Designing Protease-Triggered Protein Cages

Proteins that self-assemble into enclosed polyhedral cages, both naturally and by design, are garnering attention for their prospective utility in the fields of medicine and biotechnology. Notably, their potential for encapsulation and surface display are attractive for experiments that require protection and targeted delivery of cargo. The ability to control their opening or disassembly would greatly advance the development of protein nanocages into widespread molecular tools. Toward the development of protein cages that disassemble in a systematic manner and in response to biologically relevant stimuli, here we demonstrate a modular protein cage system that is opened by highly sequence-specific proteases, based on sequence insertions at strategically chosen loop positions in the protein cage subunits. We probed the generality of the approach in the context of protein cages built using the two prevailing methods of construction: genetic fusion between oligomeric components and (non-covalent) computational interface design between oligomeric components. Our results suggest that the former type of cage may be more amenable than the latter for endowing proteolytically controlled disassembly. We show that a successfully designed cage system, based on oligomeric fusion, is modular with regard to its triggering protease. One version of the cage is targeted by an asparagine protease implicated in cancer and Alzheimer's disease, whereas the second version is responsive to the blood-clotting protease, thrombin. The approach demonstrated here should guide future efforts to develop therapeutic vectors to treat disease states where protease induction or mis-regulation occurs.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Hypertriton Production in p-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

The study of nuclei and antinuclei production has proven to be a powerful tool to investigate the formation mechanism of loosely bound states in high-energy hadronic collisions. The first measurement of the production of _{Λ}^{3}H in p-Pb collisions at sqrt[s_{NN}]=5.02  TeV is presented in this Letter. Its production yield measured in the rapidity interval -1<y<0 for the 40% highest-multiplicity p-Pb collisions is dN/dy=[6.3±1.8(stat)±1.2(syst)]×10^{-7}. The measurement is compared with the expectations of statistical hadronization and coalescence models, which describe the nucleosynthesis in hadronic collisions. These two models predict very different yields of the hypertriton in charged particle multiplicity environments relevant to small collision systems such as p-Pb, and therefore the measurement of dN/dy is crucial to distinguish between them. The precision of this measurement leads to the exclusion with a significance larger than 6.9σ of some configurations of the statistical hadronization model, thus constraining the theory behind the production of loosely bound states at hadron colliders.

POS0712 YEAR-4 OBSERVATIONAL FOLLOW-UP OF BELIMUMAB SAFETY (MORTALITY AND MALIGNANCIES) IN PATIENTS WITH SLE WHO COMPLETED A PHASE 4, 52-WEEK, RANDOMISED, DOUBLE-BLIND PLACEBO-CONTROLLED SAFETY STUDY

Background

Belimumab (BEL) is an approved systemic lupus erythematosus (SLE) treatment. Despite BEL clinical studies demonstrating a favourable benefit–risk profile, varying incidence rates of mortality and adverse events of special interest, including malignancies, require further evaluation.

Objectives

To assess long-term safety following BEL therapy.

Methods

This was a Year (Yr)-4 post-treatment follow-up of the Phase 4, double-blind, placebo (PBO)-controlled Belimumab Assessment of Safety in SLE (BASE) study (GSK Study BEL115467; NCT01705977).1 Overall, 4003 adults with active, autoantibody-positive SLE received BEL (10 mg/kg IV) or PBO, plus standard therapy (ST), for 48 weeks. Patients (pts) then entered a Yr 2–5 follow-up period in which they received physician-directed ST. All pts were contacted annually by telephone, including pts who discontinued treatment. Mortality and new malignancies (including nonmelanoma skin cancer) were the endpoints collected, and rates summarised. We present Yr-4 follow-up data by Yr-1 treatment received.

Results

Baseline characteristics for the Yr-4 follow-up population (N=3204) were similar to the Yr-1 double-blind study population (N=4003). By the Yr-4 follow-up, cumulatively 12.7% and 11.0% of pts in the BEL and PBO Yr-1 groups had received BEL as part of physician-directed care, respectively (data not shown). As shown in the Table 1, cumulative follow-up adjusted mortality rates were lower in the BEL vs PBO Yr-1 treatment group for Yrs 2 to 4. Cumulative follow-up adjusted new primary malignancy rates were lower in the BEL vs PBO Yr-1 treatment group for Yrs 2 and 3, but similar in Yr 4.

Table 1.

Yr 1 plus Yrs 2–4 post-treatment* follow-up mortality and new primary malignancy rates by Yr-1 study treatment

Pts with events per yr, n (%)Pt incidence rate per 100 pt-yrs(Cumulative rate, %)BELPBOTotalBELPBOTotalYr-1 (as-treated) populationN=2002N=2001N=4003Deaths13 (0.65)22 (1.10)35 (0.87)0.66 (0.65)1.11 (1.10)0.87New primary malignancies†9 (0.45)10 (0.50)19 (0.47)0.450.500.47Yr-2 (as-treated in Yr-1) populationN=1695N=1670N=3365Deaths9 (0.53)21 (1.26)30 (0.89)0.60 (1.10)1.18 (2.15)0.89 (1.62)New primary malignancies3 (0.18)7 (0.42)10 (0.30)0.34 (0.60)0.48 (0.85)0.41 (0.72)Yr-3 (as-treated in Yr-1) populationN=1659N=1630N=3289Deaths9 (0.54)17 (1.04)26 (0.79)0.58 (1.55)1.14 (3.00)0.86 (2.27)New primary malignancies, n (%)7 (0.42)9 (0.55)16 (0.49)0.37 (0.95)0.49 (1.25)0.43 (1.10)Yr-4 (as-treated in Yr-1) populationN=1622N=1582N=3204Deaths by MedDRA SOC14 (0.86)13 (0.82)27 (0.84)0.65 (2.25)1.07 (3.65)0.86 (2.95)Infections/infestations4 (0.25)5 (0.32)9 (0.28)Cardiac disorders2 (0.12)1 (0.06)3 (0.09)General disorders/ administration site conditions2 (0.12)2 (0.13)4 (0.12)Respiratory/thoracic/ mediastinal disorders2 (0.12)1 (0.06)3 (0.09)Nervous system disorders2 (0.12)1 (0.06)3 (0.09)Other‡2 (0.12)3 (0.18)5 (0.15)New primary malignancies10 (0.62)5 (0.32)15 (0.47)0.43 (1.45)0.44 (1.45)0.43 (1.45)

*Pts in the post-treatment follow-up period are no longer receiving study treatment. †Includes nonmelanoma skin cancer.

‡Contains 1 event for 5 distinct pts of each of renal/urinary disorders, and neoplasms (BEL); musculoskeletal/connective tissue disorders, injury/poisoning/procedural complications, and vascular disorders (PBO).

MedDRA, Medical Dictionary for Regulatory Activities; SOC, system organ class

Conclusion

Post-treatment Yr-4 follow-up results in BASE, the largest double-blind trial in pts with SLE to date, support the safety of BEL therapy, with no new BEL safety concerns identified in this analysis.

References

[1]Sheikh SZ, et al. Lancet Rheumatol 2020;3:e122–30

Acknowledgements

This analysis was funded by GlaxoSmithKline (GSK). Medical writing support was provided by Lulu Hill, MPharmacol, Fishawack Indicia Ltd. UK, part of Fishawack Health, and was funded by GSK.

Disclosure of Interests

Saira Sheikh Consultant of: GSK, Grant/research support from: Pfizer, Morton Scheinberg Consultant of: GSK, Pfizer, Alnylam, AbbVie, PTC Therapeutics, James Cheng-Chung Wei Consultant of: TSH Biopharm, AbbVie, BMS, Celgene, Chugai, Eisai, Janssen, Novartis, Pfizer, Sanofi-Aventis, and UCB Pharma, Grant/research support from: AbbVie, Amgen, Astellas, BMS, Celgene, Eli Lilly, Gilead, Janssen, Novartis, Pfizer, Sun and UCB Pharma, Dana Tegzová: None declared, William Stohl Consultant of: GSK, Grant/research support from: GSK, Pfizer, Gilead, RICARDO ACAYABA DE TOLEDO Speakers bureau: AbbVie, Janssen, UCB, Novartis, Celltrion, Consultant of: AbbVie, Janssen, Novartis, UCB, Grant/research support from: Pfizer, AbbVie, Novartis, GSK, Tamara Mucenic Speakers bureau: Novartis, Janssen, BMS, AbbVie, Pfizer, Roche, Grant/research support from: GSK, Janssen, Roche, Eli Lilly, Gilead, UCB, Mauricio R Abello Banfi: None declared, Kathleen Maksimowicz-McKinnon Grant/research support from: Chemocentryx, Carlos Abud-Mendoza Speakers bureau: GSK, Lilly, Pfizer, Sandra Navarra Speakers bureau: Pfizer, Novartis, Johnson & Johnson, Consultant of: Biogen, Boehringer Ingelheim, Grant/research support from: Astellas, Mercedes García Speakers bureau: GSK, Janssen, Pfizer, Ignacio Garcia-De La Torre: None declared, Andrew Liu Shareholder of: GSK, Employee of: GSK, Abhishek Roy Employee of: GSK, Paul Wilde Shareholder of: GSK, Employee of: GSK, Sofia Fernandes Shareholder of: GSK, Employee of: GSK, Julia Harris Shareholder of: GSK, Employee of: GSK, David Roth Shareholder of: GSK, Employee of: GSK

Polarization of Λ and Λ[over ¯] Hyperons along the Beam Direction in Pb-Pb Collisions at sqrt[s]_{NN}=5.02 TeV

The polarization of the Λ and Λ[over ¯] hyperons along the beam (z) direction, P_{z}, has been measured in Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV recorded with ALICE at the Large Hadron Collider (LHC). The main contribution to P_{z} comes from elliptic flow-induced vorticity and can be characterized by the second Fourier sine coefficient P_{z,s2}=⟨P_{z}sin(2φ-2Ψ_{2})⟩, where φ is the hyperon azimuthal emission angle and Ψ_{2} is the elliptic flow plane angle. We report the measurement of P_{z,s2} for different collision centralities and in the 30%-50% centrality interval as a function of the hyperon transverse momentum and rapidity. The P_{z,s2} is positive similarly as measured by the STAR Collaboration in Au-Au collisions at sqrt[s_{NN}]=200  GeV, with somewhat smaller amplitude in the semicentral collisions. This is the first experimental evidence of a nonzero hyperon P_{z} in Pb-Pb collisions at the LHC. The comparison of the measured P_{z,s2} with the hydrodynamic model calculations shows sensitivity to the competing contributions from thermal and the recently found shear-induced vorticity, as well as to whether the polarization is acquired at the quark-gluon plasma or the hadronic phase.

Measurement of the Groomed Jet Radius and Momentum Splitting Fraction in pp and Pb-Pb Collisions at sqrt[s_{NN}]=5.02 TeV

This article presents groomed jet substructure measurements in pp and Pb-Pb collisions at sqrt[s_{NN}]=5.02  TeV with the ALICE detector. The soft drop grooming algorithm provides access to the hard parton splittings inside a jet by removing soft wide-angle radiation. We report the groomed jet momentum splitting fraction, z_{g}, and the (scaled) groomed jet radius, θ_{g}. Charged-particle jets are reconstructed at midrapidity using the anti-k_{T} algorithm with resolution parameters R=0.2 and R=0.4. In heavy-ion collisions, the large underlying event poses a challenge for the reconstruction of groomed jet observables, since fluctuations in the background can cause groomed parton splittings to be misidentified. By using strong grooming conditions to reduce this background, we report these observables fully corrected for detector effects and background fluctuations for the first time. A narrowing of the θ_{g} distribution in Pb-Pb collisions compared to pp collisions is seen, which provides direct evidence of the modification of the angular structure of jets in the quark-gluon plasma. No significant modification of the z_{g} distribution in Pb-Pb collisions compared to pp collisions is observed. These results are compared with a variety of theoretical models of jet quenching, and provide constraints on jet energy-loss mechanisms and coherence effects in the quark-gluon plasma.

Measurement of Prompt D^{0}, Λ_{c}^{+}, and Σ_{c}^{0,++}(2455) Production in Proton-Proton Collisions at sqrt[s]=13 TeV

The p_{T}-differential production cross sections of prompt D^{0}, Λ_{c}^{+}, and Σ_{c}^{0,++}(2455) charmed hadrons are measured at midrapidity (|y|<0.5) in pp collisions at sqrt[s]=13  TeV. This is the first measurement of Σ_{c}^{0,++} production in hadronic collisions. Assuming the same production yield for the three Σ_{c}^{0,+,++} isospin states, the baryon-to-meson cross section ratios Σ_{c}^{0,+,++}/D^{0} and Λ_{c}^{+}/D^{0} are calculated in the transverse momentum (p_{T}) intervals 2<p_{T}<12 and 1<p_{T}<24  GeV/c. Values significantly larger than in e^{+}e^{-} collisions are observed, indicating for the first time that baryon enhancement in hadronic collisions also extends to the Σ_{c}. The feed-down contribution to Λ_{c}^{+} production from Σ_{c}^{0,+,++} is also reported and is found to be larger than in e^{+}e^{-} collisions. The data are compared with predictions from event generators and other phenomenological models, providing a sensitive test of the different charm-hadronization mechanisms implemented in the models.

The Inverted U-Shaped Association of Caffeine Intake with Serum Uric Acid in U.S. Adults

BACKGROUND AND AIMS

Caffeine is a worldwide popularly consumed constituent in foods that can exert physiological effects. However, previous researches about the relationship between caffeine intake and serum uric acid (SUA) were limited and controversial. Therefore, we sought to investigate that relationship in U.S. adults.

METHODS

In this cross-sectional study, the total sample of 7888 selected participants (3838 males and 4050 females) were identified from the National Health and Nutritional Examination Surveys (NHANES) 2015-2018. All subjects were tested for serum uric acid levels (μmmol/L), and their daily caffeine intakes (mg/d) were obtained by an average of two 24-hour dietary recalls. Multivariate linear regression models were used to evaluate the association between two variables in total subjects and subgroup analyses. Generalized additive models with smooth curve fittings were also performed.

RESULTS

Multivariate regression analyses showed caffeine intake was negatively correlated with SUA after adjustment of other confounders. The subgroup analyses stratified by gender showed the negative correlation of caffeine intake with SUA was statistically significant in males but not in females. Furthermore, we observed a nonlinear inverse association of caffeine intake with SUA (P nonlinear <0.001) in the generalized additive model, followed by an inverted U-shaped curve (inflection point: 60.5mg/d) for all participants. This inverted U-shaped relationship between them could also be found in both genders, individuals aged below 60 years old, overweight (BMI of 25 to 30), and Non-Hispanic White individuals.

CONCLUSIONS

This study indicated that caffeine intake exhibited an inverse correlation with SUA, especially in males. In addition, this inverse relationship was nonlinear, which followed an inverted U-shaped curve.

Measurement of the Cross Sections of Ξ_{c}^{0} and Ξ_{c}^{+} Baryons and of the Branching-Fraction Ratio BR(Ξ_{c}^{0}→Ξ^{-}e^{+}ν_{e})/BR(Ξ_{c}^{0}→Ξ^{-}π^{+}) in pp Collisions at sqrt[s]=13 TeV

The p_{T}-differential cross sections of prompt charm-strange baryons Ξ_{c}^{0} and Ξ_{c}^{+} were measured at midrapidity (|y|<0.5) in proton-proton (pp) collisions at a center-of-mass energy sqrt[s]=13  TeV with the ALICE detector at the LHC. The Ξ_{c}^{0} baryon was reconstructed via both the semileptonic decay (Ξ^{-}e^{+}ν_{e}) and the hadronic decay (Ξ^{-}π^{+}) channels. The Ξ_{c}^{+} baryon was reconstructed via the hadronic decay (Ξ^{-}π^{+}π^{+}) channel. The branching-fraction ratio BR(Ξ_{c}^{0}→Ξ^{-}e^{+}ν_{e})/BR(Ξ_{c}^{0}→Ξ^{-}π^{+})=1.38±0.14(stat)±0.22(syst) was measured with a total uncertainty reduced by a factor of about 3 with respect to the current world average reported by the Particle Data Group. The transverse momentum (p_{T}) dependence of the Ξ_{c}^{0}- and Ξ_{c}^{+}-baryon production relative to the D^{0} meson and to the Σ_{c}^{0,+,++}- and Λ_{c}^{+}-baryon production are reported. The baryon-to-meson ratio increases toward low p_{T} up to a value of approximately 0.3. The measurements are compared with various models that take different hadronization mechanisms into consideration. The results provide stringent constraints to these theoretical calculations and additional evidence that different processes are involved in charm hadronization in electron-positron (e^{+}e^{-}) and hadronic collisions.