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2.
Adv Healthc Mater ; : e2304618, 2024 May 03.
Article in English | MEDLINE | ID: mdl-38700450

ABSTRACT

The tumor uptake of large non-targeted nanocarriers primarily occurs through passive extravasation, known as the enhanced permeability and retention (EPR) effect. Prior studies demonstrated improved tumor uptake and retention of 4-arm 40 kDa star polyethylene glycol (StarPEG) polymers for cancer imaging by adding prostate-specific membrane antigen (PSMA) targeting small molecule ligands. To test PSMA-targeted delivery and therapeutic efficacy, StarPEG nanodrugs with/without three copies of PSMA-targeting ligands, ACUPA, are designed and synthesized. For single-photon emission computed tomography (SPECT) imaging and therapy, each nanocarrier is labeled with 177Lu using DOTA radiometal chelator. The radiolabeled nanodrugs, [177Lu]PEG-(DOTA)1 and [177Lu]PEG-(DOTA)1(ACUPA)3, are evaluated in vitro and in vivo using PSMA+ PC3-Pip and/or PSMA- PC3-Flu cell lines, subcutaneous xenografts and disseminated metastatic models. The nanocarriers are efficiently radiolabeled with 177Lu with molar activities 10.8-15.8 MBq/nmol. Besides excellent in vitro PSMA binding affinity (kD = 51.7 nM), the targeted nanocarrier, [177Lu]PEG-(DOTA)1(ACUPA)3, demonstrated excellent in vivo SPECT imaging contrast with 21.3% ID/g PC3-Pip tumors uptake at 192 h. Single doses of 18.5 MBq [177Lu]PEG-(DOTA)1(ACUPA)3 showed complete resolution of the PC3-Pip xenografts observed up to 138 days. Along with PSMA-targeted excellent imaging contrast, these results demonstrated high treatment efficacy of [177Lu]PEG-(DOTA)1(ACUPA)3 for prostate cancer, with potential for clinical translation.

3.
bioRxiv ; 2024 Mar 20.
Article in English | MEDLINE | ID: mdl-38562834

ABSTRACT

New epitopes for immune recognition provide the basis of anticancer immunity. Due to the high concentration of extracellular adenosine triphosphate in the tumor microenvironment, we hypothesized that extracellular kinases (ectokinases) could have dysregulated activity and introduce aberrant phosphorylation sites on cell surface proteins. We engineered a cell-tethered version of the extracellular kinase CK2α, demonstrated it was active on cells under tumor-relevant conditions, and profiled its substrate scope using a chemoproteomic workflow. We then demonstrated that mice developed polyreactive antisera in response to syngeneic tumor cells that had been subjected to surface hyperphosphorylation with CK2α. Interestingly, these mice developed B cell and CD4+ T cell responses in response to these antigens but failed to develop a CD8+ T cell response. This work provides a workflow for probing the extracellular phosphoproteome and demonstrates that extracellular phosphoproteins are immunogenic even in a syngeneic system.

4.
bioRxiv ; 2024 Mar 14.
Article in English | MEDLINE | ID: mdl-38558995

ABSTRACT

The histone methyltransferase Polycomb repressive complex 2 (PRC2) is required for specification of the neural crest, and mis-regulation of the neural crest can cause severe congenital malformations. PRC2 is required for induction of the neural crest, but the embryonic, cellular, and molecular consequences of PRC2 activity after neural crest induction are incompletely understood. Here we show that Eed, a core subunit of PRC2, is required for craniofacial osteoblast differentiation and mesenchymal proliferation after induction of the neural crest. Integrating mouse genetics with single-cell RNA sequencing, our results reveal that conditional knockout of Eed after neural crest cell induction causes severe craniofacial hypoplasia, impaired craniofacial osteogenesis, and attenuated craniofacial mesenchymal cell proliferation that is first evident in post-migratory neural crest cell populations. We show that Eed drives mesenchymal differentiation and proliferation in vivo and in primary craniofacial cell cultures by regulating diverse transcription factor programs that are required for specification of post-migratory neural crest cells. These data enhance understanding of epigenetic mechanisms that underlie craniofacial development, and shed light on the embryonic, cellular, and molecular drivers of rare congenital syndromes in humans.

5.
bioRxiv ; 2024 Feb 28.
Article in English | MEDLINE | ID: mdl-38463958

ABSTRACT

Despite the success of BCMA-targeting CAR-Ts in multiple myeloma, patients with high-risk cytogenetic features still relapse most quickly and are in urgent need of additional therapeutic options. Here, we identify CD70, widely recognized as a favorable immunotherapy target in other cancers, as a specifically upregulated cell surface antigen in high risk myeloma tumors. We use a structure-guided design to define a CD27-based anti-CD70 CAR-T design that outperforms all tested scFv-based CARs, leading to >80-fold improved CAR-T expansion in vivo. Epigenetic analysis via machine learning predicts key transcription factors and transcriptional networks driving CD70 upregulation in high risk myeloma. Dual-targeting CAR-Ts against either CD70 or BCMA demonstrate a potential strategy to avoid antigen escape-mediated resistance. Together, these findings support the promise of targeting CD70 with optimized CAR-Ts in myeloma as well as future clinical translation of this approach.

6.
ACS Photonics ; 11(1): 301-309, 2024 Jan 17.
Article in English | MEDLINE | ID: mdl-38344384

ABSTRACT

As a result of their coherent interaction, two-dimensional periodic arrays of metallic nanostructures support collective modes commonly known as lattice resonances. Among them, out-of-plane lattice resonances, for which the nanostructures are polarized in the direction perpendicular to the array, are particularly interesting since their unique configuration minimizes radiative losses. Consequently, these modes present extremely high quality factors and field enhancements that make them ideal for a wide range of applications. However, for the same reasons, their excitation is very challenging and has only been achieved at oblique incidence, which adds a layer of complexity to experiments and poses some limitations on their usage. Here, we present an approach to excite out-of-plane lattice resonances in bipartite arrays under normal incidence. Our method is based on exploiting the electric-magnetic coupling between the nanostructures, which has been traditionally neglected in the characterization of arrays made of metallic nanostructures. Using a rigorous coupled dipole model, we demonstrate that this coupling provides a general mechanism to excite out-of-plane lattice resonances under normal incidence conditions. We complete our study with a comprehensive analysis of a potential implementation of our results using an array of nanodisks with the inclusion of a substrate and a coating. This work provides an efficient approach for the excitation of out-of-plane lattice resonances at normal incidence, thus paving the way for the leverage of the extraordinary properties of these optical modes in a wide range of applications.

7.
Nucleic Acids Res ; 52(4): 2078-2090, 2024 Feb 28.
Article in English | MEDLINE | ID: mdl-38261989

ABSTRACT

The partnership of DNA deaminase enzymes with CRISPR-Cas nucleases is now a well-established method to enable targeted genomic base editing. However, an understanding of how Cas9 and DNA deaminases collaborate to shape base editor (BE) outcomes has been lacking. Here, we support a novel mechanistic model of base editing by deriving a range of hyperactive activation-induced deaminase (AID) base editors (hBEs) and exploiting their characteristic diversifying activity. Our model involves multiple layers of previously underappreciated cooperativity in BE steps including: (i) Cas9 binding can potentially expose both DNA strands for 'capture' by the deaminase, a feature that is enhanced by guide RNA mismatches; (ii) after strand capture, the intrinsic activity of the DNA deaminase can tune window size and base editing efficiency; (iii) Cas9 defines the boundaries of editing on each strand, with deamination blocked by Cas9 binding to either the PAM or the protospacer and (iv) non-canonical edits on the guide RNA bound strand can be further elicited by changing which strand is nicked by Cas9. Leveraging insights from our mechanistic model, we create novel hBEs that can remarkably generate simultaneous C > T and G > A transitions over >65 bp with significant potential for targeted gene diversification.


Subject(s)
CRISPR-Associated Protein 9 , Cytidine Deaminase , Escherichia coli , Gene Editing , CRISPR-Associated Protein 9/metabolism , CRISPR-Cas Systems , Cytidine Deaminase/metabolism , DNA/genetics , Escherichia coli/metabolism , Mutation , RNA, Guide, CRISPR-Cas Systems , Humans , Animals
8.
Endosc Int Open ; 12(1): E155-E163, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38292591

ABSTRACT

Background and study aims There are rare data on the usefulness of endosonography-guided tissue acquisition (EUS-TA) in patients with pancreatic cystic lesions (PCLs). This study aimed to determine the accuracy of EUS-TA with ProCore 20G (PC20) for differentiating between mucinous neoplasia (MN) and non-MNs (n-MN) and identifying malignant PCLs, as well as its adverse events (AEs) in patients with PCLs without a classificatory diagnosis by imaging exams. Patients and methods In this observational, retrospective, single-center study, all patients with PCL who underwent EUS-TA due to diagnostic doubts in imaging studies were consecutively recruited from June 2017 to December 2021. The outcomes were to determine the diagnostic accuracy of EUS-TA with PC20 for differentiating between MN and n-MN, identifying malignant PCLs, and the AEs. Results Herein, 145 patients underwent EUS-TA, with 83 women (57.2%) and a mean age of 62.2 years. The mean size was 2.3 cm, with 81 patients (77.9%) having a PCL < 3.0 cm. The final diagnosis was made by EUS-TA (n = 81), surgery (n = 58), and follow-up (n = 6). The sensitivity, specificity, positive and negative predictive values, and accuracy for differentiating between MNs and n-MNs and identifying malignant PCLs were 92.6%, 98.4%, 98.7%, 91.3%, and 95.2% (kappa=0.9), and 92%, 99.2%, 95.8%, 98.3%, and 97.9% (kappa = 0.93), respectively. The AE rate was 2.7%, with no deaths in this cohort. Conclusions EUS-TA with PC20 has high accuracy and technical success with a low AE rate for PCL diagnosis.

9.
J Immunother Cancer ; 11(11)2023 11 24.
Article in English | MEDLINE | ID: mdl-38007238

ABSTRACT

BACKGROUND: Approximately 50% of patients who receive anti-CD19 CAR-T cells relapse, and new immunotherapeutic targets are urgently needed. We recently described CD72 as a promising target in B-cell malignancies and developed nanobody-based CAR-T cells (nanoCARs) against it. This cellular therapy design is understudied compared with scFv-based CAR-T cells, but has recently become of significant interest given the first regulatory approval of a nanoCAR in multiple myeloma. METHODS: We humanized our previous nanobody framework regions, derived from llama, to generate a series of humanized anti-CD72 nanobodies. These nanobody binders were inserted into second-generation CD72 CAR-T cells and were evaluated against preclinical models of B cell acute lymphoblastic leukemia and B cell non-Hodgkin's lymphoma in vitro and in vivo. Humanized CD72 nanoCARs were compared with parental ("NbD4") CD72 nanoCARs and the clinically approved CD19-directed CAR-T construct tisangenlecleucel. RNA-sequencing, flow cytometry, and cytokine secretion profiling were used to determine differences between the different CAR constructs. We then used affinity maturation on the parental NbD4 construct to generate high affinity binders against CD72 to test if higher affinity to CD72 improved antitumor potency. RESULTS: Toward clinical translation, here we humanize our previous nanobody framework regions, derived from llama, and surprisingly discover a clone ("H24") with enhanced potency against B-cell tumors, including patient-derived samples after CD19 CAR-T relapse. Potentially underpinning improved potency, H24 has moderately higher binding affinity to CD72 compared with a fully llama framework. However, further affinity maturation (KD<1 nM) did not lead to improvement in cytotoxicity. After treatment with H24 nanoCARs, in vivo relapse was accompanied by CD72 antigen downregulation which was partially reversible. The H24 nanobody clone was found to have no off-target binding and is therefore designated as a true clinical candidate. CONCLUSION: This work supports translation of H24 CD72 nanoCARs for refractory B-cell malignancies, reveals potential mechanisms of resistance, and unexpectedly demonstrates that nanoCAR potency can be improved by framework alterations alone. These findings may have implications for future engineering of nanobody-based cellular therapies.


Subject(s)
Burkitt Lymphoma , Camelids, New World , Receptors, Chimeric Antigen , Animals , Humans , Immunotherapy, Adoptive , T-Lymphocytes , Camelids, New World/metabolism , Recurrence , Antigens, Differentiation, B-Lymphocyte , Antigens, CD
10.
Cell Rep Med ; 4(11): 101290, 2023 11 21.
Article in English | MEDLINE | ID: mdl-37992684

ABSTRACT

Mutations in the receptor tyrosine kinases (RTKs) FLT3 and KIT are frequent and associated with poor outcomes in acute myeloid leukemia (AML). Although selective FLT3 inhibitors (FLT3i) are clinically effective, remissions are short-lived due to secondary resistance characterized by acquired mutations constitutively activating the RAS/MAPK pathway. Hereby, we report the pre-clinical efficacy of co-targeting SHP2, a critical node in MAPK signaling, and BCL2 in RTK-driven AML. The allosteric SHP2 inhibitor RMC-4550 suppresses proliferation of AML cell lines with FLT3 and KIT mutations, including cell lines with acquired resistance to FLT3i. We demonstrate that pharmacologic SHP2 inhibition unveils an Achilles' heel of RTK-driven AML, increasing apoptotic dependency on BCL2 via MAPK-dependent mechanisms, including upregulation of BMF and downregulation of MCL1. Consequently, RMC-4550 and venetoclax are synergistically lethal in AML cell lines and in clinically relevant xenograft models. Our results provide mechanistic rationale and pre-clinical evidence for co-targeting SHP2 and BCL2 in RTK-driven AML.


Subject(s)
Apoptosis , Leukemia, Myeloid, Acute , Humans , Cell Line, Tumor , Leukemia, Myeloid, Acute/drug therapy , Leukemia, Myeloid, Acute/genetics , Leukemia, Myeloid, Acute/metabolism , Protein Kinase Inhibitors/pharmacology , Proto-Oncogene Proteins c-bcl-2/genetics , Proto-Oncogene Proteins c-bcl-2/metabolism , fms-Like Tyrosine Kinase 3/genetics , fms-Like Tyrosine Kinase 3/pharmacology
11.
Nat Cancer ; 4(11): 1592-1609, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37904046

ABSTRACT

Safely expanding indications for cellular therapies has been challenging given a lack of highly cancer-specific surface markers. Here we explore the hypothesis that tumor cells express cancer-specific surface protein conformations that are invisible to standard target discovery pipelines evaluating gene or protein expression, and these conformations can be identified and immunotherapeutically targeted. We term this strategy integrating cross-linking mass spectrometry with glycoprotein surface capture 'structural surfaceomics'. As a proof of principle, we apply this technology to acute myeloid leukemia (AML), a hematologic malignancy with dismal outcomes and no known optimal immunotherapy target. We identify the activated conformation of integrin ß2 as a structurally defined, widely expressed AML-specific target. We develop and characterize recombinant antibodies to this protein conformation and show that chimeric antigen receptor T cells eliminate AML cells and patient-derived xenografts without notable toxicity toward normal hematopoietic cells. Our findings validate an AML conformation-specific target antigen and demonstrate a tool kit for applying these strategies more broadly.


Subject(s)
Leukemia, Myeloid, Acute , Receptors, Chimeric Antigen , Humans , Receptors, Chimeric Antigen/genetics , Receptors, Chimeric Antigen/metabolism , T-Lymphocytes , Integrins/metabolism , Immunotherapy, Adoptive/methods , Leukemia, Myeloid, Acute/therapy , Leukemia, Myeloid, Acute/genetics
12.
PLoS One ; 18(9): e0291152, 2023.
Article in English | MEDLINE | ID: mdl-37729133

ABSTRACT

The deposition and manipulation of human remains in natural caves are well known for the Neolithic of Southern Iberia. The cultural meaning of these practices is however still largely unclear. Cueva de los Marmoles (CM, Priego-Córdoba) is one of the most important cave contexts from Southern Spain, which returned a large number of commingled skeletal remains suggesting its funerary use from the Neolithic to the Late Bronze Age. Here we discuss CM from a chronological and cultural perspective based on new radiocarbon, anthropological, and taphonomic analyses. These include the estimation of the minimum number of individuals, the exploration of fragmentation patterns characterizing different skeletal regions, and the macroscopic and microscopic analysis of modifications to the remains of possible anthropic origin. Radiocarbon data point to a funerary use of CM between the 5th -2nd millennium cal. BCE. MNI estimates reveal the presence of at least 12 individuals (seven adults and five nonadults). The low representation of elements from hands and feet suggests that individuals were placed in the cave while partially decomposed. Anthropic traces on the remains (e.g. fresh fractures, marrow canal modifications, and scraping marks) hint at their intentional fragmentation, cleaning from residual soft tissues, and in some cases reutilization. These practices are well-exemplified by the recovery of one "skull cup" and of two long bones used as tools. These data align with those from other cave contexts from the same geographic region, suggesting the presence, especially during the Neolithic period, of shared ideologies centered on the human body.


Subject(s)
Body Remains , Caves , Adult , Humans , Spain , Anthropology , Foot
13.
J Cell Sci ; 136(15)2023 08 01.
Article in English | MEDLINE | ID: mdl-37439191

ABSTRACT

Abscission is the final stage of cytokinesis whereby the midbody, a thin intercellular bridge, is resolved to separate the daughter cells. Cytokinetic abscission is mediated by the endosomal sorting complex required for transport (ESCRT), a conserved membrane remodelling machinery. The midbody organiser CEP55 recruits early acting ESCRT factors such as ESCRT-I and ALIX (also known as PDCD6IP), which subsequently initiate the formation of ESCRT-III polymers that sever the midbody. We now identify UMAD1 as an ESCRT-I subunit that facilitates abscission. UMAD1 selectively associates with VPS37C and VPS37B, supporting the formation of cytokinesis-specific ESCRT-I assemblies. TSG101 recruits UMAD1 to the site of midbody abscission, to stabilise the CEP55-ESCRT-I interaction. We further demonstrate that the UMAD1-ESCRT-I interaction facilitates the final step of cytokinesis. Paradoxically, UMAD1 and ALIX co-depletion has synergistic effects on abscission, whereas ESCRT-III recruitment to the midbody is not inhibited. Importantly, we find that both UMAD1 and ALIX are required for the dynamic exchange of ESCRT-III subunits at the midbody. Therefore, UMAD1 reveals a key functional connection between ESCRT-I and ESCRT-III that is required for cytokinesis.


Subject(s)
Cytokinesis , Endosomal Sorting Complexes Required for Transport , Endosomal Sorting Complexes Required for Transport/genetics , Cell Cycle Proteins
14.
Toxins (Basel) ; 15(7)2023 06 27.
Article in English | MEDLINE | ID: mdl-37505684

ABSTRACT

Snakes of the Philodryadini tribe are included in the Dipsadidae family, which is a diverse group of rear-fanged snakes widespread in different ecological conditions, including habitats and diet. However, little is known about the composition and effects of their venoms despite their relevance for understanding the evolution of these snakes or even their impact on the occasional cases of human envenoming. In this study, we integrated venom gland transcriptomics, venom proteomics and functional assays to characterize the venoms from eight species of the Philodryadini tribe, which includes the genus Philodryas, Chlorosoma and Xenoxybelis. The most abundant components identified in the venoms were snake venom metalloproteinases (SVMPs), cysteine-rich secretory proteins (CRISPs), C-type lectins (CTLs), snake endogenous matrix metalloproteinases type 9 (seMMP-9) and snake venom serinoproteinases (SVSPs). These protein families showed a variable expression profile in each genus. SVMPs were the most abundant components in Philodryas, while seMMP-9 and CRISPs were the most expressed in Chlorosoma and Xenoxybelis, respectively. Lineage-specific differences in venom composition were also observed among Philodryas species, whereas P. olfersii presented the highest amount of SVSPs and P. agassizii was the only species to express significant amounts of 3FTx. The variability observed in venom composition was confirmed by the venom functional assays. Philodryas species presented the highest SVMP activity, whereas Chlorosoma species showed higher levels of gelatin activity, which may correlate to the seMMP-9 enzymes. The variability observed in the composition of these venoms may be related to the tribe phylogeny and influenced by their diets. In the presented study, we expanded the set of venomics studies of the Philodryadini tribe, which paves new roads for further studies on the evolution and ecology of Dipsadidae snakes.


Subject(s)
Colubridae , Snake Venoms , Animals , Humans , Snake Venoms/metabolism , Colubridae/genetics , Colubridae/metabolism , Proteomics/methods , Phylogeny , Metalloproteases/genetics , Metalloproteases/metabolism , South America
15.
J.health med.sci. ; 9(3): 65-74, jul.2023. graf, ilus, tab
Article in Spanish | LILACS | ID: biblio-1524689

ABSTRACT

Las nuevas tecnologías para el tratamiento del cáncer con radiación ionizante tienen especial interés en mejorar la calidad de las imágenes para el posicionamiento adecuado del paciente con sistemas de radioterapia guiada por imagen IGRT. El sistema Halcyon cuenta con imágenes de tomografía computarizada de haz de cono CBCT. Estas imágenes podrían ser una opción para escenarios donde no se cuente con una Tomografía Computarizada CT o el equipo se encuentre en reparación o mantenimiento especialmente para escenarios de intensión paliativa. La diferencia en la distribución de dosis en imágenes CT y CBCT fue analizada en este estudio. Los resultados mostraron diferencias en las unidades Hounsfield UH, aunque no fueron estadísticamente significativas, el volumen irradiado mostro diferencias máximas de 3,92% que no supera el 4% permitido para tratamientos de intensión paliativa. En cuanto a las dosis dispersas al tejido sano la diferencia tampoco supera el 4%. Nuestro estudio mostro que las imágenes CBCT pueden ser una alternativa para el tratamiento de metástasis óseas, sin embargo, estas imágenes todavía no pueden remplazar las imágenes CT utilizadas para el cálculo de dosis en radioterapia


New technologies for the treatment of cancer with ionizing radiation are of particular interest in improving image quality for proper patient positioning with image-guided radiation therapy IGRT systems. IGRT image-guided radiation therapy systems. The Halcyon system features cone beam computed tomography CBCT imaging. These images could be an option for scenarios where a CT scan is not available or the equipment is under repair or maintenance especially for is under repair or maintenance, especially for palliative scenarios. The difference in the The difference in dose distribution in CT and CBCT images was analyzed in this study. The results showed differences in Hounsfield UH units, although not statistically significant, the irradiated volume showed maximum differences of 3.92%, which is the maximum difference of 3.92%. Differences of 3.92%, which does not exceed the 4% allowed for palliative treatments. As for the doses dispersed to healthy tissue the difference does not exceed the 4% allowed for palliative treatments. Our study showed that CBCT imaging can be an alternative for the treatment of metastases. an alternative for the treatment of bone metastases, however, these images cannot yet replace the CT images used for dose calculation. CT images used for dose calculation in radiotherapy


Subject(s)
Humans , Bone Neoplasms/radiotherapy , Radiotherapy, Image-Guided/methods , Radiotherapy Dosage , Radiotherapy Planning, Computer-Assisted/methods , Tomography, X-Ray Computed/methods , Cone-Beam Computed Tomography/methods
16.
Biosensors (Basel) ; 13(6)2023 Jun 20.
Article in English | MEDLINE | ID: mdl-37367033

ABSTRACT

Obtaining cell concentration measurements from a culture assay by using bioimpedance is a very useful method that can be used to translate impedances to cell concentration values. The purpose of this study was to find a method to obtain the cell concentration values of a given cell culture assay in real time by using an oscillator as the measurement circuit. From a basic cell-electrode model, enhanced models of a cell culture immersed in a saline solution (culture medium) were derived. These models were used as part of a fitting routine to estimate the cell concentration in a cell culture in real time by using the oscillation frequency and amplitude delivered by the measurement circuits proposed by previous authors. Using real experimental data (the frequency and amplitude of oscillations) that were obtained by connecting the cell culture to an oscillator as the load, the fitting routine was simulated, and real-time data of the cell concentration were obtained. These results were compared to concentration data that were obtained by using traditional optical methods for counting. In addition, the error that we obtained was divided and analyzed in two parts: the first part of the experiment (when the few cells were adapting to the culture medium) and the second part of the experiment (when the cells exponentially grew until they completely covered the well). Low error values were obtained during the growth phase of the cell culture (the relevant phase); therefore, the results obtained were considered promising and show that the fitting routine is valid and that the cell concentration can be measured in real time by using an oscillator.


Subject(s)
Cell Culture Techniques , Cell Culture Techniques/methods , Electrodes , Electric Impedance
17.
Mol Biol Evol ; 40(7)2023 07 05.
Article in English | MEDLINE | ID: mdl-37352150

ABSTRACT

Snake venoms harbor a wide and diverse array of enzymatic and nonenzymatic toxic components, allowing them to exert myriad effects on their prey. However, they appear to trend toward a few optimal compositional scaffolds, dominated by four major toxin classes: SVMPs, SVSPs, 3FTxs, and PLA2s. Nevertheless, the latter appears to be restricted to vipers and elapids, as it has never been reported as a major venom component in rear-fanged species. Here, by investigating the original transcriptomes from 19 species distributed in eight genera from the Pseudoboini tribe (Dipsadidae: Xenodontinae) and screening among seven additional tribes of Dipsadidae and three additional families of advanced snakes, we discovered that a novel type of venom PLA2, resembling a PLA2-IIE, has been recruited to the venom of some species of the Pseudoboini tribe, where it is a major component. Proteomic and functional analyses of these venoms further indicate that these PLA2s play a relevant role in the venoms from this tribe. Moreover, we reconstructed the phylogeny of PLA2s across different snake groups and show that different types of these toxins have been recruited in at least five independent events in caenophidian snakes. Additionally, we present the first compositional profiling of Pseudoboini venoms. Our results demonstrate how relevant phenotypic traits are convergently recruited by different means and from homologous and nonhomologous genes in phylogenetically and ecologically divergent snake groups, possibly optimizing venom composition to overcome diverse adaptative landscapes.


Subject(s)
Colubridae , Proteomics , Animals , Snake Venoms/genetics , Phospholipases A2/genetics , Phylogeny , Colubridae/genetics , Snakes
20.
Foodborne Pathog Dis ; 20(5): 169-176, 2023 05.
Article in English | MEDLINE | ID: mdl-37172300

ABSTRACT

This study evaluated the antagonistic effect of the Lacticaseibacillus paracasei JLM strain isolated from aguamiel, against Brucella abortus RB51, S19, and 2308 strains, during the manufacture of soft-ripened cheese. First, the tolerance of Lc. paracasei JLM was tested with pH values and bile salt concentrations for 3 h to simulate digestive tract conditions. The antagonistic effect against B. abortus strains was evaluated through double-layer diffusion and agar well diffusion assays. In addition, the stability of the cell-free supernatant (CFS) was tested with the agar well diffusion method under different conditions of temperature, pH, and treatment with digestive enzymes. Finally, the antagonistic effect against B. abortus strains was observed during the manufacture of ripened cheese for 31 days at 4°C and 25°C using the Lc. paracasei JLM strain as starter culture. The results showed that the Lc. paracasei JLM strain remains viable after exposure to different pH values (from 3.00 to 7.00) and concentrations of bile salts (from 0.5% to 7%). Moreover, the results demonstrate that the growth of the three B. abortus strains was inhibited in both antagonism tests and that CFS maintained 86% activity after heat treatment at 100°C, 121°C, or enzymatic digestion (proteinase K, trypsin, chymotrypsin), but it was inactivated at pH levels above 6. Finally, Lc. paracasei JLM completely inhibited the growth of B. abortus in ripened cheese at 25°C from day 17 and showed greater inhibition on the B. abortus RB51 strain in the ripened cheese at 4°C, showing statistical differences for the B. abortus S19 and B. abortus 2308 strains. The current research concluded that the Lc. paracasei JLM strain has an antagonistic effect on B. abortus, enhancing the potential of its use in the future as a probiotic.


Subject(s)
Cheese , Lacticaseibacillus paracasei , Brucella abortus , Lacticaseibacillus , Agar
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