983 research outputs found
Sort by
Immunization-induced thymic atrophy as a contributing factor in strain differences in rat susceptibility to EAE
No full textIntroduction: It is suggested that impaired thymopoiesis in autoimmune diseases contributes to their perpetuation. To prove this hypothesis, influence of immunization for EAE on thymopoiesis and the putative thymic−dependent changes in the periphery were examined in susceptible (Dark Agouti, DA) and resistant (Albino Oxford, AO) rats. Methods: On the 13th day post−immunization, expression of differentiation/maturation markers of conventional T cells and regulatory CD4+Foxp3+CD25+ cells (nTregs) on thymocytes, their apoptosis and proliferation, frequency of recent thymic emigrants (RTEs) and CD28null cells in CD4+ and CD8+ peripheral blood lymphocytes (PBLs), and thymic expression and circulating levels of cytokines influencing thymus/thymopoiesis were investigated. Results: In rats of both strains increase in proinflammatory−cytokine circulating levels followed by thymic atrophy and changes at multiple thymocyte developmental points, leading to decreased number of the most mature CD4+ and CD8+ TCRaβhi thymocytes and frequency of RTEs among PBLs (as in chronobiological aging), was found. This was more prominent in DA rats. Consistently, compared with AO rats, in DA rats were found higher frequencies
of cytolitic CD28null cells (contributing to target tissue damage) among CD4+ PBLs and cytolitic granzyme B+ CD4+ T cells in spinal cord. Additionally, compared with non−immunized controls, DA rats exhibited greater decline in thymic nTreg generation (reflecting diminished thymic IL−7, IL−2 and IL−15 expression) than AO ones. Conclusions: The study suggests that differences in thymopoiesis, and consequently nTreg generation and CD4+CD28null cell frequency in the periphery, contribute to strain differences in EAE clinical presentation
STED Nanoscopy of the Centrosome Linker Reveals a CEP68-Organized, Periodic Rootletin Network Anchored to a C-Nap1 Ring at Centrioles
Get PDFThe centrosome linker proteins C-Nap1, rootletin and CEP68 connect the
two centrosomes of a cell during interphase into one microtubule organizing centre. This coupling is important for cell migration, cilia formation and timing of mitotic spindle formation. Very little is known about
the structure of the centrosome linker. Here, we used STimulated Emission Depletion (STED)microscopy to show that each C-Nap1 ring at the
proximal end of the two centrioles organizes a rootletin ring and in addition multiple rootletin fibres that radiate outwards from the ring into the
cytoplasm. Rootletin filaments have a repeat organization of 75 nm and
bind CEP68 via its C-terminal spectrin repeat containing region in 75
nm intervals. CEP68 is essential in forming rootletin filaments that branch
off centrioles and modulates the thickness of rootletin fibres. Thus, the
centrosome linker consists of a vast network of repeating rootletin units
with C-Nap1 as ring organizer and CEP68 as filament modulator. The
punctual contact model is consistent with the biological properties of
the centrosome linker
Corpuscular carrier enhances immune response after conjunctival immunization with chlamydial outer membrane proteins
No full textTrachoma, caused by the intracellular bacterium Chlamydia trachomatis (Ct), remains the world’s leading preventable infectious cause of blindness. Recent attempts to develop
effective vaccines rely on modified chlamydial antigen delivery platforms. We therefore characterized immune responses after conjunctival immunization with a N-terminal portion
(amino acid 1-893) of the chlamydial polymorphic membrane protein C (PmpC) and a major outer membrane protein (MOMP) expressed in Escherichia coli bacterial ghosts (BGs) in
a guinea pig model of ocular infection animals. Three immunizations were performed at two-week intervals, and the IgG immune responses were evaluated. Animals were further
infected with C. caviae (1x104
IFU/animal) two weeks after the last immunization and ocular pathology and chlamydial clearance were investigated. Antigen-specific IgG levels in
sera yielded significantly increased levels in the group immunized with MOMP BGs compared to animals immunized with PmpC BGs. Furthermore, a decrease in intensity of the
transitional inflammatory reaction in conjunctiva of challenged guinea pigs immunized with MOMP-BGs compared with PmpC-BGs-immunized animals was observed. Analysis of
changes in chlamydial load during the post-infection period revealed significantly lower absolute numbers of C. caviae in MOMP-BGs immunized guinea pigs on day 4 post-infection
(P <0.05) compared to the corresponding PmpC-BGs-immunized animals. Although neither immunization scheme provided full protection, MOMP-BGs merit further investigations
as chlamydial protein carriers with intrinsic adjuvant properties in conjunctival vaccine against Chlamydia
Propranolol influences EAE development by impairing antigen presenting cell migration into the draining lymph nodes
No full textIntroduction: Catecholamines are implicated in development of multiple sclerosis and EAE in Dark Agouti (DA) rats. To enlighten their β−adrenoceptor−mediated immunomodulatory action, DA rats of both sexes immunized for EAE were subjected to seven−day−long treatment with propranolol (β−adrenoceptor blocker) starting at the day of immunization.
Methods: The migration of antigen presenting cells (APCs) into the draining lymph nodes (dLNs) was examined using CFSE−based assay. Frequency of activated CD4+ T cells, their proliferation and frequency of IL−17−producing CD4+ T (Th17) cells in dLNs, and their infiltration into spinal cord, were analyzed using flow cytometry. Propranolol effects on CD4+ cell proliferation and Th17 cell polarization, and IL−2 and Th17 polarizing cytokine and chemokine expression in dLNs/ dLN cell cultures were examined using flow cytometry and ELISA/qRT−PCR. Results: Irrespective of sex, propranolol reduced the incidence and postponed clinical EAE onset by impairing migration of antigen−carrying APCs into the dLNs (due to diminished dLN CCL19/21 expression). Consequently, propranolol diminished CD4+ T−cell activation/proliferation, and Th17 cell number in dLNs and spinal cord. To corroborate these findings, propranolol exerted stimulatory effects on CD4+ cell proliferation (through stimulation of IL−2 secretion) and Th17 cell differentiation (reflecting enhanced Th17 polarizing cytokine production) in dLN cell cultures. Conclusions: Irrespective of sex, the stimulatory effects of propranolol on dLN CD4+ T lymphocyte proliferation and activated/ matured APC Th17 polarizing capacity were insufficient to overcome its inhibitory influence on APC migration, so propranolol impaired Th17 generation in dLNs of EAE rats, and postponed EAE development
Digestomics of Japanese abalone in real food matrix
Get PDFObjective: Haliotis discus (Japanese abalone), mollusks among various shellfish, is a highlynutritive food resource in the world, but also among the eight allergic food groups accounting forapproximately 90% of all immunoglobulin E food allergies worldwide. The general objective of ourresearch is to comprehensively investigate stability and structures of pepsin-resistant allergens, oftheir larger fragments, and of short digestion resistant peptides (SDRPs) released by pepsindigestion of whole raw and extract of shellfish, under standardized and physiologically relevantgastric conditions.Materials and Methods: Extract of raw whole shellfish (eRSS) and whole raw shellfish (wRSS),were pepsin digested according to standardized static digestion protocol. Controls were treated in asame manner without adding pepsin. Supernatant of samples and its counterpart controls wereprecipitated with TCA/acetone. Obtained proteins were assessed by 2D SDS PAGE and 1D SDS-PAGE, under reducing and non-reducing conditions. 1D SDS-PAGE of RSS were analyzed byncLC-MS/MS (Orbitrap LTQ) shot-gun proteomics. Relative quantification was performed by LFQalgorithm within Peaks 8.5 software package Bioinformatics Solutions Inc. (BSI), Waterloo,Canada.Results and Conclusion: 1D SDS-PAGE analysis of eRSS and wRSS, and its controls showed arange of proteins in varied concentrations between 10-250 kDa. In extracted and whole rawshellfish, approximately 22 prominent protein bands were observed including the distinct bandscorresponding with the molecular weights of recognized shellfish allergen, tropomyosin (37-39kDa). Fewer high molecular weight proteins were observed followed by protein smearing,specifically around the low molecular weight protein bands. The smearing could possibly be due tothe breakdown products and the glycation. There were slight differences between the proteinprofiles under reducing and non-reducing conditions as well. Nevertheless, there was the retentionof a band in the 37kDa molecular weight marker in all 4 samples, likely consistent with heat stabletropomyosin (TM). Mass spectrometry showed allergens that are characterized (Hal d 1 and Hal di1), with 90% of sequence homology with main tropomyosin allergens from seafood.Scientific impact and relevance: The results will highlight effects of food matrix on shellfishallergens digestibility proving its relevancy in molecular allergology. Moreover, an insight will beobtained on the differences in digestibility of allergenic versus non-allergenic tropomyosins in thereal food matrix.Book of Abstract
Monitoring change in ige/igg4 ratio has predictive significance for estimating efficacy of allergen-specific immunotherapy (ait) and enhances rendering clinical decisions during treatment
No full textDigestomics of cow's milk: casein-derived digestion-resistant peptides aggregate into functional complexes
Get PDFStrain differences in thymic atrophy in rats immunized for EAE correlate with the clinical outcome of immunization
Get PDFAn accumulating body of evidence suggests that development of autoimmune pathologies leads to thymic dysfunction and changes in peripheral T-cell compartment, which, in turn, perpetuate their pathogenesis. To test this hypothesis, thymocyte differentiation/maturation in rats susceptible (Dark Agouti, DA) and relatively resistant (Albino Oxford, AO) to experimental autoimmune encephalomyelitis (EAE) induction was examined. Irrespective of strain, immunization for EAE (i) increased the circulating levels of IL-6, a cytokine causally linked with thymic atrophy, and (ii) led to thymic atrophy reflecting partly enhanced thymocyte apoptosis associated with downregulated thymic IL-7 expression. Additionally, immunization diminished the expression of Thy-1, a negative regulator of TCR alpha beta-mediated signaling and activation thresholds, on CD4+CD8+ TCR alpha beta(lo/hi) thymocytes undergoing selection and thereby impaired thymocyte selection/survival. This diminished the generation of mature CD4+ and CD8+ single positive TCR alpha beta(hi) thymocytes and, consequently, CD4+ and CD8+ recent thymic emigrants. In immunized rats, thymic differentiation of natural regulatory CD4+Foxp3+CD25+ T cells (nTregs) was particularly affected reflecting a diminished expression of IL-7, IL-2 and IL-15. The decline in the overall thymic T-cell output and nTreg generation was more pronounced in DA than AO rats. Additionally, differently from immunized AO rats, in DA ones the frequency of CD28- cells secreting cytolytic enzymes within peripheral blood CD4+ T lymphocytes increased, as a consequence of thymic atrophy-related replicative stress (mirrored in CD4+ cell memory pool expansion and p16(INK4a) accumulation). The higher circulating level of TNF-alpha in DA compared with AO rats could also contribute to this difference. Consistently, higher frequency of cytolytic CD4+ granzyme B+ cells (associated with greater tissue damage) was found in spinal cord of immunized DA rats compared with their AO counterparts. In conclusion, the study indicated that strain differences in immunization-induced changes in thymopoiesis and peripheral CD4+CD28- T-cell generation could contribute to rat strain-specific clinical outcomes of immunization for EAE
Sex bias in mouse humoral immune response to influenza vaccine depends on the vaccine type
No full textThe study explored influence of biological sex on development of humoral immune response to seasonal trivalent whole inactivated virus (WIV) and split virus (SV) influenza vaccines in outbred Swiss mouse model. To this end, mice of both sexes were immunized with WIV (WIV mice) and SV vaccines (SV mice) and examined for specific antibody response. Irrespective of sex, total IgG and neutralizing antibody responses to distinct virus strains were weaker in SV than in WIV mice. In WIV mice of both sexes, irrespective of strain specificity, IgG isotype response was dominated by IgG2a antibodies, while in SV mice nearly equal representation of IgG2a and IgG1 antibodies was found. The analyses of sex differences showed higher titers of H1N1-specific and both H1N1- and H3N2-specific total IgG and neutralizing antibodies in female WIV and SV mice, respectively. Additionally, sexual dimorphism in IgG subclass profile depended on vaccine type. Specifically, compared with males, in females WIV shifted IgG2a/IgG1 antibody ratio towards IgG2a isotype on the account of weaker IgG1 response, whereas in SV mice, irrespective of virus strain, IgG2a and IgG1 isotypes were equally represented in both sexes. These findings indicate the vaccine type-dependent sex bias in antibody response to inactivated influenza vaccines
Oral treatment with Lactobacillus rhamnosus 64 during the early postnatal period improves the health of adult rats with TNBS-induced colitis
No full textThe current study investigated a potential modulating effect of orally applied Lactobacillus rhamnosus 64 (LB64) during the early postnatal period (day of life: similar to 3-30), during young adult period (day of life: 31-70) or throughout experiment, on parameters of trinitrobenzenesulfonic acid (TNBS)-induced colitis in adult rats. Treatment with LB64 during early postnatal, but not during young adult period reduced clinical damage score, neutrophil and macrophage infiltration into colon, the level of cytokine and myeloperoxidase (MPO) activity, but had no influence on other parameters of oxidative damage. Early postnatal treatment with LB64 also increased the diversity of fecal Bifidobacteria and Eubacteria, and improved maturation of ileal villi in 30-days old rats. When LB64 is applied during a critical period early in life, it affects immune system functioning of adults, probably by interactions with the mucosal immune system of the gastrointestinal tract that provides immune system maturation and shapes the overall immune response