Lethal Agents Research Articles

An ICT-based organic framework for the fluorogenic detection of lethal pulmonary agent phosgene

A biphenyl-benzoimidazole based (BPCI) chemodosimeter has been developed for the rapid, sensitive and ratiometric detection of lethal pulmonary agent phosgene.

Lethal effects of mitochondria via microfluidics.

Tumor cells can respond to therapeutic agents by morphologic alternations including formation of tunneling nanotubes. Using tomographic microscope, which can detect the internal structure of cells, we found that mitochondria within breast tumor cells migrate to an adjacent tumor cell through a tunneling nanotube. To investigate the relationship between mitochondria and tunneling nanotubes, mitochondria were passed through a microfluidic device that mimick tunneling nanotubes. Mitochondria, through the microfluidic device, released endonuclease G (Endo G) into adjacent tumor cells, which we referred to herein as unsealed mitochondria. Although unsealed mitochondria did not induce cell death by themselves, they induced apoptosis of tumor cells in response to caspase-3. Importantly, Endo G-depleted mitochondria were ineffective as lethal agents. Moreover, unsealed mitochondria had synergistic apoptotic effects with doxorubicin in further increasing tumor cell death. Thus, we show that the mitochondria of microfluidics can provide novel strategies toward tumor cell death.

Prevalence of Bacterial Coinfections with Vibrio harveyi in the Industrialized Flow-through Aquaculture Systems in Hainan Province: A Neglected High-Risk Lethal Causative Agent to Hybrid Grouper.

Vibrio harveyi is one of the most serious bacterial pathogens to aquatic animals worldwide. Evidence is mounting that coinfections caused by multiple pathogens are common in nature and can alter the severity of diseases in marine animals. However, bacterial coinfections involving V. harveyi have received little attention in mariculture. In this study, the results of pathogen isolation indicated that bacterial coinfection was a common and overlooked risk for hybrid groupers (♀ Epinephelus polyphekadion × ♂ E. fuscoguttatus) reared in an industrialized flow-through pattern in Hainan Province. The artificial infection in hybrid groupers revealed that coinfections with V. harveyi strain GDH11385 (a serious lethal causative agent to groupers) and other isolated pathogens resulted in higher mortality (46.67%) than infection with strain GDH11385 alone (33.33%), whereas no mortality was observed in single infection with other pathogens. Furthermore, the intestine, liver and spleen of hybrid groupers are target organs for bacterial coinfections involving V. harveyi. Based on the infection patterns found in this study, we propose that V. harveyi may have a specific spatiotemporal expression pattern of virulence genes when infecting the host. Taken together, bacterial coinfection with V. harveyi is a neglected high-risk lethal causative agent to hybrid groupers in the industrialized flow-through aquaculture systems in Hainan Province.

Fluoroquinolone heteroresistance, antimicrobial tolerance, and lethality enhancement.

With tuberculosis, the emergence of fluoroquinolone resistance erodes the ability of treatment to interrupt the progression of MDR-TB to XDR-TB. One way to reduce the emergence of resistance is to identify heteroresistant infections in which subpopulations of resistant mutants are likely to expand and make the infections fully resistant: treatment modification can be instituted to suppress mutant enrichment. Rapid DNA-based detection methods exploit the finding that fluoroquinolone-resistant substitutions occur largely in a few codons of DNA gyrase. A second approach for restricting the emergence of resistance involves understanding fluoroquinolone lethality through studies of antimicrobial tolerance, a condition in which bacteria fail to be killed even though their growth is blocked by lethal agents. Studies with Escherichia coli guide work with Mycobacterium tuberculosis. Lethal action, which is mechanistically distinct from blocking growth, is associated with a surge in respiration and reactive oxygen species (ROS). Mutations in carbohydrate metabolism that attenuate ROS accumulation create pan-tolerance to antimicrobials, disinfectants, and environmental stressors. These observations indicate the existence of a general death pathway with respect to stressors. M. tuberculosis displays a variation on the death pathway idea, as stress-induced ROS is generated by NADH-mediated reductive stress rather than by respiration. A third approach, which emerges from lethality studies, uses a small molecule, N-acetyl cysteine, to artificially increase respiration and additional ROS accumulation. That enhances moxifloxacin lethality with M. tuberculosis in culture, during infection of cultured macrophages, and with infection of mice. Addition of ROS stimulators to fluoroquinolone treatment of tuberculosis constitutes a new direction for suppressing the transition of MDR-TB to XDR-TB.

BCG Vaccine-The Road Not Taken.

The Bacillus Calmette-Guérin (BCG) vaccine has been used for over one hundred years to protect against the most lethal infectious agent in human history, tuberculosis. Over four billion BCG doses have been given and, worldwide, most newborns receive BCG. A few countries, including the United States, did not adopt the WHO recommendation for routine use of BCG. Moreover, within the past several decades, most of Western Europe and Australia, having originally employed routine BCG, have discontinued its use. This review article articulates the impacts of those decisions. The suggested consequences include increased tuberculosis, increased infections caused by non-tuberculous mycobacteria (NTM), increased autoimmune disease (autoimmune diabetes and multiple sclerosis) and increased neurodegenerative disease (Parkinson’s disease and Alzheimer’s disease). This review also offers an emerged zoonotic pathogen, Mycobacterium avium ss. paratuberculosis (MAP), as a mostly unrecognized NTM that may have a causal role in some, if not all, of these diseases. Current clinical trials with BCG for varied infectious, autoimmune and neurodegenerative diseases have brought this century-old vaccine to the fore due to its presumed immuno-modulating capacity. With its historic success and strong safety profile, the new and novel applications for BCG may lead to its universal use–putting the Western World back onto the road not taken.

Ophthalmic Complications and Managements of Sulfur Mustard Exposure: A Narrative Review.

Sulfur mustard (SM) is a lethal chemical agent that affects many organs, particularly the eyes, respiratory system and skin. Even asymptomatic patients with documented SM vapor exposure may develop organ disorder many years later. Patients with even minor signs in the acute stage may experience late complications that necessitate surgery. Early decontamination and conservative measures could help the patients and decrease the complications. Despite decades of research, there is still no effective treatment for either acute or long-term SM-induced ocular complications. Even after multiple medications and surgical procedures, the majority of patients continue to have symptoms. For dry eye, punctual occlusion, autologous eye drops, and aggressive lubrication are used; for persistent epithelial defects (PED), tarsorrhaphy, amniotic membrane transplant, and stem cell transplantation are used; for total limbal stem cell deficiency (LSCD), living-related conjunctivolimbal allograft and keratolimbal allograft are used; for corneal vascularization, steroids, non-steroidal anti-inflammatory drugs, and anti-vascular endothelial growth factor prescribed; and for corneal opacities, corneal transplantation is done. Platelet rich plasma and topical drops containing stem cell transplantation for LSCD, photodynamic therapy paired with subconjunctival or topical anti-vascular endothelial growth factors for corneal vascularization, topical curcumin and topical ciclosporin-A for dry eye, and orbital fat-derived stem cells for PED are all alternative treatments that can be suggested. Despite the experimental and clinical research on the complications of SM exposure over the past decades, there is still no effective treatment for eye complications. However, supportive medical and surgical management has been applied with relatively good outcome.

Disposal, Destruction and Disarmament: Comparative Analysis of US Chemical Weapon and Weapons Plutonium Stockpile Reductions

The elimination of stockpiled weaponry constitutes a key step in arms control and disarmament processes, lending permanence and irreversibility to arms reductions. Yet it has proven challenging in practice. The destruction of advanced weapon components, like lethal chemical agents and the fissile materials from which nuclear weapons are constructed, is often technically complex and costly. To elucidate the dynamics of this back-end of arms control and disarmament processes, this article compares two representative cases involving analogous challenges but divergent outcomes: the nearly complete elimination of the US chemical weapon stockpile and stalled efforts to shrink the US weapons plutonium stockpile. Drawing from both engineering and organisation theory, technical and social distinctions between these efforts are assessed to identify key factors governing their outcomes. This analysis shows that the technical bases for stockpile reductions were broadly analogous between the two cases, and thus fail to explain their divergence. Rather, differing organisational characteristics among the responsible institutions proved decisive. These fostered either adaptive (in the chemical weapon case) or path-dependent (in the weapons plutonium case) organisational planning, influencing the ability of the responsible entities to pivot from stockpile maintenance to an unfamiliar reductions mission.

Abstract 5442: LP-184, a tumor site activated small molecule synthetic lethal therapeutic, is effective in central nervous system cancers

Abstract Blood-brain barrier (BBB) permeable agents effective against recurrent, chemotherapy-resistant central nervous system (CNS) tumors are urgently needed, particularly in Glioblastoma multiforme (GBM) and atypical teratoid/rhabdoid tumors (ATRT). These represent 2 extremely aggressive and lethal types of CNS malignancies sharing a median overall survival of 12-18 months and 5-year survival rate of 5 to 30% in the US. LP-184 has received orphan drug designation for the treatment of malignant gliomas. LP-184 is activated to a highly labile metabolite by Prostaglandin Reductase 1 (PTGR1) and has potential to be a potent therapeutic as a single agent for PTGR1-expressing malignancies. LP-184 was found to have nanomolar range potency (IC50 30-400 nM) against multiple human GBM cell lines and patient-derived neurospheres in vitro. Intravenous LP-184 induced complete and durable regression of pre-established subcutaneous U87 and M1123 GBM xenografts and prolonged survival of mice bearing orthotopic U87 and M1123 xenografts (p<0.0001). Activated LP-184 creates covalent DNA adducts (e.g. N3 of adenine) that are selectively repaired via ERRC-dependent nucleotide excision repair or by homologous recombination. Consistent with this, we observed 2-5X increase in cytotoxicity in U87, Mayo39, M1123 GBM cells treated with LP-184 in combination with the ERCC3 inhibitor Spironolactone relative to LP-184 alone. This supports LP-184’s function as a synthetic lethal agent in the presence of DNA repair deficiencies. > 50% of newly diagnosed GBMs fail to respond to standard of care temozolomide (TMZ) due to MGMT expression (i.e.unmethylated mgmt promoter) and essentially all GBMs ultimately develop TMZ resistance. Our in silico analyses and type of DNA adduct generated by LP-184 indicate that sensitivity to LP-184 is independent of MGMT expression and potentially higher in MGMT unmethylated cancers. This is supported by in vitro toxicity assays showing LP-184 IC50s of 46 nM in LN-18 (unmethylated mgmt) and 203 nM in U87 (hypermethylated mgmt) cell lines. Analysis of genes associated with LP-184 sensitivity in solid tumor cell lines revealed that expression of SMARCB1 is significantly anti-correlated to LP-184 sensitivity, suggesting that LP-184 will be effective in ATRTs and other tumors with SMARCB1 loss. LP-184 treatment induced tumor regression in mice implanted with SMARCB1 deficient CHLA06 ATRT subcutaneous xenografts, with 2 of 10 treated mice being virtually tumor-free after 2 cycles over 22 days. Pharmacokinetic analyses showed favorable in vivo BBB permeability (mouse brain/blood ratio=0.112) comparable to that reported for TMZ. LP-184 was also active in vitro against models of brain metastases from primary lung and breast cancers. These findings identify LP-184 as a promising new agent and support its further development for treating CNS tumors in adult and pediatric populations. Citation Format: Aditya Kulkarni. LP-184, a tumor site activated small molecule synthetic lethal therapeutic, is effective in central nervous system cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5442.

The use of UAV interceptors to increase the detection range of intruder drones

Various threats of terrorist attacks on the social infrastructure arise due to strengthening of terrorist organizations, both in the context of their coming to power in certain countries (Afghanistan), and their association with the drug business, which significantly increases the financing of terrorist structures, allowing them to acquire modern weapons. Unmanned aerial vehicles (UAVs) are cheap, readily available and capable of carrying containers of lethal agents, what make them a common means of terrorist attack. Effective protection of critical industrial facilities from UAV terrorist attacks is an important task for improving systems and means of electronic warfare against terrorism.
 This paper considers the possibility of detecting an UAV near a critically important industrial facility using small-sized radar stations (SRS) placed on board of UAV-interceptors. Typically, SRS are placed on board drones for radio mapping of the terrain, operational-tactical and reconnaissance combat missions, and rescue operations. The possibility of using SRS on board interceptor drones to detect intruder drones as an additional channel to a remote radar channel has not been considered anywhere before.
 The paper provides a review of existing small-sized radar stations (SRS) that can be used or are used on-board of UAVs, as well as a review of existing UAV-interceptors. It is shown that UAV-interceptors equipped with SRS can be used to fly around the area about a critical industrial facility, by analogy with overflights performed by multicopters around agricultural areas, with recharging in specially equipped places for this at different distances from the control center and from critical industrial facility.
 A method is proposed to increase the existing optical and acoustic channel for detecting an intruder drone by an order of magnitude, and the radar channel by 5 km, if not only small-sized radar, but also optoelectronic with the acoustic UAV detection system are installed on the UAV-interceptor with the integrated use of these channels with remote radar UAV detection system.

Досвід використання бойових отруйних речовин у повоєнні періоди та роки Другої світової війни

Надходження в арсенали озброєнь фосфорорганічних отруйних речовин (ОР) нервово-паралітичної дії знаменувало апогей розвитку хімічної зброї. У 1939 р. було отримано зарин, а наприкінці 1944 р. — зоман, що належали до нового класу смертельних ОР нервово-паралітичної дії й у багато разів перевершували за своєю токсичністю ОР часів Першої світової війни. Промислове виробництво зарину почалося в 1952 р. В середині 1961 р. у США почали виробляти малолетючу стійку фосфорорганічну ОР під шифром VХ, особливо небезпечну при потраплянні навіть невеликих кількостей її на шкіру. За роки Другої світової війни в США на 17 технологічних установках було вироблено 135 тис. т різних ОР, з яких більше половини припадало на іприт. Останнім було споряджено близько 5 млн снарядів і 1 млн хімічних авіаційних бомб. Результатом робіт у галузі ОР, що впливають на центральну нервову систему людини, стало детальне дослідження до 1962 р. 3-хінуклідинілового ефіру бензилової кислоти, що має шифр ВZ. Вона перебувала на озброєнні американської армії і в експериментальному варіанті застосовувалася у В’єтнамі. У післявоєнні роки в армії США на зміну старих речовин подразнюючої дії були прийняті нові речовини — СS і СR, що стали результатом спільних англо-американських досліджень. За подразнюючою дією речовина CS значно перевершує іританти часів Першої світової війни. У 1993 р. було прийнято Міжнародну конвенцію про заборону хімічної зброї, що набрала чинності 29 квітня 1997 р.

Proposed classifications of immunogenomic editing by cancers and pathogens.

Several evolutionary mechanisms exist between a lethal disease agent, such as a cancer or a pathogen, and the immune system of a surviving subpopulation of hosts. Immunogenomic editing is herein defined as the evolution of a lethal disease agent genome or the surviving carrier or host subpopulation immune system genomes. One type of immunogenomic editing called immunoediting has already been identified for cancer genomes. The effects of two other types of immunogenomic editing have been observed for pathogens and humans. However, these types of editing are only a few types of a much broader immunogenomic editing process, and some of the other types of immunogenomic editing have not been explicitly recognized. Immunogenomic editing can include seven types, and several types of immunogenomic editing have applications including analysis of subpopulation responses to cancers and pathogens. Applications would also include facilitating analysis of substantial subpopulation vulnerability differences to lethal pathogen epidemics. The need for quicker analysis of the actual transmission chains and the immunogenomic mechanisms for the faster spread of dangerously virulent pathogens can be expected to increase, since modern transportation technology can spread new pathogens very rapidly around the world.

Impact of nonthermal food processing techniques on mycotoxins and their producing fungi

AbstractMycotoxins are a significant threat to food safety and quality. Over the years, mycotoxins have been detected in almost all food and feed crops without any regional barrier. Conventional techniques for decontamination of mycotoxin involve physical, chemical, and biological methods, but these technologies often impact the quality of food in terms of changes in nutritional and sensory attributes. We examined the effects of nonthermal techniques on mycotoxins and their producing fungi to remove or reduce mycotoxin levels in food products without compromising food quality. Nonthermal technologies employ different lethal agents (including ozone, cold plasma, light, pressure, radiation, ultrasound, electric field, and magnetic field) to degrade mycotoxins while minimising product thermal exposure. However, the degradation pathway and toxicology of treated products need further research for a better understanding. With such food process development and optimisation efforts, food processors can employ various nonthermal technologies as tools for delivering consumer‐desired mycotoxin‐free food products with intact nutritional and sensory quality.

In Vitro Evaluation of Hydroalcoholic Extracts of Capparis spinosa, Ricinus communis, and Solanum luteum on Leishmania major (MRHO/IR/75/ER) Promastigotes

Background: Plant extracts or compounds derived from plants are a valuable source for finding new anti-leishmaniasis drugs. Objective: In this study, Capparis spinosa, Ricinus communis, and Solanum luteum were used as lethal agents for the promastigotes of Leishmania major parasites in the culture medium. Methods: Diluted extracts of 12.5, 100, and 500 mg/mL were prepared from medicinal plant dried extracts. Glucantime at a concentration of 500 mg/mL was used as a positive control. Results: For all three extracts, concentrations of 100 and 500 mg/mL could kill promastigotes at higher rates and speeds compared to other concentrations. The high concentrations of extracts (500 mg/mL) presented similar effects. According to the findings, hydroalcoholic extract of C. spinosa presented considerably lower antiparasitic effects, and S. luteum and R. communis extracts could kill most of the parasitic promastigotes at higher doses. The ANOVA test did not show any significant viability percentage difference of Leishmania extracts between different extract types. Conclusions: In this study, the lethal effects of R. communis and S. luteum hydroalcoholic extracts on L. major promastigotes were found to be stronger than the C. spinosa L. extract.

Autophagy as a Mechanism for Adaptive Prediction-Mediated Emergence of Drug Resistance.

Drug resistance is a major problem in treatment of microbial infections and cancers. There is growing evidence that a transient drug tolerant state may precede and potentiate the emergence of drug resistance. Therefore, understanding the mechanisms leading to tolerance is critical for combating drug resistance and for the development of effective therapeutic strategy. Through laboratory evolution of yeast, we recently demonstrated that adaptive prediction (AP), a strategy employed by organisms to anticipate and prepare for a future stressful environment, can emerge within 100 generations by linking the response triggered by a neutral cue (caffeine) to a mechanism of protection against a lethal agent (5-fluoroorotic acid, 5-FOA). Here, we demonstrate that mutations selected across multiple laboratory-evolved lines had linked the neutral cue response to core genes of autophagy. Across these evolved lines, conditional activation of autophagy through AP conferred tolerance, and potentiated subsequent selection of mutations in genes specific to overcoming the toxicity of 5-FOA. These results offer a new perspective on how extensive genome-wide genetic interactions of autophagy could have facilitated the emergence of AP over short evolutionary timescales to potentiate selection of 5-FOA resistance-conferring mutations.

Diatomaceous earth low-lethal dose effects on the fitness of entomopathogenic fungus, Beauveria bassiana, against two coleopteran stored product pests

Efficacy of different doses of the Beauveria bassiana-IRAN441C alone (66,125, 250, 500, 1000 mg conidia. Kg−1 grains) and combined with a low-lethal dose (LD25) of diatomaceous earth (DE) SilicoSec® as lethal agents were assessed against the adults of Callosobruchus maculatus (F.) (Chrysomelidae) on mung, and cowpeas, and Oryzaephilus surinamensis (L.) (Silvanidae) on wheat and barley seeds. In both species, mortality reached 60–73% in B. bassiana alone and 83–100% in fungus combined with the DE at the highest dose. A synergistic effect between B. bassiana conidia and the DE was confirmed. The DE low-lethal dose alters fungal mycosis and sporogenesis (conidia mL−1) rates in the infected cadavers. The adult populations of both species were suppressed desirably despite a decrease in the number of cadaver-derived mycosis and their spore production at the highest combination doses (1000 mg kg−1+ LD25 of DE). Seed type had no significant effect on mycosis and sporogenesis on both insects in several combination doses. The cadaver-derived aerial conidia germination rate was increased in the presence of DE low-lethal dose, but it declined by increasing the fungal dose. Type of commodity failed to affect the germination rate of O. surinamensis-derived conidia; however, the mung bean intensified this case for another insect. In both beetles, offspring's emergence was suppressed dose-dependently seven weeks after removing exposed parents to the lethal agents as well it was more in doses mixed with DE. The most significant reduction in progeny production of treated C. maculatus occurred on cowpeas and that of treated O. surinamensis on wheat seeds. Our findings demonstrate that DE's low-lethal dose enhances the virulence of B. bassiana in the various mixtures synergistically, and co-applications of the two substances were feasible. As well, the lethal agents' adverse effects were found to carry over onto both species' offspring during two-month storage time.

A self-degradable hydrogel sensor for a nerve agent tabun surrogate through a self-propagating cascade

SUMMARYNerve agents that irreversibly deactivate the enzyme acetylcholinesterase are extremely toxic weapons of mass destruction. Thus, developing methods to detect these lethal agents is important. To create an optical sensor for a surrogate of the nerve agent tabun, as well as a physical barrier that dissolves in response to this analyte, we devise a network hydrogel that decomposes via a self-propagating cascade. A Meldrums acid-derived linker is incorporated into a hydrogel that undergoes a declick reaction in response to thiols, thereby breaking network connections, which releases more thiols, propagating the response throughout the gel. A combination of chemical reactions triggered by the addition of the tabun mimic initiates the cascade. The dissolving barrier is used to release dyes, as well as nanocrystals that undergo a spontaneous aggregation. Thus, this sensing system for tabun generates a physical response and the delivery of chemical agents in response to an initial trigger.

Spectroscopic studies of binding interactions of 2-chloroethylphenyl sulphide with bovine serum albumin

Sulphur mustard is a lethal chemical warfare agent, known for its vesicant or blistering action on skin and mucous membrane. 2-chloroethylphenyl sulphide (CEPS) is a simulant of sulphur mustard. In the present study, the binding interaction of CEPS with bovine serum albumin (BSA) was investigated to determine its binding potential with skin proteins. The binding interactions studies were performed using UV–Vis absorbance, steady-state fluorescence, synchronous fluorescence, circular dichroism techniques. It is observed in UV–Vis absorption study, absorbance of BSA at 280 nm increases with a slight blue shift in the presence of CEPS indicated a complex formation between CEPS and BSA. Fluorescence quenching of emission intensity of BSA in the presence of CEPS indicated change in the microenvironment of fluorophores (Tryptophan residues). Stern-Volmer plot showed an inverse relationship between quenching (Ksv) and temperature. Thus, the quenching is operative via static quenching. The binding parameters suggested the role of non-covalent interactions and involvement of single set of equivalent binding sites. Change in thermodynamic parameters suggested that the binding is essentially enthalpy driven and spontaneous in nature. A synchronous fluorescence of BSA spectra in the presence of CEPS causes maximum change around the microenvironment of Tryptophan residues than Tyrosine residues. The intermolecular distance between the donor (BSA) and acceptor (CEPS) molecule was 3.5 nm as calculated from FRET analysis and indicated no significant transfer of energy between donor and acceptor. CD spectrum confirmed the changes in secondary structure of BSA upon binding with CEPS. The esterase enzyme activity of BSA in presence of CEPS showed a decrease in enzyme activity. The binding interactions were modeled in binding pockets using molecular docking calculations.

A Self-Degradable Hydrogel Sensor for a Nerve Agent Tabun Surrogate Through a Self-Propagating Cascade

SUMMARYNerve agents which irreversibly deactivate the enzyme acetylcholinesterase are extremely toxic weapons of mass destruction. Thus, developing methods to detect these lethal agents are important. To create an optical sensor for a surrogate of the nerve agent tabun, as well as a physical barrier that dissolves in response to this analyte, we devised a network hydrogel that decomposes via a self-propagating cascade. A Meldrum’s acid-derived linker was incorporated into a hydrogel which undergoes a declick reaction in response to thiols, thereby breaking network connections, which release more thiols; propagating the response throughout the gel. A combination of chemical reactions triggered by the addition of the tabun mimic initiates the cascade. The dissolving barrier was used to release dyes, as well as nanocrystals that undergo a spontaneous aggregation. Thus, this sensing system for tabun generates a physical response and the delivery of chemical agents in response to an initial trigger.

The genetic variation landscape of African swine fever virus reveals frequent positive selection and adaptive flexibility.

African swine fever virus (ASFV) is a lethal disease agent that causes high mortality in swine population and devastating loss in swine industries. The development of efficacious vaccines has been hindered by the gap in knowledge concerning genetic variation of ASFV and the genetic factors involved in host adaptation and virus-host interactions. In this study, we performed a meta-genetic study of ASFV aiming to profile the variation landscape and identify genetic factors with signatures of positive selection and relevance to host adaptation. Our data reveal a high level of genetic variability of ASFV shaped by both diversifying selection and selective sweep. The selection signatures are widely distributed across the genome with the diversifying selection falling within 29 genes and selection sweep within 25 genes, highlighting strong signals of adaptive evolution of ASFV. Further examination of the sequence properties reveals the link of the selection signatures with virus-host interactions and adaptive flexibility. Specifically, we discovered a site at 157th of the key antigen protein EP402R under diversifying selection, which is located in the cytotoxic T-cell epitope related to the low level of cross-reaction in T-cell response. Importantly, two multigene families MGF360 and MGF505, the host range factors of ASFV, exhibit divergent selection among the paralogous members, conferring sequence pools for genetic diversification and adaptive capability. By integrating the genes with selection signatures into a unified framework of interactions between ASFV and hosts, we showed that the genes are involved in multiple processes of host immune interaction and virus life cycles, and may play crucial roles in circumventing host defence systems and enhancing adaptive fitness. Our findings will allow enhanced understanding of genetic basis of rapid spreading and adaptation of ASFV among the hosts.

Molecular determinants of binding of non-oxime bispyridinium nerve agent antidote compounds to the adult muscle nAChR

Organophosphorus nerve agents (NAs) are the most lethal chemical warfare agents and have been used by state and non-state actors since their discovery in the 1930s. They covalently modify acetylcholinesterase, preventing the breakdown of acetylcholine (ACh) with subsequent loss of synaptic transmission, which can result in death. Despite the availability of several antidotes for OPNA exposure, none directly targets the nicotinic acetylcholine receptor (nAChR) mediated component of toxicity. Non-oxime bispyridinium compounds (BPDs) have been shown previously to partially counteract the effects of NAs at skeletal muscle tissue, and this has been attributed to inhibition of the muscle nAChR. Functional data indicate that, by increasing the length of the alkyl linker between the pyridinium moieties of BPDs, the antagonistic activity at nAChRs can be improved. Molecular dynamics simulations of the adult muscle nAChR in the presence of BPDs identified key residues likely to be involved in binding. Subsequent two-electrode voltage clamp recordings showed that one of the residues, εY131, acts as an allosteric determinant of BPD binding, and that longer BPDs have a greater stabilizing effect on the orthosteric loop C than shorter ones. The work reported will inform future design work on novel antidotes for treating NA exposure.