Ilkgul Akmayan

Safe and effective vaccine candidates are needed to address the limitations of existing vaccines against Brucellosis, a disease responsible for substantial economic losses in livestock. The present study aimed to encapsulate recombinant Omp25 and EipB proteins, knowledged antigen properties, into PLGA nanoparticles, characterize synthesized nanoparticles with different methods, and assessed their in vitro/in vivo immunostimulatory activities to develop new vaccine candidates. The recombinant Omp25 and EipB proteins produced with recombinant DNA technology were encapsulated into PLGA nanoparticles by double emulsion solvent evaporation technique. The nanoparticles were characterized using FE-SEM, Zeta-sizer, and FT-IR instruments to determine size, morphology, zeta potentials, and polydispersity index values, as well as to analyze functional groups chemically. Additionally, the release profiles and encapsulation efficiencies were assessed using UV–Vis spectroscopy. After loading with recombinant proteins, O-NPs reached sizes of 221.2 ± 5.21 nm, while E-NPs reached sizes of 274.4 ± 9.51 nm. The cumulative release rates of the antigens, monitored until the end of day 14, were determined to be 90.39% for O-NPs and 56.1% for E-NPs. Following the assessment of the in vitro cytotoxicity and immunostimulatory effects of both proteins and nanoparticles on the J774 murine macrophage cells, in vivo immunization experiments were conducted using concentrations of 16 µg ml⁻¹ for each protein. Both free antigens and antigen-containing nanoparticles excessively induced humoral immunity by increasing produced Brucella-specific IgG antibody levels for 3 times in contrast to control. Furthermore, it was also demonstrated that vaccine candidates stimulated Th1-mediated cellular immunity as well since they significantly raised IFN-gamma and IL-12 cytokine levels in murine splenocytes rather than IL-4 following to immunization. Additionally, the vaccine candidates conferred higher than 90% protection from the infection according to challenge results. Our findings reveal that PLGA nanoparticles constructed with the encapsulation of recombinant Omp25 or EipB proteins possess great potential to trigger Brucella-specific humoral and cellular immune response.

Recent SARS-CoV-2 pandemic elevated research interest in microorganism-related diseases, and protective health application importance such as vaccination and immune promoter agents emerged. Among the production methods for proteins, recombinant technology is an efficient alternative and frequently preferred method. However, since the production and purification processes vary due to the protein nature, the effect of these differences on the cost remains ambiguous. In this study, brucellosis and its two important vaccine candidate proteins (rOmp25 and rEipB) with different properties were selected as models, and industrial-scale production processes were compared with the SuperPro Designer^® for estimating the unit production cost. Simulation study showed raw material cost by roughly 60% was one of the barriers to lower-cost production and 52.5 and 559.8 $/g were estimated for rEipB and rOmp25, respectively.

After the COVID-19 pandemic, vaccine production technologies have become the focus of attention of researchers. As a matter of fact, recombinant protein-based antigen production, which is one of them, has taken its place in the first place. Proteins obtained by recombinant DNA technology are used in many industrial areas, especially vaccine applications, due to their reliability. Therefore, it is very important to produce targeted recombinant proteins in large quantities. This study, for the high amounts production of Omp25 protein, which is used as a vaccine candidate against brucellosis, in laboratory conditions, is aimed to reveal the effects of conditions that are the pre-culturing process, inoculation in LB or TB media, denatured or native purification, culturing with/without IPTG. All the results were analyzed by SDS-PAGE, confirmed Western Blot, and the total protein amounts were measured Bradford method. According to the results, Omp25 protein could not be obtained under native purification conditions in both cultures without induction, but it was observed under denatured conditions. This result can be explained that the protein in the cell is either misfolded or incorporated into the membrane. The amount of protein appears to be much higher in the presence of the inducer in both media inoculated with the starter pre-culture compared to the overnight pre-culture; 8.79 mg and 39.4 mg from 1 L culture, respectively. Additionally, as expected, the addition of IPTG increased the amount of protein, approximately one-and-a-half-fold for LB and about three-fold for TB. Finally, it was observed that TB medium provided higher protein production than LB, which can be explained by the presence of glycerol and high yeast extract in the medium. Although our study contains results that will attract the attention of vaccine industry, it should be kept in mind that all process should always be optimized depending on the structure of the targeted protein and thus the production amount can be further increased.

Seminal stains acquired from fabric surfaces stand as pivotal biological evidence of utmost significance for elucidating sexual assault cases. The ability to determine the temporal aspect of a forensic incident via the analysis of a biological specimen found at the crime scene is crucial in resolving most cases. This study aimed to investigate the time-dependent change in the microbiota structure of human seminal stains exposed to indoor environmental conditions. Stains on polyester fabric generated using semen samples from five male volunteers were kept indoors for varying durations of up to 20 days, followed by sequencing of the V1–V9 regions of the 16S rRNA gene of the microbial DNA extracted from the stains. The acquired data provided the taxonomic composition, and microbial alterations across different days were examined. The most abundantly detected phyla in all samples were Firmicutes, Proteobacteria, and Bacteroidetes, and the relative abundances of bacteria were observed to change over time. Statistically significant changes at the species level were found for Treponema medium, Corynebacterium tuberculostearicum, Faecalibacterium prausnitzii, and Anaerostipes hadrus. Alterations observed in the samples between the analyzed time periods were investigated. The changes during the specified time periods were examined, identifying rare bacterial species that were initially present on certain days but later ceased to exist in the environment. Conversely, bacterial species that were absent before exposure but emerged at a later stage were also identified. The findings of this study demonstrate that species-level evaluations, in particular, can provide crucial insights into semen stain age.

Wound healing is a process getting affected by internal and external factors and might be interrupted by infections. To overcome infections during wound healing, novel antibacterial agents such as antimicrobial peptides have gained popularity because of the rising antibiotic resistance. Therefore, in this study, a three‐dimensional polymeric scaffold was designed for the controlled release of HF‐18 peptide, with the contribution of hyaluronic acid, chondroitin sulfate, and chitosan polymers with the crosslinker genipin. The obtained scaffold structure (OPT) was found to have interconnected pores, was pH‐responsive and swelled more in acidic conditions (5446.5% at pH: 5.0). It was observed that HF‐18‐loaded OPT (P‐OPT) was able to release HF‐18 peptide both in acidic and neutral conditions in a controlled release manner. This study also demonstrated that both OPT and P‐OPT were biocompatible and promoted L929 cell attachment and migration. Antimicrobial activity assessments demonstrated that P‐OPT was effectively bactericidal on Staphylococcus aureus and methicillin‐resistant S. aureus . Moreover, OPT produced a synergistic effect on the antimicrobial activity of HF‐18 peptide, as P‐OPT showed activity below the reported MIC value. As a result, OPT is considered a promising scaffold as a carrier for HF‐18 for wound healing.