Plasmodium sporozoite phospholipid scramblase interacts with mammalian carbamoyl-phosphate synthetase 1 to infect hepatocytes

After inoculation by the bite of an infected mosquito, Plasmodium sporozoites enter the blood stream and infect the liver, where each infected cell produces thousands of merozoites. These in turn, infect red blood cells and cause malaria symptoms. To initiate a productive infection, sporozoites must exit the circulation by traversing the blood lining of the liver vessels after which they infect hepatocytes with unique specificity. We screened a phage display library for peptides that structurally mimic (mimotope) a sporozoite ligand for hepatocyte recognition. We identified HP1 (hepatocyte-binding peptide 1) that mimics a ~50 kDa sporozoite ligand (identified as phospholipid scramblase). Further, we show that HP1 interacts with a ~160 kDa hepatocyte membrane putative receptor (identified as carbamoyl-phosphate synthetase 1). Importantly, immunization of mice with the HP1 peptide partially protects them from infection by the rodent parasite P. berghei. Moreover, an antibody to the HP1 mimotope inhibits human parasite P. falciparum infection of human hepatocytes in culture. The sporozoite ligand for hepatocyte invasion is a potential novel pre-erythrocytic vaccine candidate.

Monoclonal Antibodies to S and N SARS-CoV-2 Proteins as Probes to Assess Structural and Antigenic Properties of Coronaviruses

Antibodies targeting the spike (S) and nucleocapsid (N) proteins of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are essential tools. In addition to important roles in the treatment and diagnosis of infection, the availability of high-quality specific antibodies for the S and N proteins is essential to facilitate basic research of virus replication and in the characterization of mutations responsible for variants of concern. We have developed panels of mouse and rabbit monoclonal antibodies (mAbs) to the SARS-CoV-2 spike receptor-binding domain (S-RBD) and N protein for functional and antigenic analyses. The mAbs to the S-RBD were tested for neutralization of native SARS-CoV-2, with several exhibiting neutralizing activity. The panels of mAbs to the N protein were assessed for cross-reactivity with the SARS-CoV and Middle East respiratory syndrome (MERS)-CoV N proteins and could be subdivided into sets that showed unique specificity for SARS-CoV-2 N protein, cross-reactivity between SARS-CoV-2 and SARS-CoV N proteins only, or cross-reactivity to all three coronavirus N proteins tested. Partial mapping of N-reactive mAbs were conducted using truncated fragments of the SARS-CoV-2 N protein and revealed near complete coverage of the N protein. Collectively, these sets of mouse and rabbit monoclonal antibodies can be used to examine structure/function studies for N proteins and to define the surface location of virus neutralizing epitopes on the RBD of the S protein.

Advanced Materials for Immunosensing of Pharmaceutical and Drug Compounds

Real-time and accurate levels of pharmaceuticals undertake critical effects in the therapy process. Thus, reliable detection of pharmaceuticals is important for regulating the proper concentration of them to enhance the effectiveness and to decrease possible side effects. However, the development of new reliable sensory systems is the main prerequisite for the mentioned aims. Immunosensors can be regarded as an effective tool due to their sensitivity and unique specificity originating from the intrinsic nature of the antigen-antibody interaction. This review reports material tendencies in the development of immunosensors for pharmaceuticals (veterinary and human) which have been reported in the last few years. Carbon-based (graphene, graphene oxide, carbon nanotubes, etc.), gold, and magnetic materials are the main materials for the fabrication of pharmaceutical immunosensors. Also, this review reports benefits and limitations on the reported immunosensor and mechanism and analytical performance of the immunoplatforms to address future researches.

Role of Lectin as Potential Biomarker in Ovarian Cancer

: Lectin acts as an effective tool for screening potential biomarkers and gives an indication of highly valued research. Lectin offers the advantage of having the ability to recognize carbohydrate moiety of glycoprotein, peptidoglycan, glycosides, glycopeptides, lipopolysaccharide, etc., aiding in the detection of a new cancer biomarker in most complex tissues and fluids. The unique specificity of lectin in detecting single anomalously expressed lectin-based glycosylation method that can often go down the line for future cancer biomarker. This article explores the different types of lectin, their sources, and possible application in masking the activity of ovarian cancer cell.

Differential recognition of oligomannose isomers by glycan-binding proteins involved in innate and adaptive immunity

The recognition of oligomannose-type glycans in innate and adaptive immunity is elusive due to multiple closely related isomeric glycan structures. To explore the functions of oligomannoses, we developed a multifaceted approach combining mass spectrometry assignments of oligomannose substructures and the development of a comprehensive oligomannose microarray. This defined microarray encompasses both linear and branched glycans, varying in linkages, branching patterns, and phosphorylation status. With this resource, we identified unique recognition of oligomannose motifs by innate immune receptors, including DC-SIGN, L-SIGN, Dectin-2, and Langerin, broadly neutralizing antibodies against HIV gp120, N-acetylglucosamine-1-phosphotransferase, and the bacterial adhesin FimH. The results demonstrate that each protein exhibits a unique specificity to oligomannose motifs and suggest the potential to rationally design inhibitors to selectively block these protein-glycan interactions.

The acyltransferase lycat controls specific phosphoinositides and related membrane traffic and hormone receptor signaling

Phosphoinositdes (PIPs) are a group of signaling phospholipids involved in regulating many cellular processes, including organelle dynamics, nutrient uptake, autophagy and apoptosis. Through the action of lipid kinases and phosphatases, phosphatidylinositol (PI) can be phosphorylated on three different positions of the inositol headgroup resulting in seven distinct PIP species. Substantial research has focused on elucidating the function and importance of headgroup phosphorylation while much less is known about the significance of the incorporation of specific acyl chains within PI. PI exhibits unique specificity of acyl chain composition, where majority contains 1-stearoyl-2-arachidonoyl acyl species. This unique acyl chain enrichment is, in part, controlled by the PI acyltransferase lysocardiolipin acyltransferase (LYCAT). How LYCAT and, in turn, incorporation of specific fatty acids, controls the function of PI and PIPs is poorly understood. Thus, I investigated the impact of LYCAT perturbation on PIP acyl profile and effects on PIP-dependent processes. Perturbation of LYCAT by siRNA gene silencing resulted in a shift in the acyl profile of PIP2 species to contain shorter species. Additionally, LYCAT silencing altered the cellular localization and levels of phosphatidylinositol-4,5-bisphosphate and phosphatidylinositol-3-phosphate but was without effect on other PI species examined. Consistent with this, silencing of LYCAT perturbed the membrane traffic of transferrin receptor dependent on these specific PIPs. I also observed changes in PI-dependent receptor tyrosine kinase signaling pathways that control cell survival and proliferation, which are regulated by phosphatidylinositol-3,4,5-trisphosphate. LYCAT perturbation altered activation of Akt1, which impacted a number of Akt substrates. Additionally, using fluorescence microscopy, I discovered that LYCAT is localized to peripheral ER vesicles that contain PI synthase enzyme, which is responsible for PI synthesis. These peripheral vesicles partially overlap with endoplasmic reticulum-plasma membrane contact sites marked by E-Syt2 but showed little overlap with the ER maker, KDEL. Collectively, my results show that the PI acyltransferase LYCAT controls the function of specific species of PIPs, which in turn selectively impacts specific stages of endomembrane traffic and hormone receptor signaling. Hence, the regulation of acyl content of PI is an important new dimension for the control of PI and PIP function.

The acyltransferase lycat controls specific phosphoinositides and related membrane traffic and hormone receptor signaling

Phosphoinositdes (PIPs) are a group of signaling phospholipids involved in regulating many cellular processes, including organelle dynamics, nutrient uptake, autophagy and apoptosis. Through the action of lipid kinases and phosphatases, phosphatidylinositol (PI) can be phosphorylated on three different positions of the inositol headgroup resulting in seven distinct PIP species. Substantial research has focused on elucidating the function and importance of headgroup phosphorylation while much less is known about the significance of the incorporation of specific acyl chains within PI. PI exhibits unique specificity of acyl chain composition, where majority contains 1-stearoyl-2-arachidonoyl acyl species. This unique acyl chain enrichment is, in part, controlled by the PI acyltransferase lysocardiolipin acyltransferase (LYCAT). How LYCAT and, in turn, incorporation of specific fatty acids, controls the function of PI and PIPs is poorly understood. Thus, I investigated the impact of LYCAT perturbation on PIP acyl profile and effects on PIP-dependent processes. Perturbation of LYCAT by siRNA gene silencing resulted in a shift in the acyl profile of PIP2 species to contain shorter species. Additionally, LYCAT silencing altered the cellular localization and levels of phosphatidylinositol-4,5-bisphosphate and phosphatidylinositol-3-phosphate but was without effect on other PI species examined. Consistent with this, silencing of LYCAT perturbed the membrane traffic of transferrin receptor dependent on these specific PIPs. I also observed changes in PI-dependent receptor tyrosine kinase signaling pathways that control cell survival and proliferation, which are regulated by phosphatidylinositol-3,4,5-trisphosphate. LYCAT perturbation altered activation of Akt1, which impacted a number of Akt substrates. Additionally, using fluorescence microscopy, I discovered that LYCAT is localized to peripheral ER vesicles that contain PI synthase enzyme, which is responsible for PI synthesis. These peripheral vesicles partially overlap with endoplasmic reticulum-plasma membrane contact sites marked by E-Syt2 but showed little overlap with the ER maker, KDEL. Collectively, my results show that the PI acyltransferase LYCAT controls the function of specific species of PIPs, which in turn selectively impacts specific stages of endomembrane traffic and hormone receptor signaling. Hence, the regulation of acyl content of PI is an important new dimension for the control of PI and PIP function.

Live weight of rams of Dagestan mountain breed and crossbreeds obtained from crossing with rams of the Russian meat merino breed

Relevance and methods. The article considers the experience of studying the effect of crossing Kalmyk sheep and dorper sheep-breeders in order to increase meat productivity. Crossbred rams of the experimental group had better indicators than rams in the control group in terms of live weight, depending on the conditions of pasture maintenance. Dagestan has a fifth of the Russian sheep and goat population and a quarter of wool production. In this area sheep breeding has a unique specificity, twice a year cattle are driven from summer to winter pastures and back. The distance between the pasture areas is more than 570 km. Of the total number of sheep, 71.5% falls on the Dagestan mountain breed.Results. To further increase the level of profitability of fine-wool sheep breeding it is of great importance to develop research on the economic and useful characteristics of young Dagestani fine-wool sheep and their crossbreeds with Russian meat merino sheep, depending on the driving and pasture system of keeping.

A Potential Innovative Therapy for Parkinson’s Disease: Selective Destruction of the Pathological Assemblies of Alpha-Synuclein

With the aging of the population, Parkinson’s disease poses a serious socio-economic problem; there is no effective therapy that can arrest/revert the progression of the disease. The hallmarks of Parkinson’s disease and other synucleinopathies are the disordered alpha-synuclein and TPPP/p25. These proteins have neomorphic moonlighting characteristics by displaying both physiological and pathological functions. Physiologically TPPP/p25 regulates the dynamics/stability of the microtubules and is crucial for oligodendrocyte differentiation; while alpha-synuclein is involved in neuronal plasticity modulation and synaptic vesicle pool maintenance. In healthy brain, alpha-synuclein and TPPP/p25 occur predominantly in neurons and oligodendrocytes, respectively; however, they are co-enriched and co-localized in both cell types in brain inclusions in the cases of Parkinson’s disease and multiple system atrophy, respectively. The pathomechanisms of these diseases are largely unknown; the fatal species are the small, soluble homo- and hetero-associations of alpha-synuclein. These proteins with their high conformational plasticity and chameleon feature are challenging drug targets. Nevertheless, the contact surface of TPPP/p25-alpha-synuclein assemblies has been validated as a specific drug target. This new strategy with innovative impact, namely targeting the interface of the TPPP/p25-alpha-synuclein complex, could contribute to the development of anti-Parkinson drugs with unique specificity.

Bioprocessing and integration of a high flux screening systematic platform based on isothermal amplification for the detection on 8 common pathogens

During a large variety of common pathogens, E. coli, P. aeruginosa, MRSA, MRCNS, V. parahaemolyticus, L. monocytogenes and Salmonella are the leading pathogens responsible for large number of human infections and diseases. In this study, a high flux screening based on nucleic acid isothermal amplification technique has been developed. For the 8 common pathogens, species-specific targets had been selected and analyzed for their unique specificity. After optimization, separate LAMP reaction assays had been bioprocessed and integrated into one systematic detection platform, including 8 strips (PCR tubes) and 96-well plates. Eight standard strains verified for the accuracy. Application of the established high flux screening platform was used for detection for 48 samples in 4 different 96-well plates, with 2 groups of 2 operators using double-blind procedure. The accuracy of 100% was obtained, with the total time consumption as 66–75 min (for 12 samples detection on 8 different pathogens). As concluded, through the bioprocess of the systematic platform based on LAMP technique, it’s been demonstrated to be capable of simultaneous detection of 8 pathogens, with high sensitivity, specificity, rapidity and convenience.