大二下学习-微生物课件17.virus病毒持续感染类型

Chapter

21infection

and

pathogenicmechanismp.272主要内容的致病作用抗免疫重点和难点垂直持续

的类型的致病机制干扰素的抗

作用机制抗

免疫中和抗体Infection

patternandpathwaySection

1I. Infections

pattern

and

pathway1.

Horizontal

transmission--- from

each

other

of

groups1) Via

mucous

membranerespiratory ---- surface

infectiongastrointestinal----nakedgenitourinary --- occur

with

sexualor

newborn

delivery2) Via

skininjection-------HBV,

HIVbite

--------

rabiesdamagedskin------HPV2.

Vertical

transmission--- from

parents

to

progeny--- more

than

10

es--- the

most

common:

Rubella,

CMV,

HBV,

HIV3.

Spreading

within

the

host--- Local

(superficial

)

spreading--- Generalized

spreading

by

blood,

lymph

fluidand

nervefiberskin,

mucousinfluenzarotapapilomalymphonodeviroemialiverspleenDengueBlood

vesselSkinbrainlung,

kidney,

sialic

glandPox,

varicella, rabies,

polio measles,

mumpsHBVyellow

feversecond

viroemiaSpreadingwithin

the

hostsheddingSites

ofreplicationinfectionⅡ.

Types

ofbodyinfectioninapparent

viral

infectionacute

viral

infectionpersistent

viral

infectionAppar-entpercentage

of

apparent

infectionwith

different

es1. Inapparent

viral

infectionbodyasymptomReasons:

immunity

＞

viral

virulence2. Acute

viral

infectionbodysymptomtissue

damageResults---toxic

products3. Persistent

infectionbodypersisting

a

long

periodReasons

---weaker

immunityweaker Ag

or

change

of

Agabnormal

replication

or

DIP

interfereIntegration

of

nucleic

acid1)

Chronic

infection--- chronic

and

in

progress--- course

of

illness

＞

1

year--- e.g.

chronic

hepatitis

cirrhosiscancer2) Latent

infection--- recurrent

or

repeatedly

onset---

e.g.

Varicella-zosteror

HSV-I水痘-带状疱疹,VZV单纯疱疹,HSV-13)

Delayed

infection

(slowinfection)--- long

incubation

period--- bad

prognosis--- e.g.

AIDS,SSPE,

KuruMechanisms

of

viralpathogenesisSection

21.

Effect

ofinfection

on

host

cell(celllevel)1) Cytocidal

effect

(naked

)inhibition

of macromolecular

biosynthsisself

lysislysosome

damagecell

organella

damagechange

of

Antigenitycytotoxicity

of

viral

proteinRsults--- cytopathic

effects(CPE)Verocells

infected

with

SARSuninfectedHIV

infectedHIV

infected(at

higher

magnifcation)tissue

culture

cellsepithelialepithelioidfibroblasticepithelial

cells

-adenouninfectedearly

infectionlate

infectionepithelial

cells

-

respiratory

syncytialuninfectedrespiratory

syncytialfibroblastic

cells

-

herpes

simplexuninfectedearly

infectionlate

infectionfibroblastic

cells

-

poliouninfectedearly

infectionlate

infection2)

Steadystateinfection(enveloped

)--- appearance

of

new

antigenic

determinantson

the

cell

surface cell

fusion---

eg.

Influenza

and

hemagglutininD:

Hemadsorption.

Erythrocytes

adhere

to

those

cells

in

the

monolayer

that

are

infected

by

athat

causes

a

hemagglutinin

to

be

incorporated

into

the

plasma

membrane.

Many

envelopedes

that

mature

by

budding

from

cytoplasmicmembranes

produce

hemadsorption.(Courtesy

ofI

Jack.)3) Cell

apoptosis4)

Integration

of

viral

gene

with

host

chromosomeCell

transformation

and

malignant---

cancer,

such

as

EBV,

HBVFormation

of

inclusion

bodyinclusion

body

of

CMV(nucleus,

cytoplasm,

acid-philics)Negribody

in

neuron(cytoplasm,

acid-philics)2.

Effect

ofinfection

on

host(body

level)1) Direct

damage---

eg.

Polio.

Vmotor

neuronImmunopathology

system---

Type

I,

II,

III

and

IV

hypersensitivityDirect

effect

on

immune

systemImmune

suppression---

HSV,

Measles Humor

ImmunityImmune

competent

cells---

HIVCD4

cells+(3)

Auto-immune

diseases:

HBV

vs

LSP3.

InteractionbetweenandbodyIncluding

receptors,

VAP(p.279-281)with

cell

structureswith

productionsSection

3Immunity

againstviral

infectionp.2811.

Innate

immunityBiology

barriers:skin,

mucous

membranes,

blood-brain,blood-placentaPhagocytosismacrophage(mononuclear

&

lymphocytes)neutrophilsNK

cellsInnate

immune:component

ofHuman

body2.

Adaptive

(specific)

immunity1)

humoral

immunity---mediated

byantibodies2)

Cell-mediated

immunity---

mediated

by

T

lymphocytesTh1

and

Tc3).

inhibitorsCondition

of

host

genetics,

age

andphsiologyInterferon

(IFN)---mainly

acquiredp.282nonspecific

immunitya.

conceptor

a

variety

of

agentscellsglycoproteins

with

multiple

activitiesb.

nature

of

interferonspecies-specific,

butnot -specific

α-IFN-------leukocyte,9

β-IFN----fibroblast,9γ-IFN-------T

cell,12Differences

between

type

I

and

type

II

IFNc.

antiviral

activity

of

interferoninterferon

are

inducers

that

cause

cell

tosynthesize

antiviral

proteins

(AVP)AVP

is

controlled

by

a

gene

on

chromosome

21IFNIFN

receptorantiviral

protein

geneactivatedAVP2’-5’A

synthetasePKRATPeIF-2phosphorylated2’-5’Aactivateendonuclease

Lhydrolyze

viral

mRNA inactivating

eIF-2(degrade)inhibiting

viral

proteins

synthesis2.

Specific

immunityHumoral

immunityviralAbto

viral*

neutrilizing

antibody:

IgG,IgM,

IgAinterfering

with

the

initial

events

ofmultiplication

cycle,

e.g: combine

with

receptorhemagglutination

inhibition

antibody:

IgGcomplement

fixation

antibody:

IgG,

IgMc.roles

of

antibodies

to

esto

preventre-infectionto

terminate

primary

infection

bylimiting

the

spread

of

extracellularto

bemarker

for

diagnosis,

especially

forepidemiology2) Cellular

immunityonce es

enter

cells,

the

roles

of

humoralimmunity

is

limiteda.

cells

of

cellular

immunityTc----cytotoxicityh1T -----lymphokinesmacrophagesK

and

NKb.

roles

of

cellular

immunityto

kill

the es

in

cellsto

promote

recovering

from

viral

illness3)

ImmunopathologyT

cell思考题1.2.的类型？干扰素?它有哪些特性，是怎样产生的，其抗

作用机制如何?的特异性免疫？致病机制与细菌致病机制有何不试述抗试述同？中英文细胞病变作用cytopathic

effect,CPE包涵体inclusion

body内基小体Negri

body携带者viral

carrier潜伏慢latent

infection染chronic

infection干扰素Interferon，IFN课外阅读材料专著•学纲要. :

复旦大学学.

:人民卫生

,闻玉梅.医学分子,

2005.2008黄文林.分子学（第二版）. :人民卫生•,

2002