Reactive oxygen species (ROS), byproducts of cellular metabolism and environmental factors, are linked to diseases like cancer and aging. Antioxidant peptides (AOPs) have emerged as effective countermeasures against ROS-induced damage. The genus is well known for its extraordinary resilience to ionizing radiation (IR) and possesses complex antioxidant systems designed to neutralize ROS generated by IR.
View Article and Find Full Text PDFRecently, respiratory syncytial virus (RSV) vaccines based on the prefusion F (pre-F) antigen were approved in the United States. We aimed to develop an enzyme-linked immunosorbent assay (ELISA)-based protocol for the practical and large-scale evaluation of RSV vaccines. Two modified pre-F proteins (DS-Cav1 and SC-TM) were produced by genetic recombination and replication using an adenoviral vector.
View Article and Find Full Text PDFLow-dose radiation therapy (LDRT) can suppress intractable inflammation, such as that in rheumatoid arthritis, and is used for treating more than 10,000 rheumatoid arthritis patients annually in Europe. Several recent clinical trials have reported that LDRT can effectively reduce the severity of coronavirus disease (COVID-19) and other cases of viral pneumonia. However, the therapeutic mechanism of LDRT remains unelucidated.
View Article and Find Full Text PDFRespiratory syncytial virus (RSV) is a common respiratory pathogen that causes lower respiratory diseases among infants and elderly people. Moreover, formalin-inactivated RSV (FI-RSV) vaccine induces serious enhanced respiratory disease (ERD). Radiation has been investigated as an alternative approach for producing inactivated or live-attenuated vaccines, which enhance the antigenicity and heterogeneous protective effects of vaccines compared with conventional formalin inactivation.
View Article and Find Full Text PDFThere is a substantial need for the development of biomaterials for protecting hematopoietic stem cells and enhancing hematopoiesis after radiation damage. Bacterial exopolysaccharide (EPS) has been shown to be very attractive to researchers as a radioprotectant owing to its high antioxidant, anti-cancer, and limited adverse effects. In the present study, we isolated EPS from a novel strain, BRD125, which produces EPS in high abundance, and investigated its applicability as a radioprotective biomaterial.
View Article and Find Full Text PDFDeinococcus radiodurans is an extremophile, well known to be extremely resistant to external stresses due to its unique physiological system and structure of cellular components. Although the proportion of D. radiodurans has been reported to be negatively correlated with atopic dermatitis, the exact function of D.
View Article and Find Full Text PDFis a leading cause of food-borne diseases in humans worldwide, resulting in severe morbidity and mortality. They are carried asymptomatically in the intestine or gallbladder of livestock, and are transmitted predominantly from animals to humans the fecal-oral route. Thus, the best preventive strategy is to preemptively prevent transmission to humans by vaccinating livestock.
View Article and Find Full Text PDFis an extremely resistant bacterium against extracellular stress owing to on its unique physiological functions and the structure of its cellular constituents. Interestingly, it has been reported that the pattern of alteration in proportion on the skin is negatively correlated with skin inflammatory diseases, whereas the proportion of was increased in patients with chronic skin inflammatory diseases. However, the biological mechanisms of deinococcal interactions with other skin commensal bacteria have not been studied.
View Article and Find Full Text PDFInitiation and progression of oral infectious diseases are associated with streptococcal species. Bacterial infection induces inflammatory responses together with reactive oxygen species (ROS), often causing cell death and tissue damage in the host. In the present study, we investigated the effects of oral streptococci on cytotoxicity and ROS production in human periodontal ligament (PDL) cells.
View Article and Find Full Text PDFsubsp. serovar Gallinarum (SG) is a common pathogen in chickens, and causes an acute systemic disease that leads to high mortality. The live attenuated vaccine 9R is able to successfully protect chickens older than six weeks by activating a robust cell-mediated immune response, but its safety and efficacy in young chickens remains controversial.
View Article and Find Full Text PDFStreptococcus agalactiae is the leading cause of meningitis in newborns and a significant cause of invasive diseases in pregnant women and adults with underlying diseases. Antibiotic resistance against erythromycin and clindamycin in group B streptococcus (GBS) isolates has been increasing worldwide. GBS expresses the Srr1 and Srr2 proteins, which have important roles in bacterial infection.
View Article and Find Full Text PDFExpression of bacteriophage lysin by Streptococcus oralis strain SF100 is thought to be important for the pathogenesis of infective endocarditis, due to its ability to mediate bacterial binding to fibrinogen. To better define the lysin binding site on fibrinogen Aα, and to investigate the impact of binding on fibrinolysis, we examined the interaction of lysin with a series of recombinant fibrinogen Aα variants. These studies revealed that lysin binds the C-terminal region of fibrinogen Aα spanned by amino acid residues 534 to 610, with an affinity of equilibrium dissociation constant () of 3.
View Article and Find Full Text PDF(pneumococcus) can cause respiratory and systemic diseases. Recently, γ-irradiation-inactivated, non-encapsulated, intranasal (r-SP) vaccine has been introduced as a novel serotype-independent and cost-effective vaccine. However, the immunogenic mechanism of r-SP is poorly understood.
View Article and Find Full Text PDFHum Vaccin Immunother
February 2021
The most widely used influenza vaccines are prepared by chemical inactivation. However, chemical, especially formalin, treatment-induced modifications of the antigenic structure of the virus are frequently associated with adverse effects including low efficacy of protection, unexpected immune responses, or exacerbation of disease. Gamma-irradiation was suggested as an alternative influenza virus inactivation method due to its great features of completely inactivating virus while not damaging the structures of protein antigens, and cross-protective ability against heterologous strains.
View Article and Find Full Text PDFSalmonella enterica serovar Typhimurium causes invasive non‑typhoidal Salmonella diseases in animals and humans, resulting in a high mortality rate and huge economic losses globally. As the prevalence of antibiotic‑resistant Salmonella has been increasing, vaccination is thought to be the most effective and economical strategy to manage salmonellosis. The present study aimed to investigate whether dysfunction in the phosphoenolpyruvate:carbohydrate phosphotransferase system (PTS), which is critical for carbon uptake and survival in macrophages, may be adequate to generate Salmonella‑attenuated vaccine strains.
View Article and Find Full Text PDFA critical limitation of Salmonella typhimurium (S. typhimurium) as an anti-cancer agent is the loss of their invasive or replicative activities, which results in no or less delivery of anti-cancer agents inside cancer cells in cancer therapy. Here we developed an oxytolerant attenuated Salmonella strain (KST0650) from the parental KST0649 (ΔptsIΔcrr) strain using radiation mutation technology (RMT).
View Article and Find Full Text PDFis the most common respiratory bacterial pathogen among cases of community-acquired infection in young children, older adults, and individuals with underlying medical conditions. Although capsular polysaccharide-based pneumococcal vaccines have contributed to significant decrease in invasive pneumococcal infections, these vaccines have some limitations, including limited serotype coverage, lack of effective mucosal antibody responses, and high costs. In this study, we investigated the safety and immunogenicity of a live, whole-cell pneumococcal vaccine constructed by deleting the gene for prolipoprotein diacylglyceryl transferase () from the encapsulated pneumococcal strain TIGR4 (TIGR4Δ) for protection against heterologous pneumococcal strains.
View Article and Find Full Text PDFIntroduction: Apical periodontitis is an inflammatory disease in the periradicular region of teeth that results from infection by multispecies bacterial biofilm residing in the root canal system. In this study, we investigated whether Lactobacillus plantarum lipoteichoic acid (Lp.LTA) could inhibit multispecies oral pathogenic bacterial biofilm formation.
View Article and Find Full Text PDFEnterococcus faecalis, a Gram-positive bacterium commonly isolated in patients with refractory apical periodontitis, invades dentin tubules easily and forms biofilms. Bacteria in biofilms, which contribute to recurrent and/or chronic inflammatory diseases, are more resistant to antimicrobial agents than planktonic cells and easily avoid phagocytosis. Although Lactobacillus plantarum lipoteichoic acid (Lp.
View Article and Find Full Text PDFSalmonella enterica is a major human pathogen that causes invasive non-typhoidal Salmonellosis (iNTS), resulting in significant morbidity and mortality. Although a number of pre-clinical and clinical studies have reported on the feasibility of developing a safe and effective vaccine against iNTS, there have been no licensed Salmonella vaccines available to protect against NTS strains. Vaccine formulations of highest priority for NTS are live attenuated vaccines, which can elicit effective induction of intestinal mucosal and intracellular bacteria-specific cell mediated immune responses.
View Article and Find Full Text PDFGram-positive bacteria such as Streptococcus gordonii causing life-threatening infective endocarditis are mainly recognized by Toll-like receptor 2 (TLR2). Lipoteichoic acid (LTA) and lipoproteins are representative TLR2 ligands that play important roles in bacterial infection and in host inflammatory responses. In the present study, we generated an LTA-deficient mutant (ΔltaS) and a lipoprotein-deficient mutant (Δlgt) and investigated the contributions of LTA and lipoproteins to bacterial morphology and their effect on induction of proinflammatory cytokines in THP-1 and mouse bone-marrow derived macrophages (BMDMs).
View Article and Find Full Text PDFDendritic cells (DCs) play an important role in antigen presentation, which is an essential step for the induction of antigen-specific adaptive immunity. Inactivated bacterial whole cell vaccines have been widely used to prevent many bacterial infections because they elicit good immunogenicity due to the presence of various antigens and are relatively inexpensive and easy to manufacture. Recently, gamma-irradiated whole cells of nonencapsulated Streptococcus pneumoniae were developed as a broad-spectrum and serotype-independent multivalent vaccine.
View Article and Find Full Text PDFA biofilm is an aggregate of microorganisms in which cells adhere to biological or non-biological surfaces and is responsible for various infectious diseases. Infections caused by , including pneumonia, endocarditis, and osteomyelitis, are often associated with colonization and biofilm formation. Although lipoteichoic acid (LTA) is involved in biofilm formation, the specific role of LTA is not clearly understood.
View Article and Find Full Text PDFDental caries is a biofilm-dependent oral disease and Streptococcus mutans is the known primary etiologic agent of dental caries that initiates biofilm formation on tooth surfaces. Although some Lactobacillus strains inhibit biofilm formation of oral pathogenic bacteria, the molecular mechanisms by which lactobacilli inhibit bacterial biofilm formation are not clearly understood. In this study, we demonstrated that Lactobacillus plantarum lipoteichoic acid (Lp.
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