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Compare and contrast the replication cycles of paramyxoviruses




Compare and contrast the replication cycles of paramyxoviruses (e. g., measles virus), retroviruses (e. g., human immunodeficiency virus or HIV) and alphaherpesviruses (e. g., Varicella-zoster virus or VZV).;please refer to their structure +/-, DNA/RNA, Lytic/lysogenic cycles to compare and contrast. I have attached lecture slides to know what points our professors has focused on!;Attachment Preview;Lecture_5-0206_Medical_Virology.pdf Download Attachment;BIOL304;Infectious Disease Biology;Biology;Instructor: Dr. Carsten Sanders;BIOL304;Infectious Disease Biology;Biology;Lecture 5 02/06/2014;Medical Virology;Part 1 Virus Structures and Functions;Terminology;General Significance;Si;Defining Characteristics;Morphologies and Types;Morphologies and Types;Sourceofcoverpicture:Reeceetal. (2010),CampbellBiology,9th edition;PearsonBenjaminCummings,SanFrancisco(CA),Figure19.1;BIOL304;Infectious Disease Biology;Biology;Lecture 5 02/06/2014;Medical Virology;Part 2 Growth;Culturing Viruses;Assay and Quantification;Identification;Part 3 Multiplication Mechanisms;Multiplication Mechanisms;Bacteriophages;Animal Viruses;BIOL304;Infectious Disease Biology;Biology;Lecture 5 02/06/2014;Medical Virology;Part 4 Cytopathogenesis Mechanisms;Transformation of Host Cells;Lytic Infections;Latent and Persistent Infections;Part 5 Classification;Classification;The ICTV Classification System;The Baltimore Classification System;Other Classification Schemes;BIOL304;Infectious Disease Biology;Biology;Lecture 5 02/06/2014;Medical Virology;Part 6 Protein-based Infectious Particles;General Characteristics;Process of Conversion into Infectious Particle;Disease Mechanisms;Pathogenic Features and Symptoms;Pathogenic Features and Symptoms;BIOL304;Infectious Disease Biology;Biology;Homework Assignment;Homework Assignment 3;Compare and contrast the replication cycles of;paramyxoviruses (e. g., measles virus), retroviruses;(e. g., human immunodeficiency virus or HIV) and;alphaherperviruses (e. g., Varicella-zoster virus or VZV);(This assignment is due on 02/13/2014);Part 1 Virus Structures and Functions;A. Terminology;Virus: genetic element that cannot replicate;Virus genetic element that cannot replicate;independently of a living (host) cell;Virology: the study of viruses;Virus particle: extracellular form of a virus, allows;virus to exist outside host and facilitates transmission;from one host cell to another;Virion: the infectious virus particle, the nucleic acid;genome surrounded by a protein coat and, in some;cases, other layers of material;Part 1 Virus Structures and Functions;B. General Significance;Viruses;Viruses;are small, acellular infectious agents that replicate only inside;cellular organisms. They can infect all types of life forms;from animals and plants to bacteria and archaea, and exist;naturally within host organisms in complex ecosystems;the most important roles of viruses are to;1. limit population density of hosts (without their extinction);2. select for host diversity (by preventing dominance of any;di;(b;one species);More than 3000 viral species have been described;More than 3000 viral species have been described;about 200 of these are human pathogens;Part 1 Virus Structures and Functions;C. Defining Features;Viruses are obligatory intracellular parasites;Vi;Contain DNA or RNA (genomes), which can be;single-stranded or double-stranded;or double;positive-sense or negative-sense (in relation to;mRNA, defined as positive-sense RNA, if;single-stranded);circular, linear and segmented;most viral genomes are very small (between 3 and 50;kilobase pairs or kb);Defining Features;Viral Genomes;Defining Features;Viruses contain a protein coat;Some are enclosed by an envelope;Some viruses have spikes;Most viruses infect only specific types of cells in one host;Host range is determined by specific host attachment;sites and cellular factors;Viruses are submicroscopic in size;Viruses are submicroscopic in size;an electron microscope is needed to see them;Defining Features;Comparison of Viruses and Cells;Part 1 Virus Functions and Structures;C. Morphologies and Types;Morphologies and Types;Capsid and Capsomere;Capsid: the protein shell that surrounds the genome of a;th;th;th;virus particle;composed of highly repetitive pattern of protein;of highly repetitive pattern of protein;molecules around the nucleic acid genome;Capsomere: subunit of the capsid;smallest morphological unit visible with an electron;microscope;Nucleocapsid: complete complex of nucleic acid and protein;packaged in a virion;Capsids and Capsomeres;Symmetric Patterns;Capsid (proteins) are generally arranged in one or a limited;set of symmetric patterns;in capsids with rotational symmetry, the subunits;pack about the rotational axes to form closed structures;capsids with helical symmetry tend to form more;helical symmetry tend to form more;open-ended structures, with subunits added in a;spiraling array;Symmetry Patterns;Rotational Symmetry;Rotational Symmetry;Polyhedral Viruses;Symmetry Patterns;Helical Symmetry;Helical Symmetry;Helical Viruses;Symmetry;Patterns;Summary;Morphologies and Types;Enveloped Viruses;have membranes, which;surround nucleocapsids;are lipid bilayers;lipid bilayers;with embedded;proteins;Envelopes make;initial contact;with host cell;Morphologies and;Ty;T pes;Complex Viruses;Complex Viruses;Virions composed of several;parts, each with separate;shapes and symmetries;some bacteriophages;have icosahedral;heads and helical tails;Morphologies and Types;Comparison of Naked and Enveloped Virus Particles;Morphologies and Types;Viral Diversity - Animal Viruses;Nonenveloped;ssDNA;Parvovirus;Enveloped;Nonenveloped;EnvelopedallssRNA;partially;dsDNA;Hepadnavirus;dsDNA;Papovavirus;dsDNA;ssRNA;Picornavirus;Rhabdovirus;Togavirus;Orthomyxovirus;dsDNA;Poxvirus;Adenovirus;dsDNA;Bunyavirus;Coronavirus;Arenavirus;dsRNA;Retrovirus;Reovirus;100nm;dsDNA;Herpesvirus;Iridovirus;DNAviruses;Paramyxovirus;100nm;RNAviruses;Viral Diversity Animal Viruses;Morphologies and Types;Enzymes Included in a Virion;Some virions contain enzymes critical to infection;lysozyme;nucleic acid polymerases such as RNA-dependent;acid polymerases such as RNA;DNA polymerase (aka reverse transcriptase) or;RNA polymease;neuramidases, which are enzymes that cleave glycosidic;bonds in glycoproteins and glycolipids, and allow;liberation of viruses from host;Part 2 Growth;A. Culturing Viruses;Viruses only replicate in certain types of cells or whole;organisms;Bacterial viruses are typically easiest to grow and are;hence often used as model systems;may be cultured either in batch culture (in liquid) or as;be cultured either in batch culture (in liquid) or as;isolated plaques on a bacterial lawn (on a plate);Animal viruses can be cultivated in living animals;in embryogenated eggs, or in tissue or cell cultures;Plant viruses typically are the most difficult experimental;models because study often requires growth of a whole plant;Culturing Viruses;Batch Culture;Culturing Viruses;Embryonated Egg;Culturing Viruses;Cell or Tissue Culture;Part 2 Growth;B. Assay and Quantification;Titer: number of infectious units per volume of fluid;Plaque assay: analogous to the bacterial colony;one of the most accurate ways to measure virus infectivity;of the most accurate ways to measure virus infectivity;Plaques are clear zones that develop on lawns of host cells;each plaque results from infection by a single virus;plaque results from infection by single virus;particle;Animal viruses that do not kill their host cells can be detected;by assaying foci, groups of cells infected by the virus;Quantification;Plaque Assay;of Bacteriophages;Quantification;Plaque Assay;of Animal Viruses;Quantification;Focus Assay;of Animal Viruses;Part 2 Growth;C. Identification;Distinct patterns of cytopathic effects in culture;Serological tests;use antibodies to identify virus antigens;antibodies to identify virus antigens;detection of antibodies against viruses in a patient;Nucleic acid-based tests;Nucleic acid;tests;restriction fragment length polymorphism/RFLP;or polymerase chain reaction/PCR of isolated viral;genomes or genome fragments (including reverse;transcription for suspected RNA viruses);nucleic acid hybridization;Identification;Cytopathic Effects - Normal Cells versus Infected Cells;Part 3 Multiplication Mechanisms;A. Bacteriophages;exhibit two distinct multiplication cycles;1. Lytic or replication cycle;phage causes lysis and death of host cell;causes lysis;death of host cell;generalized transduction: DNA derived from any;portion of the host genome is packaged inside the;portion of the host genome is packaged inside the;mature virion in place of the virus genome;Bacteriophages;2. Lysogenic cycle;virus DNA is incorporated into the host DNA (the phage;lysogenizes the host cell and becomes a prophage);phage conversion: when lysogenized by a phage, the;host cell becomes immune to further infection by the;same type of phage;specialized transduction: DNA from a specific region;DNA;of the host chromosome is integrated directly into the;virus genome, usually replacing some viral genes;genome usually replacing some viral genes;Bacteriophages;Five Steps of the Lytic Cycle;Attachment: Phage attaches by tail fibers to host cell;Attachment Phage attaches by tail fibers to host cell;Penetration: Phage lysozyme opens cell wall, tail;sheath contracts to force tail core and DNA into cell;contracts to force tail core and DNA into cell;Biosynthesis: Production of phage DNA and proteins;Maturation: Assembly of phage particles;Release: Phage lysozyme breaks cell wall;Five Steps of the;Lytic Cycle;Five Steps of the Lytic Cycle;Bacteriophage Attachment and Penetration;Five Steps of the Lytic Cycle;One-Step Viral Growth Curve in Bacterial Hosts;during Biosynthesis, Maturation, and Release;Five Steps of the Lytic Cycle;Time Course of Events in Bacterial Virus Infection;Five Steps of the Lytic Cycle;Assembly of Complex Bacteriophages;Five Steps of the Lytic Cycle;Generalized Transduction;Bacteriophages;Lysogenic Cycle;Lysogenic Cycle;Induction;Generalized;Transduction;Transduction;PhageDNA;circularizes;anddetaches;fromhostDNA;Aportionof;hostDNAis;exchangedfor;phageDNA;Detached;DNA;replicates;Phagereplication;iscompleted.;Celllyses;Part 3 Multiplication Mechanisms;B. Animal Viruses;Replication Cycle in Six Steps;Cycle in Six Steps;Attachment: Viruses attach to cell membrane, binding;to specific host cell receptors;Penetration by endocytosis (pinocytosis) or fusion;Uncoating by viral or host enzymes;Biosynthesis: Production of nucleic acids and proteins;Maturation: Nucleic acid and capsid proteins assemble;Release: by budding (enveloped viruses) or rupture;Replication Cycle in Six Steps;A Prototypical Life Cycle of an Animal Virus;Replication Cycle in Six Steps;1;Phage genome;inside capsid;2;Capsid;Cytoplasmic membrane;of host engulfs virus;(endocytosis);3;2;1;3;4;Receptors on;cytoplasmic membrane;Viral genome;Direct penetration;6;Viral;glycoproteins;1;2;Envelope;3;Viral;glycoproteins;remain in;cytoplasmic;membrane;Viral;genome;Uncoating;capsid;5;Endocytosis;4;Receptors on;cytoplasmic;membrane;of host;Attachment and;and;Penetration;Viral genome;Uncoating;capsid;Membrane fusion;Replication Cycle in Six Steps;Uncoating;Replication Cycle in Six Steps;Production of Viral Nucleic Acids and Proteins;Once a host has been infected, new copies of the viral;th;genome must be made and virus-specific proteins;synthesized in order for the virus to replicate;synthesized in order for the virus to replicate;Generation of messenger RNA (mRNA) occurs first;yp;Typically, the viral genome serves as a template for;viral mRNA;In some RNA viruses, viral RNA itself is the mRNA;In some other cases, essential transcriptional;enzymes are contained in the virion;Replication Cycle in Six Steps;Formation of mRNA by DNA Viruses;Replication Cycle in Six Steps;DNA Viruses Protein Synthesis and Genome Replication;Replication Cycle;in Six Steps;Multiplication;Multiplication;Mechanism;of a DNA Virus;DNA Virus;(Papillomavirus);Replication Cycle in Six Steps;Formation of mRNA by RNA Viruses;Replication Cycle in Six Steps;RNA Viruses Protein Synthesis and Genome Replication;Replication;Cycle;in Six Steps;Multiplication;Mechanism;of a RNA Virus;(Coronavirus);Replication Cycle in Six Steps;Release of;Enveloped;Animal Viruses;by Budding;by Budding;Animal Viruses;Comparison of Bacteriophage and;Animal Viral Multiplication;Part 4 Cytopathogenesis Mechanisms;A. Transformation of Host Cells;The genetic material of tumor-inducing or oncogenic;The genetic material of tumor;or oncogenic;viruses becomes integrated into the host cell DNA;Activated oncogenes transform normal cells into;cancerous cells;Virus-transformed cells;contain virus-specific cell surface antigens;exhibit (like other cancer cells) increased growth;loss of contact inhibition, and certain chromosomal;abnormalities, such as unusual numbers of;chromosomes and fragmented chromosomes;chromosomes and fragmented chromosomes;Viral Transformation of Host Cells;Oncogenic DNA and RNA Viruses;Oncogenic DNA viruses;Adenoviridae;Herpesviridae;Poxviridae;Papovaviridae;Hepadnaviridae;Oncogenic RNA viruses;viral RNA is transcribed;into DNA which can;into DNA, which can;integrate into host DNA;Retroviridae;Part 4 Cytopathogenesis Mechanisms;B. Lytic Infections;results when virus replication kills the target cells;results when virus replication kills the target cells;some viruses prevent cellular growth and repair by;inhibiting the synthesis of cellular macromolecules or;by producing degradative enzymes and toxic proteins;virus replication and the accumulation of viral;components and progeny within cells can disrupt;the function and structure of cells or their organelles;virus infection (or cytolytic immune responses) may;induce apoptosis (programmed cell death), which may;facilitate the viral release from cells;the viral release from cells;Lytic Infections;Cell surface expression of viral glycoproteins triggers;the fusion of neighboring cells into multinucleated cells;called syncytia;cell-to-cell fusion may occur in the absence of new;protein synthesis (fusion from without) or may;(f;require new protein synthesis (fusion from within);Syncytia formation allows viruses to spread from cell;Syncytia;allows viruses to spread from cell;to cell and to escape antibody detection;cells in the state of syncytia are fragile and susceptible;to lysis;Part 4 Cytopathogenesis Mechanisms;C. Latent and Persistent Infections;usually follow acute infections, but occur in infected cells;that are not killed by a virus (nonlytic infections);Latent infections: viruses remain in asymptomatic;host cells for a long period of time until reactivation;cold sores (herpes simplex virus) or shingles;sores (herpes simplex virus) or shingles;(varicella-zoster virus);Persistent (or chronic) infections: disease processes occur;Persistent (or chronic) infections disease processes occur;gradually over a long period of time and are often fatal;subacute sclerosing panencephalitis (measles virus);virus);Latent and Persistent Infections;Part 4;Cyt;C topathogenesis;Mechanisms;Tumor;cell;division;Transformation;intotumorcell;Lysis;Cell;Virus;Deathof;celland;release;ofvirus;Attachment;andpenetration;Virus;multiplication;Cell;fusion;Persistent;infection;Slowrelease;ofviruswithout;celldeath;Latent;infection;Viruspresent;butnotreplicating;Mayreverttolyticinfection;D. Summary;Transformation;Part 5 Classification;A. The ICTV Classification System;The International Committee on Taxonomy of Viruses;The International Committee on Taxonomy of Viruses;(ICTV) has devised a classification system, based on;several criteria;1. Genome composition;2. Symmetry of the capsid (protein coat surrounding the;viral genome);3. Envelope;4. Size;5. Host range;The ICTV Classification System;Nomenclature and Species Definition;A unified taxonomy (universal system) for classifying viruses);has been established;order (names end in -virales, not assigned for all families);(names end in;not assigned for all families);family (names end in -viridae);subfamily (names end in -virinae);genus (names end in -virus);species (names end in -virus);taxonomic names are used for genus (e. g., lentivirus);while common names are used for species (e. g., human;immunodeficiency virus or HIV);Nomenclature and Species Definition;Viral species: a group of viruses sharing the same;genetic information and ecological niche (host);subspecies, strains and isolates are not distinguished;but are designated by a number (e. g., HIV-1);over 3,000 species have been described and are organized;in 6 orders (Caudovirales, Herpesvirales, Mononegavirales;Nidovirales Picornavirales;Nidovirales, Picornavirales and Tymovirales. A seventh;Tymovirales seventh;order, Ligamenvirales, has been proposed recently) with;108 families (including about 20 subfamilies and 350 genera);Part 5 Classification;B. The Baltimore Classification System;The Nobel Prize-winning biologist David Baltimore divided;The Nobel Prize;biologist David Baltimore divided;viruses into seven groups (Baltimore classification system);group I: Double-stranded DNA;group II: Single-stranded DNA;group III: Double-stranded RNA;group IV: (+) single-stranded RNA;group V: () single-stranded RNA;group VI: RNA retroviruses;group VII: DNA pararetroviruses;The ICTV classification system is used in conjunction with the;The ICTV classification system is used in conjunction with the;Baltimore classification system in modern virus classification;The Baltimore Classification System;The Baltimore Classification System;DNA Viruses;DNA Viruses;Group I Double-Stranded DNA Viruses;DNA Viruses;Group II Single-Stranded DNA Viruses;DNA Viruses;Group VII Pararetroviruses;DNA Viruses;Protein Synthesis and Genome Replication;DNA Viruses;The Main Groups of Human DNA Viruses;The Main Groups of Human DNA Viruses;Representative Genera and Associated Diseases;Representative Genera and Associated Diseases;Herpes Simplex Virus (Simplexvirus) - Herpes Lesions;Representative Genera and Associated Diseases;Papillomavirus Warts (Papilloma);The Baltimore Classification System;RNA Viruses;RNA Viruses;Group III Double-Stranded RNA Viruses;RNA Viruses;Group IV (+) Single-Stranded RNA Viruses;RNA Viruses;Group V (-) Single-Stranded RNA Viruses;RNA Viruses;Group VI Retroviruses;RNA Viruses;Protein Synthesis and Genome Replication;RNA Viruses;The Main Groups of Human RNA Viruses;The Main Groups of Human RNA Viruses;Representative Genera and Associated Diseases;Representative Genera and Associated Diseases;Morbillivirus (Measles Virus);Measles Rash and Koplik Spots;Part 5 Classification;C. Other Classification Schemes;On the basis of the hosts they infect (host spectrum), viruses;On the basis of the hosts they infect;spectrum viruses;can also be divided into;bacterial viruses (bacteriophages);animal viruses;plant viruses (etc.);Moreover, animal viruses may be categorized clinically;according to their tropisms (affinities towards specific types;of tissues);this scheme is limited by the fact that some viruses do;not reveal tissue preferences and can infect more than;not reveal tissue preferences and can infect more than;a single organ or organ system;Other Classification Schemes;Other Classification Schemes;Modes of Transmission;As seen for bacterial, protozoan and helminthic pathogens;viruses (and the infections or diseases they cause) can thirdly;be distinguished by their major modes of transmission into;be distinguished by their major modes of transmission into;1. foodborne and waterborne;2. airborne;2. airborne;3. acquired via direct contact (including genital contact or;sexual transmission);4. vectorborne (especially arthropodborne = arboviruses);Mode of Transmission;Foodborne and Waterborne Infections;Mode of Transmission;Airborne;Infections;Infections;Mode of Transmission;Infections acquired by Direct Contact;Infections acquired by Direct Contact;Sexually Transmitted Infections;Mode of Transmission;Vectorborne Infections;Part 6 Protein-based Infectious Particles;A. General Characteristics of Prions;Prions are infectious proteins whose extracellular form does;not contain nucleic acid;are inherited and transmissible by ingestion, transplant, and;surgical instruments;are the etiological agent of spongiform encephalopathies;are the etiological agent of spongiform encephalopathies;in humans: Kuru, Creutzfeldt-Jakob disease;Gerstmann;Gerstmann-Straeussler-Scheinker (GSS) syndrome;syndrome;Fatal Familial Insomnia (FFI);in animals: Scrapie (sheeps and goats), Bovine;Spongiform Encephalopathy (BSE, mad cow disease).;General Characteristics of Prions;Human and Animal;Prion Diseases;General Characteristics of Prions;Spongiform Encephalopathies are characterized by;the appearance of vacuolated neurons including their;loss of function;the lack of an immune response or inflammation;Part 4 Protein-based Infectious Particles;B. Process of Conversion into Infectious Particle;Host cell contains a gene (PrnP) encoding a native prion;protein form that is found in healthy animals and humans;PrPC: normal prion protein localized on the cell surface;PrPSc: scrapie protein, which due to misfolding;accumulates in brain cells, forms plaques and results;in brain cells forms plaques and results;in fusions of neurons and glial cells;Prion misfolding leads to neurological symptoms of disease;Prion;to neurological symptoms of disease;(e. g., resistance to proteases, insolubility, and aggregation);Process of Conversion into Infectious Particle;Process of Conversion into Infectious Particle;Process of Conversion into Infectious Particle;Part 4 Protein-based Infectious Particles;C. Disease Mechanisms;Prion disease occurs by three distinct mechanisms;1. infectious prion disease: pathogenic form of prion;protein is transmitted between animals or humans;2. sporadic prion disease: random misfolding of a normal;healthy prion;healthy prion protein in an uninfected individual;in an uninfected individual;3. inherited prion disease: mutation in prion gene yields a;protein that changes more often into disease;protein that changes more often into disease-causing;PrPSc form;Part 4 Protein-based Infectious Particles;D. Pathogenic Features and Symptoms;Prions have no cytopathologic effect in vitro;Long doubling time of at least 5 days;Long incubation time of up to 30 years;Neurological effects of prion misfolding can be;observed as, e. g., vacuolation of neurons (spongiform);and amyolid-like plaques;Symptoms include loss of muscle control, shivering;Symptoms include loss of muscle control shivering;tremors, and dementia;Prion accumulation does not lead to antigenicity;inflammation, immune response, or inferon production;Pathogenic Features and Symptoms;Progression of transmissible Creutzfeldt-Jakob Disease;BIOL304;Infectious Disease Biology;Biology;Check of Understanding;Distinguish virus and virion.;What are capsids and capsomeres?;Wh;Compare and contrast the general structures of enveloped;and nonenveloped;and nonenveloped viruses.;How are viruses cultured, assayed and quantified?;Describe the lytic and lysogenic cycles of bacteriophages.;Define the general multiplication (replication) steps;of animal viruses.;Describe the general cytopathogenesis mechanisms of viruses.;BIOL304;Infectious Disease Biology;Biology;Check of Understanding;How are viruses classified?;Define viral species.;Compare and contrast the protein synthesis and genome;replication mechanisms of DNA and RNA viruses;replication mechanisms of DNA and RNA viruses.;What are the main groups of human DNA and RNA viruses?;What are the general characteristics of protein-based;infectious particles (prions) as well as the pathogenic features;and symptoms of prion-associated diseases?;BIOL304;Infectious Disease Biology;Biology;Reading Assignment;Engleberg et al., Chapters 31-43, 56 and 71;Krasner, Chapters 5 and 10;Ch;10;Brief Outline of the Upcoming Lecture;Lecture 6 02/13/2014;Principles of Infection, Disease, and Epidemiology;of Infection Disease and Epidemiology;Part 1 A few reminders from lectures 3-5;Part 2 Infection and Disease;Part 3 Epidemiology


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