Immunization for HIV-1 Broadly Neutralizing Antibodies in Human Ig Knockin Mice.

A subset of individuals infected with HIV-1 develops broadly neutralizing antibodies (bNAbs) that can prevent infection, but it has not yet been possible to elicit these antibodies by immunization. To systematically explore how immunization might be tailored to produce them, we generated mice expressing the predicted germline or mature heavy chains of a potent bNAb to the CD4 binding site (CD4bs) on the HIV-1 envelope glycoprotein (Env). Immunogens specifically designed to activate B cells bearing germline antibodies are required to initiate immune responses, but they do not elicit bNAbs. In contrast, native-like Env trimers fail to activate B cells expressing germline antibodies but elicit bNAbs by selecting for a restricted group of light chains bearing specific somatic mutations that enhance neutralizing activity. The data suggest that vaccination to elicit anti-HIV-1 antibodies will require immunization with a succession of related immunogens.

Structural Repertoire of HIV-1-Neutralizing Antibodies Targeting the CD4 Supersite in 14 Donors.

The site on the HIV-1 gp120 glycoprotein that binds the CD4 receptor is recognized by broadly reactive antibodies, several of which neutralize over 90% of HIV-1 strains. To understand how antibodies achieve such neutralization, we isolated CD4-binding-site (CD4bs) antibodies and analyzed 16 co-crystal structures -8 determined here- of CD4bs antibodies from 14 donors. The 16 antibodies segregated by recognition mode and developmental ontogeny into two types: CDR H3-dominated and VH-gene-restricted. Both could achieve greater than 80% neutralization breadth, and both could develop in the same donor. Although paratope chemistries differed, all 16 gp120-CD4bs antibody complexes showed geometric similarity, with antibody-neutralization breadth correlating with antibody-angle of approach relative to the most effective antibody of each type. The repertoire for effective recognition of the CD4 supersite thus comprises antibodies with distinct paratopes arrayed about two optimal geometric orientations, one achieved by CDR H3 ontogenies and the other achieved by VH-gene-restricted ontogenies.

HIV-1 VRC01 Germline-Targeting Immunogens Select Distinct Epitope-Specific B Cell Receptors.

Activating precursor B cell receptors of HIV-1 broadly neutralizing antibodies requires specifically designed immunogens. Here, we compared the abilities of three such germline-targeting immunogens against the VRC01-class receptors to activate the targeted B cells in transgenic mice expressing the germline VH of the VRC01 antibody but diverse mouse light chains. Immunogen-specific VRC01-like B cells were isolated at different time points after immunization, their VH and VL genes were sequenced, and the corresponding antibodies characterized. VRC01 B cell sub-populations with distinct cross-reactivity properties were activated by each immunogen, and these differences correlated with distinct biophysical and biochemical features of the germline-targeting immunogens. Our study indicates that the design of effective immunogens to activate B cell receptors leading to protective HIV-1 antibodies will require a better understanding of how the biophysical properties of the epitope and its surrounding surface on the germline-targeting immunogen influence its interaction with the available receptor variants in vivo.

An Antibody Targeting the Fusion Machinery Neutralizes Dual-Tropic Infection and Defines a Site of Vulnerability on Epstein-Barr Virus.

Epstein-Barr virus (EBV) is a causative agent of infectious mononucleosis and is associated with 200,000 new cases of cancer and 140,000 deaths annually. Subunit vaccines against this pathogen have focused on the gp350 glycoprotein and remain unsuccessful. We isolated human antibodies recognizing the EBV fusion machinery (gH/gL and gB) from rare memory B cells. One anti-gH/gL antibody, AMMO1, potently neutralized infection of B cells and epithelial cells, the two major cell types targeted by EBV. We determined a cryo-electron microscopy reconstruction of the gH/gL-gp42-AMMO1 complex and demonstrated that AMMO1 bound to a discontinuous epitope formed by both gH and gL at the Domain-I/Domain-II interface. Integrating structural, biochemical, and infectivity data, we propose that AMMO1 inhibits fusion of the viral and cellular membranes. This work identifies a crucial epitope that may aid in the design of next-generation subunit vaccines against this major public health burden.

Validation of Ligand Tetramers for the Detection of Antigen-Specific Lymphocytes.

The study of Ag-specific lymphocytes has been a key advancement in immunology over the past few decades. The development of multimerized probes containing Ags, peptide:MHC complexes, or other ligands was one innovation allowing the direct study of Ag-specific lymphocytes by flow cytometry. Although these types of study are now common and performed by thousands of laboratories, quality control and assessment of probe quality are often minimal. In fact, many of these types of probe are made in-house, and protocols vary between laboratories. Although peptide:MHC multimers can often be obtained from commercial sources or core facilities, few such services exist for Ag multimers. To ensure high quality and consistency with ligand probes, we have developed an easy and robust multiplexed approach using commercially available beads able to bind Abs specific for the ligand of interest. Using this assay, we have sensitively assessed the performance of peptide:MHC and Ag tetramers and have found considerable batch-to-batch variability in performance and stability over time more easily than using murine or human cell-based assays. This bead-based assay can also reveal common production errors such as miscalculation of Ag concentration. This work could set the stage for the development of standardized assays for all commonly used ligand probes to limit laboratory-to-laboratory technical variation and experimental failure caused by probe underperformance.

One Health Approach to Globalizing, Accelerating, and Focusing Amphibian and Reptile Disease Research-Reflections and Opinions from the First Global Amphibian and Reptile Disease Conference.

The world's reptiles and amphibians are experiencing dramatic and ongoing losses in biodiversity, changes that can have substantial effects on ecosystems and human health. In 2022, the first Global Amphibian and Reptile Disease Conference was held, using One Health as a guiding principle. The conference showcased knowledge on numerous reptile and amphibian pathogens from several standpoints, including epidemiology, host immune defenses, wild population effects, and mitigation. The conference also provided field experts the opportunity to discuss and identify the most urgent herpetofaunal disease research directions necessary to address current and future threats to reptile and amphibian biodiversity.

Winter is coming-Temperature affects immune defenses and susceptibility to Batrachochytrium salamandrivorans.

Environmental temperature is a key factor driving various biological processes, including immune defenses and host-pathogen interactions. Here, we evaluated the effects of environmental temperature on the pathogenicity of the emerging fungal pathogen, Batrachochytrium salamandrivorans (Bsal), using controlled laboratory experiments, and measured components of host immune defense to identify regulating mechanisms. We found that adult and juvenile Notophthalmus viridescens died faster due to Bsal chytridiomycosis at 14°C than at 6 and 22°C. Pathogen replication rates, total available proteins on the skin, and microbiome composition likely drove these relationships. Temperature-dependent skin microbiome composition in our laboratory experiments matched seasonal trends in wild N. viridescens, adding validity to these results. We also found that hydrophobic peptide production after two months post-exposure to Bsal was reduced in infected animals compared to controls, perhaps due to peptide release earlier in infection or impaired granular gland function in diseased animals. Using our temperature-dependent susceptibility results, we performed a geographic analysis that revealed N. viridescens populations in the northeastern United States and southeastern Canada are at greatest risk for Bsal invasion, which shifted risk north compared to previous assessments. Our results indicate that environmental temperature will play a key role in the epidemiology of Bsal and provide evidence that temperature manipulations may be a viable disease management strategy.

Effectiveness of SPECT/CT Imaging for Sentinel Node Biopsy Staging of Primary Cutaneous Melanoma and Patient Outcomes.

PURPOSE: Coregistered SPECT/CT can improve accuracy of sentinel node biopsy (SNB) for staging melanoma. This benefit has implications for pathology services and surgical practice with increased diagnostic and surgical workload. The purpose of this study was to investigate the effectiveness of SPECT/CT imaging. METHODS: SNB data were collected over a 10-year period. Preoperative SLN mapping was performed by using planar lymphoscintigraphy (LSG) for all patients (n = 1522) and after October 2015, patients underwent a second co-registered SPECT/CT scan (n = 559). The patients were stratified according to the imaging protocol. The number of nodes and nodal basins were assessed. The reasons for cancellation also were assessed. RESULTS: A total of 95% (1446/1522) of patients underwent a successful SNB procedure. Significantly more sentinel nodes were identified by the SPECT/CT protocol (3 vs. 2; p < 0.0001). More patients were cancelled in the SPECT/CT cohort (9.3% vs. 2.5%; p < 0.0001). Head & neck, lower limb, and AJCC IB primaries were significantly less likely to proceed to SNB. SPECT/CT identified significantly more positive SNBs (20.9% vs. 16.5%; p = 0.038). SPECT/CT imaging was associated with improved disease-free (hazard ratio [HR] = 0.74; 95% confidence interval [CI]: 0.54-1.0); p = 0.048) and disease-specific survival (HR = 0.48; 95% CI: 0.3-0.78; p = 0.003). Patients who did not proceed to SNB had a significantly increased nodal relapse rate (23.5% vs. 6.8%; HR = 3.4; 95% CI: 1.9-6.2; p < 0.0001) compared with those who underwent SNB. CONCLUSIONS: This large cohort study confirms the increased accuracy of SPECT/CT for identifying SLN metastases, which would appear to have a significant therapeutic benefit, although an increased risk of cancellation of the SNB procedure on the day of surgery.

A Pharmacovigilance Study of Adverse Drug Reactions Reported for Cardiovascular Disease Medications Approved Between 2012 and 2017 in the United States Food and Drug Administration Adverse Event Reporting System (FAERS) Database.

PURPOSE: Between 2012 and 2017, the FDA approved 29 therapies for a cardiovascular disease (CVD) indication. Due to the limited literature on patient safety outcomes for recently approved CVD medications, this study investigated adverse drug reports (ADRs) reported in the FDA Adverse Event Reporting System (FAERS). METHODS: A disproportionality analysis of spontaneously reported ADR was conducted. Reports in FAERS from Quarter 1, 2012, through Quarter 1, 2019, were compiled, allowing a 2-year buffer following drug approval in 2017. Top 10 reported ADRs and reporting odds ratios (ROR; confidence interval (CI)), a measure of disproportionality, were analyzed and compared to drugs available prior to 2012 as appropriate. RESULTS: Of 7,952,147 ADR reports, 95,016 (1.19%) consisted of reports for newly approved CVD medications. For oral anticoagulants, apixaban had significantly lower reports for anemia and renal failure compared to dabigatran and rivaroxaban but greater reports for neurological signs/symptoms, and arrhythmias. Evaluating heart failure drugs, sacubitril/valsartan had greater reports for acute kidney injury, coughing, potassium imbalances, and renal impairment but notably, lower for angioedema compared to lisinopril. Assessing familial hypercholesterolemia drugs, alirocumab had greater reports for joint-related-signs/symptoms compared to other agents in this category. A newer pulmonary arterial hypertension treatment, selexipag, had greater reports of reporting for bone/joint-related-signs/symptoms but riociguat had greater reports for hemorrhages and vascular hypotension. CONCLUSION: Pharmacovigilance studies allow an essential opportunity to evaluate the safety profile of CVD medications in clinical practice. Additional research is needed to evaluate these reported safety concerns for recently approved CVD medications.

Kidney and Mortality Outcomes Associated with Ondansetron in Critically Ill Patients.

Background: Ondansetron is a preferred anti-emetic in critical care to treat nausea and vomiting, and has historically been considered a largely safe option. A recent pharmacoepidemiology study reported that ondansetron may be associated with an increased risk for acute kidney injury (AKI). Methods: We interrogated the High-Density Intensive Care (HiDenIC-15) database containing intensive care data for 13 hospitals across Western Pennsylvania between Oct 2008-Dec 2014. AKI was defined using the Kidney Disease, Improving Global Outcomes 2012 guidelines. Ondansetron use was considered as receiving any form of ondansetron within 24 h of admission. The subsequent 48 h (hours 25-72 after admission) were analyzed for outcomes. Primary outcome was development of AKI; secondary outcomes included 90-day mortality and time to AKI. Propensity-matched, multivariate logistic regression was applied for both outcomes. Comparator groups were metoclopramide and prochlorperazine using the same exposure criteria. Results:AKI occurred in 965 (5.6%), 12 (3.0%), and 61 (6.5%) patients receiving ondansetron, prochlorperazine, and metoclopramide, respectively. In the adjusted analysis, no anti-emetic was associated with a significant change in the odds of developing AKI. Ondansetron was associated with a 5.48% decrease (CI -6.17--4.79) in death within 90 days of ICU-admission, which was independent of AKI status; an effect not seen with other anti-emetics. Anti-emetic usage was not associated with a change in the time to first AKI. Conclusion:Anti-emetic usage did not alter AKI risk. Ondansetron was associated with a significant decrease in 90-day mortality that was not seen by other anti-emetics, which requires further exploration.

Correction: HIV-1 envelope glycan modifications that permit neutralization by germline-reverted VRC01-class broadly neutralizing antibodies.

[This corrects the article DOI: 10.1371/journal.ppat.1007431.].

Lucky Number 13: A 13-Layer Polytype of the Alkyne Hydrogenation Catalyst CaGaGe.

Polytypism, the ability of materials to form crystal structures with different stacking sequences, occasionally causes materials with the same stoichiometry and similar local structures to have profoundly different properties. Herein, we discover a metastable 13-layer trigonal (13T) polytype of CaGaGe, a layered intermetallic phase comprised of [GaGe]2- honeycombs separated by Ca2+. 13T-CaGaGe is synthesized from arc-melting the elements, and its structure is elucidated via neutron powder diffraction. Air-stable 13T-CaGaGe has one misaligned [GaGe]2- layer for every 13 and transforms into the more stable 4-layer hexagonal (4H) CaGaGe polytype after annealing at 500 °C. Transition-metal-free 13T-CaGaGe shows remarkable activity in the catalytic hydrogenation of phenylacetylene to styrene and ethylbenzene, much higher than the 4H polytype. This work identifies the first 13-layer polytype for any crystal structure and further establishes the influence of polytypism on catalysis.

Anti-HIV-1 B cell responses are dependent on B cell precursor frequency and antigen-binding affinity.

The discovery that humans can produce potent broadly neutralizing antibodies (bNAbs) to several different epitopes on the HIV-1 spike has reinvigorated efforts to develop an antibody-based HIV-1 vaccine. Antibody cloning from single cells revealed that nearly all bNAbs show unusual features that could help explain why it has not been possible to elicit them by traditional vaccination and instead would require a sequence of different immunogens. This idea is supported by experiments with genetically modified immunoglobulin (Ig) knock-in mice. Sequential immunization with a series of specifically designed immunogens was required to shepherd the development of bNAbs. However, knock-in mice contain superphysiologic numbers of bNAb precursor-expressing B cells, and therefore how these results can be translated to a more physiologic setting remains to be determined. Here we make use of adoptive transfer experiments using knock-in B cells that carry a synthetic intermediate in the pathway to anti-HIV-1 bNAb development to examine how the relationship between B cell receptor affinity and precursor frequency affects germinal center (GC) B cell recruitment and clonal expansion. Immunization with soluble HIV-1 antigens can recruit bNAb precursor B cells to the GC when there are as few as 10 such cells per mouse. However, at low precursor frequencies, the extent of clonal expansion is directly proportional to the affinity of the antigen for the B cell receptor, and recruitment to GCs is variable and dependent on recirculation.

Emerging Pathogens and a Current-Use Pesticide: Potential Impacts on Eastern Hellbenders.

Populations of the eastern hellbender Cryptobranchus alleganiensis alleganiensis have been declining for decades, and emerging pathogens and pesticides are hypothesized to be contributing factors. However, few empirical studies have attempted to test the potential effects of these factors on hellbenders. We simultaneously exposed subadult hellbenders to environmentally relevant concentrations of either Batrachochytrium dendrobatidis (Bd) or a frog virus 3-like ranavirus (RV), a combination of the pathogens, or each pathogen following exposure to a glyphosate herbicide (Roundup). Additionally, we measured the ability of the skin mucosome to inactivate Bd and RV in growth assays. We found that mucosome significantly inactivated RV by an average of 40% but had no negative effects on Bd growth. All treatments that included RV exposure experienced reduced survival compared to controls, and the combination of RV and herbicide resulted in 100% mortality. Histopathology verified RV as the cause of mortality in all RV-exposed treatments. No animals were infected with Bd or died in the Bd-only treatment. Our results suggest that RV exposure may be a significant threat to the survival of subadult hellbenders and that Roundup exposure may potentially exacerbate this threat.

Lysosome enlargement during inhibition of the lipid kinase PIKfyve proceeds through lysosome coalescence.

Lysosomes receive and degrade cargo from endocytosis, phagocytosis and autophagy. They also play an important role in sensing and instructing cells on their metabolic state. The lipid kinase PIKfyve generates phosphatidylinositol-3,5-bisphosphate to modulate lysosome function. PIKfyve inhibition leads to impaired degradative capacity, ion dysregulation, abated autophagic flux and a massive enlargement of lysosomes. Collectively, this leads to various physiological defects, including embryonic lethality, neurodegeneration and overt inflammation. The reasons for such drastic lysosome enlargement remain unclear. Here, we examined whether biosynthesis and/or fusion-fission dynamics contribute to swelling. First, we show that PIKfyve inhibition activates TFEB, TFE3 and MITF, enhancing lysosome gene expression. However, this did not augment lysosomal protein levels during acute PIKfyve inhibition, and deletion of TFEB and/or related proteins did not impair lysosome swelling. Instead, PIKfyve inhibition led to fewer but enlarged lysosomes, suggesting that an imbalance favouring lysosome fusion over fission causes lysosome enlargement. Indeed, conditions that abated fusion curtailed lysosome swelling in PIKfyve-inhibited cells.

HIV-1 envelope glycan modifications that permit neutralization by germline-reverted VRC01-class broadly neutralizing antibodies.

Broadly neutralizing antibody (bnAb) induction is a high priority for effective HIV-1 vaccination. VRC01-class bnAbs that target the CD4 binding site (CD4bs) of trimeric HIV-1 envelope (Env) glycoprotein spikes are particularly attractive to elicit because of their extraordinary breadth and potency of neutralization in vitro and their ability to protect against infection in animal models. Glycans bordering the CD4bs impede the binding of germline-reverted forms of VRC01-class bnAbs and therefore constitute a barrier to early events in initiating the correct antibody lineages. Deleting a subset of these glycans permits Env antigen binding but not virus neutralization, suggesting that additional barriers impede germline-reverted VRC01-class antibody binding to functional Env trimers. We investigated the requirements for functional Env trimer engagement of VRC01-class naïve B cell receptors by using virus neutralization and germline-reverted antibodies as surrogates for the interaction. Targeted deletion of a subset of N-glycans bordering the CD4bs, combined with Man5 enrichment of remaining N-linked glycans that are otherwise processed into larger complex-type glycans, rendered HIV-1 426c Env-pseudotyped virus (subtype C, transmitted/founder) highly susceptible to neutralization by near germline forms of VRC01-class bnAbs. Neither glycan modification alone rendered the virus susceptible to neutralization. The potency of neutralization in some cases rivaled the potency of mature VRC01 against wildtype viruses. Neutralization by the germline-reverted antibodies was abrogated by the known VRC01 resistance mutation, D279K. These findings improve our understanding of the restrictions imposed by glycans in eliciting VRC01-class bnAbs and enable a neutralization-based strategy to monitor vaccine-elicited early precursors of this class of bnAbs.

Rb3InCl6: A Monoclinic Double Perovskite Derivative with Bright Sb3+-Activated Photoluminescence.

Here, we present the synthesis and crystal structure of Rb3InCl6 prepared from air stable reagents via a two-step process that proceeds through the intermediate Rb2InCl5·H2O. Rb3InCl6 crystallizes with the Rb3YCl6 structure type (C2/c), which can be derived from the double perovskite structure by noncooperative tilting of isolated [InCl6]3- octahedra. Despite this lowering of symmetry, the optical properties are similar to the cubic double perovskite Cs2NaInCl6. Partial substitution of In3+ with Sb3+ in Rb3InCl6 results in intense cyan-green photoluminescence originating from localized 5s2 to 5s15p1 electronic transitions of [SbCl6]3- polyatomic anions. In comparison with the cubic double perovskite phosphor Cs2NaInCl6:Sb3+, the octahedral tilting distortion increases the electronic isolation of the In/Sb-centered octahedra thus facilitating electron and hole localization on Sb3+ sites, leading to bright photoluminescence. The distorted crystal structure also leads to a larger Stokes shift (1.29 eV) and a corresponding red shift of the emission peak (λmax = 522 nm) compared to the more symmetric Cs2NaInCl6:Sb3+ (Stokes shift ≈ 0.94 eV, λmax = 445 nm).

Safety concerns reported by consumers, manufacturers and healthcare professionals: A detailed evaluation of opioid-related adverse drug reactions in the FDA database over 15 years.

To perform an in-depth analysis of opioid-related ADRs reported by consumers, manufacturers and healthcare professionals. Delving into the depth and breadth of reported opioid-related adverse drug reactions (ADRs) provides an opportunity to strategize better clinical management and alleviate safety concerns. Retrospective pharmacovigilance disproportionality analysis for opioid-related ADRs in the FDA Adverse Event Reporting System (FAERS) database was performed. Detailed analysis of patient (sex, age) and report (year of report; reporter: healthcare worker vs consumer) characteristics were conducted using reports from 2004 quarter 1 to 2018 quarter 4. Reporting odds ratios and confidence intervals (RORs,CI) were calculated. Of the 1 916 674 ADR reports, 300 985 indicated opioids as the primary medication. There was a surge in opioid-related ADRs reported in 2018 with six times more reports compared to 2004 and twice the number of reports compared to 2017. The largest ROR among the 20 common ADRs was depression and suicide-self-injury (ROR 3.12, 95% CI 3.01-3.22) for reports in age group ≥65 compared to age group 18 to 64, and lack of efficacy (ROR 6.80, 95% CI 6.61-7.00) for males compared to females. ADRs with the largest RORs for consumers included lack of efficacy/effect (ROR 3.37, 95% CI 3.28-3.46), administration site reactions (ROR 3.21, 95% CI 3.11-3.32), depression and suicide self-injury (ROR 2.26, 95% CI 2.14-2.38) compared to healthcare professionals. Important aspects of opioid ADR voluntary reporting included suicidal ideation in elderly patients and lack of efficacy, especially in male patients. This examination provides insight to better manage safety concerns of opioids.

Isolation and maintenance of Batrachochytrium salamandrivorans cultures.

Discovered in 2013, the chytrid fungus Batrachochytrium salamandrivorans (Bsal) is an emerging amphibian pathogen that causes ulcerative skin lesions and multifocal erosion. A closely related pathogen, B. dendrobatidis (Bd), has devastated amphibian populations worldwide, suggesting that Bsal poses a significant threat to global salamander biodiversity. To expedite research into this emerging threat, we seek to standardize protocols across the field so that results of laboratory studies are reproducible and comparable. We have collated data and experience from multiple labs to standardize culturing practices of Bsal. Here we outline common culture practices including a medium for standardized Bsal growth, standard culturing protocols, and a method for isolating Bsal from infected tissue.

Assessing Adverse Drug Reactions from Psychotropic Medications Reported to the U.S. Food and Drug Administration in Older Adults.

OBJECTIVE: Identify trends in adverse drug reactions (ADRs) reported to the U.S. Food and Drug Administration's Adverse Event Reporting System in three subpopulations of older adults (ages 55-64, 65-74, 75+) receiving psychotropic medications. METHODS: Almost 12 years of ADR reports were compiled for adults over 55 years of age receiving psychotropic medications with known side effect profiles. A comparison of the frequency of ADRs reported, odds ratios (ORs), and 95% confidence intervals (CIs) between subpopulations to the whole population of patients aged 55+ was conducted. RESULTS: ADRs reported in three subpopulations of older adults differed significantly when receiving the same psychotropic medications. For example, reports of increased blood glucose (OR, 1.8, CI, 1.4-2.2) were all significantly increased in the youngest population (55-64). CONCLUSION: Current classification of age greater than 65 years when evaluating likely ADRs in older adults using psychotropic medications may be inadequate and require further assessment by subpopulations of older adults.