Vaccination induces broadly neutralizing antibody precursors to HIV gp41.

A key barrier to the development of vaccines that induce broadly neutralizing antibodies (bnAbs) against human immunodeficiency virus (HIV) and other viruses of high antigenic diversity is the design of priming immunogens that induce rare bnAb-precursor B cells. The high neutralization breadth of the HIV bnAb 10E8 makes elicitation of 10E8-class bnAbs desirable; however, the recessed epitope within gp41 makes envelope trimers poor priming immunogens and requires that 10E8-class bnAbs possess a long heavy chain complementarity determining region 3 (HCDR3) with a specific binding motif. We developed germline-targeting epitope scaffolds with affinity for 10E8-class precursors and engineered nanoparticles for multivalent display. Scaffolds exhibited epitope structural mimicry and bound bnAb-precursor human naive B cells in ex vivo screens, protein nanoparticles induced bnAb-precursor responses in stringent mouse models and rhesus macaques, and mRNA-encoded nanoparticles triggered similar responses in mice. Thus, germline-targeting epitope scaffold nanoparticles can elicit rare bnAb-precursor B cells with predefined binding specificities and HCDR3 features.

Glycans Function as Anchors for Antibodies and Help Drive HIV Broadly Neutralizing Antibody Development.

Apex broadly neutralizing HIV antibodies (bnAbs) recognize glycans and protein surface close to the 3-fold axis of the envelope (Env) trimer and are among the most potent and broad Abs described. The evolution of apex bnAbs from one donor (CAP256) has been studied in detail and many Abs at different stages of maturation have been described. Using diverse engineering tools, we investigated the involvement of glycan recognition in the development of the CAP256.VRC26 Ab lineage. We found that sialic acid-bearing glycans were recognized by germline-encoded and somatically mutated residues on the Ab heavy chain. This recognition provided an "anchor" for the Abs as the core protein epitope varies, prevented complete neutralization escape, and eventually led to broadening of the response. These findings illustrate how glycan-specific maturation enables a human Ab to cope with pathogen escape mechanisms and will aid in optimization of immunization strategies to induce V2 apex bnAb responses.

A Prominent Site of Antibody Vulnerability on HIV Envelope Incorporates a Motif Associated with CCR5 Binding and Its Camouflaging Glycans.

The dense patch of high-mannose-type glycans surrounding the N332 glycan on the HIV envelope glycoprotein (Env) is targeted by multiple broadly neutralizing antibodies (bnAbs). This region is relatively conserved, implying functional importance, the origins of which are not well understood. Here we describe the isolation of new bnAbs targeting this region. Examination of these and previously described antibodies to Env revealed that four different bnAb families targeted the (324)GDIR(327) peptide stretch at the base of the gp120 V3 loop and its nearby glycans. We found that this peptide stretch constitutes part of the CCR5 co-receptor binding site, with the high-mannose patch glycans serving to camouflage it from most antibodies. GDIR-glycan bnAbs, in contrast, bound both (324)GDIR(327) peptide residues and high-mannose patch glycans, which enabled broad reactivity against diverse HIV isolates. Thus, as for the CD4 binding site, bnAb effectiveness relies on circumventing the defenses of a critical functional region on Env.

Early Antibody Lineage Diversification and Independent Limb Maturation Lead to Broad HIV-1 Neutralization Targeting the Env High-Mannose Patch.

The high-mannose patch on HIV Env is a preferred target for broadly neutralizing antibodies (bnAbs), but to date, no vaccination regimen has elicited bnAbs against this region. Here, we present the development of a bnAb lineage targeting the high-mannose patch in an HIV-1 subtype-C-infected donor from sub-Saharan Africa. The Abs first acquired autologous neutralization, then gradually matured to achieve breadth. One Ab neutralized >47% of HIV-1 strains with only ∼11% somatic hypermutation and no insertions or deletions. By sequencing autologous env, we determined key residues that triggered the lineage and participated in Ab-Env coevolution. Next-generation sequencing of the Ab repertoire showed an early expansive diversification of the lineage followed by independent maturation of individual limbs, several of them developing notable breadth and potency. Overall, the findings are encouraging from a vaccine standpoint and suggest immunization strategies mimicking the evolution of the entire high-mannose patch and promoting maturation of multiple diverse Ab pathways.

Identification of Common Features in Prototype Broadly Neutralizing Antibodies to HIV Envelope V2 Apex to Facilitate Vaccine Design.

Broadly neutralizing antibodies (bnAbs) directed to the V2 apex of the HIV envelope (Env) trimer isolated from individual HIV-infected donors potently neutralize diverse HIV strains, but strategies for designing immunogens to elicit bnAbs have not been identified. Here, we compared four prototypes (PG9, CH01, PGT145, and CAP256.VRC26.09) of V2 apex bnAbs and showed that all recognized a core epitope of basic V2 residues and the glycan-N160. Two prototype bnAbs were derived from VH-germlines that were 99% identical and used a common germline D-gene encoded YYD-motif to interact with the V2-epitope. We identified isolates that were neutralized by inferred germline (iGL) versions of three of the prototype bnAbs. Soluble Env derived from one of these isolates was shown to form a well-ordered Env trimer that could serve as an immunogen to initiate a V2-apex bnAb response. These studies illustrate a strategy to transition from panels of bnAbs to vaccine candidates.

HBV reactivation in HBsAg-/HBcAb+ rheumatoid arthritis patients receiving biologic/targeted synthetic DMARDs.

BACKGROUND: Rheumatoid arthritis (RA) patients seropositive for hepatitis B core antibody (HBcAb) and negative for hepatitis B surface antigen (HBsAg) are at risk of hepatitis B virus (HBV) reactivation when treated with biologic or targeted synthetic (b/ts) disease-modifying antirheumatic drugs (DMARDs). The study aims to investigate the risk in this population. METHODS: From January 2004 through December 2020, 1068 RA patients undergoing b/tsDMARDs therapy and 416 patients with HBsAg-/HBcAb+ were enrolled. Factors associated with HBV reactivation were analysed. RESULTS: During 2845 person-years of follow-up, 27 of 416 (6.5%,9.5 per 1000 person-years) patients developed HBV reactivation, with a cumulative rate of HBV reactivation of 3.5% at 5 years, 6.1% at 10 years and 24.2% at 17 years. The median interval from beginning b/tsDMARDs to HBV reactivation was 85 months (range: 9-186 months). The risk of HBV reactivation varied by type of b/tsDMARD, with rituximab having the highest risk (incidence rate: 48.3 per 1000 person-years), followed by abatacept (incidence rate: 24.0 per 1000 person-years). In multivariate analysis, rituximab (adjusted hazard ratio [aHR]: 15.77, 95% confidence interval [CI]: 4.12-60.32, p = .001), abatacept (aHR: 9.30, 1.83-47.19, p = .007), adalimumab (aHR: 3.86, 1.05-14.26, p = .04) and negative baseline HBV surface antibody (anti-HBs, <10 mIU/mL) (aHR: 3.89, 1.70-8.92, p < .001) were independent risk factors for HBV reactivation. CONCLUSION: HBsAg-/HBcAb+ RA patients are susceptible to HBV reactivation during b/tsDMARD therapy. Those with negative baseline anti-HBs and those on certain b/tsDMARDs, such as rituximab, abatacept and adalimumab, have high reactivation risks. Risk stratification and management should be based on the patient's baseline anti-HBs titre and type of therapy.

Follistatin mediates learning and synaptic plasticity via regulation of Asic4 expression in the hippocampus.

The biological mechanisms underpinning learning are unclear. Mounting evidence has suggested that adult hippocampal neurogenesis is involved although a causal relationship has not been well defined. Here, using high-resolution genetic mapping of adult neurogenesis, combined with sequencing information, we identify follistatin (Fst) and demonstrate its involvement in learning and adult neurogenesis. We confirmed that brain-specific Fst knockout (KO) mice exhibited decreased hippocampal neurogenesis and demonstrated that FST is critical for learning. Fst KO mice exhibit deficits in spatial learning, working memory, and long-term potentiation (LTP). In contrast, hippocampal overexpression of Fst in KO mice reversed these impairments. By utilizing RNA sequencing and chromatin immunoprecipitation, we identified Asic4 as a target gene regulated by FST and show that Asic4 plays a critical role in learning deficits caused by Fst deletion. Long-term overexpression of hippocampal Fst in C57BL/6 wild-type mice alleviates age-related decline in cognition, neurogenesis, and LTP. Collectively, our study reveals the functions for FST in adult neurogenesis and learning behaviors.

Broadly neutralizing HIV antibodies define a glycan-dependent epitope on the prefusion conformation of gp41 on cleaved envelope trimers.

Broadly neutralizing HIV antibodies are much sought after (a) to guide vaccine design, both as templates and as indicators of the authenticity of vaccine candidates, (b) to assist in structural studies, and (c) to serve as potential therapeutics. However, the number of targets on the viral envelope spike for such antibodies has been limited. Here, we describe a set of human monoclonal antibodies that define what is, to the best of our knowledge, a previously undefined target on HIV Env. The antibodies recognize a glycan-dependent epitope on the prefusion conformation of gp41 and unambiguously distinguish cleaved from uncleaved Env trimers, an important property given increasing evidence that cleavage is required for vaccine candidates that seek to mimic the functional HIV envelope spike. The availability of this set of antibodies expands the number of vaccine targets on HIV and provides reagents to characterize the native envelope spike.

Design of Intelligent Protective Composite Material with Stress Rate Sensitivity, Strong Interface Adhesion, and Recyclability.

Poly(dimethyl siloxane) (PDMS) elastomers play a significant role in smart materials, actuators, and flexible electronics. However, current PDMS lacks adhesion abilities and intelligent responsive properties, which limit its further application. In this study, the polydimethylsiloxane-ureidopyrimidinone impact hardening polymer (PDMS-UI) composites are manufactured by a dual cross-linking compositing tactic. PDMS, a chemically stable cross-linked network, acts as a framework owing to its excellent mechanical strength, whereas UI, a reversible dynamic physically cross-linked network with quadruple hydrogen bonding, endows the PDMS-UI with excellent self-healing ability (efficiency > 90%) and energy absorption (75.23%). Impressively, owing to multivalent hydrogen bonds, the PDMS-UI exhibits superior adhesion performance: the adhesion strength on various substrates exceed 150 kPa and that on the Ferrum substrate reaches 570 kPa. These outstanding properties make the PDMS-UI a potential candidate for application in both well-developed fields, such as, wearable protective materials, artificial skin and soft robotics.

Rapid elicitation of broadly neutralizing antibodies to HIV by immunization in cows.

No immunogen to date has reliably elicited broadly neutralizing antibodies to HIV in humans or animal models. Advances in the design of immunogens that antigenically mimic the HIV envelope glycoprotein (Env), such as the soluble cleaved trimer BG505 SOSIP, have improved the elicitation of potent isolate-specific antibody responses in rabbits and macaques, but so far failed to induce broadly neutralizing antibodies. One possible reason for this failure is that the relevant antibody repertoires are poorly suited to target the conserved epitope regions on Env, which are somewhat occluded relative to the exposed variable epitopes. Here, to test this hypothesis, we immunized four cows with BG505 SOSIP. The antibody repertoire of cows contains long third heavy chain complementary determining regions (HCDR3) with an ultralong subset that can reach more than 70 amino acids in length. Remarkably, BG505 SOSIP immunization resulted in rapid elicitation of broad and potent serum antibody responses in all four cows. Longitudinal serum analysis for one cow showed the development of neutralization breadth (20%, n = 117 cross-clade isolates) in 42 days and 96% breadth (n = 117) at 381 days. A monoclonal antibody isolated from this cow harboured an ultralong HCDR3 of 60 amino acids and neutralized 72% of cross-clade isolates (n = 117) with a potent median IC50 of 0.028 µg ml-1. Breadth was elicited with a single trimer immunogen and did not require additional envelope diversity. Immunization of cows may provide an avenue to rapidly generate antibody prophylactics and therapeutics to address disease agents that have evolved to avoid human antibody responses.

How Nitrogen and Sulfur Doping Modified Material Structure, Transformed Oxidation Pathways, and Improved Degradation Performance in Peroxymonosulfate Activation.

Current research has widely applied heteroatom doping for the promotion of catalyst activity in peroxymonosulfate (PMS) systems; however, the relationship between heteroatom doping and stimulated activation mechanism transformation is not fully understood. Herein, we introduce nitrogen and sulfur doping into a Co@rGO material for PMS activation to degrade tetracycline (TC) and systematically investigate how heteroatom doping transformed the activation mechanism of the original Co@rGO/PMS system. N was homogeneously inserted into the reduced graphene oxide (rGO) matrix of Co@rGO, inducing a significant increase in the degradation efficiency without affecting the activation mechanism transformation. Additionally, S doping converted Co3O4 to Co4S3 in Co@rGO and transformed the cooperative oxidation pathway into a single non-radical pathway with stronger intensity, which led to a higher stability against environmental interferences. Notably, based on density functional theory (DFT) calculations, we demonstrated that Co4S3 had a higher energy barrier for PMS adsorption and cleavage than Co3O4, and therefore, the radical pathway was not easily stimulated by Co4S3. Overall, this study not only illustrated the improvement due to the heteroatom doping of Co@rGO for TC degradation in a PMS system but also bridged the knowledge gap between the catalyst structure and degradation performance through activation mechanism transformation drawn from theoretical and experimental analyses.

Identification and management of contraindicated drug-drug interactions through pharmaceutical care programs: Experience in direct-acting antivirals therapy.

BACKGROUND/PURPOSE: To investigate the impact of pharmaceutical care programs for the management of contraindicated drug-drug interactions (DDIs) in direct-acting antivirals (DAAs) therapy. METHODS: A prospective observational study was performed at Dalin Tzu Chi Hospital between January 2018 and December 2019. Pharmacists screened DDIs for all hepatitis C patients before DAA therapy. The study outcome included the frequency of contraindicated DDIs, acceptance rate, and cost avoidance of the pharmaceutical care program. RESULTS: A total of 1053 patients were enrolled in the study, with a mean age of 67.1 ± 11.9 years. Most patients received therapy with sofosbuvir/ledipasvir (37.1%; n = 391), elbasvir/grazoprevir (23.8%; n = 251), or glecaprevir/pibrentasvir (21.1%; n = 222). A total of 796 (75.6%) patients received at least one co-medication, with the average number of co-medications being 5.2 per patient (SD: 4.4/patient). In total, 1356 DDIs were identified, with the average DDIs per patient of 1.3 (SD: 1.7). For patients with contraindicated DDIs (2%, n = 102), statins and amiodarone were the most common co-medications. Physicians often accepted pharmacists' recommendations (acceptance rate of 72.5%) or withheld co-medication to avoid severe adverse drug events (ADEs). The estimated cost avoidance of preventable ADEs was USD 14,033 for contraindicated DDIs with pharmaceutical care programs. CONCLUSION: The implementation of pharmaceutical care programs in DAA therapy provides a favorable outcome and substantial cost avoidance.

Studies of Mercaptosuccinic Acid-Crosslinked Chitosan Hydrogel with Grafted Cinnamaldehyde and Silver Nanoparticles for Antibacterial Biomedical Application.

For the effective clinical antibacterial application of biomaterials, such as for wound management and tissue repair, the biomaterials need to show proper antibacterial capability as well as non-cytotoxicity. Furthermore, the material needs to have suitable mechanical characteristics for further medical use. Chitosan hydrogel is a potential candidate for various antibacterial biomedical applications due to its amine functionalities that lead to antimicrobial characteristics. Nevertheless, its antimicrobial capability is dependent upon the degree of protonation of amine groups caused by the pH value. Moreover, its mechanical compressive strength may not be high enough for clinical use if not chemically or physically crosslinked. This study utilized a novel chemical crosslinker, mercaptosuccinic acid, to improve its mechanical characteristics. The natural antibacterial agent, cinnamaldehyde, was grafted onto the crosslinked chitosan to improve its antimicrobial capability. Meanwhile, to take advantage of the thiol functionality in the mercaptosuccinic acid, the bactericidal silver nanoparticles were incorporated through silver-thiol covalent bounding. NMR analyses indicated the chitosan was successfully mercaptosuccinic acid-crosslinked and grafted with cinnamaldehyde at different ratios. Combined the results from the mechanical assessment, swelling experiments, antimicrobial assessment, and cytotoxicity assay, the chitosan hydrogel with the highest crosslinked degree and grafted with cinnamaldehyde and silver nanoparticles is of great promise for further clinical uses.

Genome-wide identification and functional characterization of LEA genes during seed development process in linseed flax (Linum usitatissimum L.).

BACKGROUND: LEA proteins are widely distributed in the plant and animal kingdoms, as well as in micro-organisms. LEA genes make up a large family and function in plant protection against a variety of adverse conditions. RESULTS: Bioinformatics approaches were adopted to identify LEA genes in the flax genome. In total, we found 50 LEA genes in the genome. We also conducted analyses of the physicochemical parameters and subcellular location of the genes and generated a phylogenetic tree. LuLEA genes were unevenly mapped among 15 flax chromosomes and 90% of the genes had less than two introns. Expression profiles of LuLEA showed that most LuLEA genes were expressed at a late stage of seed development. Functionally, the LuLEA1 gene reduced seed size and fatty acid contents in LuLEA1-overexpressed transgenic Arabidopsis lines. CONCLUSION: Our study adds valuable knowledge about LEA genes in flax which can be used to improve related genes of seed development.

The amino acid variants in HLA II molecules explain the major association with adult-onset Still's disease in the Han Chinese population.

Adult-onset Still's disease (AOSD) is a rare autoinflammatory disease with systemic involvement, and its pathophysiology remains unclear. Genome-wide association studies (GWAS) in the Chinese population have revealed an association between AOSD and the major histocompatibility complex (MHC) locus; however, causal variants in the MHC remain undetermined. In the present study, we identified independent amino-acid polymorphisms in human leukocyte antigen (HLA) molecules that are associated with Han Chinese patients with AOSD by fine-mapping the MHC locus. Through conditional analyses, we identified position 34 in HLA-DQα1 (p = 1.44 × 10-14) and Asn in HLA-DRß1 position 37 (p = 5.12 × 10-11) as the major determinants for AOSD. Moreover, we identified the associations for three main HLA class II alleles: HLA-DQB1*06:02 (OR = 2.70, p = 3.02 × 10-14), HLA-DRB1*15:01 (OR = 2.44, p = 3.66 × 10-13), and HLA-DQA1*01:02 (OR = 1.97, p = 1.09 × 10-9). This study reveals the relationship between functional variations in the class II HLA region and AOSD, implicating the MHC locus in the pathogenesis of AOSD.

Nuciferine prevents bone loss by disrupting multinucleated osteoclast formation and promoting type H vessel formation.

Recently, type H vessels were reported to couple angiogenesis and osteogenesis during osteoclastogenesis, and tartrate-resistant acid phosphatase (Trap)+ preosteoclasts were found to secrete increased PDGF-BB to promote type H vessel formation. Therefore, utilization of type H vessels may be a strategy to treat diseases involving bone loss. In the present study, we found that nuciferine, a natural bioactive compound, has various effects, including inhibiting osteoclastogenesis and promoting type H vessel formation. Nuciferine inhibited osteoclastogenesis and bone resorption but increased the relative number of Trap+ preosteoclasts. Nuciferine restrained the expression of osteoclast-specific genes and proteins, promoted PDGF-BB production and potentiated related angiogenic activities by inhibiting the MAPK and NF-κB signaling pathways in vitro. We confirmed the bone-protective effects of nuciferine in ovariectomized mice and found that nuciferine treatment increased the PDGF-BB concentration and the number of type H vessels in the femur. In conclusion, our results demonstrated that nuciferine can decrease multinucleated osteoclast formation and promote type H vessel formation through preservation of Trap+ preosteoclasts via inhibition of the MAPK and NF-κB signaling pathways and may be an excellent agent for the treatment of diseases involving bone loss.

Barrier performance and biodegradability of antibacterial poly(butylene adipate-co-terephthalate) nanocomposites reinforced with a new MWCNT-ZnO nanomaterial.

A new nanomaterial or nano-filler in the form of multiwalled carbon nanotube-zinc oxide (MWCNT-ZnO) was synthesized for the purpose of modifying poly(butylene adipate-co-terephthalate) (PBAT) and its derivative (modified PBAT or MPBAT) through a melt-blending method (MPBAT was obtained by introducing maleic anhydride groups into PBAT). The effect of the new nano-filler on the properties of resultant nanocomposites was determined from the characterization of mechanical properties, morphology, crystallinity, thermal stability, barrier properties, hydrophilicity, conductivity, antibacterial property, and biodegradability. The results showed that MPBAT nanocomposites had stronger mechanical properties, better barrier properties, and higher electrical conductivity than PBAT nanocomposites. Scanning electron microscopy illustrated that MWCNT-ZnO had better compatibility with MPBAT than with PBAT. At 0.2% MWCNT-ZnO, the MPBAT/MWCNT-ZnO nanocomposite film exhibited the greatest mechanical properties (17.74% increase in tensile strength, 22.17% in yield strength, and 14.29% in elongation at break). When the MWCNT-ZnO content was 0.4%, the nanocomposite film demonstrated the best water vapor barrier ability (an increase of 30.4%). The MPBAT/MWCNT-ZnO film with 0.6% MWCNT-ZnO turned out to have the best oxygen barrier performance (an increase of 130% relative to pure PBAT). It was shown from the results of antibacterial evaluation that the new nanomaterial could impart PBAT and MPBAT with antibacterial activity. The biodegradability tests indicated that an MWCNT-ZnO content of 0.2% could slightly reduce the biodegradability, and when the content was higher than 0.2%, the weight loss rate would increase.

Disseminated intravascular coagulation in Stevens-Johnson syndrome and toxic epidermal necrolysis.

BACKGROUND: Patients with Stevens-Johnson syndrome (SJS)/toxic epidermal necrolysis (TEN) have high mortality rates. Disseminated intravascular coagulation has been reported in SJS/TEN patients. The influence of this lethal complication in patients with SJS/TEN is not well known. OBJECTIVE: This study aimed to investigate the risk and outcomes of disseminated intravascular coagulation in patients with SJS/TEN. METHODS: We analyzed the disseminated intravascular coagulation profiles of patients receiving a diagnosis of SJS/TEN between 2010 and 2019. RESULTS: We analyzed 150 patients with SJS/TEN (75 with SJS, 22 with overlapping SJS/TEN, and 53 with TEN) and their complete disseminated intravascular coagulation profiles. Disseminated intravascular coagulation was diagnosed in 32 patients (21.3%), primarily those with TEN. It was significantly associated with systemic complications, including gastrointestinal bleeding, respiratory failure, renal failure, liver failure, infection, and bacteremia. Additionally, SJS/TEN patients with disseminated intravascular coagulation had elevated procalcitonin levels. Among patients with SJS/TEN, disseminated intravascular coagulation was associated with a greater than 10-fold increase in mortality (78.1% vs 7%). LIMITATIONS: The study limitations include small sample size and a single hospital system. CONCLUSION: Disseminated intravascular coagulation is a potential complication of SJS/TEN and associated with higher mortality. Early recognition and appropriate management of this critical complication are important for patients with SJS/TEN.