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Noradrenaline synthesized locally in draining lymph node cells modulates CD4+ T-cell development in rat EAE model: a role for a1-adrenoceptor
No full textIntroduction: It has been suggested that: i) noradrenaline synthesis in ,,adrenergic“ immune cells changes during development of EAE and multiple sclerosis and ii) noradrenaline influences EAE development through a1−adrenoceptor. To elucidate mechanisms standing behind this phenomenon, a1−adrenoceptor−mediated influence of draining lymph node (dLN) cell−derived noradrenaline on CD4+ T−cell response in dLNs from Dark Agouti rats of both sexes immunized for EAE was examined. Methods: Cells recovered from dLNs on 7th day post−immunization were examined for noradrenaline synthesis/content and a1B−adrenoceptor expression using HPLC and/or flow cytometry. Additionally, effects of prazosin (a1- AR blocker) on CD4+ T−cell proliferation, the frequency of IL−17+ CD4+ T−cells and regulatory (Foxp3+CD25+) CD4+ T−cells (Tregs), activational/maturational molecule expression on antigen presenting cells (APCs) and their cytokine profile in dLN cell culture were examined using flow cytometry and/or qRT−PCR/ELISA. Results: Irrespective of sex, conventional CD4+ T−cells and Tregs, and APCs from rat dLNs synthesized noradrenaline, while only Tregs and APCs expressed a1B-adrenoceptor.
In myelin basic protein−stimulated dLN cell cultures from rats of both sexes prazosin increased Treg frequency and Foxp3 expression, but diminished co−stimulatory CD80 and CD86
molecule expression on APCs, thereby reducing CD4+ cell proliferation
Intrinsic and Extrinsic Thymic Adrenergic Networks: Sex Steroid-Dependent Plasticity
Get PDFThe thymus is sexually differentiated organ providing microenvironment for T-cell precursor differentiation/maturation in the major histocompatibility complex-restricted self-tolerant T cells. With increasing age, the thymus undergoes involution leading to the decline in efficacy of thymopoiesis. Noradrenaline from thymic nerve fibers and "(nor) adrenergic" cells is involved in the regulation of thymopoiesis. In rodents, noradrenaline concentration in thymus and adrenoceptor (AR) expression on thymic cells depend on sex and age. These differences are suggested to be implicated in the development of sexual diergism and the age-related decline in thymopoiesis. The programming of both thymic sexual differentiation and its involution occurs during the critical early perinatal period and may be reprogrammed during peripubertal development. The thymic (re) programming is critically dependent on circulating levels of gonadal steroids. Although the underlying molecular mechanisms have not yet been elucidated fully, it is assumed that the gonadal steroid action during the critical perinatal/peripubertal developmental periods leads to long-lasting changes in the efficacy of thymopoiesis partly through (re) programming of "(nor) adrenergic" cell networks and AR expression on thymic cells
AggLr, a novel aggregation factor in Lactococcus raffinolactis BGTRK10-1: its role in surface adhesion
No full textThe ability of lactic acid bacteria to form multi-cellular aggregates via self-aggregation is regarded as an important mechanism for stress tolerance, adhesion, colonization and genetic material exchange. The novel aggLr gene encoding for the auto-aggregation promoting protein (AggLr) of Lactococcus raffinolactis BGTRK10-1 was cloned. Heterologous expression of AggLr enabled auto-aggregation, higher hydrophobicity and collagen and fibronectin binding of the carrier strains. Domain analysis and the type of aggregates formed by cells expressing AggLr confirmed that this aggregation factor belongs to the family of high molecular weight proteins that the authors propose to be called Snow-flake Forming Collagen Binding Aggregation Factors (SFCBAF). An additional feature of SFCBAF is that they are rich in threonine and lysine and are free of cysteine in all of the aggregation factors described so far. In contrast to previously discovered SFCBAF, the gene encoding for AggLr is located on the chromosome in the strain BGTRK10-1
Application of the 3r concept in the production of European antiviperinum on horses - multisite, low volumes immunization protocol and Elisa
Get PDFDuring time, both professionals and general public became aware of the importance of animal welfare. This term not only covers endangered wild animal species, animals used in food industry, pets and experimental animals, but also animals used in production of biologics. The implementation of the 3R concept (Replacement, Reduction and Refinement) is especially important in this type of production. In this article, we describe for the first time the low dose, low volume and multi-site immunization protocol, as well as appropriate ELISA we developed for production of European anti-viper (V. ammodytes, long horned) antivenom in horses, which can help to significantly improve the welfare of the used animals
Rat strain differences in peritoneal immune cell response to selected gut microbiota: A crossroad between tolerance and autoimmunity?
No full textAims: Some gut commensals can be protective, whereas others are implicated as necessary for development of inflammatory/autoimmune diseases. Peritoneal immune cells may play an important role in promoting auto-immunity in response to gut microbiota. This study investigated the phenotype and the function of peritoneal immune cells in the autoimmunity-resistant Albino Oxford (AO), and the autoimmunity-prone Dark Agouti (DA) rat strains upon stimulation with their own colonic E. coli or Enterococcus. Main methods: Rats were intraperitoneally injected with their own E. coli or Enterococcus. Peritoneal cells isolated two days later were tested for nitric oxide (NO) and cytokine production, and for arginase and myeloperoxidase (MPO) activity. The phenotype of cells was determined using flow cytometry. Key findings: While the Enterococcus injection did not affect the composition of peritoneal cells in AO rats, the E. coli treatment increased the percentages of activated CD11b(int)HIS48(hi) neutrophils, and decreased the proportion of resident (CD11b(hi)HIS48(int/low), CD163+ CD86+) and anti-inflammatory CD68+ CD206+ macrophages. E. coli increased the production of NO and urea, but preserved their ratio in cells from AO rats. Conversely, both E. coli and Enterococcus diminished the proportion of resident and anti-inflammatory macrophages, increased the proportion of activated neutrophils, and induced inflammatory polarization of peritoneal cells in DA rats. However, injection of E. coli maintained the ratio of typical CD11b(int)HIS48(int) neutrophils in DA rats, which correlated with the sustained MPO activity. Significance: The rat strain differences in peritoneal cell response to own commensal microbiota may contribute to differential susceptibility to inflammatory/autoimmune diseases
Strain specificities in age-related changes in mechanisms promoting and controlling rat spinal cord damage in experimental autoimmune encephalomyelitis
No full textThe study investigated strain specificities in age-related differences in CD8+ T cell-and microglial cell-mediated mechanisms implicated in induction/perpetuation and/or control of neuroinflammation in experimental autoimmune encephalomyelitis (EAE) in Albino Oxford (AO) and Dark Agouti (DA) rats exhibiting age-related changes in the susceptibility to EAE in the opposite direction (increase in relatively resistant AO rats vs decrease in DA rats). In the inductive phase of EAE, the greater number of fully differentiated effector CD8+ T lymphocytes was found in draining lymph nodes (dLNs) from aged rats of both strains than in strain-matched young rats, but this was particularly prominent in AO rats, which exhibited milder EAE of prolonged duration compared with their DA counterparts. Consistently, dLN IFN-gamma+ and IL-17+ CD8+ T cell counts were greater in aged AO than in DA rats. Additionally, the magnitudes of myelin basic protein (MBP)-induced rise in the frequency of IFN-gamma+ and IL-17+ CD8+ T cells (providing important help to neuroantigen-specific CD4+ T cells in EAE models characterized by clinically mild disease) were greater in dLN cell cultures from aged AO rats. Consistently, the magnitudes of MBP-induced rise in the frequency of both IFN-gamma+ and IL-17+ CD8+ T cells were greater in spinal cord mononuclear cell cultures from aged AO rats compared with their DA counterparts. Besides, with aging CD4+ CD25+ Foxp3+/CD8+ CD25+ Foxp3+ regulatory T cell ratio changed in spinal cord in the opposite direction. Consequently, in aged AO rats it was shifted towards CD8+ CD25+ Foxp3+ regulatory T cells (exhibiting lower suppressive capacity) when compared with DA rats. Moreover, the frequency of CX3CR1+ cells among microglia changed with aging and the disease development. In aged rats, in the effector phase of EAE it was lower in AO than in DA rats. This was accompanied by higher frequency of cells expressing IL-1 beta (whose down-regulation is central for CX3CR1-mediated neuroprotection), but lower that of phagocyting cells among microglia from aged AO compared their DA counterparts. The study indicates the control points linked with strain differences in age-related changes in EAE pathogenesis
Microcin C-like peptide-adenylate antibiotic from Rubidus massiliensis
No full textMicrocin C (McC) from E. coli is a founding member of the
growing family of ribosomally-synthetized post-translationally
modified peptide-nucleotide antibiotics. The peptide portion of
McC is bound to adenosine monophosphate though a nonhydrolyzable
phosphoramidate link. Taken into the cytoplasm of sensitive bacterium through the peptide transporter, YejABEF,
McC is processed by aminopeptidases, resulting in the release of
an aspartamide-adenylate. Asp-AMP binds to aspartyl tRNAsynthetase,
thus causing translation inhibition and cell death.
Recently we have shown that genomes of various microorganisms
contain functional mcc gene clusters. Most of the mcc clusters
are comprised of only three (mccABC) genes that are sufficient
for toxic peptidyl-adenylate production. Many of the newly identified
mcc clusters contain additional genes, the products of which
are responsible for additional post-translational modifications on
the compound, or provide immunity to the producing cell. Here
we describe an expanded mcc cluster present in the genome of
the amoeba-associated bacterium, Rubidus massiliensis. The mcc
(Rma) cluster consists of five genes (mccABCFE2) organized into
an operon. We show that MccB(Rma) is a bona fide adenylyltransferase
that modifies the C-terminal asparagine residue of the
MccA(Rma) heptapeptide with an adenosine monophosphate.
The product of mccC(Rma) encodes an export pump belonging
to the MFS family. Two additional genes, mccF(Rma) and
mccE2(Rma), are homologous to E. coli mccF and mccE and
provide immunity to a wide variety of McC-like compounds.
This work was supported by Russia Science Foundation RSF 16-
14-10356
Newly designed hemagglutinin-Der p 2 chimera is a potential candidate for allergen specific immunotherapy
Get PDFAim To investigate the immunomodulatory potential of a chimera composed of the receptor-binding domain of hemagglutinin 1 (H1s) from Influenza virus and Der p 2 (D2) allergen for allergen-specific immunotherapy of house-dust mite allergy (HDM). Main methods: H1sD2 chimera and D2 allergen were produced by genetic engineering in E. coli. Recombinant antigens were extracted from inclusion bodies by urea, then refolded and purified by immobilized-metal affinity chromatography (IMAC). Purity was verified by 2D-PAGE and secondary structures were assessed by CD spectroscopy. IgE reactivity of H1sD2 and D2 was tested in western blot with sera from 8 persons with clinical history of HDM allergy. Immunogenicity of H1sD2 and D2 were analyzed in Balb/c mice. Cytokine profile was analyzed by ELISA after stimulation of mouse spleen cells with H1sD2 and D2. Leukocyte population abundance of cells isolated from spleen and lymph node was assessed by flow cytometry. Key findings: Purified recombinant proteins H1sD2 (42 kDa) and D2 (15 kDa) revealed well defined secondary structures, and preserved IgE reactive epitopes. Analysis of supernatants of mouse spleen cells after stimulation with H1sD2 and D2, revealed a qualitatively different cytokine profile from H1sD2 immunized mouse cells (increase in IL10). CD8+ cells were decreased in the lymph node of D2 immunized mice, whereas H1sD2 immunization led to an increase of CD8+ cells in both the lymph node and the spleen. Significance: H1sD2 chimera attenuates Der p 2-inherent Th2 response and directs the immune response toward Th1 and Treg phenotype.This is the peer-reviewed version of the following article: Mrkić, I.; Minić, R.; Popović, D.; Živković, I.; Gavrović-Jankulović, M. Newly Designed Hemagglutinin-Der p 2 Chimera Is a Potential Candidate for Allergen Specific Immunotherapy. Life Sciences 2018, 213, 158–165. [https://doi.org/10.1016/j.lfs.2018.10.036
Digestomics of walnut and its nsLTPs allergens reveals their ultimate resistance to gastric digestion
Get PDFBackground: Sensitization to non-specific lipid transfer protein (ns-LTPs) in plant foods is regarded as a risk factor for generalized allergic reactions. Stability to gastric digestion represents very important parameter of food proteins allergenicity. Usually studies of digestion were carried out on purified proteins, but has never been examined the influence of different food matrices on different allergens. Allergens from the nsLTP family are known to share a characteristic structure which is highly resistant to proteolysis, and therefore, IgE cross-reactivity of nsLTPs needs to be investigated in the environment such as complex food matrix.Objective: The aim of this research project is to reveal how proteins are digested (by Minekus protocol) within the natural food matrix and possible consequences on their allergenicity, with the special focus on ns-LTP.Methods: Pure nsLTPs from walnut were labelled with Alexa 633 and added to whole grain of grounded raw walnuts, incubated with human α-amylase, and pepsin, therefore mimicking the effects of oral and gastric digestion, in total duration of 2h. Proteins extracted from the mixture were analyzed by one-dimensional (1D) and two-dimensional SDS-PAGe, and respective 1D and 2D immunoblots.Results: Most proteins from pepsin digested walnut sample were more resistant to digestion according to 1D SDS PAGE. Pepsin digested raw walnut sample with nsLTP were assessed by 2D PAGE to compare profiles of the digested and control sample (no pepsin added). 2D SDSPAGE of digested and control walnut samples showed almost identical profiles, especially in the context of fluorescently labelled nsLTP allergens. These results demonstrate substantial resistance of nsLTP allergens to gastric digestion since they remained mostly intact after 2 h of gastric (pepsin) digestion.Conclusion: Further research is needed to be able to grade stability/resistance of selected food allergens to gastric digestion as a consequence of food matrix modulating effects. We propose that certain combinations of foods and allergens could provide additional protection or on the contrary ease the digestion, by comparing trends between control and digested samples and between different digested combinations as well