scholarly journals The vectorial release of nascent immunoglobulin peptides

1971 ◽  
Vol 122 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Michael J. Bevan
Keyword(s):  
Immunoglobulin A ◽  
Specific Antiserum ◽  
Microsomal Preparation ◽  
Radioactive Label ◽  
Large Background

A microsomal preparation from a mouse plasmacytoma, MOPC 47A, that secretes immunoglobulin A was used to study the release of nascent immunoglobulin peptides in vitro. Nascent chains were released with puromycin and characterized with specific antiserum against the immunoglobulin product of the tumour. When the tissue had been prelabelled with [3H]leucine the experiments were complicated by the large background of completed radioactive polypeptides in the microsomal preparation. Up to one-third of the released radioactivity in the microsomal preparation could be recognized as immunoglobulin. With [3H]-puromycin as the radioactive label, however, the results are much easier to interpret, although the proportion of released radioactivity that can be identified as immunoglobulin is lower (up to one-tenth). Both types of experiment demonstrate that all of the recognizable nascent immunoglobulin chains remain in association with the microsomal vesicles after release from the ribosomes.

scholarly journals Antigen-Specific Immunoglobulin A Antibodies Secreted from Circulating B Cells Are an Effective Marker for Recent Local Immune Responses in Patients with Cholera: Comparison to Antibody-Secreting Cell Responses and Other Immunological Markers

2003 ◽  
Vol 71 (8) ◽  
pp. 4808-4814 ◽  
Author(s):  
Firdausi Qadri ◽  
Edward T. Ryan ◽  
A. S. G. Faruque ◽  
Firoz Ahmed ◽  
Ashraful Islam Khan ◽  
...  
Keyword(s):  
Immune Responses ◽  
Immunoglobulin A ◽  
Peripheral Circulation ◽  
Secreting Cell ◽  
Antibody Secreting Cell ◽  
Immunological Responses ◽  
B Subunit ◽  
Mucosal Infection ◽  
Circulating Lymphocytes

ABSTRACT Gut-derived lymphocytes transiently migrate through the peripheral circulation before homing back to mucosal sites and can be detected using an ELISPOT-based antibody secreting cell (ASC) assay. Alternatively, transiently circulating lymphocytes may be cultured in vitro, and culture supernatants may be assayed for antigen-specific responses (antibody in lymphocyte supernatant [ALS] assay). The ALS assay has not been validated extensively in natural mucosal infection, nor has the ALS response been compared to the ASC assay and other cholera-specific immunological responses. Accordingly, we examined immune responses in 30 adult patients with acute cholera in Bangladesh, compared with 10 healthy controls, measuring ALS-immunoglobulin A (IgA), ASC-IgA, and serum and fecal IgA responses to two potent Vibrio cholerae immunogens, the nontoxic B subunit of cholera toxin (CtxB) and lipopolysaccharide (LPS) and a weaker V. cholerae immunogen, the mannose-sensitive hemagglutinin (MSHA). We found significant increases of anti-CtxB, anti-LPS, and anti-MSHA IgA in supernatants of lymphocytes cultured 7 days after onset of cholera using the ALS assay. We found that ALS and ASC responses correlated extremely well; both had comparable sensitivities as the vibriocidal responses, and both procedures were more sensitive than fecal IgA measurements. An advantage of the ALS assay for studying mucosal immune responses is the ability to freeze antibodies in supernatants for subsequent evaluation; like the ASC assay, the ALS assay can distinguish recent from remote mucosal infection, a distinction that may be difficult to make in endemic settings using other procedures.

scholarly journals Porcine Milk-Derived Small Extracellular Vesicles Promote Intestinal Immunoglobulin Production through pIgR

Animals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1522
Author(s):  
Bin Zeng ◽  
Hailong Wang ◽  
Junyi Luo ◽  
Meiying Xie ◽  
Zhengjiang Zhao ◽  
...  
Keyword(s):  
Small Intestine ◽  
Extracellular Vesicles ◽  
Immunoglobulin A ◽  
Luciferase Reporter ◽  
Epithelial Cell Line ◽  
Intestinal Immunity ◽  
In Vivo Experiments ◽  
Porcine Milk

Secretory immunoglobulin A (SIgA) plays an important role in gut acquired immunity and mucosal homeostasis. Breast milk is the irreplaceable nutritional source for mammals after birth. Current studies have shown the potential functional role of milk-derived small extracellular vesicles (sEVs) and their RNAs cargo in intestinal health and immune regulation. However, there is a lack of studies to demonstrate how milk-derived sEVs affect intestinal immunity in recipient. In this study, through in vivo experiments, we found that porcine milk small extracellular vesicles (PM-sEVs) promoted intestinal SIgA levels, and increased the expression levels of polymeric immunoglobulin receptor (pIgR) both in mice and piglet. We examined the mechanism of how PM-sEVs increased the expression level of pIgR in vitro by using a porcine small intestine epithelial cell line (IPEC-J2). Through bioinformatics analysis, dual-luciferase reporter assays, and overexpression or knockdown of the corresponding non-coding RNAs, we identified circ-XPO4 in PM-sEVs as a crucial circRNA, which leads to the expression of pIgR via the suppression of miR-221-5p in intestinal cells. Importantly, we also observed that oral administration of PM-sEVs increased the level of circ-XPO4 and decreased the level of miR-221-5p in small intestine of piglets, indicating that circRNAs in milk-derived sEVs act as sponge for miRNAs in recipients. This study, for the first time, reveals that PM-sEVs have a capacity to stimulate intestinal SIgA production by delivering circRNAs to receptors and sponging the recipient’s original miRNAs, and also provides valuable data for insight into the role and mechanism of animal milk sEVs in intestinal immunity.

Depletion of gut secretory immunoglobulin A coated Lactobacillus reuteri is associated with gestational diabetes mellitus-related intestinal mucosal barrier damage

2021 ◽  
Author(s):  
Haowen Zhang ◽  
Ce Qi ◽  
Yuning Zhao ◽  
Mengyao Lu ◽  
Xinyue Li ◽  
...  
Keyword(s):  
Diabetes Mellitus ◽  
Gestational Diabetes ◽  
Gestational Diabetes Mellitus ◽  
Lactobacillus Reuteri ◽  
Immunoglobulin A ◽  
Mucosal Damage ◽  
Secretory Iga ◽  
Mucosal Barrier ◽  
Secretory Immunoglobulin

Gestational diabetes mellitus (GDM) may be related to intestinal mucosal damage and inflammation-induced dysbiosis of secretory IgA (SIgA) coated microbiota. SIgA coated L. reuteri can reduce the level of inflammation of GDM in vitro.

scholarly journals Identification of Rotavirus VP6-Specific CD4+ T Cell Epitopes in a G1P[8] Human Rotavirus-Infected Rhesus Macaque

2008 ◽  
Vol 1 ◽  
pp. VRT.S563 ◽  
Author(s):  
Wei Zhao ◽  
Bapi Pahar ◽  
Karol Sestak
Keyword(s):  
T Cell ◽  
Rhesus Macaques ◽  
Immunoglobulin A ◽  
Cd4 T Cell ◽  
T Cell Epitopes ◽  
Primate Model ◽  
Human Rotavirus ◽  
Ifn Γ ◽  
Rotavirus Vp6

A non-human primate model was used to evaluate its potential for identification of rotavirus viral protein 6 (VP6) CD4+ T cell epitopes. Four juvenile rhesus macaques were inoculated with a mixed inoculum (G1P[8] and G9P[8]) of human rotaviruses. Infection accompanied by G1P[8] shedding was achieved in the two macaques that had no rotavirus immunoglobulin A (IgA) in plasma. To measure the interferon gamma (IFN-γ) and tumor necrosis factor (TNF) anti-viral cytokines produced by peripheral CD4+ cells that recognize VP6 epitopes, whole blood cells from one infected macaque were stimulated in vitro with VP6 peptides. Stimulation with peptide pools derived from the simian rotavirus VP6161–395 region revealed reactivity of CD4+ T cells with the VP6281–331 domain. A VP6301–315 region was identified as the epitope responsible for IFN-γ production while a broader VP6293–327 domain was linked to TNF production. These results suggest that human rotavirus-infected macaques can be used for identification of additional epitopes and domains to address specific questions related to the development of pediatric vaccines.

scholarly journals The transfer of mannose to dolichol diphosphate oligosaccharides in pig liver endoplasmic reticulum

1975 ◽  
Vol 152 (2) ◽  
pp. 191-199 ◽  
Author(s):  
Gerard J. A. Oliver ◽  
Frank W. Hemming
Keyword(s):  
Endoplasmic Reticulum ◽  
Periodate Oxidation ◽  
The Other ◽  
Microsomal Preparation ◽  
Pig Liver ◽  
Mannose Residue ◽  
Chromatographic Data ◽  
Endogenous Lipid

The transfer, catalysed by pig liver microsomal preparations, of mannose, from GDP-mannose, to lipid-linked oligosaccharides and the properties of the products are described. Solubility, hydrolytic and chromatographic data suggest that they are dolichol diphosphate derivatives. The presence of two N-acetyl groups in at least part of the heterogenous oligosaccharide portion was tentatively deduced. Reduction with borohydride of the oligosaccharide showed that the newly added mannose residues were not at its reducing end. Periodate oxidation suggested that 60% of these were at the non-reducing terminus and that 40% were positioned internally. T.l.c. showed the presence of seven oligosaccharide fractions with chromatographic mobilities corresponding to glucose oligomers with 7–13 residues. The molar proportions of the oligosaccharide fractions in the mixture were determined by borotritiide reduction and the number of mannose residues added to each oligosaccharide fraction during the incubation was calculated. Two of the oligosaccharide fractions had received on average one, or slightly more than one, mannose residue per chain during the incubation; four of the other fractions were each shown to be a mixture, 20–25% of which had received one mannose residue during the incubation and 75–80% of which had not been mannosylated during the incubation. This supported other evidence for the presence of endogenous lipid-linked oligosaccharides in the microsomal preparation which had been formed before the incubation in vitro. Evidence for the possibility of two pools of dolichol monophosphate mannose, one being more closely associated with mannosyl transfer to dolichol diphosphate oligosaccharides than the other, is also discussed.

Virus Induced Thrombocytopenia: The Role Of Viral Hemolysin And Neuraminidase

1981 ◽  
Author(s):  
M Chernesky ◽  
A Bromke
Keyword(s):  
Influenza A ◽  
Constant Number ◽  
Subsequent Removal ◽  
Significant Drop ◽  
Radioactive Label ◽  
Platelet Counts ◽  
Rabbit Platelets ◽  
Storage Pools

Newcastle disease virus (NDV) which aggregates washed suspensions of human or rabbit platelets in vitro was compared to non-aggregating viruses such as influenza A and chikungunya virus (CV) in their capacities to induce thrombocytopenia in rabbits previously infused with 5lCr- labelled platelets. NDV and influenzavirus induced a dramatic drop in platelet and radioactive counts. Five minutes after the injection of NDV, platelet counts fell to 78% of preinjection levels and only 40% of the radioactivity was recoverable. Platelet numbers returned to normal by 30 min. but label never responded past 55% of preinjection. Influenza virus demonstrated a similar pattern of platelet and radioactive counts but the responses were approximately 65% of those induced by NDV. Magnitude of thrombocytopenia was dependent upon the strength of virus injected. CV did not induce a significant drop in platelet counts. Plotting radioactive counts against a constant number of platelets in the circulation suggested that during thrombocytopenia the radioactive label may have been removed from the platelets which could be cleared from the circulation. Return to preinjection numbers may have been due to subsequent removal of platelet- free radioactivity or a movement of platelets from sequestration or storage pools. A second series of rabbits were injected with 51Cr-labelled platelets previously reacted in vitro with virus or purified neuraminidase. Approximately 80% of the platelets pretreated with NDV or influenzavirus were cleared from the circulation within 10 minutes. Only 3.6% of radioactivity was present in the rabbit circulation 10 min. after the injection of platelets which had had 8.65 nanograms of NANA/ml cleaved from their surface by neuraminidase. A mechanism for virus-induced thrombocytopenia may involve platelet aggregation and/or enzymatic platelet membrane modification, which may result in immunological clearance in the animal.

scholarly journals Measurement of Immunoreactive Angiotensin-(1–7) Heptapeptide in Human Blood

2001 ◽  
Vol 47 (4) ◽  
pp. 726-729 ◽  
Author(s):  
Juerg Nussberger ◽  
Dorette B Brunner ◽  
Juerg A Nyfeler ◽  
Lilly Linder ◽  
Hans R Brunner
Keyword(s):  
Detection Limit ◽  
Human Plasma ◽  
Human Blood ◽  
Plasma Concentrations ◽  
Specific Antiserum ◽  
Clinical Settings ◽  
Physiological Effects ◽  
Reliable Measurement ◽  
Blood Concentrations

Abstract Background: The renal enzyme renin cleaves from the hepatic α2-globulin angiotensinogen angiotensin-(1–10) decapeptide [Ang-(1–10)], which is further metabolized to smaller peptides that help maintain cardiovascular homeostasis. The Ang-(1–7) heptapeptide has been reported to have several physiological effects, including natriuresis, diuresis, vasodilation, and release of vasopressin and prostaglandins. Methods: To investigate Ang-(1–7) in clinical settings, we developed a method to measure immunoreactive (ir-) Ang-(1–7) in 2 mL of human blood and to estimate plasma concentrations by correcting for the hematocrit. A sensitive and specific antiserum against Ang-(1–7) was raised in a rabbit. Human blood was collected in the presence of an inhibitor mixture including a renin inhibitor to prevent peptide generation in vitro. Ang-(1–7) was extracted into ethanol and purified on phenylsilylsilica. The peptide was quantified by radioimmunoassay. Increasing doses of Ang-(1–7) were infused into volunteers, and plasma concentrations of the peptide were measured. Results: The detection limit for plasma ir-Ang-(1–7) was 1 pmol/L. CVs for high and low blood concentrations were 4% and 20%, respectively, and between-assay CVs were 8% and 13%, respectively. Reference values for human plasma concentrations of ir-Ang-(1–7) were 1.0–9.5 pmol/L (median, 4.7 pmol/L) and increased linearly during infusion of increasing doses of Ang-(1–7). Conclusions: Reliable measurement of plasma ir-Ang-(1–7) is achieved with efficient inhibition of enzymes that generate or metabolize Ang-(1–7) after blood sampling, extraction in ethanol, and purification on phenylsilylsilica, and by use of a specific antiserum.

scholarly journals Effect of Denture Base Reinforcement Using Light Cured E- Glass Fibers on the Level of Salivary Immunoglobulin A

2018 ◽  
Vol 6 (11) ◽  
pp. 2168-2172
Author(s):  
Shady M. El Naggar ◽  
Mohamed I. Seif El Nasr ◽  
Hassan M. Sakr ◽  
Sherihan M. Eissa ◽  
Asmaa N. Elboraey ◽  
...  
Keyword(s):  
Immunoglobulin A ◽  
Acrylic Resin ◽  
Enzyme Linked Immunosorbent Assay ◽  
Complete Dentures ◽  
Denture Base ◽  
Mean Values ◽  
Glass Fibres ◽  
Significant Difference ◽  
Salivary Immunoglobulin A

BACKGROUND: A gap still exists between in vitro and clinical studies concerning the biocompatibility of the material in the oral environment and their potential to cause immunological undesirable side effects. The uses of glass fibres to improve the mechanical properties of acrylic resin denture base polymers are well documented in vitro. AIM: The present study aimed to evaluate the effect of denture base reinforcement using light-cured E- glass fibres mesh on the level of salivary immunoglobulin A (S-IgA) in patients wearing complete dentures. MATERIAL AND METHODS: Fourteen completely edentulous patients, in need of complete dentures, participated in the study. The patients were divided into two groups (n = 7) according to the treatment protocol. In the first group, patients received conventional heat-cured acrylic resin dentures. In the second group, the mandibular dentures were reinforced using light cured resin impregnated E glass fibres mesh. In both groups, salivary samples were collected using passive drool technique. The level IgA was assessed by enzyme-linked immunosorbent assay (ELISA) technique at different time intervals. Statistical analysis was carried out using one-way ANOVA followed by Tukey`s post-hoc test and independent t-test. The significant level was set at P ≤ 0.05. RESULTS: Acrylic resin dentures and reinforced ones demonstrated an increase in the mean values of IgA level at the end of the follow-up intervals. And this increase was statistically significant (P ≤ 0.05). Although, the reinforced dentures revealed higher mean values, there was no statistically significant difference between the two groups (P > 0.05) CONCLUSIONS: Within the limitations of the present study, the following could be concluded: (1) the insertion of complete dentures induced changes in the level of IgA; and (2) denture base reinforcement using light cured resin impregnated E-glass fibres mesh had a similar effect to that of heat cured acrylic resin on the level of IgA.

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