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Belaid B, Mahammed LL, Oussaid AM, Migaud M, Khadri Y, Casanova JL, Puel A, Ben Halla N, Djidjik R
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Case Report: Interleukin-2 Receptor Common Gamma Chain Defect Presented as a Hyper-IgE Syndrome

FRONTIERS IN IMMUNOLOGY 2021 JUN 24; 12(?):? Article 696350
X-linked severe combined immunodeficiency (X-SCID) is caused by mutations of IL2RG, the gene encoding the interleukin common gamma chain (IL-2R gamma or gamma c) of cytokine receptors for interleukin (IL)-2, IL-4, IL-7, IL-9, IL-15, and IL-21. Hypomorphic mutations of IL2RG may cause combined immunodeficiencies with atypical clinical and immunological presentations. Here, we report a clinical, immunological, and functional characterization of a missense mutation in exon 1 (c.115G>A; p. Asp39Asn) of IL2RG in a 7-year-old boy. The patient suffered from recurrent sinopulmonary infections and refractory eczema. His total lymphocyte counts have remained normal despite skewed T cell subsets, with a pronounced serum IgE elevation. Surface expression of IL-2R gamma was reduced on his lymphocytes. Signal transducer and activator of transcription (STAT) phosphorylation in response to IL-2, IL-4, and IL-7 showed a partially preserved receptor function. T-cell proliferation in response to mitogens and anti-CD3/anti-CD28 monoclonal antibodies was significantly reduced. Further analysis revealed a decreased percentage of CD4(+) T cells capable of secreting IFN-gamma, but not IL-4 or IL-17. Studies on the functional consequences of IL-2R gamma variants are important to get more insight into the pathogenesis of atypical phenotypes which may lay the ground for novel therapeutic strategies.
Ibrahim K, Khodursky S, Yasseri T
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Gender Imbalance and Spatiotemporal Patterns of Contributions to Citizen Science Projects: The Case of Zooniverse

FRONTIERS IN PHYSICS 2021 JUN 4; 9(?):? Article 650720
Citizen Science is research undertaken by professional scientists and members of the public collaboratively. Despite numerous benefits of citizen science for both the advancement of science and the community of the citizen scientists, there is still no comprehensive knowledge of patterns of contributions, and the demography of contributors to citizen science projects. In this paper we provide a first overview of spatiotemporal and gender distribution of citizen science workforce by analyzing 54 million classifications contributed by more than 340 thousand citizen science volunteers from 198 countries to one of the largest online citizen science platforms, Zooniverse. First we report on the uneven geographical distribution of the citizen scientist and model the variations among countries based on the socio-economic conditions as well as the level of research investment in each country. Analyzing the temporal features of contributions, we report on high "burstiness" of participation instances as well as the leisurely nature of participation suggested by the time of the day that the citizen scientists were the most active. Finally, we discuss the gender imbalance among online citizen scientists (about 30% female) and compare it with other collaborative projects as well as the gender distribution in more formal scientific activities. Online citizen science projects need further attention from outside of the academic community, and our findings can help attract the attention of public and private stakeholders, as well as to inform the design of the platforms and science policy making processes.
Fetter-Pruneda I, Hart T, Ulrich Y, Gal A, Oxley PR, Olivos-Cisneros L, Ebert MS, Kazmi MA, Garrison JL, Bargmann CI, Kronauer DJC
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An oxytocin/vasopressin-related neuropeptide modulates social foraging behavior in the clonal raider ant

PLOS BIOLOGY 2021 JUN; 19(6):? Article e3001305
Oxytocin/vasopressin-related neuropeptides are highly conserved and play major roles in regulating social behavior across vertebrates. However, whether their insect orthologue, inotocin, regulates the behavior of social groups remains unknown. Here, we show that in the clonal raider ant Ooceraea biroi, individuals that perform tasks outside the nest have higher levels of inotocin in their brains than individuals of the same age that remain inside the nest. We also show that older ants, which spend more time outside the nest, have higher inotocin levels than younger ants. Inotocin thus correlates with the propensity to perform tasks outside the nest. Additionally, increasing inotocin pharmacologically increases the tendency of ants to leave the nest. However, this effect is contingent on age and social context. Pharmacologically treated older ants have a higher propensity to leave the nest only in the presence of larvae, whereas younger ants seem to do so only in the presence of pupae. Our results suggest that inotocin signaling plays an important role in modulating behaviors that correlate with age, such as social foraging, possibly by modulating behavioral response thresholds to specific social cues. Inotocin signaling thereby likely contributes to behavioral individuality and division of labor in ant societies.
King H, Castro SA, Pohane AA, Scholte CM, Fischetti VA, Korotkova N, Nelson DC, Dorfmueller HC
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Research Article Molecular basis for recognition of the Group A Carbohydrate backbone by the PlyC streptococcal bacteriophage endolysin

BIOCHEMICAL JOURNAL 2021 JUN; 478(12):2385-2397
Endolysins are peptidoglycan (PG) hydrolases that function as part of the bacteriophage (phage) lytic system to release progeny phage at the end of a replication cycle. Notably, endolysins alone can produce lysis without phage infection, which offers an attractive alternative to traditional antibiotics. Endolysins from phage that infect Gram-positive bacterial hosts contain at least one enzymatically active domain (EAD) responsible for hydrolysis of PG bonds and a cell wall binding domain (CBD) that binds a cell wall epitope, such as a surface carbohydrate, providing some degree of specificity for the endolysin. Whilst the EADs typically cluster into conserved mechanistic classes with welldefined active sites, relatively little is known about the nature of the CBDs and only a few binding epitopes for CBDs have been elucidated. The major cell wall components of many streptococci are the polysaccharides that contain the polyrhamnose (pRha) backbone modified with species-specific and serotype-specific glycosyl side chains. In this report, using molecular genetics, microscopy, flow cytometry and lytic activity assays, we demonstrate the interaction of PlyCB, the CBD subunit of the streptococcal PlyC endolysin, with the pRha backbone of the cell wall polysaccharides, Group A Carbohydrate (GAC) and serotype c-specific carbohydrate (SCC) expressed by the Group A Streptococcus and Streptococcus mutans, respectively.
Ulrich Y, Kawakatsu M, Tokita CK, Saragosti J, Chandra V, Tarnita CE, Kronauer DJC
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Response thresholds alone cannot explain empirical patterns of division of labor in social insects

PLOS BIOLOGY 2021 JUN; 19(6):? Article e3001269
The effects of heterogeneity in group composition remain a major hurdle to our understanding of collective behavior across disciplines. In social insects, division of labor (DOL) is an emergent, colony-level trait thought to depend on colony composition. Theoretically, behavioral response threshold models have most commonly been employed to investigate the impact of heterogeneity on DOL. However, empirical studies that systematically test their predictions are lacking because they require control over colony composition and the ability to monitor individual behavior in groups, both of which are challenging. Here, we employ automated behavioral tracking in 120 colonies of the clonal raider ant with unparalleled control over genetic, morphological, and demographic composition. We find that each of these sources of variation in colony composition generates a distinct pattern of behavioral organization, ranging from the amplification to the dampening of inherent behavioral differences in heterogeneous colonies. Furthermore, larvae modulate interactions between adults, exacerbating the apparent complexity. Models based on threshold variation alone only partially recapitulate these empirical patterns. However, by incorporating the potential for variability in task efficiency among adults and task demand among larvae, we account for all the observed phenomena. Our findings highlight the significance of previously overlooked parameters pertaining to both larvae and workers, allow the formulation of theoretical predictions for increasing colony complexity, and suggest new avenues of empirical study.
Lin XC, Leicher R, Liu SX, Zhang B
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Cooperative DNA looping by PRC2 complexes

NUCLEIC ACIDS RESEARCH 2021 JUN 21; 49(11):6238-6248
Polycomb repressive complex 2 (PRC2) is an essential protein complex that silences gene expression via post-translational modifications of chromatin. This paper combined homology modeling, atomistic and coarse-grained molecular dynamics simulations, and single-molecule force spectroscopy experiments to characterize both its full-length structure and PRC2-DNA interactions. Using free energy calculations with a newly parameterized protein-DNA force field, we studied a total of three potential PRC2 conformations and their impact on DNA binding and bending. Consistent with cryo-EM studies, we found that EZH2, a core subunit of PRC2, provides the primary interface for DNA binding, and its curved surface can induce DNA bending. Our simulations also predicted the C2 domain of the SUZ12 subunit to contact DNA. Multiple PRC2 complexes bind with DNA cooperatively via allosteric communication through the DNA, leading to a hairpin-like looped configuration. Single-molecule experiments support PRC2-mediated DNA looping and the role of AEBP2 in regulating such loop formation. The impact of AEBP2 can be partly understood from its association with the C2 domain, blocking C2 from DNA binding. Our study suggests that accessory proteins may regulate the genomic location of PRC2 by interfering with its DNA interactions. [GRAPHICS] .
Frew JW, Singh N, Jiang CS, Vaughan R, Krueger JG
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The Impact of Body Mass Index Upon the Efficacy of Adalimumab in Hidradenitis Suppurativa

FRONTIERS IN MEDICINE 2021 JUN 22; 8(?):? Article 603281
Elevated BMI in Hidradenitis Suppurativa is associated with decreased response to Adalimumab therapy. BMI is proposed to segregate distinct disease subtypes. It remains unresolved whether a threshold BMI exists above which increased dosages may provide clinical benefit. Individual patient data from 578 PIONEER Phase 3 participants were analyzed. Descriptive, multivariable regression analysis and receiver operating characteristic (ROC) curves were calculated to assess the relationship between BMI and clinical outcome measures using R v3.5.3. Participants in the overweight and obese BMI category had reduced odds (58 and 67%, respectively) of achieving HiSCR [OR = 0.42 (95%CI -0.19, 0.91) p = 0.03], [OR = 0.33 (95%CI 0.16, 0.67) p = 0.002] compared to participants with BMI < 25. Reduction in AN count and IHS4 score was not significantly associated. ROC analysis did not reveal any cut off value predictive of treatment outcome. No correlation between BMI and baseline disease activity or covariate interactions were identified. These findings suggest BMI is a significant covariate in the setting of lower baseline disease activity, supporting the concept of disease heterogeneity and differential therapeutic response to Adalimumab.
Foreman HCC, Kirillov V, Paniccia G, Catalano D, Andrunik T, Gupta S, Krug LT, Zhang Y
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RNA-guided gene editing of the murine gammaherpesvirus 68 genome reduces infectious virus production

PLOS ONE 2021 JUN 4; 16(6):? Article e0252313
Epstein-Barr virus (EBV) and Kaposi sarcoma herpesvirus (KSHV) are cancer-causing viruses that establish lifelong infections in humans. Gene editing using the Cas9-guideRNA (gRNA) CRISPR system has been applied to decrease the latent load of EBV in human Burkitt lymphoma cells. Validating the efficacy of Cas9-gRNA system in eradicating infection in vivo without off-target effects to the host genome will require animal model systems. To this end, we evaluated a series of gRNAs against individual genes and functional genomic elements of murine gammaherpesvirus 68 (MHV68) that are both conserved with KSHV and important for the establishment of latency or reactivation from latency in the host. gRNA sequences against ORF50, ORF72 and ORF73 led to insertion, deletion and substitution mutations in these target regions of the genome in cell culture. Murine NIH3T3 fibroblast cells that stably express Cas9 and gRNAs to ORF50 were most resistant to replication upon de novo infection. Latent murine A20 B cell lines that stably express Cas9 and gRNAs against MHV68 were reduced in their reactivation by approximately 50%, regardless of the viral gene target. Lastly, co-transfection of HEK293T cells with the vector expressing the Cas9-MHV68 gRNA components along with the viral genome provided a rapid read-out of gene editing and biological impact. Combinatorial, multiplex MHV68 gRNA transfections in HEK293T cells led to near complete ablation of infectious particle production. Our findings indicate that Cas9-gRNA editing of the murine gammaherpesvirus genome has a deleterious impact on productive replication in three independent infection systems.
Almeida ST, Paulo AC, Babo J, Borralho J, Figueiredo C, Goncalves B, Lanca J, Louro M, Morais H, Queiroz J, de Lencastre H, Sa-Leao R
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Absence of methicillin-resistant Staphylococcus aureus colonization among immunocompetent healthy adults: Insights from a longitudinal study

PLOS ONE 2021 JUN 30; 16(6):? Article e0253739
Methicillin-resistant Staphylococcus aureus (MRSA) has long been known as a major cause of hospital-acquired (HA-MRSA) infections worldwide. For the past twenty years, an increasing number of studies have described its emergence in the community as well. In Portugal, a country with a high-prevalence of HA-MRSA, there are only limited data available on the epidemiology of MRSA in the community. We studied the prevalence of S. aureus and MRSA colonization among healthy adults in Portugal. Between February 2015 and December 2016, a longitudinal study was conducted in which 87 adults aged 25-50 years old were followed for six months. For each participant nasopharyngeal, oropharyngeal and saliva samples were obtained monthly and, in some cases, weekly. A total of 1,578 samples (n = 526 for each sampling site) were examined for the presence of S. aureus and MRSA by classical culture-based methods. Fifty-seven adults (65.5%) carried S. aureus at least once during the six months period of the study: 19.5% were persistent S. aureus carriers and 46.0% were intermittent carriers. Carriage rates per sampling site were 20.5% in nasopharynx, 18.3% in oropharynx, and 13.5% in saliva. Simultaneous screening of the three sampling sites increased detection of S. aureus, which overall occurred in 34.4% of the 526 sampling time-points. No MRSA were isolated. In conclusion, this study adds novel information about the MRSA scenario in the Portuguese community. Our results indicate that, in Portugal, MRSA does not seem to circulate among healthy adults without risk factors and therefore this age group does not constitute, at the current time, a reservoir of MRSA in the community.
Frank MO, Blachere NE, Parveen S, Hacisuleyman E, Fak J, Luna JM, Michailidis E, Wright S, Stark P, Campbell A, Foo A, Sakmar TP, Huffman V, Bergh M, Goldfarb A, Mansisidor A, Patriotis AL, Palmquist KH, Poulton N, Leicher R, Vargas CDM, Duba I, Hurley A, Colagreco J, Pagane N, Orange DE, Mora K, Rakeman JL, Fowler RC, Fernandes H, Lamendola-Essel MF, Didkovsky N, Silvera L, Masci J, Allen M, Rice CM, Darnell RB
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DRUL for school: Opening Pre-K with safe, simple, sensitive saliva testing for SARS-CoV-2

PLOS ONE 2021 JUN 25; 16(6):? Article e0252949
To address the need for simple, safe, sensitive, and scalable SARS-CoV-2 tests, we validated and implemented a PCR test that uses a saliva collection kit use at home. Individuals self-collected 300 mu l saliva in vials containing Darnell Rockefeller University Laboratory (DRUL) buffer and extracted RNA was assayed by RT-PCR (the DRUL saliva assay). The limit of detection was confirmed to be 1 viral copy/mu l in 20 of 20 replicate extractions. Viral RNA was stable in DRUL buffer at room temperature up to seven days after sample collection, and safety studies demonstrated that DRUL buffer immediately inactivated virus at concentrations up to 2.75x10(6) PFU/ml. Results from SARS-CoV-2 positive nasopharyngeal (NP) swab samples collected in viral transport media and assayed with a standard FDA Emergency Use Authorization (EUA) test were highly correlated with samples placed in DRUL buffer. Direct comparison of results from 162 individuals tested by FDA EUA oropharyngeal (OP) or NP swabs with co-collected saliva samples identified four otherwise unidentified positive cases in DRUL buffer. Over six months, we collected 3,724 samples from individuals ranging from 3 months to 92 years of age. This included collecting weekly samples over 10 weeks from teachers, children, and parents from a pre-school program, which allowed its safe reopening while at-risk pods were quarantined. In sum, we validated a simple, sensitive, stable, and safe PCR-based test using a self-collected saliva sample as a valuable tool for clinical diagnosis and screening at workplaces and schools.