Upload
lianazulak
View
216
Download
0
Embed Size (px)
Citation preview
8/8/2019 2-Resistance and Acquired Immunity 3
1/20
Resistance and ImmunityResistance and Immunity
8/8/2019 2-Resistance and Acquired Immunity 3
2/20
ImmunityImmunity signifies all those properties of the host thatsignifies all those properties of the host that
confer resistance to a specific infectious agent.confer resistance to a specific infectious agent.
ImmunityImmunity
Natural Acquired or adaptiveNatural Acquired or adaptive
(Innate, nonspecific) (specific)(Innate, nonspecific) (specific)
Active P Active P
8/8/2019 2-Resistance and Acquired Immunity 3
3/20
Differences between natural (innate) andDifferences between natural (innate) and
acquired (adaptive) immunityacquired (adaptive) immunity
Innate immunityInnate immunity
11--Present since birth.Present since birth.
22--D
oesnt depend on previousD
oesnt depend on previousexposure to a particularexposure to a particular
pathogen.pathogen.
33--NonNon--specific.specific.
44--Genetically controlled.Genetically controlled.
Adaptive immunityAdaptive immunity
11-- Not present since birth.Not present since birth.
22-- Depends on previousDepends on previousexposure to a particularexposure to a particular
pathogen.pathogen.
33-- Specific.Specific.
44--Genetically controlled andGenetically controlled andinfluenced by hormonesinfluenced by hormones
and cytokines.and cytokines.
8/8/2019 2-Resistance and Acquired Immunity 3
4/20
Innate immunityInnate immunity
55-- No immunologicNo immunologic
memory.memory.
66-- Modified by : age,Modified by : age,hormones, nutritionalhormones, nutritional
status.status.
Adaptive immunityAdaptive immunity
55-- Involves theInvolves the
development ofdevelopment of
memory cells.memory cells.
66-- Formed of 2 arms:Formed of 2 arms:humoral and cellhumoral and cell--
mediated.mediated.
8/8/2019 2-Resistance and Acquired Immunity 3
5/20
Determinants of Innate ImmunityDeterminants of Innate Immunity
11-- Species and strain.Species and strain.
22-- Individual differences.Individual differences.
33-- Age and sex.Age and sex.44-- Hormonal factors.Hormonal factors.
55-- Nutritional factors.Nutritional factors.
66-- Racial immunity.Racial immunity.
8/8/2019 2-Resistance and Acquired Immunity 3
6/20
Mechanisms of Innate ImmunityMechanisms of Innate Immunity
11-- Mechanical barriers and surface secretions:Mechanical barriers and surface secretions:intact skin, mucous membrane.intact skin, mucous membrane.
22-- Commensal bacteria:Commensal bacteria:salivary streptococci, vaginalsalivary streptococci, vaginal
lactobacilli.lactobacilli.
33-- Bactericidal substances:Bactericidal substances: present normally in bodypresent normally in bodyfluids and include:fluids and include:
a)a)--Lysozyme b)Lysozyme b)--GIT secretions c)GIT secretions c)--Lactenin d)Lactenin d)--Oleic acidOleic acide)e)--Spermine and spermidineSpermine and spermidine
f)f)--Bactericidal activity of the blood due to:Bactericidal activity of the blood due to:
1. Complement 2. Natural Abs1. Complement 2. Natural Abs
3. Properdin 4.Phagocytes3. Properdin 4.Phagocytes
8/8/2019 2-Resistance and Acquired Immunity 3
7/20
44-- Phagocytosis:Phagocytosis: enhanced by opsonization of particles byenhanced by opsonization of particles by
opsonins as: Abs, C3 or C reactive protein (CRP).opsonins as: Abs, C3 or C reactive protein (CRP).
55-- Inflammatory response:Inflammatory response: limits the spread oflimits the spread oforganisms.organisms.
66-- Fever:Fever: induced by ILinduced by IL--1, IL1, IL--6, TNF alpha.6, TNF alpha.
77-- Natural killer (NK) cells :Natural killer (NK) cells : nonnon--specifically recognizespecifically recognizeand attack tumour cells and virusand attack tumour cells and virus--infected cells .infected cells .
88-- TollToll--like receptors (TLRs).like receptors (TLRs).
8/8/2019 2-Resistance and Acquired Immunity 3
8/20
OpsonizationOpsonization
8/8/2019 2-Resistance and Acquired Immunity 3
9/20
ADCC by NK CellsADCC by NK Cells
8/8/2019 2-Resistance and Acquired Immunity 3
10/20
Destruction of VirusDestruction of Virus--Infected Cells by NK Cells throughInfected Cells by NK Cells through
AntibodyAntibody--Dependent Cellular Cytotoxicity (ADCC)Dependent Cellular Cytotoxicity (ADCC)
8/8/2019 2-Resistance and Acquired Immunity 3
11/20
TollToll--like receptorslike receptors
They are glycoproteins.They are glycoproteins.
They are found on the surface of most bodyThey are found on the surface of most body
immune cells.immune cells.They recognize and bind to pathogenThey recognize and bind to pathogen
associated molecular patterns (PAMPs).associated molecular patterns (PAMPs).
8/8/2019 2-Resistance and Acquired Immunity 3
12/20
PAMPs:PAMPs:
These are highly conserved structures presentThese are highly conserved structures present
in different organisms.in different organisms.
They include:They include:11-- Bacterial moleculesBacterial molecules as peptidoglycan,as peptidoglycan,
teichoic acid and LPS.teichoic acid and LPS.
22-- Fungal moleculesFungal molecules as zymosan and mannan.as zymosan and mannan.33-- Viral moleculesViral molecules as viral nucleic acids andas viral nucleic acids and
proteins.proteins.
8/8/2019 2-Resistance and Acquired Immunity 3
13/20
Binding of TLRs to PAMPs ofBinding of TLRs to PAMPs ofbacteria andbacteria and
fungifungi triggers synthesis of cytokines bytriggers synthesis of cytokines byimmune cells (e.g. ILimmune cells (e.g. IL--2, IL2, IL--8 and TNF8 and TNF--
alpha) which triggers immune defences asalpha) which triggers immune defences as
inflammation, fever and phagocytosis.inflammation, fever and phagocytosis.
Binding of TLRs toBinding of TLRs toviral componentsviral components
triggers synthesis of interferon and blockstriggers synthesis of interferon and blocksviral replication.viral replication.
8/8/2019 2-Resistance and Acquired Immunity 3
14/20
8/8/2019 2-Resistance and Acquired Immunity 3
15/20
8/8/2019 2-Resistance and Acquired Immunity 3
16/20
Acquired ( Adaptive) ImmunityAcquired ( Adaptive) Immunity
ActiveActive PassivePassiveNaturalNatural ArtificialArtificial NaturalNatural ArtificialArtificial
(Infection)(Infection)
(Immunizing agents)(Immunizing agents)
Clinical SubclinicalClinical Subclinical (Placental transfer,(Placental transfer,
colostrum)colostrum)
(administration of immune sera)(administration of immune sera)
8/8/2019 2-Resistance and Acquired Immunity 3
17/20
Acquired (Acquired (AdaptiveAdaptive) Immunity) Immunity
Acquired Active ImmunityAcquired Active Immunity
11-- The host actively producesThe host actively produces
Abs.Abs.
22-- Immunity is of delayedImmunity is of delayed
onset.onset.
33-- Abs last longer.Abs last longer.
Acquired Passive ImmunityAcquired Passive Immunity
11-- The host receives preformedThe host receives preformed
Abs.Abs.
22-- It gives immediate protection.It gives immediate protection.
33-- Immunity is temporary.Immunity is temporary.
8/8/2019 2-Resistance and Acquired Immunity 3
18/20
ImmunizingImmunizing AgentsAgents
Bacterial Vaccines:Bacterial Vaccines:a)a) Heat killed:Heat killed:T.A.B for enteric fever.T.A.B for enteric fever.
b)b) Live attenuated:Live attenuated: B.C.G. for tuberculosis.B.C.G. for tuberculosis.
c)c) Bacterial components:Bacterial components: CapsularCapsularpolysaccharides of meningococci and H.polysaccharides of meningococci and H.
influenzae for meningitis.influenzae for meningitis.
d)d) Bacterial products:Bacterial products:Toxoids ofToxoids ofDiphtheria bacilli for diphtheria, and Cl.Diphtheria bacilli for diphtheria, and Cl.
tetani for tetanus.tetani for tetanus.
8/8/2019 2-Resistance and Acquired Immunity 3
19/20
ImmunizingImmunizing AgentsAgents
Viral Vaccines:Viral Vaccines:
a) Inactivated:a) Inactivated: Salk vaccine for poliomyelitisSalk vaccine for poliomyelitis..
b) Attenuated:b) Attenuated: Sabin vaccine for poliomyelitis.Sabin vaccine for poliomyelitis.
c) Recombinant peptide:c) Recombinant peptide: Hepatitis B vaccine.Hepatitis B vaccine.
8/8/2019 2-Resistance and Acquired Immunity 3
20/20
Adjuvants:Adjuvants:
-- nonnon--specifically enhance the immunespecifically enhance the immune
response to an Ag.response to an Ag.
-- usually required with nonusually required with non--living vaccines.living vaccines.
-- e.g. aluminium hydroxide used withe.g. aluminium hydroxide used with
diphtheria and tetanus toxoids.diphtheria and tetanus toxoids.