Elucidating functional epitopes within the N-terminal region of malaria transmission blocking vaccine antigen Pfs230

Pfs230 is a leading malaria transmission blocking vaccine (TBV) candidate. Comprising 3135 amino acids (aa), the large size of Pfs230 necessitates the use of sub-fragments as vaccine immunogens. Therefore, determination of which regions induce functional antibody responses is essential. We previously reported that of 27 sub-fragments spanning the entire molecule, only five induced functional antibodies. A “functional” antibody is defined herein as one that inhibits Plasmodium falciparum parasite development in mosquitoes in a standard membrane-feeding assay (SMFA). These five sub-fragments were found within the aa 443–1274 range, and all contained aa 543–730. Here, we further pinpoint the location of epitopes within Pfs230 that are recognized by functional antibodies using antibody depletion and enrichment techniques. Functional epitopes were not found within the aa 918–1274 region. Within aa 443–917, further analysis showed the existence of functional epitopes not only within the aa 543–730 region but also outside of it. Affinity-purified antibodies using a synthetic peptide matching aa 543–588 showed activity in the SMFA. Immunization with a synthetic peptide comprising this segment, formulated either as a carrier-protein conjugate vaccine or with a liposomal vaccine adjuvant system, induced antibodies in mice that were functional in the SMFA. These findings provide key insights for Pfs230-based vaccine design and establish the feasibility for the use of synthetic peptide antigens for a malaria TBV.

PELATIHAN ENRICHMENT DAPHNIA UNTUK MENINGKATKAN KECERAHAN WARNA IKAN CUPANG (Betta sp.)

ABSTRAKPermasalahan yang dihadapi mitra adalah rendahnya kualitas warna ikan cupang yang mitra peroleh dari agen, sehingga harga jual ikan cupang juga rendah. Setelah mengetahui permasalahan mitra, tim menawarkan solusi yaitu pelatihan enrichment Daphnia untuk memanipulasi pigmen warna ikan cupang. Tujuan dari pengabdian ini adalah memberikan pelatihan kepada pemuda dan para penggiat ikan cupang di Gampong Teungoh, Kota Langsa tentang enrichment Daphnia sebagai pakan ikan cupang yang dapat meninngkatkan kecerahan warna ikan cupang. Metode yang digunakan adalah sosialisasi dan penjaringan mitra, pemberian materi tentang faktor-faktor yang mempengaruhi kecerahan warna ikan cupang serta teknik enrichment pakan ikan cupang dan pelatihan teknik enrichment pakan ikan cupang. Mitra yang mengikuti kegiatan ini adalah pemuda gampong dan penggiat ikan cupang di Gampong Teungoh yang berjumlah 25 orang. Evaluasi keberhasilan pelatihan dihitung berdasarkan kepahaman para peserta terhadap materi pelatihan. Hasil yang dicapai dari pelatihan ini yaitu adanya peningkatan ketrampilan para pemuda dan penggiat ikan cupang dalam meningkatkan warna ikan cupang dan juga adanya peningkatan harga jual ikan yang telah diberikan pakan Daphnia yang telah di enrichment. Kata kunci: astaxhantin; daphnia; ikan cupang; kecerahan warna; pakan alami. ABSTRACTThe problem faced by partners is the low quality of betta fish colors that partners get from agents, so the selling price of betta fish is also low. After knowing the partners' problems, the team offered a solution, namely Daphnia enrichment training to manipulate betta fish color pigments. The purpose of this service is to provide training to youth and betta fish activists in Gampong Teungoh, Langsa City on the enrichment of Daphnia as betta fish food that can increase the brightness of the color of betta fish. The methods used were socialization and partner networking, providing material about the factors that affect the color brightness of betta fish and betta fish feed enrichment techniques and training on betta fish feed enrichment techniques. Partners who participated in this activity were village youth and betta fish activists in Teungoh Village, totaling 25 people. The evaluation of the success of the training is calculated based on the participants' understanding of the training material. The results achieved from this training are an increase in the skills of young people and betta fish activists in increasing the color of betta fish and also an increase in the selling price of fish that have been given enrichment Daphnia feed. Keywords: astaxhantin; daphnia; betta fish; color brightness; natural food

Liquid Biopsy-Based Colorectal Cancer Screening via Surface Markers of Circulating Tumor Cells

Colorectal cancer (CRC) is ranked second for cancer-related deaths worldwide with approximately half of the patients being diagnosed at the late stages. The untimely detection of CRC results in advancement to the metastatic stage and nearly 90% of cancer-related deaths. The early detection of CRC is crucial to decrease its overall incidence and mortality rates. The recent introduction of circulating tumor cells (CTCs) has enabled a less invasive sampling method from liquid biopsies, besides revealing key information toward CRC metastasis. The current gold standard for CTC identification is the CellSearch® system (Veridex). This first-generation instrumentation relies on a single cell surface marker (CSM) to capture and count CTCs. Detection of CTCs allows the identification of patients at risk for metastasis, whereas CTC enumeration could improve risk assessment, monitoring of systemic therapy, and detection of therapy resistance in advanced metastatic CRC. In this review, we compared the pros and cons between single CSM-based CTC enrichment techniques and multi-marker-based systems. We also highlighted the challenges faced in the routine implementation of CSM-dependent CTC detection methods in CRC screening, prediction, prognosis, disease monitoring, and therapy selection toward precision medicine, as well as the dwelling on post-CTC analysis and characterization methods.

Biotinylation-based proximity labeling proteomics: Basics, applications, and technical considerations

Summary Recent advances in biotinylation-based proximity labeling (PL) have opened up new avenues for mapping the protein composition of cellular compartments and protein complexes in living cells at high spatiotemporal resolution. In particular, PL combined with mass spectrometry-based proteomics has been successfully applied to defining protein-protein interactions, protein-nucleic acid interactions, (membraneless) organelle proteomes, and secretomes in various systems ranging from cultured cells to whole animals. In this review, we first summarize the basics and recent biological applications of PL proteomics, and then highlight recent developments in enrichment techniques for biotinylated proteins and peptides, focusing on the advantages of PL and technical considerations.

Kaolinite clays as a source of raw materials for the aluminum industry of the Republic of Kazakhstan

Kaolinite clays can serve as an additional source of alumina in the Republic of Kazakhstan. The most promising is the Alekseevsky kaolinite deposit. To obtain high-quality kaolinite and quartzite products, it is necessary to develop special enrichment techniques, since no satisfactory results were achieved when using standard methods of gravitational enrichment of kaolinites. The paper presents the results of studies of the effect of preliminary chemical activation during the processing of kaolinite clays of the Alekseevsky deposit. Previously, the method of preliminary chemical activation of raw materials in a solution of sodium bicarbonate has proven itself well in the processing of various mineral raw materials. It was determined that during the preliminary chemical activation in a solution of sodium bicarbonate, changes occurred in the phase composition of the kaolinite fraction: the content of muscovite decreased almost twice; the phase of sodium aluminosilicate was formed. The dependence of the yield of Al2O3 in the kaolinite fraction on the temperature of chemical activation, duration, and the ratio of L:S and the concentration of the sodium bicarbonate solution during chemical activation. The optimal mode of preliminary chemical activation of kaolinite clay of the Alekseevsky deposit has been established: the temperature is 150 oC, the duration is 120 minutes and the concentration of sodium bicarbonate solution is 120 g/dm3. A basic technological scheme is proposed for the processing of kaolinite clays.

PHIDA: A High Throughput Turbidimetric Data Analytic Tool to Compare Host Range Profiles of Bacteriophages Isolated Using Different Enrichment Methods

Bacteriophages are viruses that infect bacteria and are present in niches where bacteria thrive. In recent years, the suggested application areas of lytic bacteriophage have been expanded to include therapy, biocontrol, detection, sanitation, and remediation. However, phage application is constrained by the phage’s host range—the range of bacterial hosts sensitive to the phage and the degree of infection. Even though phage isolation and enrichment techniques are straightforward protocols, the correlation between the enrichment technique and host range profile has not been evaluated. Agar-based methods such as spotting assay and efficiency of plaquing (EOP) are the most used methods to determine the phage host range. These methods, aside from being labor intensive, can lead to subjective and incomplete results as they rely on qualitative observations of the lysis/plaques, do not reflect the lytic activity in liquid culture, and can overestimate the host range. In this study, phages against three bacterial genera were isolated using three different enrichment methods. Host range profiles of the isolated phages were quantitatively determined using a high throughput turbidimetric protocol and the data were analyzed with an accessible analytic tool “PHIDA”. Using this tool, the host ranges of 9 Listeria, 14 Salmonella, and 20 Pseudomonas phages isolated with different enrichment methods were quantitatively compared. A high variability in the host range index (HRi) ranging from 0.86–0.63, 0.07–0.24, and 0.00–0.67 for Listeria, Salmonella, and Pseudomonas phages, respectively, was observed. Overall, no direct correlation was found between the phage host range breadth and the enrichment method in any of the three target bacterial genera. The high throughput method and analytics tool developed in this study can be easily adapted to any phage study and can provide a consensus for phage host range determination.

Current Methods of Post-Translational Modification Analysis and Their Applications in Blood Cancers

Post-translational modifications (PTMs) add a layer of complexity to the proteome through the addition of biochemical moieties to specific residues of proteins, altering their structure, function and/or localization. Mass spectrometry (MS)-based techniques are at the forefront of PTM analysis due to their ability to detect large numbers of modified proteins with a high level of sensitivity and specificity. The low stoichiometry of modified peptides means fractionation and enrichment techniques are often performed prior to MS to improve detection yields. Immuno-based techniques remain popular, with improvements in the quality of commercially available modification-specific antibodies facilitating the detection of modified proteins with high affinity. PTM-focused studies on blood cancers have provided information on altered cellular processes, including cell signaling, apoptosis and transcriptional regulation, that contribute to the malignant phenotype. Furthermore, the mechanism of action of many blood cancer therapies, such as kinase inhibitors, involves inhibiting or modulating protein modifications. Continued optimization of protocols and techniques for PTM analysis in blood cancer will undoubtedly lead to novel insights into mechanisms of malignant transformation, proliferation, and survival, in addition to the identification of novel biomarkers and therapeutic targets. This review discusses techniques used for PTM analysis and their applications in blood cancer research.