983 research outputs found
Sort by
Increased sensivity to infection due to memantine-induced blocking of inlammatory cell trafficking
No full textMemantine is a selective N-methyl-d-aspartate receptor
antagonist, used clinically for treating Alzheimer’s disease. The
proposed mechanism of action is the blocking of inflammatory
cells infiltration into the brain and spinal cord. Previously, we
uncovered the potential of memantine to ameliorate symptoms of
experimental autoimmune encephalomyelitis (EAE) in old rats
[previously published in: Bufan B et al (2024), Biomedicines 12
(4):717]. Here, we have treated female dark agouti rats (3 and 22
months old) with memantine (60 mg/kg body weight) for 7 days
(1st–7th day post-immunization for EAE). On the 7th day, we
assayed peritoneal and blood leukocytes for their phenotype and
functionality. Memantine treatment reduced the expression of the
surface major histocompatibility complex class II (MHCII) on
peritoneal macrophages. Peritoneal macrophages were weakly
responsive to in vitro LPS stimulation. Macrophages from old
rats produced more nitric oxide (NO) ex vivo compared to
macrophages from young rats. Cellularity of peritoneal cavity
was inversely correlated with NO production, however
memantine treatment seemed to reverse that correlation in old
rats. Peritoneal cells from memantine-treated rats responded
differently to phorbol 12-myristate 13-acetate (PMA) – there was
an increased dihidrorhodamine fluorescence in all leucokytes,
which was abrogated with memantine treatment, and in the old
rat group there was a stronger PMA stimulation but reduced
inhibitory effect of memantine. Among blood lymphocytes, there
was a decreased expression of CD49d
(CD43+CD62L+CD49d+), as well as an increased percentage of
CD62L+ cells. Finally, while our results show a more
pronounced effect of memantine in young rats, we have noticed
that old rats under memantine treatment showed signs of nonEAE distress (rough fur, lethargy, respiratory issues). These
results show the fast effect of memantine on a systemic level, as
well as the potential downsides of its mechanism of action. *The
authors marked with an asterisk equally contributed to the work
Investigation of novel clusters of bacterial head-to-tail cyclized peptides from the Bacillus pumilus genome
No full textBacterial headtotail cyclized peptides are a group of ribosomally synthesized and post -translationally modified peptides (RiPPs) of relatively large size. During maturation, the peptideundergoes cyclization, forming a peptide bond between its Cterminus and Nterminus. Comparedto other cyclic RiPPs bacterial cyclized peptides are distinguished by their larger cyclic structureand likely by their cyclization mechanism. The sequences of these peptides are highly diverse, andare not similar to each other. However, they share key properties: remarkable resistance to hightemperatures, proteases, and pH fluctuations. These features make them promising candidates forapplications in food preservation and medicine, for example, as antimicrobial agents. All thesepeptides are hydrophobic, and their mechanism of action is thought to involve disrupting the targetorganism’s membrane. It is believed that they form pores in the membrane, altering ionpermeability and ultimately leading to cell death. However, information on their mode of actionremains scarce, and the mechanisms for specific representat ives of this group are not fullyunderstood. Recently, our research team identified two novel clusters of bacterial headtotailcyclized peptides in the genome of Bacillus pumilus. The clusters differ from each other in boththe primary sequence of the precursor peptide and the number of genes within the cluster.Moreover, one of the clusters contains two precursor peptides, which is highly unusual for a clusterof this type. We tested the antibacterial activity of this strain against a range of Gram positive andGram negative bacteria, observing zones of growth inhibition likely linked to the production ofcyclized peptides. To further investigate their antibacterial activity, functions of genes, andcyclization mechanism, we constructed a recombinant shuttle vector based on the pHT01 plasmidfor heterologous expression of these clusters in another Bacillus strain.BeCELS 2025: Belgrade Conference for Early-Career Life Scientists, taking place on Friday, September 5, 2025, at the Institute of Molecular Genetics and Genetic Engineering (IMGGE) in Belgrad
Discrete changes in peripheral blood lymphocyte population abundance and increased TGF-β1 levels in obese women after supplementation with a novel probiotic formulation
No full textObjective: To evaluate the combination of 7×10^10 CFU
Lactiplantibacillus plantarum 299v (DSM9843), 5×10^9 CFU
Saccharomyces cerevisiae var. boulardii, and 40 mg octacosanol in
a randomized, double-blind, placebo-controlled trial, in particular
the influence on selected immunological parameters, obese
premenopausal women received one capsule daily for three months.
Methods: Cell phenotyping was performed by flow cytometry,
serum TGF-β1 levels were measured using a commercial reagent,
while antibody levels specific for the consumed microorganisms
were measured using an in-house ELISA. Measurements were
performed at two time points, at t=0 and t=1.
Results: In the experimental group, a significant reduction in the
proportion of CD3+CD8+ cells and CD4+CD45RO+ lymphocytes
was observed after 90 days (p=0.0430 and p= 0.0429, respectively).
Contrary, no significant changes in the abundance of CD3+CD4+,
CD3+CD56+ or CD3-CD56+ limphocytes were detected between
the groups or over time. No significant difference was found
in antibody levels specific to the consumed microorganisms.
Elevated total TGF-β1 serum levels were detected in the
intervention group at t=1 (p=0.0045), and at this time point the
difference between the groups was also significant (p=0.0488).
No difference in specific antibody levels was measured.
Conclusions: Here we report that supplementation with a novel
formulation reduced CD3+CD8+ cytotoxic cells and CD4+CD45RO+
memory T-helper cell counts, associated with low grade inflammation
in the peripheral blood. We also detected an increased total serum
TGF-β1, an important regulator of lean-fat body mass. The increase
in TGF-β1 levels has been previously associated with probiotic
consumption which should be examined with further studies
Herd Immunity To The Measles, Mumps And Rubella Viruses Among The Belgradian Population In May, 2024
No full textBackground/Objectives: In the Republic of Serbia, anti-measles vaccination was first introduced in 1971, while combined vaccination (measles, mumps, rubella) was made mandatory in 1996 as part of the national vaccination program. Reported prevalence values for 2023 were: < 0.75 cases per 100K population for measles; 0.09 cases per 100K for mumps; and no cases of rubella. Methods: This cross-sectional study was performed in May, 2024 as part of the project "Herd Immunity to Vaccine-Preventable and Other Relevant Infections in the Belgradian Population." It focused on assessing herd immunity to measles, mumps and rubella (MMR) among residents, insofar as these remain a public concern despite the availability of vaccines. A total of 2,533 subjects were distributed across nine age groups, covering those aged 1-70+ years and various professional groups, residing in Belgrade. Participants were stratified by age and activity. Upon obtaining individual information by online questionnaire, and receiving a signed statement of in-formed consent, blood samples were obtained for IgG antibody testing (ELISA) to de-termine MMR serological status. The results were compared to national and interna-tional immunization standards to evaluate herd immunity levels. Results: Our results indicate varying levels of immunity for each virus, with specific demographic groups showing different immunity levels. Total measles seroprevalence during this study was 74.7%, with significant variation across all age groups. While high seropositivity was observed in both children (90.7%) and elder age groups (98.4%), middle-aged individuals in the age group 30-49 years showed significantly lower IgG levels. Between 2021 and 2023, there were no registered cases of rubella detected in Serbia, which indicates a high level of immunity. This was confirmed here with consistently high IgG levels across all age groups, with an average seropositivity of 94.8%. Average mumps seropositivity across all age groups was 85.1%. The lowest value was in the young child (1-5 years) age group (76.1%); the highest was in the elderly group (92.6%). Conclusions: The current findings suggest that the Belgradian population has strong overall immunity to MMR, yet with some concerns regarding measles immunity in middle-aged adults, suggesting a potential need for catch-up vaccinations. While rubella status indicates strong herd immunity and minimal risk of outbreaks, mumps immunity in some groups (children, middle-aged adults) is below the protective threshold. While it is still sufficient to pre-vent widespread transmission, it should be closely observed. To our knowledge, this study is the first of its kind to provide data about MMR seroprevalence in Belgrade. Findings indicate the need for constant surveillance and revaccination of vulnera-ble/seronegative groups
Modulation of BCG-induced immune response using β-glucan: boosting immune regulation and reducing severe inflammatory reactions
No full textBCG (Bacillus Calmette-Gue´rin) vaccination is well-known for
its ability to stimulate immune responses, which lead to trained
immunity and various inflammatory responses. The addition of
β-glucan, a recognized immunomodulator, may help redirect this
response toward a more balanced immune response. The
interaction between BCG and β-glucan in modulating monocyte
and macrophage populations remains an unexplored topic. Aim
of this study was to investigate the effects of BCG and β-glucan
on immune cell populations in mice. Sixteen animals were
divided into four test groups, with three groups receiving
intraperitoneal treatment with BCG, β-glucan, or a combination
of both. Flow cytometry analysis of peritoneal cells, spleen, bone
marrow, and PBMC showed varying immune responses among
the groups. BCG alone triggered a robust inflammatory reaction,
increasing the population of M1 macrophages and dendritic cells,
along with the expression of MHCII and CD11b. β-glucan also
expanded these populations, indicating independent immune
activation. However, in the BCG+β-glucan group, a decrease in
inflammatory monocytes was observed, suggesting that β-glucan
tempers excessive inflammation when combined with BCG. The
reduction of MHCII+CD11blowF4/80+CD11c- macrophages in BCG+β-glucan group compared to the β-glucan group alone
suggests that β-glucan modulates BCG-induced inflammation by
favoring immune regulation over prolonged activation.
Furthermore, MHCII+CD19+ B cells were progressively reduced
in the BCG and β-glucan group, most significantly in the
BCG+β-glucan group, indicating a shift in B cell dynamics
toward regulatory or antibody-secreting phenotypes. These
findings indicate that β-glucan does not merely enhance BCGinduced activation but modulates it, balancing inflammatory and
regulatory immune pathways. The combination of BCG and βglucan leads to controlled immune activation, limiting excessive
inflammation while supporting immune adaptation. *The authors
marked with an asterisk equally contributed to the work
Prognostic Impact of Vaccination, Comorbidity, and Inflammatory Biomarkers on Clinical Outcome in Hospitalized Patients with COVID-19
No full textBackground/Objectives: The coronavirus disease 2019 (COVID-19) has more severe symptoms and increased mortality among men than women. To address the prognostic impact of vaccination, comorbidities, and inflammatory biomarkers on classified clinical outcomes in hospitalized COVID-19 patients, we compared common and sex differences. Methods: Besides laboratory and clinical parameters at hospital admission, we performed a common and sex-based comparative analysis for the clinical outcomes, RT-qPCR analyses, and measured severe acute respiratory syndrome coronavirus (SARS-CoV-2)-specific IgM and IgG antibody levels of 702 COVID-19 patients in a single centre from June 2020 to April 2022. Results: Pro-inflammatory biomarkers (C-reactive protein (CRP), interleukin-6 (IL-6), fibrinogen, lactate dehydrogenase (LDH), D-dimer, ferritin), and liver enzymes (AST, ALT, GGT) were significantly more increased in COVID-19 male patients and generally elevated with the severity of clinical outcome, regardless of the SARS-CoV-2 variant. Cycle threshold (Ct) values of RT-qPCR testing were in negative correlation with IL-6 in COVID-19 male patients, indicating that higher viral load largely increased IL-6 levels in parallel with the severity of clinical outcome and regardless of vaccination. IgG levels were higher in early post-COVID-19 male patients. Comorbidities were more frequent in COVID-19 female patients and generally more common in the severe clinical outcomes. Vaccination was negatively correlated with the severity of clinical outcome, liver enzymes, LDH, and inflammatory parameters in hospitalized COVID-19 patients, while the risk of pneumonia was reduced. Vaccination reduced the need for corticosteroid and anti-inflammatory therapies, but increased the need for antiviral drug treatment. Conclusions: In addition to confirming inflammatory biomarkers and the importance of anti-inflammatory therapy in vaccinated patients, this study showed that vaccination reduces, but does not prevent, mortality in patients with COVID-19
Bioinformatic discovery of novel collagen-binding aggregation factors in lactic acid bacteria
No full textLactic acid bacteria (LABs) are a unique group of microorganisms found in the diet of nearly all humans and form an integral part of the healthy human microbiome. Some LAB strains exhibit a remarkable ability for autoaggregation, mediated by Snowflake Forming Collagen Binding Aggregation Factors (SFCBAFs)—a fascinating group of proteins described so far only in LABs. To date, only five SFCBAFs have been characterized in detail: AggL from Lactococcus lactis, AggE from Enterococcus faecium, AggLb from Lacticaseibacillus paracasei, AggLr from Lactococcus raffinolactis, and AggA from Tetragenococcus halophilus. In this study, we present bioinformatically predicted novel SFCBAF candidates and demonstrate their widespread distribution among LAB species. Furthermore, we provide evidence that such proteins may not be exclusive to LABs, as homologous sequences were also identified in phylogenetically distant bacteria such as Staphylococcus aureus, Oceanobacillus spp., Bacillus spp., and others, expanding our understanding of this unique protein family
Probiotic Supplementation Improves Hematological Indices and Morphology of Red Blood Cells and Platelets in Obese Women: A Double-Blind, Controlled Pilot Study
No full textBackground/Objectives: The prevalence of obesity worldwide has rapidly increased. Numerous studies showed a beneficial effect of probiotics in obese individuals, and changes in hematological parameters are observed in obesity. Therefore, the aim of this study was to investigate the effect of a novel probiotic approach on the red blood cells (RBCs) and platelets. Methods: Twenty-five obese women participated in a randomized, placebo-controlled study and were divided into the experimental group (one capsule daily containing Lactiplantibacillus plantarum 299v (DSM9843), Saccharomyces cerevisiae var. boulardii, and 40 mg octacosanol; n = 13) and the placebo group (n = 12). Blood samples were collected for light microscopic examination, morphometric analysis, and an automated hematology analyzer. A possible relationship between hematological parameters and body mass index (BMI), a common indicator of obesity, was investigated using Spearman correlation. The plasma concentration of soluble P-selectin and fibrinogen were determined using an ELISA assay. All measurements were performed before (T0) and after 12 weeks of supplementation (T1). Results: The three-month supplementation of probiotics improved hemoglobin levels, chromic status, and red blood cell morphology. The mean platelet volume (MPV), a measure of platelet size, was restored to normal levels, platelet morphology was improved, and the number of activated platelets was significantly reduced (p < 0.05). A strong negative correlation (r = −0.5904, p < 0.05) was found between BMI and platelet distribution width (PDW), a measure of variation in platelet size and shape. Conclusions: The results show that the probiotic approach improves morphology and normalizes the values of disturbed hematological parameters of RBCs and platelets in obese women
Identification and Characterization of New Hafnia Strains from Common Carp (Cyprinus carpio), Potentially Possessing Probiotic Properties and Plastic Biodegradation Capabilities
No full textFinding and characterizing new bacterial strains, including probiotic strains, is a crucial task in today’s world to expand the genetic data pool and identify new genes. In this study, we investigated the gut microbiota of one industrial species, Cyprinus carpio, and identified representatives of various microbial genera, including Citrobacter, Serratia, Bacillus, Enterococcus, and Kocuria. Notably, we discovered two strains of Hafnia with potentially probiotic properties. We conducted next-generation sequencing (NGS) of these strains, described their antibiotic resistance and antibacterial activity, and compared them with other representatives of the Hafnia genus. These strains, characterized by rapid growth, the presence of the ClpB heat shock protein gene, and genes associated with microplastic degradation, provide a promising basis for further research, including studies on their potential application in plastic biodegradation
Utilizing the Banana S-Adenosyl-L-Homocysteine Hydrolase Allergen to Identify Cross-Reactive IgE in Ryegrass-, Latex-, and Kiwifruit-Allergic Individuals
No full textFood allergies mediated by specific IgE (sIgE) have a significant socioeconomic impact on society. Evaluating the IgE cross-reactivity between allergens from different allergen sources can enable the better management of these potentially life-threatening adverse reactions to food proteins and enhance food safety. A novel banana fruit allergen, S-adenosyl-L-homocysteine hydrolase (SAHH), has been recently identified and its recombinant homolog was heterologously overproduced in E. coli. In this study, we performed a search in the NCBI (National Center for Biotechnology Information) for SAHH homologs in ryegrass, latex, and kiwifruit, all of which are commonly associated with pollen-latex-fruit syndrome. In addition, Western immunoblot analysis was utilized to identify the cross-reactive IgE to banana SAHH in the sera of patients with a latex allergy, kiwifruit allergy, and ryegrass allergy. ClustalOmega analysis showed more than 92% amino acid sequence identity among the banana SAHH homologs in ryegrass, latex, and kiwifruit. In addition to five B-cell epitopes, in silico analysis predicted eleven T-cell epitopes in banana SAHH, seventeen in kiwifruit SAHH, twelve in ryegrass SAHH, and eight in latex SAHH, which were related to the seven-allele HLA reference set (HLA-DRB1*03:01, HLA-DRB1*07:01, HLA-DRB1*15:01, HLA-DRB3*01:01, HLA-DRB3*02:02, HLA-DRB4*01:01, HLA-DRB5*01:01). Four T-cell epitopes were identical in banana and kiwifruit SAHH (positions 328, 278, 142, 341), as well as banana and ryegrass SAHH (positions 278, 142, 96, and 341). All four SAHHs shared two T-cell epitopes (positions 278 and 341). In line with the high amino acid sequence identity and B-cell epitope homology among the analyzed proteins, the cross-reactive IgE to banana SAHH was detected in three of three latex-allergic patients, five of six ryegrass-allergic patients, and two of three kiwifruit-allergic patients. Although banana SAHH has only been studied in a small group of allergic individuals, it is a novel cross-reactive food allergen that should be considered when testing for pollen-latex-fruit syndrome