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ELLSA based profiling of surface glycosylation in microorganisms reveals that ss-glucan rich yeasts' surfaces are selectively recognized with recombinant banana lectin
Get PDFThe surface of microorganisms is covered with polysaccharide structures which are in immediate contact with receptor structures on host's cells and antibodies. The interaction between microorganisms and their host is dependent on surface glycosylation and in this study we have tested the interaction of plant lectins with different microorganisms. Enzyme-linked lectin sorbent assay - ELLSA was used to test the binding of recombinant Musa acuminata lectin - BL to 27 selected microorganisms and 7 other lectins were used for comparison: Soy bean agglutinin - SBA, Lens culinaris lectin - LCA, Wheat germ agglutinin - WGA, RCA(120) - Ricinus communis agglutinin, Con A - from Canavalia ensiformis, Sambucus nigra agglutinin - SNA I and Maackia amurensis agglutinin - MAA. The goal was to define the microorganisms' surface glycosylation by means of interaction with the selected plant lectins and to make a comparison with BL. Among the tested lectins most selective binding was observed for RCA(120) which preferentially bound Lactobacillus casei DG. Recombinant banana lectin showed specific binding to all of the tested fungal species. The binding of BL to Candida albicans was further tested with fluorescence microscopy and flow cytometry and it was concluded that this lectin can differentiate ss-glucan rich surfaces. The binding of BL to S. boulardii could be inhibited with ss-glucan from yeast with IC50 1.81 mu g mL(-1) and to P. roqueforti with 1.10 mu g mL(-1). This unique specificity of BL could be exploited for screening purposes and potentially for the detection of ss-glucan in solutions.This is the peer‐reviewed version of the article: (1) Dragačević, L.; Đorđević, B.; Gavrović-Jankulović, M.; Ilić, V.; Kanazir, D.; Minić, R. ELLSA Based Profiling of Surface Glycosylation in Microorganisms Reveals That Ss-Glucan Rich Yeasts’ Surfaces Are Selectively Recognized with Recombinant Banana Lectin. Glycoconjugate Journal 2020, 37 (1), 95–105. [https://doi.org/10.1007/s10719-019-09898-8]
Diversity of non-starter lactic acid bacteria in autochthonous dairy products from Western Balkan Countries - Technological and probiotic properties
No full textThe aim of this review was to summarize the data regarding diversity of non-starter lactic acid bacteria (NSLAB) isolated from various artisanal dairy products manufactured in Western Balkan Countries. The dairy products examined were manufactured from raw cow's, sheep's or goat's milk or mixed milk, in the traditional way without the addition of commercial starter cultures. Dairy products such as white brined cheese, fresh cheese, hard cheese, yogurt, sour cream and kajmak were sampled in the households of Serbia, Croatia, Slovenia, Bosnia and Herzegovina, Montenegro, and North Macedonia. It has been established that the diversity of lactic acid bacteria (LAB) from raw milk artisanal dairy products is extensive. In the reviewed literature, 28 LAB species and a large number of strains belonging to the Lactobacillus, Lactococcus, Enterococcus, Streptococcus, Pediococcus, Leuconostoc and Weissella genera were isolated from various dairy products. Over 3000 LAB strains were obtained and characterized for their technological and probiotic properties including: acidification and coagulation of milk, production of aromatic compounds, proteolytic activity, bacteriocins production and competitive exclusion of pathogens, production of exopolysaccharides, aggregation ability and immunomodulatory effect. Results show that many of the isolated NSLAB strains had one, two or more of the properties mentioned. The data presented emphasize the importance of artisanal products as a valuable source of NSLAB with unique technological and probiotic features important both as a base for scientific research as well as for designing novel starter cultures for functional dairy food.Peer-reviewed manuscript: [https://intor.torlakinstitut.com/handle/123456789/733
Antimicrobial immunoglobulin prophylaxis and therapy
No full textImmunoglobulins, either natural or induced, represent powerful means for eliminating microbial threats. For decades, vaccines have been used which function by inducing antibodies for the successful elimination of microbes, preventing disease and mortality. Polyclonal immunoglobulin products from human plasma were used for the first time to treat immune deficiency during the 1950s. Nowadays, the administration of immunoglobulin, either intravenous or subcutaneous, is the cornerstone of the treatment of primary immunodeficiency affecting the humoral immune system. The therapy can help people with weakened or underdeveloped immune system fight off infections. This is also the treatment of choice for certain autoimmune and neurological diseases. The polyclonal antibody preparation consists of both natural antibodies and antigen-induced antibodies and reflects the history of antigen experience of the donor population. Natural antibodies are germline-encoded, polyspecific, low-affinity antibodies that also have a regulatory role in maintaining the immune system homeostasis. Antibody preparations, enriched for certain desired specificities, or hyperimmune human globulins are used for prophylaxis and treatment of infectious diseases with a high mortality rate. It was shown that lymphocytes from survivors of viral infections, without available vaccines, could be used for protective monoclonal antibodies production. This chapter provides insight into the current knowledge of the usage of antibody preparations, efficacy and mechanism of action, with respect to specific diseases, including the treatment of infectious diseases and future prospects
Sex differences in Tfh cell help to B cells contribute to sexual dimorphism in severity of rat collagen-induced arthritis
Get PDFThe study examined germinal centre (GC) reaction in lymph nodes draining inflamed joints and adjacent tissues (dLNs) in male and female Dark Agouti rat collagen type II (CII)-induced arthritis (CIA) model of rheumatoid arthritis. Female rats exhibiting the greater susceptibility to CIA mounted stronger serum CII-specific IgG response than their male counterparts. This correlated with the higher frequency of GC B cells in female compared with male dLNs. Consistently, the frequency of activated/proliferating Ki-67+ cells among dLN B cells was higher in females than in males. This correlated with the shift in dLN T follicular regulatory (Tfr)/T follicular helper (Tfh) cell ratio towards Tfh cells in females, and greater densities of CD40L and CD40 on their dLN T and B cells, respectively. The higher Tfh cell frequency in females was consistent with the greater dLN expression of mRNA for IL-21/27, the key cytokines involved in Tfh cell generation and their help to B cells. Additionally, in CII-stimulated female rat dLN cell cultures IFN-gamma /IL-4 production ratio was shifted towards IFN-gamma. Consistently, the serum IgG2a(b)/IgG1 CII-specific antibody ratio was shifted towards an IgG2a(b) response in females. Thus, targeting T-/B-cell interactions should be considered in putative further sex-based translational pharmacology research
ELLSA based profiling of surface glycosylation in microorganisms reveals that ss-glucan rich yeasts' surfaces are selectively recognized with recombinant banana lectin
No full textThe surface of microorganisms is covered with polysaccharide structures which are in immediate contact with receptor structures on host's cells and antibodies. The interaction between microorganisms and their host is dependent on surface glycosylation and in this study we have tested the interaction of plant lectins with different microorganisms. Enzyme-linked lectin sorbent assay - ELLSA was used to test the binding of recombinant Musa acuminata lectin - BL to 27 selected microorganisms and 7 other lectins were used for comparison: Soy bean agglutinin - SBA, Lens culinaris lectin - LCA, Wheat germ agglutinin - WGA, RCA(120) - Ricinus communis agglutinin, Con A - from Canavalia ensiformis, Sambucus nigra agglutinin - SNA I and Maackia amurensis agglutinin - MAA. The goal was to define the microorganisms' surface glycosylation by means of interaction with the selected plant lectins and to make a comparison with BL. Among the tested lectins most selective binding was observed for RCA(120) which preferentially bound Lactobacillus casei DG. Recombinant banana lectin showed specific binding to all of the tested fungal species. The binding of BL to Candida albicans was further tested with fluorescence microscopy and flow cytometry and it was concluded that this lectin can differentiate ss-glucan rich surfaces. The binding of BL to S. boulardii could be inhibited with ss-glucan from yeast with IC50 1.81 mu g mL(-1) and to P. roqueforti with 1.10 mu g mL(-1). This unique specificity of BL could be exploited for screening purposes and potentially for the detection of ss-glucan in solutions
Antiproliferative and antimigratory effects of 3-(4-substituted benzyl)-5-isopropyl-5-phenylhydantoin derivatives in human breast cancer cells
Get PDFIn this study, a series of synthesized 3-(4-substituted benzyl)-5-isopropyl-5-phenylhydantoin derivatives as a potential antiproliferative and antimigratory agents were investigated. The possible antitumor mechanisms of investigated hydantoin derivatives were examined on human breast cancer cell line MDA-MB-231. The cells were treated with different concentrations of compounds (from 0.01 mu M to 100 mu M) during 24 h and 72 h. The proliferation index, nitric oxide production, apoptosis rate, and migration capacity were measured. The cell invasion potential was examined by measuring the level of MMP-9 and COX-2 gene expression. All tested compounds expressed antiproliferative activity and induced dose- and time-dependent increase in the level of nitrites. The investigated molecules significantly decreased cell survival rate, migration capacity and the expression levels of genes included in the process of tumor invasion. Obtained data suggest that the tested hydantoin derivatives express considerable antitumor activity by reducing cell division rate, elevating apoptosis level, and inhibiting the motility and invasiveness of breast cancer cells. The results obtained in this study indicate that investigated compounds express potential as a novel chemotherapeutic agents against breast cancer growth and progression. (C) 2020 The Author(s). Published by Elsevier B.V. on behalf of King Saud University
Comparison of Specific IGG and IGA Subclass Levels to Lactobacillus and Streptococcus in Young Healthy Adults
No full textDigestomics of Cow's Milk: Short Digestion-Resistant Peptides of Casein Form Functional Complexes by Aggregation
Get PDFThe aim of this study was to identify short digestion-resistant peptides (SDRPs) released by pepsin digestion of the whole cow's milk and examine their IgE reactivity and allergenicity. Raw milk was subjected to simulated gastric digestion. SDRPs were fractionated from the digests and identified by MS. Milk SDRPs were evaluated for aggregability, propensity to compete for IgE binding with individual milk allergens, and ability to bind IgG4 from allergic and milk-tolerant individuals. The majority of milk SDRPs originated from caseins (97% of peptides) and overlapped with the known IgE epitopes of cow's milk allergens. SDRPs competed with milk proteins for binding to human IgE and readily formed aggregates. The average peptide length was 10.6 +/- 3.5 amino acids. The ability to provoke allergenic in vivo responses was confirmed by skin-prick testing (SPT) in five milk-allergic subjects. This was attributed to the peptide ability to aggregate into non-covalent complexes. SDRPs are able to induce response in SPT, but only in 50% of the sera SDRPs were able to inhibit IgG4 binding to caseins. Hence, SDRPs corresponding to the mainly continuous epitopes of milk proteins induce allergenic in vivo responses in milk-allergic subjects due to aggregation.Supplementary information: [https://hdl.handle.net/21.15107/rcub_intor_645
Optimization, Validation and Standardization of ELISA
Get PDFThe enzyme-linked immunosorbent assay (ELISA) is a commonly used analytical immunochemistry assay based on the specific bond between the antigen and the antibody. The application of this test has significantly changed the practice of medical laboratories in which it is used for detection and quantification of molecules such as hormones, peptides, antibodies, and proteins. Various technical variants of this test can detect antigen (native or foreign) or antibody, determine the intensity of the immune response whether pathological or not; the type of induced immune response as well as the innate immunity potential; and much more. These capabilities, as well as the high sensitivity and robustness of the test and a small price, make it possible to quickly and reliably diagnose diseases in most laboratories. Besides, ELISA is a test that is also used in veterinary medicine, toxicology, allergology, food industry, etc. Despite the fact that it has existed for almost 50 years, different ELISA tests with different technical solutions are still being developed, which improves and expands the application of the this exceptional test. The aim of this chapter is to empower the rider to optimize, standardize and validate an enzyme linked immunosorbent assay
Strain specificities in influence of ageing on germinal centre reaction to inactivated influenza virus antigens in mice: Sex-based differences
No full textConsidering variability in vaccine responsiveness across human populations, in respect to magnitude and quality, and importance of vaccines in the elderly, the influence of recipient genetic background on the kinetics of age-related changes in the serum IgG antibody responses to seasonal trivalent inactivated split-virus influenza bulk (TIV) was studied in BALB/c and C57BL/6 mice showing quantitative and qualitative differences in this responses in young adult ages. With ageing the total serum IgG response to influenza viruses declined, in a strain-specific manner, so the strain disparity observed in young adult mice (the greater magnitude of IgG response in BALB/c mice) disappeared in aged mice. However, the sexual dimorphisms in this response (more prominent in females of both strains) remained in aged ones. The strain-specific differences in age-related decline in the magnitude of IgG response to TIV correlated with the number of germinal centre (GC) B splenocytes. The agerelated decline in GC B cell number was consistent with the decrease in the proliferation of B cells and CD4 + cells in splenocyte cultures upon restimulation with TIV. Additionally, the age-related decrease in the magnitude of IgG response correlated with the increase in follicular T regulatory (fTreg)/follicular T helper (fTh) and fTreg/GC B splenocyte ratios (reflecting decrease in fTh and GC B numbers without changes in fTreg number), and the frequency of CD4 + splenocytes producing IL-21, a key factor in balancing the B cell and fTreg cell activity. With ageing the avidity of virus influenza-specific antibody increased in females of both strains. Moreover, ageing affected IgG2a/IgG1 and IgG2c/IgG1 ratios (reflecting Thl/Th2 balance) in male BALB/c mice and female C57BL/6 mice, respectively. Consequently, differently from young mice exhibiting the similar ratios in male and female mice, in aged female mice of both strains IgG2a(c)/IgG1 ratios were shifted towards a less effective IgG1 response (stimulated by IL-4 cytokines) compared with males. The age-related alterations in IgG subclass profiles in both strains correlated with those in IFN-gamma/IL-4 production level ratio in splenocyte cultures restimulated with TIV. These findings stimulate further research to formulate sex-specific strategies to improve efficacy of influenza vaccine in the elderly