Unleashing the power of shark variable single domains (VNARs): broadly neutralizing tools for combating SARS-CoV-2

The pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) generated a joint global effort to develop vaccines and other treatments that could mitigate the negative effects and the rapid spread of the virus. Single-domain antibodies derived from various sources, including cartilaginous fish, camelids, and humans, have gained attention as promising therapeutic tools against coronavirus disease 2019. Shark-derived variable new antigen receptors (VNARs) have emerged as the smallest naturally occurring antigen-binding molecules. Here, we compile and review recent published studies on VNARs with the capacity to recognize and/or neutralize SARS-CoV-2. We found a close balance between the use of natural immune libraries and synthetic VNAR libraries for the screening against SARS-CoV-2, with phage display being the preferred display technology for the selection of VNARs against this virus. In addition, we discuss potential modifications and engineering strategies employed to improve the neutralization potential of VNARs, such as exploring fusion with the Fc domain of human Immunoglobulin G (IgG) to increase avidity and therapeutic potential. This research highlights the potential of VNARs as powerful molecular tools in the fight against infectious diseases

Effect of hydrosoluble polysaccharides of Macrocystis pyrifera on physiological and metabolic responses of Litopenaeus vannamei infected with Vibrio campbellii

Adult white shrimp Litopenaeus vannamei between 23 and 32 g of wet weight were injected or submerged in a hydrosoluble polysaccharides extract from Macrocystis pyrifera and infected with Vibrio campbellii. The infection decreased the oxygen consumption rate to 24 mg O2 h-1 kg-1 w.w., in shrimps of the control group, which were only infected with V. campbellii. Immunestimulated shrimps did not decrease their oxygen consumption rate at any hour p.i. (46 mg O2 h-1 kg-1 w.w.) maintaining it similar to the pre-injection group. Glucose level in the hemolymph of V. campbellii infected shrimps at two hours p.i. was significantly higher (p > 0.05) than the level of the pre-injection group. L. vannamei injected with the extract showed a significant decrease (p > 0.05) in their glucose level at 12 hours p.i., but at 24 hours p.i. it returned to normal level. Shrimps submerged in the extract showed no significant glucose level difference (p < 0.05). Lactate concentration in the hemolymph of the pre-injection group was 11.4 mg dL-1 , but adults injected with the extract had the lowest lactate levels throughout the experiment. Shrimps submerged in the extract decreased lactate levels at 6 and 12 hours p.i. but at 24 hours p.i. the level returned to 9.0 mg dL-1 . The total protein concentration in the hemolymph of pre-injection group was 115.3 mg mL-1 , shrimp injected with saline solution showed no significant differences (p < 0.05) compared to basal control; shrimps injected with V. campbellii had the lowest values of total proteins 6 hours p.i (p > 0.05) immunoestimulated shrimps showed an increase in their total proteins levels. This study concluded that administration of extract of M. pyrifera via injection and immersion in adult white shrimp can be used for immunostimulation purposes

Single domain antibodies: promising experimental and therapeutic tools in infection and immunity

Antibodies are important tools for experimental research and medical applications. Most antibodies are composed of two heavy and two light chains. Both chains contribute to the antigen-binding site which is usually flat or concave. In addition to these conventional antibodies, llamas, other camelids, and sharks also produce antibodies composed only of heavy chains. The antigen-binding site of these unusual heavy chain antibodies (hcAbs) is formed only by a single domain, designated VHH in camelid hcAbs and VNAR in shark hcAbs. VHH and VNAR are easily produced as recombinant proteins, designated single domain antibodies (sdAbs) or nanobodies. The CDR3 region of these sdAbs possesses the extraordinary capacity to form long fingerlike extensions that can extend into cavities on antigens, e.g., the active site crevice of enzymes. Other advantageous features of nanobodies include their small size, high solubility, thermal stability, refolding capacity, and good tissue penetration in vivo. Here we review the results of several recent proof-of-principle studies that open the exciting perspective of using sdAbs for modulating immune functions and for targeting toxins and microbes.Centro de Investigación y Desarrollo en Fermentaciones Industriale

Targeting Serous Epithelial Ovarian Cancer with Designer Zinc Finger Transcription Factors

Ovarian cancer is the leading cause of death among gynecological malignancies. It is detected at late stages when the disease is spread through the abdominal cavity in a condition known as peritoneal carcinomatosis. Thus, there is an urgent need to develop novel therapeutic interventions to target advanced stages of ovarian cancer. Mammary serine protease inhibitor (Maspin) represents an important metastasis suppressor initially identified in breast cancer. Herein we have generated a sequence-specific zinc finger artificial transcription factor (ATF) to up-regulate the Maspin promoter in aggressive ovarian cancer cell lines and to interrogate the therapeutic potential of Maspin in ovarian cancer. We found that although Maspin was expressed in some primary ovarian tumors, the promoter was epigenetically silenced in cell lines derived from ascites. Transduction of the ATF in MOVCAR 5009 cells derived from ascitic cultures of a TgMISIIR-TAg mouse model of ovarian cancer resulted in tumor cell growth inhibition, impaired cell invasion, and severe disruption of actin cytoskeleton. Systemic delivery of lipid-protamine-RNA nanoparticles encapsulating a chemically modified ATF mRNA resulted in inhibition of ovarian cancer cell growth in nude mice accompanied with Maspin re-expression in the treated tumors. Gene expression microarrays of ATF-transduced cells revealed an exceptional specificity for the Maspin promoter. These analyses identified novel targets co-regulated with Maspin in human short-term cultures derived from ascites, such as TSPAN12, that could mediate the anti-metastatic phenotype of the ATF. Our work outlined the first targeted, non-viral delivery of ATFs into tumors with potential clinical applications for metastatic ovarian cancers

Bacterial Diversity and the Geochemical Landscape in the Southwestern Gulf of Mexico

Marine sediments are an example of one of the most complex microbial habitats. These bacterial communities play an important role in several biogeochemical cycles in the marine ecosystem. In particular, the Gulf of Mexico has a ubiquitous concentration of hydrocarbons in its sediments, representing a very interesting niche to explore. Additionally, the Mexican government has opened its oil industry, offering several exploration and production blocks in shallow and deep water in the southwestern Gulf of Mexico (swGoM), from which there are no public results of conducted studies. Given the higher risk of large-scale oil spills, the design of contingency plans and mitigation activities before oil exploitation is of growing concern. Therefore, a bacterial taxonomic baseline profile is crucial to understanding the impact of any eventual oil spill. Here, we show a genus level taxonomic profile to elucidate the bacterial baseline, pointing out richness and relative abundance, as well as relationships with 79 abiotic parameters, in an area encompassing ∼150,000 km2, including a region where the exploitation of new oil wells has already been authorized. Our results describe for the first time the bacterial landscape of the swGoM, establishing a bacterial baseline “core” of 450 genera for marine sediments in this region. We can also differentiate bacterial populations from shallow and deep zones of the swGoM based on their community structure. Shallow sediments have been chronically exposed to aromatic hydrocarbons, unlike deep zones. Our results reveal that the bacterial community structure is particularly enriched with hydrocarbon-degrading bacteria in the shallow zone, where a greater aromatic hydrocarbon concentration was determined. Differences in the bacterial communities in the swGoM were also observed through a comprehensive comparative analysis relative to various marine sediment sequencing projects, including sampled sites from the Deep Water Horizon oil spill. This study in the swGoM provides clues to the bacterial population adaptation to the ubiquitous presence of hydrocarbons and reveals organisms such as Thioprofundum bacteria with potential applications in ecological surveillance. This resource will allow us to differentiate between natural conditions and alterations generated by oil extraction activities, which, in turn, enables us to assess the environmental impact of such activities

Ocean monitoring, observation network and modelling of the Gulf of Mexico by CIGOM

The tragic accident of the Macondo platform operated by British Petroleum (BP) unleashed in 2010 one of the largest oil spills in history, lasting over three months, spilling nearly 500 million liters of oil in one of the most biodiverse ocean regions. This accident revealed the technological deficiencies for the control of a spill in deep waters of the hydrocarbon industry. Simultaneously it showed important gaps in knowledge to predict the propagation and fate of the large volumes of hydrocarbons at depth and on the surface ocean and, more importantly, on their impact on the great ecosystem of the Gulf of Mexico. The necessity to understand and predict the transport, fate and ecosystem-level impacts of large oil spills in the southern Gulf of Mexico, a key region for oil exploration and extraction, led policymakers, scientists, and industry representatives from PEMEX (the Mexican oil company) to jointly launch an ocean observation project (2015-22) aimed to provide a multi-layered environmental baseline, develop a modern monitoring and computational modeling capacity and promote scientific understanding of the marine environment throughout the Mexican Exclusive Economic Zone (EEZ). The initiative, led by the Research Consortium for the Gulf of Mexico (CIGoM), brought together more than 300 multidisciplinary researchers from more than a two dozen institutions in Mexico and abroad, including the Centre for Scientific Research and Higher Education of Ensenada (CICESE) as the leading institution, the National Autonomous University of Mexico (UNAM), the Centre for Research and Advanced Studies of the National Polytechnic Institute (CINVESTAV) in Mérida, the Autonomous University of Baja California (UABC), and the Centre for Engineering and Industrial Development (CIDESI). Financial support was provided by the National Council for Science and Technology and the Ministry of Energy Hydrocarbon Fund

Single domain antibodies: promising experimental and therapeutic tools in infection and immunity

Antibodies are important tools for experimental research and medical applications. Most antibodies are composed of two heavy and two light chains. Both chains contribute to the antigen-binding site which is usually flat or concave. In addition to these conventional antibodies, llamas, other camelids, and sharks also produce antibodies composed only of heavy chains. The antigen-binding site of these unusual heavy chain antibodies (hcAbs) is formed only by a single domain, designated VHH in camelid hcAbs and VNAR in shark hcAbs. VHH and VNAR are easily produced as recombinant proteins, designated single domain antibodies (sdAbs) or nanobodies. The CDR3 region of these sdAbs possesses the extraordinary capacity to form long fingerlike extensions that can extend into cavities on antigens, e.g., the active site crevice of enzymes. Other advantageous features of nanobodies include their small size, high solubility, thermal stability, refolding capacity, and good tissue penetration in vivo. Here we review the results of several recent proof-of-principle studies that open the exciting perspective of using sdAbs for modulating immune functions and for targeting toxins and microbes

Evaluación de la actividad antibacteriana de diferentes especies de fitoplancton

The antibiotic activity of organic extracts from cultures of six species of phytoplankton, Synechococcus elongatus, Synechocystis sp., Amphiprora paludosa, Porphyridium cruentum, Chaetoceros muelleri and Dunaliella tertiolecta was examined. The bacteria used were Gram(-) strains, Escherichia coli, Pseudomonas aeruginosa, and Klebsiella pneumoniae, and the Gram(+) strains were Bacillus subtilis, Staphylococcus aureus, and Microccocus luteus. All extracts inhibited the growth of B. subtilis and effected the generation of inhibition halos, ranging in diameter from 7.06 to 15.23 mm, for several bacteria species. Wide-spectrum antibacterial activity was observed in extracts from S. elongatus, Synechocystis sp., A. paludosa, P. cruentum, and C. muelleri. Thus, this five phytoplankton species can be used to control bacteria

Conotoxin Patenting Trends in Academia and Industry

Sea snails of the genus Conus produce toxins that have been the subjects of numerous studies, projects, publications, and patents over the years. Since Conus toxins were discovered in the 1960s, their biological activity has been thought to have high pharmaceutical potential that could be explored beyond the limits of academic laboratories. We reviewed 224 patent documents related to conotoxins and conopeptides globally to determine the course that innovation and development has taken over the years, their primary applications, the technological trends over the last six years, and the leaders in the field, since the only previous patent review was performed in 2015 and focused in USA valid patents. In addition, we explored which countries/territories protect their inventions and patents and the most relevant collaborations among assignees. We also evaluated whether academia or pharmaceutical companies are the future of conotoxin research. We concluded that the 224 conotoxin patents reviewed in this study have more academic value than industrial value, which was noted by the number of active patents that have not yet been licensed and the contributions to medical research, especially as tools to study neuropathic pain, inflammation, immunology, drug design, receptor binding sites, cancer, neurotransmission, epilepsy, peptide biosynthesis, and depression. The aim of this review is to provide an overview of the current state of conotoxin patents, their main applications, and success based on the number of licensing and products in the market

Decreasing of bacterial content in Isochrysis galbana cultures by using some antibiotics

The axenic microalgae cultures are a difficult task and they are hard to maintain. Microalgae cultures with reduced bacterial load can be an option to axenic microalgae cultures to produce compounds with biotechnological and pharmaceutical potential. Also they can be used for cryopreservation and in biochemical, physiology, ecology and genetic studies. The aim of this study was to develop a protocol to decrease the bacterial load in an Isochrysis galbana culture, through washes by centrifugation and the administration of various antibiotics (ampicillin, neomycin, kanamycin, chloramphenicol, sulphate G418, streptomycin, and carbencillin), at several doses and combinations. The concentrations of heterotrophic bacteria and I. galbana cell densities were monitored daily. Maximum non-lethal concentration and lethal concentration 50% (LC50) were calculated. Individually, antibiotics and washes by centrifugation failed to reduce bacterial load, but their combination removed bacteria from the cultures. Peak survival (84.6 ± 1.4%) and reduction of bacterial load in I. galbana cultures were effected with the combination of 5 washes by centrifugation and administration of a cocktail, comprising ampicillin, kanamycin, neomycin, and streptomycin at 48 h. Values of maximum non-lethal concentration varied from 75 to 106 µg mL-1 and LC50 between 194 and 332 µg mL-1, thus, our protocol is an effective and rapid method of producing I. galbana cultures with reduced bacterial load.La obtención de cultivos axénicos es una tarea laboriosa y resultan difíciles de mantener. Los cultivos de microalgas con carga bacteriana reducida pueden ser una alternativa a los cultivos axénicos de microalgas para producir compuestos con potencial biotecnológico y farmaceútico. También éstos pueden ser usados para la criopreservación, y en estudios bioquímicos, fisiológicos, ecológicos y genéticos. El propósito de este estudio fue desarrollar un protocolo para reducir la carga bacteriana en cultivos de Isochrysis galbana por medio de lavados por centrifugación y la administración de varios antibióticos (ampicilina, neomicina, kanamicina, cloranfenicol, sulfato G418, estreptomicina y carbencilina), adicionados en varias dosis y combinaciones. Todos los tratamientos fueron realizados por triplicado. La concentración de bacterias heterotróficas y la densidad de células de I. galbana fue evaluada diariamente. Se calculó la concentración no letal máxima y la concentración letal (LC50). De forma individual, los antibióticos y los lavados por centrifugación no fueron efectivos para reducir la carga bacteriana, pero su combinación removió las bacterias de los cultivos. El máximo de sobrevivencia (84,6 ± 1,4%) y la reducción de la carga bacteriana en I. galbana fue efectiva con la combinación de 5 lavados por centrifugación y la administración de un coctel de ampicilina, kanamicina, neomicina, y estreptomicina por 48 h. Los valores de concentración no letal máxima varían entre 75 a 106 µg mL-1 y LC50 se encontró entre 194 y 332 µg mL-1, por lo anterior, este protocolo resulta ser un método efectivo y rápido para obtener cultivos de I. galbana con carga bacteriana baja