viruses and their important (c1)[1]

7/23/2019 Viruses and Their Important (C1)[1]

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Laboratory of Virology MABI: Plant Virology Lectures

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• Causing a lot of serious diseases

• No medical treatment

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Why we have virology

course?




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btmdieu&ctu'edu'(n

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What we have in General virology

course?

Carter and "aunders

)**+

C,a-ters ./.*

mailto:[email protected]















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Content of General virology course

• Chapter 1: Viruses and their important

• Chapter 2: Methods used in virology

• Chapter 3: Virus structure

• Chapter : Virus transmission

• Chapter !: "ttachment and entry of viruses into cells

• Chapter #: $ranscription% $ranslation and $ransport

• Chapter &: Virus Genome 'eplication

• Chapter (: "ssem)ly and e*it of virions from cells

• Chapter +: Classification and nomenclature of

viruses




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1, -apova. / papillomaviruses0small ds "

2, 4erpesviruses 0large ds "

3, -icornaviruses 05ve ss '"

, 6rthomy*oviruses 0.ve ss

'"

!, 'etroviruses 0'"/"

#, 4epadnavirus comple*

&, 7aculovirus 0insect virus

Cervical cancer

Chic8en po*

-olio

9lu

4V . ";

4epatitis Virus

7iocontrol

"gropathogen

"ssigments




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1, What 0;tructure

2, Where? When? 04istory

3, 4ow . Who? 0<pidemiology . transmission

, $ranscription mechanism 0related to structure .

host

!, $ranslation mechanism 0related to structure . host

#, 'esearches a)out this virus 0method

&, 4ow to prevent = treat

"ssigments




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.' Viruses are ubi0uitous on Eart,

)' Reasons for studying (iruses

1' T,e beginning of

(irology

2' T,e nature of (iruses 3(irus

definition4

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Chapter 1: Viruses and their

important5lu

$acterio-,age

IV




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Viruses

are

u)i>uit

ous on

<arth

.' Viruses infect allcellular forms6

7 Eu8aryotes

3(ertebrate9in(erteb

rate animals:

-lants: fungi4 7 ;ro8aryotes

3bacteria and

arc,aea46

bacterio-,ages




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7 Causing disease6 tri(ial 3common

colds4 7 cancer 7 affect =ell/being

of societies 3small-o@/AI%"4 / let,al

3rabies4 7 Causing t,e most economic im-act6

(iruses in Veterinary 7 -lant 7 dairy

Need :

7 Understanding t,e 3nature 7

re-lication

/ =ays of causing disease4 of (iruses

7 %e(elo-ment of 6 -re(ention 7

diagnosis 7 treatment 3(accines</


'easons for studying viruses

.' "ome (iruses areharmful 6

e-atitis C "mall-o@

$acterio-,ageIV




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'easons for studying viruses

)' "ome (iruses are useful 6 7 ;,age ty-ing of bacteria 6 "almonella 3e-idemiological

information4

7"ources of enBymes6 re(erse transcri-tase 3retro(iruses4 7RNA

-olymerases 3-,ages4

7 ;esticides6 baculo(iruses 3insect -ests4 7 y@oma (iruses

3rabbits4

7 Anti/bacterial agents6 >? antibiotic / resistant bacteria strains4 7 Anti/cancer agents6 genetically modified of ,er-es sim-le@ and

(accinia (iruses

7 Gene (ectors for -rotein -roduction6 baculo(iruses and

adeno(iruses

7 Gene (ectors for treatment of genetic diseases 6 retro(iruses




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'easons for studying

viruses

1' Virus studies ,a(e

contributed to

8no=ledge6 molecular

biology / cellbiology 7 cancer

7 Genes are

com-osed of %NA6

3;,age T) and

E'coli4

7 T,e first

c,aracteriBed

en,ancer6 3"imian

(irus 3"V2*4

7 T,e first




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Mayer

0'i@8sland)ouwschool te

Wageningen

a tobacco mosaic disease'

$elie(es it is caused by a

bacterium of some 8ind< but

attem-ts to isolate a bacterium fail

vanows8i

!n .)t, 5ebruary .F)<

%mitriRe-orts in .F) results on a study of I=ano=s8i< a Russian botanist<-resented a -a-er to t,e "t'

;etersburg Academy of "cience

s,o=ing t,at e@tracts from diseased

tobacco -lants could transmit disease

to ot,er -lants after -assage t,roug,

ceramic filters fine enoug, to retaint,e smallest 8no=n bacteria'

Unfortunately< I=ano=s8i did not fully

realiBe t,e significance of t,eseresults'

7ei@erinc8

A fe= years later< in .F< artinus

$eierinic8 confirmed H e@tended

I=ano=s8is results on tobacco

mosaic (irus H =as t,e first to

de(elo- t,e modern idea of t,e (irus<

=,ic, ,e referred to as contagium

(i(um luidum 3soluble li(ing germ4'

"dolf Mayer

01(3.1+2

7ei@erinc8

01(!1.1+31

wanows8i

01(#.1+2A


T,e beginning of Virology




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Viruses

nfluenBa pandemic 2AA+




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• $he disease 0and also measles was transferred to "merica )y

the;panish% when they con>uered the ew World in the early 1!AA,

3,! million "Btecs died in the ne*t 2 years,

• n the cities of 1(th century <urope% smallpo* reached plague

proportions and was a feared scourge . highly infectious,

• 9ive reigning <uropean monarchs died from smallpo* during the1(th century,

-haraoh

'amses V

0<gypt had

smallpo* hedied 11!&

7,C,

'eport on

"Btec po*


Viruses t,at c,anged t,e course of

,istory

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-o*virus

-o*virus 5

influenBavirus

4uman mmunodeficiency

Virus


Viruses t,at c,anged t,e course of

,istory

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A million deaths 0more than on all )attle fields of World War


T,e J"-anis,‟ flu

.F.

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1(%AAA deaths 0D

01+1(: A million deathsW,y is it called J"-anis,‟

flu K‟


T,e Je@ican‟ flu

)**F

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;ome e*amples of viruses and disease control

;mallpo* virus:

irradicated in the &AEs

due to vaccination programss

-oliovirus:irradication ongoing 0F 2A2A

Measles: future

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caused )y a

herpesvirus

'ash versus neuralgia


C,ic8en -o@ and s,ingles 3girdle ,er-es4

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<*ample of

a mostly

)enign virus

;ome variants

however

;tarting 2AA+% a vaccine against

cervical cancer.causing 4-V is

part of a national vaccination

program, 0etherlands% <urope


uman -a-illoma(irus 3;V: =art (irusM4

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4V.infection can lead to ";

"c>uired mmunoeficiency ;yndrome: Virus targets the immunesystem

7rea8s down the immune

system: opportunistic infections

such as )y Candida lead to1AA D mortality

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5oot/and/out, %isease Virus 35%V4

28 nm


;mall causes% large conse>uences

an e*tremely infectious picornavirus 0pico small

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e*ample of an isometric

0spherical virus

0envelope partially removed

Cf, 6lympic <>uestry in 4ong8ong in 2AA(


er-es sim-le@ (irus 3"V4

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"tomic model of a picornavirus

poliovirus% common cold virus% 9MV

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-hocine distemper virus

0epiBootic every decade or

so in the utch Wadden

;ea'elative of measles and ru)ella

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Ne= outbrea8s of e@isting or ne= (iruses

nfectious diseases often

dictate population

dynamics

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9ungi 7acteria

nsects

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Viruses of ot,er organisms t,an (ertebrates K

-lants: potato% tomato% to)acco

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• Air

• Water

• Contact

• 5ood

• Vectors

influenBa< "AR"

-olio< diarr,ea

IV< Ebola< ,er-es

noro(irus

West Nile (irus<

C,i8ungunya< endra<

yello= fe(er

7 os0uitoes and tic8s

• Vertical -lant (irus

7 Germ line

7ats: ;"';% 4endra

virus reservoir


Routes of (irus

transmission

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Virus Way of transmission

4V

<)ola

Classical swine fever

9oot.and.mouth disease

4uman / "vian influenBa

;"';

orovirus

engue

West ile virus

7luetongue 0sheep

-eppino mosaic virus 0pepper

White spot syndrome virus

)lood

)lood

aerosolaerosol

aerosol

aerosol

food

mos>uito

mos>uito

mos>uito

contact

cani)alism

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;ome recent virus out)rea8s

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$ulipomaniaW,en first desribed it =as assumed t,at t,e colour

beautification =as an ende(our of t,e tuli-s to -leaset,eir masters eyes before bidding a last fare=ell -rior to

e(anescence'

;oty(irus: +D* nm / .) nm


E@am-les of (irus disease6 Tuli- brea8ing (irus

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-6H6V'I;

Viruses are t,e smallest genetic

entities

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$he nature of viruses

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(iruse

s

bacteria

fungi

-lant

s

mammal

s

yeast

.*'O**'**

*E. coli

2'+**'**

*

.*) .*1 .*2 .*F

.*.* .*..

")

1'D**

CV

)1*'***

.*D .*O .*+

.*

Viruses6

• "ubmicrosco-ic

• %NA or RNA

•need cells tore-licate

• intracellular -arasites

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Viral genome siBes compared to those of cellular

organisms

,uman

O'***'***'***

f

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Nucleu

s

Host cell replication

Protecting protein

coat

RNA or DNA genome

Penetration

of cell

progeny virus

103-106 per cell

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" virus is an encapsidated piece of genetic information 0'" or " which replicates

on the e*pense of the host 0cell% thus causing an 0infectious disease

L b t f Vi l MABI Pl t Vi l L t

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WAGENINGEN UR$iR%I

$he nature of viruses

• Viruses are smallest genetic entity

• Viruses ,a(e genes 6

• RNA or %NA 9 single or double stranded

• nucleic acid P -rotein3s4 3P li-id membrane4

• Viruses lac8 many -rere0uisites for lifeM

• no enBymes for metabolism

• no ribosomes // absence of de no(o -rotein

synt,esis

• anifestation only in li(ing ,ost• Use ,ost cell -roteins

• Code efficiently

• any (irus -roteins are multifunctional

• !bligate -arasites•


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Coat -rotein6

-rotection of genetic

material

recognition of ,ost 3-lant4

crucial in (irus

transmission 3(irus/(ector

interactions4

coat or capsid

-rotein<

glyco-roteins

2, -rotein

surrounding membrane or

envelop

)* / )** nm

only some (iruses

obtained from ,ost cell

al=ays contains

glyco-roteins

3G;4

3, Hipids

ds or ss

one or more

segments

) / .D genes

1, ucleic acid

RNA Q>F* of all -lant(irusesS

%NA Q?.*S

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Com-osition of (iruses


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Virus is a very small% non.cellular

parasite of cell, ts genome% which

is composed of either " or '"%

is enclosed in a protein coat,

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Virus definition


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"re viruses living or

nonliving?

Viruses belong to biology because t,ey -ossess

genes< re-licate< e(ol(e and are ada-ted to

-articular ,osts 9 biotic ,abitats 9 ecological nic,es'

o=e(er< 't,ey are non li(ing infectious entities

t,at

can be said< at best< to lead a 8ind of borro=ed lifeM

arc (an Regenmortel and $rian

a,y 3)**24


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Viros-,ere

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%i(ersity of (iruses

$acteria


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Viros-,ere

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%i(ersity of (iruses

$acteria





WAGENINGEN UR5amilies and Genera

of ;lant (iruses





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Classification

of animal.

infecting

viruses






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P%NA3DD4

5m'"

$altimore 3.F+.4

II

P9/%NA31+4

I III

VI

/%NA

.'"

IV

e'g' Gemini(iruses

P9/RNA 32+4

e'g' Reo(iruses

5'" 3OFF4

ost -lant (iruses

V

/RNA 3+.4

e'g'

Tos-o(iruses

;seudo(iridae

PRNA

Total no' -lant (iruses

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Classification of 3-lant4(iruses

0-DNA


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$asic form of

(iruses

• Viruses are 7 Isosa,edral

7 elical

7 Com-le@


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WAGENINGEN URUNIVER"IT#

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Ca-sid -roteins are arranged

,elically to form a rod/

s,a-es coat -rotecting t,e

nucleic acid

Ca-sid -roteins are arranged

in a s-,ere follo=ing t,e

basic s,a-e of t,e

icosa,edron or triangulated

forms of it'

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Morphology of virus particles






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• Isometric (iruses 3s-,erical4

• Rod/s,a-ed (iruses

TV

C;V "V

T"WV

• Com-le@ (iruses

;V#

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Morphology of plant viruses


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abo ato y o o ogy MABI: Plant Virology Lectures


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y gy gy


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.' %iscuss reasons for studying

(iruses

)' E@-lain ,o= (iruses differ from ot,er organisms

1' %efine t,e term (irusM

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Hearning outcomes

viruses and their important (c1)[1]

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