DOCSLIB.ORG

Antibody-Antigen Interaction (Anti-Nucleotide Antibody/Anti-Hapten Antibody) ROBERT J

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Antibody-Antigen Interaction (Anti-Nucleotide Antibody/Anti-Hapten Antibody) ROBERT J Proc. Nati. Acad. Sci. USA Vol. 77, No. 12, pp. 7410-7414, December 1980 Immunology Anti-AMP antibody precipitation of multiply adenylylated forms of glutamine synthetase from Escherichia coli: A model relating both concentration and density of antigenic sites with the antibody-antigen interaction (anti-nucleotide antibody/anti-hapten antibody) ROBERT J. HOHMAN*, SUE Goo RHEEt, AND EARL R. STADTMANtt tLaboratory of Biochemistry, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland 20205; and *Department of Microbiology, University of Maryland, College Park, Maryland 20742 Contributed by E. R. Stadtman, September 12, 1980 ABSTRACT Sheep antibodies directed against an AMP- ylylated forms of GS to determine the effects of the total con- bovine serum albumin conjugate exhibit highly specific binding centration of antigenic determinants, density of determinants toward AMP. These antibodies bind to the AMP moiety of ad- enylylated glutamine synthetase [-glutamate:ammonia ligase per antigen, and the topological distribution of antigenic de- (ADP-forming), EC 6.3.1.2] from Escherichia coli and to no other terminants, on the initial antibody-antigen binding, lattice antigenic determinant on the protein. E. coli glutamine syn- formation, and immunoprecipitation.§ Some of the experi- thetase can exist in variously modified (isomeric) forms that mental data were presented in an earlier preliminary com- differ with respect to the number (0-12) and the distribution of munication (3). identically adenylylated subunits [Ciardi, J. E., Cimino, F. & Stadtman, E. R. (1973) Biochemistry 12,432143301. Using this MATERIALS AND METHODS enzyme, together with the AMP-specific antibodies, we have investigated the effects of the total concentration, population Purification and Assay of GS. Various GS preparations with density, and topographical distribution of multiple identical different if values were obtained from E. coli cells that had been antigenic determinants on the antigen-antibody interaction. cultured under various degrees of nitrogen availability. GS was Stopped-flow fluorescence measurements show that the rate and extent of initial binding of the antibodies to the antigen are a purified by Zn2+ precipitation (4), followed by the acetone and function of the total concentration of AMP groups and are in- acid (NH4)2SO4 steps described by Woolfolk et al. (5). Total dependent of the number of AMP groups per dodecamer. enzyme activity and the average state of adenylylation, n, were However, the rate of lattice formation increases with increasing determined at pH 7.57 by means of the 7-glutamyltransferase epitope density, and the maximal amount of glutamine syn- reaction (6). The presence of normal sheep serum or anti-AMP thetase precipitated is directly proportional to the average antibodies in the mixture had no effect on number of adenylylated subunits per dodecamer. The data assay enzyme activity suggest that partially adenylylated enzyme preparations are or measurements of the state of adenylylation. composed of subpopulations of glutamine synthetase molecules Preparation of Antiserum and Immunoprecipitation Tests. that differ in their tendency to form precipitable aggregates, Preparation of sheep anti-AMP antiserum and the procedure due presumably to differences in the topographical distribution for immunoprecipitation tests have been described (3). of antigenic determinants on the surface of the enzyme. The Purification of Antibodies. Partially purified antibody enzyme species that form soluble immune complexes do so preparations used for immunoprecipitation experiments were possibly due to intramolecular crosslinkage of the bivalent an- tibodies with adenylylated subunits to the exclusion of inter- obtained by (NH42S04 fractionation (7) followed by dialysis molecular crosslinkage. against 10 mM imidazole/150 mM KC1 at pH 7.3. The serum was sterilized by filtration and stored at -20°C. Glutamine synthetase [GS; L-glutamate:ammonia ligase The AMP-specific antibodies used in light scattering and (ADP-forming), EC 63.1.2] from Escherichia coli is a mul- stopped-flow experiments were purified by immunoadsorbant timeric enzyme consisting of 12 identical subunits (Mr 50,000) chromatography on a gel consisting of fully adenylylated GS arranged in two superimposed hexagonal arrays. Regulation covalently coupled to AH-Sepharose 4B (Pharmacia). Partially of the enzyme involves a bicyclic cascade system that catalyzes purified serum was added to this gel, which had been equili- a covalent attachment of a 5'-AMP moiety to a specific tyrosyl brated with 10 mM imidazole/150 mM KC1 (pH 7.3), and in- residue in each subunit (1). cubated for 12 hr at 4°C with gentle mixing. The Sepharose Depending on growth conditions, the enzyme in E. coli then was washed on a coarse sintered glass filter funnel with contains, on the average, between 0 and 12 covalently bound cold 20 mM imidazole/500 mM KC1 (pH 7.3) until the effluent AMP groups per dodecamer (2). We previously reported the was free of protein. The washed gel was packed into a 0.9 X 10 isolation of sheep antibodies directed against an AMP-bovine cm column and AMP-specific antibodies were eluted with 10 serum albumin conjugate that precipitated adenylylated, but not unadenylylated GS (3). Thus, for these antibodies, aden- Abbreviations: GS, glutamine synthetase; GS-, a glutamine synthetase ylylated GS serves as a large protein antigen with between 0 and preparation containing on the average ni adenylylated subunits per 12 precisely defined antigenic determinants per protein mol- dodecameric molecule. The value of nT varies between 0 and 12 and is referred to as the average state of adenylylation. ecule. t To whom reprint requests should be addressed. We report here the results of studies with variously aden- § "Concentration of antigenic determinants" refers to the total con- centration of adenylylated subunits, in the reaction mixture, irre- The publication costs of this article were defrayed in part by page spective of the state of adenylylation. "Concentration of antigenic charge payment. This article must therefore be hereby marked "ad- determinants per antigen" refers to the number of adenylylated vertisement" in accordance with 18 U. S. C. §1734 solely to indicate subunits per GS dodecamer and is synonymous with the terms "ep- this fact. itope density" or "state of adenylylation." 7410 Downloaded by guest on September 26, 2021 Immunology: Hohman et al. Proc. Natl. Acad. Sci. USA 77 (1980) 7411 mM imidazole/250 mM KCI/50 mM AMP, pH 7.3. The frac- tions containing protein were pooled, concentrated by ultra- 1. filtration, and dialyzed extensively against 10 mM imidazole/ M. 150 mM KCl, pH 7.3. The purified antibodies were stored aseptically at 4VC until used. 0.8 Radioimmunoassay. Binding data for the Sips plot and competition experiments were obtained by the Farr technique 0.E (8). The experiments were performed by adding, in the fol- lowing order: buffer (10 mM imidazole/150 mM KCI, pH 7.3), 0.4 1.81 AM [14C]AMP, nonradioactive competing ligand (if any), and antiserum. Samples then were incubated for 18 hr at 4VC. 0.2 Bound AMP,,M 6.. The radioactivities of duplicate samples were measured in 10 L.I j ml of Aquasol. Nonimmune sheep IgG was used as a control. 0 Rapid Mixing Experiments. A stopped-flow apparatus was -0.2 used to mix purified antibodies and GS (2 msec) into a spec- trofluorometer with excitation and emission monochromators -0.4 set at 300 nm and 340 nm, respectively. Initial rates of light Ko = 4.3 MI scattering were observed by setting both excitation and emission -0.6 a = 0.89 monochromators to 400 nm and measuring the rate of increase of scattered light at a 900 angle to the incident beam. -0.8 Large-Scale Immunoprecipitation and Repurification of Partially Adenylylated GS. Eight milligrams of GS-62 in 10 mM -1.0 imidazole/100 mM KCI/1 mM MnC12, (pH 7.0) was added to a sufficient amount of partially purified antiserum to give -1.2 maximal precipitation without approaching antibody excess. After incubation at 370C for 25 min, followed by 18 hr at 40C, -4 -5 -6 -7 -8 precipitated and soluble immune complexes were separated log[free AMP], M by centrifugation. The precipitated and supernatant enzyme FIG. 1. Binding of anti-AMP antibodies to unconjugated fractions were further treated separately, but identically. To [14C]AMP. All experiments were performed at 4°C in 10 mM imid- dissociate the immune complexes, 1% by volume of 1.0 M AMP azole/150 mM KCl at pH 7.3. (Inset) Scatchard plot ofbinding data was added to each fraction, and the fractions were incubated from radioimmunoassays of partially purified anti-AMP antiserum at 370C for 20 min. The dissociated mixture of GS and IgG was and [14C]AMP. Straight lines are least-squares fit of data points in loaded onto a DEAE-agarose column that had been equili- the high- and low-affinity regions ofthe binding curve and represent brated with 10 mM imidazole/100 mM KCl/10 mM the two extremes of the range of binding affinity. The value at the x AMP/1 intercept of the extrapolated curve gives the total number of antibody mM MnCl2, pH 7.0 (room temperature). IgG, which does not binding sites that was used for the Sips plot (11). The main figure is bind to DEAE-agarose, was washed off the column with binding data represented in a Sips plot. r = mol of AMP bound per equilibration buffer. GS was eluted with buffer containing 300 mol of antibody; n = number of binding sites per antibody molecule mM KC1. Fractions containing GS were pooled, concentrated = 2. The value of the x intercept of the Sips plot is the logarithm of by ultrafiltration, and loaded onto an immunoadsorbant column the free hapten concentration that gives 50% saturation of antibody consisting of rabbit anti-sheep IgG coupled to Affigel 10 (Bio- sites. Due to the heterogeneity of binding affinity of the antiserum Rad) that had been equilibrated with 10 mM imidazole/100 for AMP, this half-saturation value (4.3 ,uM) cannot rigorously be mM referred to as a Kd (which requires normal rectangular hyperbolic KCl/1 mM MnCI2/50 mM AMP.
Load more

Recommended publications
  • IFM Innate Immunity Infographic
    UNDERSTANDING INNATE IMMUNITY INTRODUCTION The immune system is comprised of two arms that work together to protect the body – the innate and adaptive immune systems. INNATE ADAPTIVE γδ T Cell Dendritic B Cell Cell Macrophage Antibodies Natural Killer Lymphocites Neutrophil T Cell CD4+ CD8+ T Cell T Cell TIME 6 hours 12 hours 1 week INNATE IMMUNITY ADAPTIVE IMMUNITY Innate immunity is the body’s first The adaptive, or acquired, immune line of immunological response system is activated when the innate and reacts quickly to anything that immune system is not able to fully should not be present. address a threat, but responses are slow, taking up to a week to fully respond. Pathogen evades the innate Dendritic immune system T Cell Cell Through antigen Pathogen presentation, the dendritic cell informs T cells of the pathogen, which informs Macrophage B cells B Cell B cells create antibodies against the pathogen Macrophages engulf and destroy Antibodies label invading pathogens pathogens for destruction Scientists estimate innate immunity comprises approximately: The adaptive immune system develops of the immune memory of pathogen exposures, so that 80% system B and T cells can respond quickly to eliminate repeat invaders. IMMUNE SYSTEM AND DISEASE If the immune system consistently under-responds or over-responds, serious diseases can result. CANCER INFLAMMATION Innate system is TOO ACTIVE Innate system NOT ACTIVE ENOUGH Cancers grow and spread when tumor Certain diseases trigger the innate cells evade detection by the immune immune system to unnecessarily system. The innate immune system is respond and cause excessive inflammation. responsible for detecting cancer cells and This type of chronic inflammation is signaling to the adaptive immune system associated with autoimmune and for the destruction of the cancer cells.
    [Show full text]
  • Adoptive Cell Therapy Using Engineered Natural Killer Cells
    Bone Marrow Transplantation (2019) 54:785–788 https://doi.org/10.1038/s41409-019-0601-6 REVIEW ARTICLE Adoptive cell therapy using engineered natural killer cells Katayoun Rezvani1 © The Author(s), under exclusive licence to Springer Nature Limited 2019 Abstract The generation of autologous T cells expressing a chimeric antigen receptor (CAR) have revolutionized the field of adoptive cellular therapy. CAR-T cells directed against CD19 have resulted in remarkable clinical responses in patients affected by B-lymphoid malignancies. However, the production of allogeneic CAR-T cells products remains expensive and clinically challenging. Moreover, the toxicity profile of CAR T-cells means that currently these life-saving treatments are only delivered in specialized centers. Therefore, efforts are underway to develop reliable off-the-shelf cellular products with acceptable safety profiles for the treatment of patients with cancer. Natural killer (NK) cells are innate effector lymphocytes with potent antitumor activity. The availability of NK cells from multiple sources and their proven safety profile in the allogeneic setting positions them as attractive contenders for cancer immunotherapy. In this review, we discuss advantages and potential drawbacks of using NK cells as a novel cellular therapy against hematologic malignancies, as well as strategies 1234567890();,: 1234567890();,: to further enhance their effector function. Introduction need for inpatient care may ultimately be economically unviable for many health care systems; (iii) the longer time Adoptive cell therapy has become a powerful treatment that is required to generate CAR T-cells may result in modality for advanced cancers refractory to conventional unavoidable delays in therapy, especially for patients with therapy.
    [Show full text]
  • Targeting Dendritic Cells with Antigen-Delivering Antibodies for Amelioration of Autoimmunity in Animal Models of Multiple Sclerosis and Other Autoimmune Diseases
    antibodies Review Targeting Dendritic Cells with Antigen-Delivering Antibodies for Amelioration of Autoimmunity in Animal Models of Multiple Sclerosis and Other Autoimmune Diseases Courtney A. Iberg and Daniel Hawiger * Department of Molecular Microbiology and Immunology, Saint Louis University School of Medicine, Doisy Research Center, 1205 Carr Lane, St. Louis, MO 63104, USA; [email protected] * Correspondence: [email protected] Received: 31 March 2020; Accepted: 30 April 2020; Published: 15 June 2020 Abstract: The specific targeting of dendritic cells (DCs) using antigen-delivering antibodies has been established to be a highly efficient protocol for the induction of tolerance and protection from autoimmune processes in experimental autoimmune encephalomyelitis (EAE), a model of multiple sclerosis (MS), as well as in some other animal disease models. As the specific mechanisms of such induced tolerance are being investigated, the newly gained insights may also possibly help to design effective treatments for patients. Here we review approaches applied for the amelioration of autoimmunity in animal models based on antibody-mediated targeting of self-antigens to DCs. Further, we discuss relevant mechanisms of immunological tolerance that underlie such approaches, and we also offer some future perspectives for the application of similar methods in certain related disease settings such as transplantation. Keywords: dendritic cells; tolerance; antigen targeting; chimeric antibodies; autoimmunity; multiple sclerosis; diabetes 1. Introduction Over one hundred years ago, Paul Ehrlich coined the term “horror autotoxicus” to define an immune attack against an organism’s healthy tissues [1]. Since then, our knowledge of the complex mechanisms of the immune system as well as our understanding of the pathogenesis of specific autoimmune diseases have grown tremendously.
    [Show full text]
  • Eosinophil Response Against Classical and Emerging
    REVIEWS Eosinophil Response Against Classical and Emerging Respiratory Viruses: COVID-19 Rodrigo-Muñoz JM1,2, Sastre B1,2, Cañas JA1,2, Gil-Martínez M1, Redondo N1, del Pozo V1,2 1Immunology Department, Instituto de Investigación Sanitaria (IIS) Fundación Jiménez Díaz, Madrid, Spain 2CIBER de Enfermedades Respiratorias (CIBERES), Madrid, Spain J Investig Allergol Clin Immunol 2021; Vol. 31(2): 94-107 doi: 10.18176/jiaci.0624 Abstract Eosinophils were discovered more than 140 years ago. These polymorphonuclear leukocytes have a very active metabolism and contain numerous intracellular secretory granules that enable multiple effects on both health and disease status. Classically, eosinophils have been considered important immune cells in the pathogenesis of inflammatory processes (eg, parasitic helminth infections) and allergic or pulmonary diseases (eg, asthma) and are always associated with a type 2 immune response. Furthermore, in recent years, eosinophils have been linked to the immune response by conferring host protection against fungi, bacteria, and viruses, which they recognize through several molecules, such as toll-like receptors and the retinoic acid–inducible gene 1–like receptor. The immune protection provided by eosinophils is exerted through multiple mechanisms and properties. Eosinophils contain numerous cytoplasmatic granules that release cationic proteins, cytokines, chemokines, and other molecules, all of which contribute to their functioning. In addition to the competence of eosinophils as effector cells, their capabilities as antigen-presenting cells enable them to act in multiple situations, thus promoting diverse aspects of the immune response. This review summarizes various aspects of eosinophil biology, with emphasis on the mechanisms used and roles played by eosinophils in host defence against viral infections and response to vaccines.
    [Show full text]
  • Understanding the Immune System: How It Works
    Understanding the Immune System How It Works U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES NATIONAL INSTITUTES OF HEALTH National Institute of Allergy and Infectious Diseases National Cancer Institute Understanding the Immune System How It Works U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES NATIONAL INSTITUTES OF HEALTH National Institute of Allergy and Infectious Diseases National Cancer Institute NIH Publication No. 03-5423 September 2003 www.niaid.nih.gov www.nci.nih.gov Contents 1 Introduction 2 Self and Nonself 3 The Structure of the Immune System 7 Immune Cells and Their Products 19 Mounting an Immune Response 24 Immunity: Natural and Acquired 28 Disorders of the Immune System 34 Immunology and Transplants 36 Immunity and Cancer 39 The Immune System and the Nervous System 40 Frontiers in Immunology 45 Summary 47 Glossary Introduction he immune system is a network of Tcells, tissues*, and organs that work together to defend the body against attacks by “foreign” invaders. These are primarily microbes (germs)—tiny, infection-causing Bacteria: organisms such as bacteria, viruses, streptococci parasites, and fungi. Because the human body provides an ideal environment for many microbes, they try to break in. It is the immune system’s job to keep them out or, failing that, to seek out and destroy them. Virus: When the immune system hits the wrong herpes virus target or is crippled, however, it can unleash a torrent of diseases, including allergy, arthritis, or AIDS. The immune system is amazingly complex. It can recognize and remember millions of Parasite: different enemies, and it can produce schistosome secretions and cells to match up with and wipe out each one of them.
    [Show full text]
  • (COVID-19): PCR, Antigen, and Antibody Tests There Are Three Types of Tests Available for SARS-Cov-2, the Virus
    Coronavirus 2019 (COVID-19): PCR, Antigen, and Antibody Tests There are three types of tests available for SARS-CoV-2, the virus that causes COVID-19: polymerase chain reaction (PCR), antigen, and antibody (serology) testing. PCR and antigen tests detect whether a person is currently infected, and serology detects whether a person had an infection in the past. All positive and negative test results for SARS-CoV2 are reportable in the District of Columbia. This document provides information about each type of test. Topic PCR Test Antigen Test Antibody (Serology) Test Why is the test PCR tests look for pieces of Antigen tests look for pieces of Serology looks for antibodies1 against used? genetic material of SARS-CoV-2, proteins that make up the SARS- SARS-CoV-2, the virus that causes the virus that causes COVID-19, in CoV-2 virus, the virus that causes COVID-19, in the blood to determine if the nose, throat, or other areas in COVID-19, to determine if the person there was a past infection. the respiratory tract to determine if has an active (i.e., current) infection. the person has an active (i.e., current) infection. How is the test In most cases, a nasopharyngeal In most cases, a nasopharyngeal In most cases, a blood sample is taken performed? or nasal swab is taken by a nasal swab is taken by a healthcare and sent to a lab for testing. healthcare provider and tested; provider and tested. Most often the however, oral swabs and saliva test can be run while you wait, and can be used.
    [Show full text]
  • Vaccine Immunology Claire-Anne Siegrist
    2 Vaccine Immunology Claire-Anne Siegrist To generate vaccine-mediated protection is a complex chal- non–antigen-specifc responses possibly leading to allergy, lenge. Currently available vaccines have largely been devel- autoimmunity, or even premature death—are being raised. oped empirically, with little or no understanding of how they Certain “off-targets effects” of vaccines have also been recog- activate the immune system. Their early protective effcacy is nized and call for studies to quantify their impact and identify primarily conferred by the induction of antigen-specifc anti- the mechanisms at play. The objective of this chapter is to bodies (Box 2.1). However, there is more to antibody- extract from the complex and rapidly evolving feld of immu- mediated protection than the peak of vaccine-induced nology the main concepts that are useful to better address antibody titers. The quality of such antibodies (e.g., their these important questions. avidity, specifcity, or neutralizing capacity) has been identi- fed as a determining factor in effcacy. Long-term protection HOW DO VACCINES MEDIATE PROTECTION? requires the persistence of vaccine antibodies above protective thresholds and/or the maintenance of immune memory cells Vaccines protect by inducing effector mechanisms (cells or capable of rapid and effective reactivation with subsequent molecules) capable of rapidly controlling replicating patho- microbial exposure. The determinants of immune memory gens or inactivating their toxic components. Vaccine-induced induction, as well as the relative contribution of persisting immune effectors (Table 2.1) are essentially antibodies— antibodies and of immune memory to protection against spe- produced by B lymphocytes—capable of binding specifcally cifc diseases, are essential parameters of long-term vaccine to a toxin or a pathogen.2 Other potential effectors are cyto- effcacy.
    [Show full text]
  • Human Antigen-Specific Memory Natural Killer Cell Responses
    bioRxiv preprint doi: https://doi.org/10.1101/2020.11.09.374348; this version posted November 10, 2020. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. 1 Human antigen-specific memory natural killer cell responses develop 2 against HIV-1 and influenza virus and are dependent on MHC-E 3 restriction 4 5 6 Stephanie Jost1, Olivier Lucar1, Taylor Yoder1, Kyle Kroll1, Sho Sugawara1, Scott Smith1, Rhianna 7 Jones1, George Tweet1, Alexandra Werner1, Phillip J. Tomezsko2, Haley L. Dugan2†, Joshua 1 3 3 4 5 8 Ghofrani , Marcus Altfeld , Adam Grundhoff , Michaela Muller-Trutwin , Paul Goepfert , R. Keith 9 Reeves1,2 * 10 11 1Center for Virology and Vaccine Research, Beth Israel Deaconess Medical Center, Harvard 12 Medical School, Boston, MA 02115, USA; 2Ragon Institute of Massachusetts General Hospital, 13 MIT, and Harvard, Cambridge, MA 02139, USA; 3Heinrich Pette Institute, Leibniz Institute for 14 Experimental Virology, 20251 Hamburg, Germany; 4Institut Pasteur, HIV, Inflammation and 15 Persistence Unit, Paris, France; 5University of Alabama at Birmingham, Birmingham, AL 35294, 16 USA 17 18 *Corresponding author 19 R. Keith Reeves 20 Center for Virology and Vaccine Research 21 Beth Israel Deaconess Medical Center 22 3 Blackfan Circle 23 Boston, MA 02215 24 Ph: (617-735-4586) 25 Fax: (617-735-4527) 26 E-mail: [email protected] 27 28 †Current address: Committee on Immunology, University of Chicago, Chicago, IL 60637, USA 29 30 Running Title: Human Memory NK Cells 31 32 Abstract: 185 words 33 Main Text: 2713 words 34 Methods Text: 2035 words 35 5 Figures 36 7 Supplemental Figures 37 3 Supplemental Tables 38 62 references 39 40 bioRxiv preprint doi: https://doi.org/10.1101/2020.11.09.374348; this version posted November 10, 2020.
    [Show full text]
  • Humoral Immunity and Complement Humoral Immunity B Cell Antigens
    Humoral Immunity Humoral Immunity and Complement Transfer of non-cell components of blood-- Robert Beatty antibodies, complement MCB150 Humoral immunity = antibody mediated B Cell Activation of T-dependent antigens B cell Antigens T cell dependent B cell antigens T cell independent Majority of antigens. Do not require thymus. Most protein antigens. No memory. T cell help required for B cell activation and antibody production. T-cell dependent antigens T-cell independent antigens 1 B Cell Activation T-dependent antigens Location of B Cell Activation Antigen activated B cells remain in T cell zones of LN. Linked Recognition Maximize contact of Need T cell epitope along with B cell epitope to B cells with T cells. get antibody response. B cells get help from T cells, help = CD40Ligand and IL-4. Clonal proliferation In Follicles Isotype Switching Affinity maturation Somatic hypermutation 2 T cell Independent Antigens B cell mitogens (e.g. LPS) B-1 cells At low levels normal immune response to LPS Activated by repeating CHO epitopes that provide crosslinking At high levels LPS can cause non-antigen specific to induce antigen uptake and activation. activation of B cells. Mitogen effect Antigen specific immune response Lower affinity, lower numbers, no memory. Primarily IgM. Antibody Effector Functions Opsonization Neutralization Antibody Effector Functions Enhancement of phagocytosis Neutralizing abs block active site for adherence, entry into host cell, or active site of toxin Neutralizing antibodies are usually high affinity and primarily IgG. 3 Antibody-dependent cell-mediated Complement Activation cytotoxicity (ADCC) Antibody Effector Functions Antibody Effector Functions Antibody binds to pathogen or infected target cell.
    [Show full text]
  • Coronavirus Disease 2019 Testing Basics
    Coronavirus Disease 2019 Testing Basics You’ve probably heard a lot about coronavirus disease (COVID-19) testing. If you think you have COVID-19 and need a test, contact your health care provider or local health department immediately. You can also find acommunity testing site in your state, or buy an FDA-authorized at-home test. Some FDA-authorized at-home tests give you results within minutes. Others require you to mail the sample to a lab for analysis. There are two different types of tests –diagnostic tests and antibody tests. Diagnostic tests can show if you have an active Antibody tests look for antibodies in your immune Covid-19 infection and need to take steps to system produced in response to SARS-CoV-2, quarantine or isolate yourself from others. Molecular the virus that causes COVID-19. Antibody tests should and antigen tests are types of diagnostic tests than can not be used to diagnose an active COVID-19 infection. detect if you have an active COVID-19 infection. Samples Antibodies can take several days or weeks to develop for diagnostic tests are typically collected with a nasal or after you have an infection and may stay in your blood throat swab, or saliva collected by spitting into a tube. for several weeks or more after recovery. Samples for antibody tests are typically blood from a finger stick, or blood drawn by your doctor or other medical personnel. MOLECULAR TEST ANTIGEN TEST ANTIBODY TEST Also known as… Diagnostic test, viral test, molecular Diagnostic test, viral test, Serological test, serology, test, nucleic acid amplification test rapid test blood test, serology test (NAAT), RT-PCR test, LAMP test How the sample is Nasal swabs, either shallow or Nasal or nasopharyngeal swab Blood from a fingerstick or vein taken… deep (most tests).
    [Show full text]
  • Antigen-Detecting Rapid Diagnostic Tests
    SARS-CoV-2 antigen-detecting rapid diagnostic tests AN IMPLEMENTATION GUIDE SARS-CoV-2 antigen-detecting rapid diagnostic tests AN IMPLEMENTATION GUIDE SARS-CoV-2 antigen-detecting rapid diagnostic tests: an implementation guide ISBN 978-92-4-001774-0 (electronic version) ISBN 978-92-4-001775-7 (print version) © World Health Organization 2020 Some rights reserved. This work is available under the Creative Commons Attribution- NonCommercial-ShareAlike 3.0 IGO licence (CC BY-NC-SA 3.0 IGO; https://creativecommons. org/licenses/by-nc-sa/3.0/igo). Under the terms of this licence, you may copy, redistribute and adapt the work for non- commercial purposes, provided the work is appropriately cited, as indicated below. In any use of this work, there should be no suggestion that WHO endorses any specific organization, products or services. The use of the WHO logo is not permitted. If you adapt the work, then you must license your work under the same or equivalent Creative Commons licence. If you create a translation of this work, you should add the following disclaimer along with the suggested citation: “This translation was not created by the World Health Organization (WHO). WHO is not responsible for the content or accuracy of this translation. The original English edition shall be the binding and authentic edition”. Any mediation relating to disputes arising under the licence shall be conducted in accordance with the mediation rules of the World Intellectual Property Organization (http://www.wipo. int/amc/en/mediation/rules/). Suggested citation. SARS-CoV-2 antigen-detecting rapid diagnostic tests: an implementation guide.
    [Show full text]
  • Immune System
    Personal Health Series Immune System Quiz Answer Key 1. The immune system protects your body from sickness and germs. 2. Leukocytes are white blood cells that seek out and destroy organisms or substances that can cause disease. 3. Lymph nodes are glands that work like filters to remove germs. They’re found in your neck, armpit, and other areas. 4. Cells that chew up invading germs are called phagocytes . 5. Lymphocytes are the cells that recognize invaders like germs. 6. Leukocytes travel through the body via lymphatic vessels . 7. A foreign substance that invades your body is called an antigen . 8. When your body detects an antigen, antibodies are made and lock onto it. Once an antigen is recognized, your immune system can remember it the next time and protect you from getting sick again. 9. Humans are born with innate immunity. 10. Hand washing is one of the best ways to avoid infections and help keep your immune system healthy. 11. Immunodeficiencies occur when a part of the immune system is not present or is not working properly. 12. When the immune system attacks healthy organs and tissues, it’s called an autoimmune disorder. 13. An allergic reaction occurs when the immune system overreacts to exposure to antigens in the environment. 14. Acquired immunodeficiencies can develop as a result of burns, malnutrition, or other medical problems; or if a person takes certain medicines or has a disease . 15. An abnormal overgrowth of leukocytes results in leukemia , a form of cancer. WORD BANK allergic disease innate lymphocytes antibodies hand washing leukemia phagocytes antigen immune leukocytes vessels autoimmune immunodeficiencies lymph nodes © 2016 The Nemours Foundation/KidsHealth.
    [Show full text]