional link between neurotrophin signaling and cerebellar foliation is lacking. Here we show that constitutive knockout of two homologous genes encoding the RNA binding protein RBM4 results in foliation defects at cerebellar lobules VI-VII and delayed motor learning in mice. Moreover, the features of Rbm4 double knockout (dKO), including impaired differentiation of cerebellar granule cells and dendritic arborization of Purkinje cells, are reminiscent of neurotrophin deficiency. Loss of RBM4 indeed reduced brain-derived neurotrophic factor (BDNF). RBM4 promoted the expression of BDNF and full-length TrkB, implicating RBM4 in efficient BDNF-TrkB signaling. Finally, prenatal supplementation with 7,8-dihydroxyflavone, a TrkB agonist, restored granule cell differentiation, Purkinje cell dendritic complexity and foliation-the intercrural fissure in particular-in the neonatal cerebellum of Rbm4dKO mice, which also showed improved motor learning in adulthood. This study provides evidence that prenatal activation of TrkB signaling ameliorates cerebellar malformation caused by BDNF deficiency.

FAM21 is critical for TLR2/CLEC4E-mediated dendritic cell function against Candida albicans.

FAM21 (family with sequence similarity 21) is a component of the Wiskott-Aldrich syndrome protein and SCAR homologue (WASH) protein complex that mediates actin polymerization at endosomal membranes to facilitate sorting of cargo-containing vesicles out of endosomes. To study the function of FAM21 in vivo, we generated conditional knockout (cKO) mice in the C57BL/6 background in which FAM21 was specifically knocked out of CD11c-positive dendritic cells. BMDCs from those mice displayed enlarged early endosomes, and altered cell migration and morphology relative to WT cells. FAM21-cKO cells were less competent in phagocytosis and protein antigen presentation in vitro, though peptide antigen presentation was not affected. More importantly, we identified the TLR2/CLEC4E signaling pathway as being down-regulated in FAM21-cKO BMDCs when challenged with its specific ligand Candida albicans Moreover, FAM21-cKO mice were more susceptible to C. albicans infection than WT mice. Reconstitution of WT BMDCs in FAM21-cKO mice rescued them from lethal C. albicans infection. Thus, our study highlights the importance of FAM21 in a host immune response against a significant pathogen.

Occlusion-Based Three-Dimensional Craniofacial Anthropometric and Symmetric Evaluation in Preadolescences: A Comparative COHORT Study.

BACKGROUND: The importance of early diagnosis of pediatric malocclusion and early intervention has been emphasized. Without use of radiation, 3D imaging holds the potential to be an alternative for evaluating facial features in school-aged populations. METHODS: Students aged 9 and 10 years were recruited. We performed annual 3D stereophotogrammetry of the participants' heads. A total of 37 recognizable anatomical landmarks were identified for linear, angular, and asymmetric analyses using the MATLAB program. RESULTS: This study included 139 healthy Taiwanese children with a mean age of 9.13, of whom 74 had class I occlusion, 50 had class II malocclusion, and 15 had class III malocclusion. The class III group had lower soft-tissue convexity (p = 0.01) than the class II group. The boys with class II malocclusion had greater dimensions in the anteroposterior position of the mid-face (p = 0.024) at age 10. Overall asymmetry showed no significance (p > 0.05). Heat maps of the 3D models exhibited asymmetry in the mid-face of the class II group and in the lower face of the class III group. CONCLUSION: Various types of malocclusion exhibited distinct facial traits in preadolescents. Those with class II malocclusion had a protruded maxilla and convex facial profile, whereas those with class III malocclusion had a less convex facial profile. Asymmetry was noted in facial areas with relatively prominent soft-tissue features among different malocclusion types.

The Src-ZNRF1 axis controls TLR3 trafficking and interferon responses to limit lung barrier damage.

Type I interferons are important antiviral cytokines, but prolonged interferon production is detrimental to the host. The TLR3-driven immune response is crucial for mammalian antiviral immunity, and its intracellular localization determines induction of type I interferons; however, the mechanism terminating TLR3 signaling remains obscure. Here, we show that the E3 ubiquitin ligase ZNRF1 controls TLR3 sorting into multivesicular bodies/lysosomes to terminate signaling and type I interferon production. Mechanistically, c-Src kinase activated by TLR3 engagement phosphorylates ZNRF1 at tyrosine 103, which mediates K63-linked ubiquitination of TLR3 at lysine 813 and promotes TLR3 lysosomal trafficking and degradation. ZNRF1-deficient mice and cells are resistant to infection by encephalomyocarditis virus and SARS-CoV-2 because of enhanced type I interferon production. However, Znrf1-/- mice have exacerbated lung barrier damage triggered by antiviral immunity, leading to enhanced susceptibility to respiratory bacterial superinfections. Our study highlights the c-Src-ZNRF1 axis as a negative feedback mechanism controlling TLR3 trafficking and the termination of TLR3 signaling.

Evolution of estimated glomerular filtration rate in HIV/HCV-coinfected patients who received direct-acting antivirals: A multicenter retrospective study.

BACKGROUND: The short-term impact of sofosbuvir (SOF)-based direct-acting antivirals (DAAs) combined with antiretroviral therapy (ART) on renal function in patients with HIV/HCV-coinfection remains controversial. METHODS: This multicenter, retrospective study aimed to sequentially record the estimated glomerular filtration rate (eGFR) at baseline, end of therapy (EOT), 12 weeks off-treatment (SVR12), and at time points after SVR12 (post-SVR12) and to identify the factors associated with an eGFR decline to <60 ml/min/1.73 m2 in HIV/HCV-coinfected patients receiving DAAs. The evolution of mean eGFRs between different ART and DAAs combinations among patients of different HIV transmission routes were compared using a generalized linear mixed effects model. The periods between baseline and EOT, between EOT and post-SVR12, and between baseline and post-SVR12 were defined as the on-treatment, post-treatment, and all-course periods, respectively. Acute kidney disease (AKD) was defined as a decline of eGFR to <60 ml/min/1.73 m2. RESULT: A total of 445 patients with baseline eGFRs >60 ml/min/1.73 m2 were included. We found that eGFRs declined during the on-treatment period in the tenofovir-containing ART and SOF-based DAA groups. There were no differences in the slope coefficient during the on-treatment and post-treatment periods among all risk groups except for people who inject drug. Increasing age and plasma HIV RNA >20 copies/ml before DAA treatment were factors independently associated with AKD during the on-treatment period while increasing age was independently associated with AKD during the all-course period. CONCLUSION: Only increasing age was an independent factor associated with AKD among HIV/HCV-coinfected patients during and after DAA treatments.

Combination of cilostazol and clopidogrel attenuates rat critical limb ischemia.

BACKGROUND AND AIM: Procedural failure and untoward clinical outcomes after surgery remain problematic in critical limb ischemia (CLI) patients. This study tested a clopidogrel-cilostazol combination treatment compared with either treatment alone in attenuating CLI and improving CLI-region blood flow in rats. METHODS: Male Sprague-Dawley rats (n = 40) were equally divided into five groups: control, CLI induction only, CL I + cilostazol (12.0 mg/day/kg), CLI + clopidogrel (8.0 mg/kg/day) and CLI + combined cilostazol-clopidogrel. After treatment for 21 days, Laser Doppler imaging was performed. RESULTS: On day 21, the untreated CLI group had the lowest ratio of ischemic/normal blood flow (p < 0.001). Inflammation measured by VCAM-1 protein expression; oxidative stress; PAI-1, MMP-9 and TNF-α mRNA expressions; and immunofluorescence staining (IF) of CD68+ cells was lower with combined treatment than with the other treatments, and lower in the two single-treatment groups than the untreated CLI group (all p < 0.01). Anti-inflammatory mRNA expression of interleukin-10, and eNOS showed a reverse pattern among these groups. Apoptosis measured by Bax, caspase-3 and PARP; and muscle damage measured by cytosolic cytochrome-C, and serum and muscle micro-RNA-206 were all lowest with combination treatment, and the two single-treatment groups showed lower values than the untreated group (all p < 0.001). Angiogenesis measured by eNOS, IF staining of CD31+ and vWF + cells; and number of vessels in CLI region were highest with combination treatment and higher in the single-treatment groups than the untreated group (all p < 0.001). CONCLUSION: Combined cilostazol-clopidogrel therapy is superior to either agent alone in improving ischemia in rodent CLI.

Effect of obesity reduction on preservation of heart function and attenuation of left ventricular remodeling, oxidative stress and inflammation in obese mice.

BACKGROUND: Obesity is an important cardiovascular risk factor. This study tested the effect of obesity reduction on preserving left ventricular ejection fraction (LVEF) and attenuating inflammation, oxidative stress and LV remodeling in obese mice. METHODS AND RESULTS: Eight-week-old C57BL/6 J mice (n=24) were equally divided into control (fed a control diet for 22 weeks), obesity (high-fat diet, 22 weeks), and obese reduction (OR) (high-fat diet, 14 weeks; then control diet, 8 weeks). Animals were sacrificed at post 22-week high-fat diet and the LV myocardium collected. Heart weight, body weight, abdominal-fat weight, total cholesterol level and fasting blood glucose were higher in obesity than in control and OR (all p<0.001). Inflammation measured by mRNA expressions of IL-6, MMP-9, PAI-1 and leptin and protein expression of NF-κB was higher, whereas anti-inflammation measured by mRNA expressions of adiponectin and INF-γ was lower in obesity than in control and OR (all p<0.003). Oxidative protein expressions of NOX-1, NOX-2 and oxidized protein were higher, whereas expression of anti-oxidant markers HO-1 and NQO-1 were lower (all p<0.01); and apoptosis measured by Bax and caspase 3 was higher, whereas anti-apoptotic Bcl-2 was lower in obesity as compared with control and OR (all p<0.001). The expressions of fibrotic markers phosphorylated Smad3 and TGF-ß were higher, whereas expression of anti-fibrotic phosphorylated Smad1/5 and BMP-2 were lower (all p<0.02); and LVEF was lower, whereas the LV remodeling was higher in obesity than in control and OR (all p<0.001). CONCLUSION: Impaired LVEF, enhanced LV remodeling, inflammation, fibrosis, oxidative stress and apoptosis were reversed by reduction in mouse obesity.

Vaccination with SARS-CoV-2 spike protein lacking glycan shields elicits enhanced protective responses in animal models.

A major challenge to end the pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is to develop a broadly protective vaccine that elicits long-term immunity. As the key immunogen, the viral surface spike (S) protein is frequently mutated, and conserved epitopes are shielded by glycans. Here, we revealed that S protein glycosylation has site-differential effects on viral infectivity. We found that S protein generated by lung epithelial cells has glycoforms associated with increased infectivity. Compared to the fully glycosylated S protein, immunization of S protein with N-glycans trimmed to the mono-GlcNAc-decorated state (SMG) elicited stronger immune responses and better protection for human angiotensin-converting enzyme 2 (hACE2) transgenic mice against variants of concern (VOCs). In addition, a broadly neutralizing monoclonal antibody was identified from SMG-immunized mice that could neutralize wild-type SARS-CoV-2 and VOCs with subpicomolar potency. Together, these results demonstrate that removal of glycan shields to better expose the conserved sequences has the potential to be an effective and simple approach for developing a broadly protective SARS-CoV-2 vaccine.

Transcriptomic Analysis and C-Terminal Epitope Tagging Reveal Differential Processing and Signaling of Endogenous TLR3 and TLR7.

Toll-like receptor (TLR) signaling is critical for defense against pathogenic infection, as well as for modulating tissue development. Activation of different TLRs triggers common inflammatory responses such as cytokine induction. Here, we reveal differential impacts of TLR3 and TLR7 signaling on transcriptomic profiles in bone marrow-derived macrophages (BMDMs). Apart from self-regulation, TLR3, but not TLR7, induced expression of other TLRs, suggesting that TLR3 activation globally enhances innate immunity. Moreover, we observed diverse influences of TLR3 and TLR7 signaling on genes involved in methylation, caspase and autophagy pathways. We compared endogenous TLR3 and TLR7 by using CRISPR/Cas9 technology to knock in a dual Myc-HA tag at the 3' ends of mouse Tlr3 and Tlr7. Using anti-HA antibodies to detect endogenous tagged TLR3 and TLR7, we found that both TLRs display differential tissue expression and posttranslational modifications. C-terminal tagging did not impair TLR3 activity. However, it disrupted the interaction between TLR7 and myeloid differentiation primary response 88 (MYD88), the Tir domain-containing adaptor of TLR7, which blocked its downstream signaling necessary to trigger cytokine and chemokine expression. Our study demonstrates different properties for TLR3 and TLR7, and also provides useful mouse models for further investigation of these two RNA-sensing TLRs.

Autism-linked mutations of CTTNBP2 reduce social interaction and impair dendritic spine formation via diverse mechanisms.

Abnormal synaptic formation and signaling is one of the key molecular features of autism spectrum disorders (ASD). Cortactin binding protein 2 (CTTNBP2), an ASD-linked gene, is known to regulate the subcellular distribution of synaptic proteins, such as cortactin, thereby controlling dendritic spine formation and maintenance. However, it remains unclear how ASD-linked mutations of CTTNBP2 influence its function. Here, using cultured hippocampal neurons and knockin mouse models, we screen seven ASD-linked mutations in the short form of the Cttnbp2 gene and identify that M120I, R533* and D570Y mutations impair CTTNBP2 protein-protein interactions via divergent mechanisms to reduce dendritic spine density in neurons. R533* mutation impairs CTTNBP2 interaction with cortactin due to lack of the C-terminal proline-rich domain. Through an N-C terminal interaction, M120I mutation at the N-terminal region of CTTNBP2 also negatively influences cortactin interaction. D570Y mutation increases the association of CTTNBP2 with microtubule, resulting in a dendritic localization of CTTNBP2, consequently reducing the distribution of CTTNBP2 in dendritic spines and impairing the synaptic function of CTTNBP2. Finally, we generated heterozygous M120I knockin mice to mimic the genetic variation of patients and found they exhibit reduced social interaction. Our study elucidates that different ASD-linked mutations of CTTNBP2 result in diverse molecular deficits, but all have the similar consequence of synaptic impairment.

Clinical Characteristics and Predictors of Mortality in Critically Ill Influenza Adult Patients.

Severe influenza is associated with high morbidity and mortality. The aim of this study was to investigate the factors affecting the clinical outcomes of critically ill influenza patients. In this retrospective study, we enrolled critically ill adult patients with influenza at the Kaohsiung Chang Gung Memorial Hospital in Taiwan. We evaluated the demographic, clinical, and laboratory findings and examined whether any of these measurements correlated with mortality. We then created an event-based algorithm as a simple predictive tool using two variables with statistically significant associations with mortality. Between 2015 and 2018, 102 critically ill influenza patients (median age, 62 years) were assessed; among them, 41 (40.1%) patients died. Of the 94 patients who received oseltamivir therapy, 68 (72.3%) began taking oseltamivir 48 hours after the onset of illness. Of the 102 patients, the major influenza-associated complications were respiratory failure (97%), pneumonia (94.1%), acute kidney injury (65.7%), adult respiratory distress syndrome (ARDS) (51%), gastrointestinal bleeding (35.3%), and bacteremia (16.7%). In the multivariate regression model, high lactate levels, ARDS, acute kidney injury, and gastrointestinal bleeding were independent predictors of mortality in critically ill influenza patients. The optimal lactate level cutoff for predicting mortality was 3.7 mmol/L with an area under curve of 0.728. We constructed an event-associated algorithm that included lactate and ARDS. Fifteen (75%) of 20 patients with lactate levels 3.7 mmol/L and ARDS died, compared with only 1 (7.7%) of 13 patients with normal lactate levels and without ARDS. We identified clinical and laboratory predictors of mortality that could aid in the care of critically ill influenza patients. Identification of these prognostic markers could be improved to prioritize key examinations that might be useful in determining patient outcomes.