Currently, the assembly of helical plant viruses is poorly understood. The viral assembly and infection may be affected by the charge distribution on the virion surface. However, only the total virion charge (isoelectric point) has been determined for most plant viruses. Here, we report on the first application of positively charged magnetic nanoparticles for mapping the surface charge distribution of helical plant viruses. The charge was demonstrated to be unevenly distributed on the surface of viruses belonging to different taxonomic groups, with the negative charge being predominantly located at one end of the virions. This charge distribution is mainly controlled by viral RNA.

Purpose Recombinant rotavirus A vaccines are being developed as an alternative to existing live oral attenuated vaccines. One of the main problems in the production of such vaccines is the genetic diversity of the strains that are in circulation. The goal of this study was to create an antigen panel for modern broad-spectrum recombinant rotavirus A vaccine. Materials and Methods The antigens of rotavirus were cloned and expressed in Escherichia coli . Antigenic specificity was investigated by Western blot analysis, which was performed using commercial polyclonal antisera to several RVA strains. Phylogenetic analysis was based on the amino acid sequences of the VP8 * protein fragment of human RVA isolates representing genotypes P[4], P[6], and P[8]. Results A universal panel of antigens was established, including consensus and conserved sequences of structural proteins VP8 * , VP5 * , and VP7, which are the main targets of neutralizing antibodies. For the first time, a consensus approach was used in the design of extended antigens based on VP8 * (genotypes P[4], P[6], and P[8]) and VP5 * (genotype P[8]) proteins' fragments. In addition, a gene coding the protein (ep-875) containing several copies of conserved short neutralizing epitopes of VP8 * , VP7, and VP5 * was created. Western blot analysis demonstrated that three synthetic VP8 * -based antigens were not recognized by commercial antiserum against rotavirus strains isolated more than 35 years ago, but the specific activity of the VP5 * and ep-875 antigens was confirmed. The problems of serological mismatch of vaccine strains and antigens with currently circulating strains are discussed. Conclusion Five antigens representing sequences of structural proteins belonging to different genotypes can be used in various combinations (from mono- to pentavalent mixtures) for the development of an effective broad-spectrum rotavirus vaccine.

Structurally modifi ed virus particles can be obtained from the rod-shaped or fi lamentous virions of plant viruses and bacteriophages by thermal or chemical treatment. They have recently attracted attention of the researchers as promising biogenic platforms for the development of new biotechnologies. This review presents data on preparation, structure, and properties of the structurally modifi ed virus particles. In addition, their biosafety for animals is considered, as well as the areas of application of such particles in biomedicine. A separate section is devoted to one of the most relevant and promising areas for the use of structurally modifi ed plant viruses -design of vaccine candidates based on them.

Donorrecipient histocompatibility results from the presence on cell membranes of the main protein complex of histocompatibility and is a key condition for successful transplantation of cells, tissues, and organs. To determine histocompatibility, human leukocyte antigen is genotyped, and its accuracy relied significantly on the quality and quantity of nucleic acids obtained from the biomaterial. In laboratory practice, the most pure and intact deoxyribonucleic and ribonucleic acids are extracted from the blood; however, the choice of an accessible, effective, time-efficient, and viable method for their production remains challenging. The methods of isolation and purification of nucleic acids from the blood include organic extraction, salting out, and use of spin columns and magnetic particles (bidids), and their advantages and disadvantages, efficiency indicators, practicality, and cost were compared. The selection of the peripheral blood as a source of genetic material for genotyping human leukocyte antigen is justified. Experimental data comparing the pricequality ratio of commercial protocols for the extraction of deoxyribonucleic and ribonucleic acids from blood were analyzed. Prospects of modification of procedures for isolation and purification of nucleic acids from biomaterial for sequencing of genes of human leukocyte antigen classes I and II to increase efficiency of high-tech care are evaluated. Generally, the need for affordable and effective protocols for the extraction of deoxyribonucleic and ribonucleic acids from minimal biomaterial volumes stimulates the optimization and modification of existing protocols and the creation of new methods on new physicochemical principles.