SlideShare a Scribd company logo
1 of 4
IMMUNITY
THE IMMUNERESPONSE
If a pathogen getspastyourfirstline of defences,theimmunesystemkicks in
ACTIVATING THE IMMUNERESPONSE
 Whena pathogeninvade the body,the moleculesonitscell surface are identifiedasforeign,whichactivates
cellsinthe immune system
 The moleculesfoundonthe surface of the cellsare called antigens
 They`re usuallyproteinsorpolysaccharides
THE FOUR MAIN STAGES OF THE IMMUNE RESPONSE
1. PHAGOCYTOSIS
 A phagocyte isa type of white bloodcell thatcarriesout phagocytosis (engulfmentof pathogens
 They`re foundinthe bloodandin tissuesandare the firstcellsto respondtoa pathogeninside the body
 A phagocyte recognisesthe antigensonapathogen
 The cytoplasmof the phagocyte movesroundthe pathogen,engulfingit
 The pathogenisnowcontainedina phagocyticvacuole inthe cytoplasmof the phagocyte
 A lysosome thatcontainslysosomal enzymesfuseswiththe phagocyticvacuole
 The lysosomal enzymesbreakdownthe pathogen
 The phagocyte thenpresentsthe pathogen`santigens- itsticksthe antigensonit`ssurface to
activate otherimmune systemcells
2. T-CELL ACTIVATION
 A t-cell isa type of white bloodcell
 T-cellsare sometimescalledT-lymphocytes
 Lymphocytesare a type of WBC useful forprovidingimmunity
 T-cellsare made inthe marrow, butmature in the thymusgland
 T-cell hasproteinsonitssurface that bindto the antigenspresentedtoitbyphagocytes
 Thisactivatesthe T-cell
 Unlike B-cells,T-cellsdonotrecognise free-floatingantigens
 Rather,theirsurfacescontainspecializedantibody-like receptorsthatsee fragmentsof antigensonthe
surface of infectedorcancerouscells
 Differenttypesof T-cellsrespondindifferentways
HelperT-cells:
Coordinate immune responsesbycommunicatingwithothercells
Some stimulate nearb-cellstoproduce antibodies,otherscall inphagocytes
Cytotoxica.k.a. killerT-cells:
These performadifferentfunction
These cellsdirectlyattackothercellscarryingcertainforeignorabnormal moleculeson their
surfaces
Theyrelease PERFORIN tokill them
CytotoxicT-cellsare especiallyuseful forattackingvirusesbecause virusesoftenhidefromother
parts of the immune system,while theygrow inside infectedcells
CytotoxicT-cell recognise smallfragmentsof these virusespeekingoutfromthe cell membrane
and launchan attack to kill the infectedcell
3. B-CELL ACTIVATION AND PLAMA CELL PRODUCTION
 A type of WBC
 B-cellsare coveredwithantibodies-proteinsthatbindtoantigenstoforman antigen-antibodycomplex
 Each B-cell hasa differentshapedantibodyonitsmembrane,sodifferentonesbindtodifferentshaped
antigens
 Whenthe antibodyonthe surface of a B-cell meetsacomplementaryshapedantigen,itbindstoit
 This,togetherwithsubstancesreleasedfromT-cells,activatesthe B-cell
 The activatedB-cell thendividesbymitosistoproduce manymore B-cellscalledplasmacells- Allthe
cellsproducedwill be geneticallyidentical
 Thismeanstheyall produce identical antibodiesspecifictothe pathogen
4. ANTIBODY PRODUCTION
 The plasmacellsare identical tothe original B-cell (theyare clones)
 Plasmacellssecrete antibodiesdirectlyintothe bloodandthendie afterafew days
 These plasmacellsare notneededafterantibodiesare produced
 Antibodiessecretedare specifictothe pathogen
Antibodyfunctions include:
Coatingthe pathogentomake it easierfora phagocyte to engulf it
Coatingthe pathogentopreventitfromenteringhostcells
Bindingtoand neutralising(inactivating) toxinsproducedbythe pathogen
ANTIBODY STRUCTURE
 Antibodiesare proteins
 Theyare made up of chainsof aminoacidmonomerslinkedbypeptide bonds
 The specificityof anantibodydependsonitsvariable regions
 Each antibodyhasa differentshapedvariable region(due todifferentaminoacidsequences)that`s
complementarytoone specificantigen
 The constant regionsare the same inall antibodies
CELLULAR AND HUMORAL RESPONSES
The immune response isoftensplit into two:
 CELLULAR- The T-cellsformthe cellularresponse
 HUMORAL- B-cellsandthe productionof antibodiesformthe humoral response
PRIMARY AND SECONDARY IMMUNERESPONSES
PRIMARY RESPONSE
 Whenan antigenentersthe bodyforthe firsttime,itactivatesthe immune system
 Thisis calledthe primaryresponse
 The primary response isslowbecause there aren'tmanyB-cellsthatcanmake the antibodyneededtobind
to it
 Eventuallythe bodywillproduce enoughof the rightantibodytoovercome the infection
 Meanwhile the infectedpersonwillshow symptomsof the disease
 Afterbeingexposedtoanantigen,BothT-cell andB-cellsproduce memorycells
 These memorycellsremaininthe bodyforaslongtime
 MemoryT-cellsandmemoryB-cellsrememberthe specificantigenandwill binditasecondtime round
 The personis now immune- theirimmune systemhasthe abilitytorespondquicklytoa secondinfection
THE SECONDARY RESPONSE
 If the same pathogenentersthe bodyagain,the immune systemwillproduce aquicker,strongerimmune
response- the secondaryresponse
 MemoryB-cellsdivide intoplasmacellsthatproduce the rightantibodytothe antigen
 MemoryT-cellsdivide intothe correcttype of T-cellstokill the cell carryingthe antigen
 The secondaryresponse oftengetsridof the pathogenbefore youbegintoshow anysymptoms
VACCINES
 Vaccinescontainantigensthatcause yourbodyto produce memorycellsagainstaparticularpathogen,
withoutthe pathogencausingdisease
 Thismeansyou become immune withoutgettinganysymptoms
 Vaccinesprotectindividuals thathave them, and, because theyreduce the occurrence of the disease,those
not vaccinatedare alsolesslikelytocatchthe disease (there are fewerpeople tocatchit from)
 Thisis called herdimmunity
 Vaccinesalwayscontain-antigens-thesemaybe free orattachedto a dead or attenuated(weakened)
pathogen
 Vaccinesmaybe injectedortakenorally
 The disadvantages of takinga vaccine orallyare that itcouldbe brokendownbyenzymesinthe gutor the
moleculesof the vaccine maybe toolarge to be absorbedintothe blood
 Sometimesboostervaccinesare givenlaterontomake sure more memorycellsare produced
HOW A VACCINEWORKS?
 Vaccine containsantigensthatattachto a weakenordeadpathogen
 The phagocyte engulf thoughpathogen
 Cellspresentthe antigens- Thisactivates T-cells
 T-cellsdividebymitosistoproduce clones
 T-helpercellsreleasecytokines
 Cytokinesactivate B-cells
 B-cellsdividebymitosistoproduce plasmacells
 Plasmacellssecrete antibodies
 Antibodiesdestroypathogens
 Thisgivesa longerandstronger immune response
ETHICAL ISSUES SURROUNDING THE USE OF VACCINES
 All vaccinesare testedonanimalsbefore beingtestedonhumans
 Some people disagree withanimaltesting
 Also,animal basedsubstancesmaybe usedtoproduce a vaccine,whichsome peopledisagree with
 Testingvaccinesonhumanscan be riskye.g.volunteersmayputthemselvesatunnecessaryof contracting
the disease because theythinktheyare fullyprotected
 Some people don`twanttotake the vaccine due to the riskof side effects
 But theyare still protectedbecauseof herdimmunity
 Otherpeople thinkthisisunfair
 If there was an epidemicof a newdisease,therewouldbe rushtoreceive avaccine anddifficultdecisions
wouldhave tobe made aboutwhowouldbe the firstto receive it
ANTIGENICVARIATION
WHAT IS ANTIGENICVARIATION?
 Antigensonthe surface of pathogensactivate the primary response
 Whenyou're infectedasecondtime withthe same pathogen(whichhas the same antigensonits surface)
theyactivate the secondaryresponse andyoudon`tgetill
 However,some pathogenscanchange theirsurface antigens-pathogensof the same type thatshow
antigenicvariation,are oftenreferredtoasstrains
 Thisis calledantigenicvariation
 Differentantigensare formeddue tochangesinthe genesof a pathogen
 Thismeansthat whenyouare infectedforasecondtime,the memory cellsproducedfromthe first
infectionwill notrecognisethe differentantigens
 So the immune systemhasto start fromscratch andcarry out a primaryresponse againstthese new
antigens
 Thisprimaryresponse takestime togetridof the infection,whichiswhyyougetill again
 Antigenicvariationalsomakesitdifficulttodevelopvaccinesagainstsome pathogensforthe same reason
 Examplesof pathogensthatshow antigenicvariationinclude HIV andthe Influenzavirus
EXAMPLE: Antigenicvariation in the influenzavirus
 The influenzaviruscausesflu
 Proteinsonthe surface of the influenzavirusactas antigens,triggeringthe immunesystem
 These antigenscan change regularly,formingnew strainsof the virus
 Memorycellsproducedfrominfectionwithone strainof lfuwill notrecogniseotherstrainswithdifferent
antigens
 Thismeansyour immune systemproducesaprimaryresponse everytimeyouare infectedwithanewstrain
(carryingdifferentantigens)
 So thismeansyoucan sufferfromflumore than one-eachtime youare infectedwithanew strain
MONOCLONALANTIBODIES
THE USE OF MONOCLONALANTIBODIES
 Monoclonal antibodiesare antibodiesproducedformasingle groupof geneticallyidentical B-cells(plasma
cells)- Basicallycollectedfromone ancestral B-cell
 Thismeansthat theyare all identical instructure
 You can make monoclonal antibodiesthatbindtoanythingyouwante.g.a cell antigenorothersubstance,
and theywill onlybindto(target) thismolecule
FIGHTING CANCER
 Cancer cellshave differentantigenscomparedtonormal cells
 Monoclonal antibodies thatcomplementthese antigenswillbe harvestedandhave acytotoxicdrug
attachedto it
 However,there have beenissueswiththe actionof the antibodiesandthishasnotbeenassuccessful as
previouslyhoped

More Related Content

What's hot

Immunology lecture med t e ch
Immunology lecture med t e chImmunology lecture med t e ch
Immunology lecture med t e chNoel4leon
 
Immune responsetoinfectiousdiseasesfinal[2]
Immune responsetoinfectiousdiseasesfinal[2]Immune responsetoinfectiousdiseasesfinal[2]
Immune responsetoinfectiousdiseasesfinal[2]Bruno Mmassy
 
10 - Innate Immunity
10 - Innate Immunity10 - Innate Immunity
10 - Innate ImmunityRachel Belton
 
Overview of immune response
Overview of immune responseOverview of immune response
Overview of immune responseMd Murad Khan
 
Defending Against Infection
Defending Against InfectionDefending Against Infection
Defending Against Infectionguest5104a3
 
Body Defense Mechanism
Body Defense MechanismBody Defense Mechanism
Body Defense MechanismNavid J. Ayon
 
Vip immunity to infections
Vip immunity to infectionsVip immunity to infections
Vip immunity to infectionsBruno Mmassy
 
History and overview of immunology
History and overview of immunologyHistory and overview of immunology
History and overview of immunologyBruno Mmassy
 
Immunology & vaccination
Immunology & vaccinationImmunology & vaccination
Immunology & vaccinationcrisamaecatilo
 
Immunity to bacteria and related organisms in animal
Immunity to bacteria and related organisms in animalImmunity to bacteria and related organisms in animal
Immunity to bacteria and related organisms in animalPakawadee Tie
 
The immune system final
The immune system finalThe immune system final
The immune system finalrharrison545
 
The immune system
The immune systemThe immune system
The immune systempiskopos
 
What is Immunity? Explain the types of Immunity? (Presentation)
What is Immunity? Explain the types of Immunity? (Presentation)What is Immunity? Explain the types of Immunity? (Presentation)
What is Immunity? Explain the types of Immunity? (Presentation)Biochemistry Den
 

What's hot (20)

Immunology lecture med t e ch
Immunology lecture med t e chImmunology lecture med t e ch
Immunology lecture med t e ch
 
Immune responsetoinfectiousdiseasesfinal[2]
Immune responsetoinfectiousdiseasesfinal[2]Immune responsetoinfectiousdiseasesfinal[2]
Immune responsetoinfectiousdiseasesfinal[2]
 
Immunity
ImmunityImmunity
Immunity
 
Immune response
Immune responseImmune response
Immune response
 
Types of Immunity
Types of ImmunityTypes of Immunity
Types of Immunity
 
Types of immunity
Types of immunityTypes of immunity
Types of immunity
 
10 - Innate Immunity
10 - Innate Immunity10 - Innate Immunity
10 - Innate Immunity
 
Overview of immune response
Overview of immune responseOverview of immune response
Overview of immune response
 
Defending Against Infection
Defending Against InfectionDefending Against Infection
Defending Against Infection
 
Body Defense Mechanism
Body Defense MechanismBody Defense Mechanism
Body Defense Mechanism
 
Vip immunity to infections
Vip immunity to infectionsVip immunity to infections
Vip immunity to infections
 
History and overview of immunology
History and overview of immunologyHistory and overview of immunology
History and overview of immunology
 
Immunology & vaccination
Immunology & vaccinationImmunology & vaccination
Immunology & vaccination
 
Immunity to bacteria and related organisms in animal
Immunity to bacteria and related organisms in animalImmunity to bacteria and related organisms in animal
Immunity to bacteria and related organisms in animal
 
Introduction to immunology, Science of Immunity
Introduction to immunology, Science of Immunity Introduction to immunology, Science of Immunity
Introduction to immunology, Science of Immunity
 
Immunology 1, 2, 3
Immunology 1, 2, 3Immunology 1, 2, 3
Immunology 1, 2, 3
 
Lecture 13
Lecture 13Lecture 13
Lecture 13
 
The immune system final
The immune system finalThe immune system final
The immune system final
 
The immune system
The immune systemThe immune system
The immune system
 
What is Immunity? Explain the types of Immunity? (Presentation)
What is Immunity? Explain the types of Immunity? (Presentation)What is Immunity? Explain the types of Immunity? (Presentation)
What is Immunity? Explain the types of Immunity? (Presentation)
 

Viewers also liked

AQA Biology Unit 1 AS - Immunity
AQA Biology Unit 1 AS - ImmunityAQA Biology Unit 1 AS - Immunity
AQA Biology Unit 1 AS - ImmunityUmayr Dawood
 
B1 1.9 Immunity
B1 1.9 ImmunityB1 1.9 Immunity
B1 1.9 ImmunityBenLayde0
 
Cambridge AS Biology plant revision
Cambridge AS Biology plant revisionCambridge AS Biology plant revision
Cambridge AS Biology plant revisionGuerillateacher
 
NC Biology EOC Review
NC Biology EOC Review NC Biology EOC Review
NC Biology EOC Review Gena Barnhardt
 
AS Level Biology - 1) Biological Molecules
AS Level Biology - 1) Biological MoleculesAS Level Biology - 1) Biological Molecules
AS Level Biology - 1) Biological MoleculesArm Punyathorn
 
AS Level Biology - 10/11) Infectious Diseases and Immunity
AS Level Biology - 10/11) Infectious Diseases and ImmunityAS Level Biology - 10/11) Infectious Diseases and Immunity
AS Level Biology - 10/11) Infectious Diseases and ImmunityArm Punyathorn
 
AS Level Human Geography - Urbanization and Settlement
AS Level Human Geography - Urbanization and SettlementAS Level Human Geography - Urbanization and Settlement
AS Level Human Geography - Urbanization and SettlementArm Punyathorn
 
Vaccines,types,composition & failure etc
Vaccines,types,composition & failure etcVaccines,types,composition & failure etc
Vaccines,types,composition & failure etcDr. Waqas Nawaz
 

Viewers also liked (10)

AQA Biology Unit 1 AS - Immunity
AQA Biology Unit 1 AS - ImmunityAQA Biology Unit 1 AS - Immunity
AQA Biology Unit 1 AS - Immunity
 
B1 1.9 Immunity
B1 1.9 ImmunityB1 1.9 Immunity
B1 1.9 Immunity
 
Cambridge AS Biology plant revision
Cambridge AS Biology plant revisionCambridge AS Biology plant revision
Cambridge AS Biology plant revision
 
NC Biology EOC Review
NC Biology EOC Review NC Biology EOC Review
NC Biology EOC Review
 
AS Level Biology - 1) Biological Molecules
AS Level Biology - 1) Biological MoleculesAS Level Biology - 1) Biological Molecules
AS Level Biology - 1) Biological Molecules
 
AS Level Biology - 10/11) Infectious Diseases and Immunity
AS Level Biology - 10/11) Infectious Diseases and ImmunityAS Level Biology - 10/11) Infectious Diseases and Immunity
AS Level Biology - 10/11) Infectious Diseases and Immunity
 
AS Level Human Geography - Urbanization and Settlement
AS Level Human Geography - Urbanization and SettlementAS Level Human Geography - Urbanization and Settlement
AS Level Human Geography - Urbanization and Settlement
 
Vaccines,types,composition & failure etc
Vaccines,types,composition & failure etcVaccines,types,composition & failure etc
Vaccines,types,composition & failure etc
 
Classification of Immunity
Classification of ImmunityClassification of Immunity
Classification of Immunity
 
Basic immunology
Basic immunologyBasic immunology
Basic immunology
 

Similar to AQA as biology Immunity

Similar to AQA as biology Immunity (20)

IMMUNOLOGY.pptx
IMMUNOLOGY.pptxIMMUNOLOGY.pptx
IMMUNOLOGY.pptx
 
Immunology microbiology by nilesh sharma
Immunology microbiology by nilesh sharmaImmunology microbiology by nilesh sharma
Immunology microbiology by nilesh sharma
 
Vaccine delivery systems
Vaccine delivery systemsVaccine delivery systems
Vaccine delivery systems
 
Unit 2 immune systems
Unit 2  immune systemsUnit 2  immune systems
Unit 2 immune systems
 
Immunitybyasogwainnocentkingsley1 131219110304-phpapp02
Immunitybyasogwainnocentkingsley1 131219110304-phpapp02Immunitybyasogwainnocentkingsley1 131219110304-phpapp02
Immunitybyasogwainnocentkingsley1 131219110304-phpapp02
 
Immunity & principles of vaccination
Immunity & principles of vaccinationImmunity & principles of vaccination
Immunity & principles of vaccination
 
Immunity & principles of vaccination
Immunity & principles of vaccinationImmunity & principles of vaccination
Immunity & principles of vaccination
 
Lecture13 Immunity
Lecture13 ImmunityLecture13 Immunity
Lecture13 Immunity
 
3.immunity
3.immunity3.immunity
3.immunity
 
Unit 2 immune systems
Unit 2  immune systemsUnit 2  immune systems
Unit 2 immune systems
 
Immune System slides
Immune System slidesImmune System slides
Immune System slides
 
Antigen
AntigenAntigen
Antigen
 
Allergy and Immunization.pptx
Allergy and Immunization.pptxAllergy and Immunization.pptx
Allergy and Immunization.pptx
 
Unit 2 immune systems(1)
Unit 2  immune systems(1)Unit 2  immune systems(1)
Unit 2 immune systems(1)
 
Lecture13 Immunity
Lecture13 ImmunityLecture13 Immunity
Lecture13 Immunity
 
11.1 antibody production and vaccination
11.1 antibody production and vaccination11.1 antibody production and vaccination
11.1 antibody production and vaccination
 
Immunology
Immunology Immunology
Immunology
 
Immunology.pptx
Immunology.pptxImmunology.pptx
Immunology.pptx
 
Immunity types and compliment system ppt
Immunity types and compliment system pptImmunity types and compliment system ppt
Immunity types and compliment system ppt
 
1. immunity 2017 (1).pptx
1. immunity 2017 (1).pptx1. immunity 2017 (1).pptx
1. immunity 2017 (1).pptx
 

More from Madiya Afzal

AQA Variation in haemoglobin
AQA Variation in haemoglobinAQA Variation in haemoglobin
AQA Variation in haemoglobinMadiya Afzal
 
Kite runner revision
Kite runner revisionKite runner revision
Kite runner revisionMadiya Afzal
 
Exchange and transport systems
Exchange and transport systemsExchange and transport systems
Exchange and transport systemsMadiya Afzal
 
Kite runner revision pack
Kite runner revision packKite runner revision pack
Kite runner revision packMadiya Afzal
 
The plasma membrane
The plasma membraneThe plasma membrane
The plasma membraneMadiya Afzal
 
psychological investigations
psychological investigationspsychological investigations
psychological investigationsMadiya Afzal
 
The kite runner structure
The kite runner structureThe kite runner structure
The kite runner structureMadiya Afzal
 
the importance of being earnest
the importance of being earnestthe importance of being earnest
the importance of being earnestMadiya Afzal
 
The importance of being earnest
The importance of being earnestThe importance of being earnest
The importance of being earnestMadiya Afzal
 
Introduction to comedy
Introduction to comedyIntroduction to comedy
Introduction to comedyMadiya Afzal
 

More from Madiya Afzal (12)

AQA Variation in haemoglobin
AQA Variation in haemoglobinAQA Variation in haemoglobin
AQA Variation in haemoglobin
 
Kite runner revision
Kite runner revisionKite runner revision
Kite runner revision
 
Exchange and transport systems
Exchange and transport systemsExchange and transport systems
Exchange and transport systems
 
Kite runner revision pack
Kite runner revision packKite runner revision pack
Kite runner revision pack
 
The plasma membrane
The plasma membraneThe plasma membrane
The plasma membrane
 
Cells- biology as
Cells- biology asCells- biology as
Cells- biology as
 
psychological investigations
psychological investigationspsychological investigations
psychological investigations
 
The kite runner structure
The kite runner structureThe kite runner structure
The kite runner structure
 
the importance of being earnest
the importance of being earnestthe importance of being earnest
the importance of being earnest
 
The importance of being earnest
The importance of being earnestThe importance of being earnest
The importance of being earnest
 
Introduction to comedy
Introduction to comedyIntroduction to comedy
Introduction to comedy
 
Electron config
Electron configElectron config
Electron config
 

Recently uploaded

How to Fix XML SyntaxError in Odoo the 17
How to Fix XML SyntaxError in Odoo the 17How to Fix XML SyntaxError in Odoo the 17
How to Fix XML SyntaxError in Odoo the 17Celine George
 
Q-Factor General Quiz-7th April 2024, Quiz Club NITW
Q-Factor General Quiz-7th April 2024, Quiz Club NITWQ-Factor General Quiz-7th April 2024, Quiz Club NITW
Q-Factor General Quiz-7th April 2024, Quiz Club NITWQuiz Club NITW
 
BIOCHEMISTRY-CARBOHYDRATE METABOLISM CHAPTER 2.pptx
BIOCHEMISTRY-CARBOHYDRATE METABOLISM CHAPTER 2.pptxBIOCHEMISTRY-CARBOHYDRATE METABOLISM CHAPTER 2.pptx
BIOCHEMISTRY-CARBOHYDRATE METABOLISM CHAPTER 2.pptxSayali Powar
 
Grade Three -ELLNA-REVIEWER-ENGLISH.pptx
Grade Three -ELLNA-REVIEWER-ENGLISH.pptxGrade Three -ELLNA-REVIEWER-ENGLISH.pptx
Grade Three -ELLNA-REVIEWER-ENGLISH.pptxkarenfajardo43
 
4.16.24 21st Century Movements for Black Lives.pptx
4.16.24 21st Century Movements for Black Lives.pptx4.16.24 21st Century Movements for Black Lives.pptx
4.16.24 21st Century Movements for Black Lives.pptxmary850239
 
Beauty Amidst the Bytes_ Unearthing Unexpected Advantages of the Digital Wast...
Beauty Amidst the Bytes_ Unearthing Unexpected Advantages of the Digital Wast...Beauty Amidst the Bytes_ Unearthing Unexpected Advantages of the Digital Wast...
Beauty Amidst the Bytes_ Unearthing Unexpected Advantages of the Digital Wast...DhatriParmar
 
4.11.24 Mass Incarceration and the New Jim Crow.pptx
4.11.24 Mass Incarceration and the New Jim Crow.pptx4.11.24 Mass Incarceration and the New Jim Crow.pptx
4.11.24 Mass Incarceration and the New Jim Crow.pptxmary850239
 
Mythology Quiz-4th April 2024, Quiz Club NITW
Mythology Quiz-4th April 2024, Quiz Club NITWMythology Quiz-4th April 2024, Quiz Club NITW
Mythology Quiz-4th April 2024, Quiz Club NITWQuiz Club NITW
 
Multi Domain Alias In the Odoo 17 ERP Module
Multi Domain Alias In the Odoo 17 ERP ModuleMulti Domain Alias In the Odoo 17 ERP Module
Multi Domain Alias In the Odoo 17 ERP ModuleCeline George
 
Q-Factor HISPOL Quiz-6th April 2024, Quiz Club NITW
Q-Factor HISPOL Quiz-6th April 2024, Quiz Club NITWQ-Factor HISPOL Quiz-6th April 2024, Quiz Club NITW
Q-Factor HISPOL Quiz-6th April 2024, Quiz Club NITWQuiz Club NITW
 
Textual Evidence in Reading and Writing of SHS
Textual Evidence in Reading and Writing of SHSTextual Evidence in Reading and Writing of SHS
Textual Evidence in Reading and Writing of SHSMae Pangan
 
Active Learning Strategies (in short ALS).pdf
Active Learning Strategies (in short ALS).pdfActive Learning Strategies (in short ALS).pdf
Active Learning Strategies (in short ALS).pdfPatidar M
 
Measures of Position DECILES for ungrouped data
Measures of Position DECILES for ungrouped dataMeasures of Position DECILES for ungrouped data
Measures of Position DECILES for ungrouped dataBabyAnnMotar
 
Congestive Cardiac Failure..presentation
Congestive Cardiac Failure..presentationCongestive Cardiac Failure..presentation
Congestive Cardiac Failure..presentationdeepaannamalai16
 
Blowin' in the Wind of Caste_ Bob Dylan's Song as a Catalyst for Social Justi...
Blowin' in the Wind of Caste_ Bob Dylan's Song as a Catalyst for Social Justi...Blowin' in the Wind of Caste_ Bob Dylan's Song as a Catalyst for Social Justi...
Blowin' in the Wind of Caste_ Bob Dylan's Song as a Catalyst for Social Justi...DhatriParmar
 
Mental Health Awareness - a toolkit for supporting young minds
Mental Health Awareness - a toolkit for supporting young mindsMental Health Awareness - a toolkit for supporting young minds
Mental Health Awareness - a toolkit for supporting young mindsPooky Knightsmith
 
Reading and Writing Skills 11 quarter 4 melc 1
Reading and Writing Skills 11 quarter 4 melc 1Reading and Writing Skills 11 quarter 4 melc 1
Reading and Writing Skills 11 quarter 4 melc 1GloryAnnCastre1
 
Oppenheimer Film Discussion for Philosophy and Film
Oppenheimer Film Discussion for Philosophy and FilmOppenheimer Film Discussion for Philosophy and Film
Oppenheimer Film Discussion for Philosophy and FilmStan Meyer
 

Recently uploaded (20)

How to Fix XML SyntaxError in Odoo the 17
How to Fix XML SyntaxError in Odoo the 17How to Fix XML SyntaxError in Odoo the 17
How to Fix XML SyntaxError in Odoo the 17
 
Q-Factor General Quiz-7th April 2024, Quiz Club NITW
Q-Factor General Quiz-7th April 2024, Quiz Club NITWQ-Factor General Quiz-7th April 2024, Quiz Club NITW
Q-Factor General Quiz-7th April 2024, Quiz Club NITW
 
BIOCHEMISTRY-CARBOHYDRATE METABOLISM CHAPTER 2.pptx
BIOCHEMISTRY-CARBOHYDRATE METABOLISM CHAPTER 2.pptxBIOCHEMISTRY-CARBOHYDRATE METABOLISM CHAPTER 2.pptx
BIOCHEMISTRY-CARBOHYDRATE METABOLISM CHAPTER 2.pptx
 
Grade Three -ELLNA-REVIEWER-ENGLISH.pptx
Grade Three -ELLNA-REVIEWER-ENGLISH.pptxGrade Three -ELLNA-REVIEWER-ENGLISH.pptx
Grade Three -ELLNA-REVIEWER-ENGLISH.pptx
 
4.16.24 21st Century Movements for Black Lives.pptx
4.16.24 21st Century Movements for Black Lives.pptx4.16.24 21st Century Movements for Black Lives.pptx
4.16.24 21st Century Movements for Black Lives.pptx
 
Beauty Amidst the Bytes_ Unearthing Unexpected Advantages of the Digital Wast...
Beauty Amidst the Bytes_ Unearthing Unexpected Advantages of the Digital Wast...Beauty Amidst the Bytes_ Unearthing Unexpected Advantages of the Digital Wast...
Beauty Amidst the Bytes_ Unearthing Unexpected Advantages of the Digital Wast...
 
4.11.24 Mass Incarceration and the New Jim Crow.pptx
4.11.24 Mass Incarceration and the New Jim Crow.pptx4.11.24 Mass Incarceration and the New Jim Crow.pptx
4.11.24 Mass Incarceration and the New Jim Crow.pptx
 
Mythology Quiz-4th April 2024, Quiz Club NITW
Mythology Quiz-4th April 2024, Quiz Club NITWMythology Quiz-4th April 2024, Quiz Club NITW
Mythology Quiz-4th April 2024, Quiz Club NITW
 
Multi Domain Alias In the Odoo 17 ERP Module
Multi Domain Alias In the Odoo 17 ERP ModuleMulti Domain Alias In the Odoo 17 ERP Module
Multi Domain Alias In the Odoo 17 ERP Module
 
Q-Factor HISPOL Quiz-6th April 2024, Quiz Club NITW
Q-Factor HISPOL Quiz-6th April 2024, Quiz Club NITWQ-Factor HISPOL Quiz-6th April 2024, Quiz Club NITW
Q-Factor HISPOL Quiz-6th April 2024, Quiz Club NITW
 
Textual Evidence in Reading and Writing of SHS
Textual Evidence in Reading and Writing of SHSTextual Evidence in Reading and Writing of SHS
Textual Evidence in Reading and Writing of SHS
 
Active Learning Strategies (in short ALS).pdf
Active Learning Strategies (in short ALS).pdfActive Learning Strategies (in short ALS).pdf
Active Learning Strategies (in short ALS).pdf
 
Measures of Position DECILES for ungrouped data
Measures of Position DECILES for ungrouped dataMeasures of Position DECILES for ungrouped data
Measures of Position DECILES for ungrouped data
 
Congestive Cardiac Failure..presentation
Congestive Cardiac Failure..presentationCongestive Cardiac Failure..presentation
Congestive Cardiac Failure..presentation
 
Blowin' in the Wind of Caste_ Bob Dylan's Song as a Catalyst for Social Justi...
Blowin' in the Wind of Caste_ Bob Dylan's Song as a Catalyst for Social Justi...Blowin' in the Wind of Caste_ Bob Dylan's Song as a Catalyst for Social Justi...
Blowin' in the Wind of Caste_ Bob Dylan's Song as a Catalyst for Social Justi...
 
Paradigm shift in nursing research by RS MEHTA
Paradigm shift in nursing research by RS MEHTAParadigm shift in nursing research by RS MEHTA
Paradigm shift in nursing research by RS MEHTA
 
Faculty Profile prashantha K EEE dept Sri Sairam college of Engineering
Faculty Profile prashantha K EEE dept Sri Sairam college of EngineeringFaculty Profile prashantha K EEE dept Sri Sairam college of Engineering
Faculty Profile prashantha K EEE dept Sri Sairam college of Engineering
 
Mental Health Awareness - a toolkit for supporting young minds
Mental Health Awareness - a toolkit for supporting young mindsMental Health Awareness - a toolkit for supporting young minds
Mental Health Awareness - a toolkit for supporting young minds
 
Reading and Writing Skills 11 quarter 4 melc 1
Reading and Writing Skills 11 quarter 4 melc 1Reading and Writing Skills 11 quarter 4 melc 1
Reading and Writing Skills 11 quarter 4 melc 1
 
Oppenheimer Film Discussion for Philosophy and Film
Oppenheimer Film Discussion for Philosophy and FilmOppenheimer Film Discussion for Philosophy and Film
Oppenheimer Film Discussion for Philosophy and Film
 

AQA as biology Immunity

  • 1. IMMUNITY THE IMMUNERESPONSE If a pathogen getspastyourfirstline of defences,theimmunesystemkicks in ACTIVATING THE IMMUNERESPONSE  Whena pathogeninvade the body,the moleculesonitscell surface are identifiedasforeign,whichactivates cellsinthe immune system  The moleculesfoundonthe surface of the cellsare called antigens  They`re usuallyproteinsorpolysaccharides THE FOUR MAIN STAGES OF THE IMMUNE RESPONSE 1. PHAGOCYTOSIS  A phagocyte isa type of white bloodcell thatcarriesout phagocytosis (engulfmentof pathogens  They`re foundinthe bloodandin tissuesandare the firstcellsto respondtoa pathogeninside the body  A phagocyte recognisesthe antigensonapathogen  The cytoplasmof the phagocyte movesroundthe pathogen,engulfingit  The pathogenisnowcontainedina phagocyticvacuole inthe cytoplasmof the phagocyte  A lysosome thatcontainslysosomal enzymesfuseswiththe phagocyticvacuole  The lysosomal enzymesbreakdownthe pathogen  The phagocyte thenpresentsthe pathogen`santigens- itsticksthe antigensonit`ssurface to activate otherimmune systemcells 2. T-CELL ACTIVATION  A t-cell isa type of white bloodcell  T-cellsare sometimescalledT-lymphocytes  Lymphocytesare a type of WBC useful forprovidingimmunity  T-cellsare made inthe marrow, butmature in the thymusgland  T-cell hasproteinsonitssurface that bindto the antigenspresentedtoitbyphagocytes  Thisactivatesthe T-cell  Unlike B-cells,T-cellsdonotrecognise free-floatingantigens  Rather,theirsurfacescontainspecializedantibody-like receptorsthatsee fragmentsof antigensonthe surface of infectedorcancerouscells  Differenttypesof T-cellsrespondindifferentways HelperT-cells: Coordinate immune responsesbycommunicatingwithothercells Some stimulate nearb-cellstoproduce antibodies,otherscall inphagocytes Cytotoxica.k.a. killerT-cells: These performadifferentfunction These cellsdirectlyattackothercellscarryingcertainforeignorabnormal moleculeson their surfaces Theyrelease PERFORIN tokill them CytotoxicT-cellsare especiallyuseful forattackingvirusesbecause virusesoftenhidefromother parts of the immune system,while theygrow inside infectedcells CytotoxicT-cell recognise smallfragmentsof these virusespeekingoutfromthe cell membrane and launchan attack to kill the infectedcell 3. B-CELL ACTIVATION AND PLAMA CELL PRODUCTION
  • 2.  A type of WBC  B-cellsare coveredwithantibodies-proteinsthatbindtoantigenstoforman antigen-antibodycomplex  Each B-cell hasa differentshapedantibodyonitsmembrane,sodifferentonesbindtodifferentshaped antigens  Whenthe antibodyonthe surface of a B-cell meetsacomplementaryshapedantigen,itbindstoit  This,togetherwithsubstancesreleasedfromT-cells,activatesthe B-cell  The activatedB-cell thendividesbymitosistoproduce manymore B-cellscalledplasmacells- Allthe cellsproducedwill be geneticallyidentical  Thismeanstheyall produce identical antibodiesspecifictothe pathogen 4. ANTIBODY PRODUCTION  The plasmacellsare identical tothe original B-cell (theyare clones)  Plasmacellssecrete antibodiesdirectlyintothe bloodandthendie afterafew days  These plasmacellsare notneededafterantibodiesare produced  Antibodiessecretedare specifictothe pathogen Antibodyfunctions include: Coatingthe pathogentomake it easierfora phagocyte to engulf it Coatingthe pathogentopreventitfromenteringhostcells Bindingtoand neutralising(inactivating) toxinsproducedbythe pathogen ANTIBODY STRUCTURE  Antibodiesare proteins  Theyare made up of chainsof aminoacidmonomerslinkedbypeptide bonds  The specificityof anantibodydependsonitsvariable regions  Each antibodyhasa differentshapedvariable region(due todifferentaminoacidsequences)that`s complementarytoone specificantigen  The constant regionsare the same inall antibodies CELLULAR AND HUMORAL RESPONSES The immune response isoftensplit into two:  CELLULAR- The T-cellsformthe cellularresponse  HUMORAL- B-cellsandthe productionof antibodiesformthe humoral response PRIMARY AND SECONDARY IMMUNERESPONSES PRIMARY RESPONSE  Whenan antigenentersthe bodyforthe firsttime,itactivatesthe immune system  Thisis calledthe primaryresponse  The primary response isslowbecause there aren'tmanyB-cellsthatcanmake the antibodyneededtobind to it  Eventuallythe bodywillproduce enoughof the rightantibodytoovercome the infection  Meanwhile the infectedpersonwillshow symptomsof the disease  Afterbeingexposedtoanantigen,BothT-cell andB-cellsproduce memorycells  These memorycellsremaininthe bodyforaslongtime  MemoryT-cellsandmemoryB-cellsrememberthe specificantigenandwill binditasecondtime round  The personis now immune- theirimmune systemhasthe abilitytorespondquicklytoa secondinfection
  • 3. THE SECONDARY RESPONSE  If the same pathogenentersthe bodyagain,the immune systemwillproduce aquicker,strongerimmune response- the secondaryresponse  MemoryB-cellsdivide intoplasmacellsthatproduce the rightantibodytothe antigen  MemoryT-cellsdivide intothe correcttype of T-cellstokill the cell carryingthe antigen  The secondaryresponse oftengetsridof the pathogenbefore youbegintoshow anysymptoms VACCINES  Vaccinescontainantigensthatcause yourbodyto produce memorycellsagainstaparticularpathogen, withoutthe pathogencausingdisease  Thismeansyou become immune withoutgettinganysymptoms  Vaccinesprotectindividuals thathave them, and, because theyreduce the occurrence of the disease,those not vaccinatedare alsolesslikelytocatchthe disease (there are fewerpeople tocatchit from)  Thisis called herdimmunity  Vaccinesalwayscontain-antigens-thesemaybe free orattachedto a dead or attenuated(weakened) pathogen  Vaccinesmaybe injectedortakenorally  The disadvantages of takinga vaccine orallyare that itcouldbe brokendownbyenzymesinthe gutor the moleculesof the vaccine maybe toolarge to be absorbedintothe blood  Sometimesboostervaccinesare givenlaterontomake sure more memorycellsare produced HOW A VACCINEWORKS?  Vaccine containsantigensthatattachto a weakenordeadpathogen  The phagocyte engulf thoughpathogen  Cellspresentthe antigens- Thisactivates T-cells  T-cellsdividebymitosistoproduce clones  T-helpercellsreleasecytokines  Cytokinesactivate B-cells  B-cellsdividebymitosistoproduce plasmacells  Plasmacellssecrete antibodies  Antibodiesdestroypathogens  Thisgivesa longerandstronger immune response ETHICAL ISSUES SURROUNDING THE USE OF VACCINES  All vaccinesare testedonanimalsbefore beingtestedonhumans  Some people disagree withanimaltesting  Also,animal basedsubstancesmaybe usedtoproduce a vaccine,whichsome peopledisagree with  Testingvaccinesonhumanscan be riskye.g.volunteersmayputthemselvesatunnecessaryof contracting the disease because theythinktheyare fullyprotected  Some people don`twanttotake the vaccine due to the riskof side effects  But theyare still protectedbecauseof herdimmunity  Otherpeople thinkthisisunfair  If there was an epidemicof a newdisease,therewouldbe rushtoreceive avaccine anddifficultdecisions wouldhave tobe made aboutwhowouldbe the firstto receive it
  • 4. ANTIGENICVARIATION WHAT IS ANTIGENICVARIATION?  Antigensonthe surface of pathogensactivate the primary response  Whenyou're infectedasecondtime withthe same pathogen(whichhas the same antigensonits surface) theyactivate the secondaryresponse andyoudon`tgetill  However,some pathogenscanchange theirsurface antigens-pathogensof the same type thatshow antigenicvariation,are oftenreferredtoasstrains  Thisis calledantigenicvariation  Differentantigensare formeddue tochangesinthe genesof a pathogen  Thismeansthat whenyouare infectedforasecondtime,the memory cellsproducedfromthe first infectionwill notrecognisethe differentantigens  So the immune systemhasto start fromscratch andcarry out a primaryresponse againstthese new antigens  Thisprimaryresponse takestime togetridof the infection,whichiswhyyougetill again  Antigenicvariationalsomakesitdifficulttodevelopvaccinesagainstsome pathogensforthe same reason  Examplesof pathogensthatshow antigenicvariationinclude HIV andthe Influenzavirus EXAMPLE: Antigenicvariation in the influenzavirus  The influenzaviruscausesflu  Proteinsonthe surface of the influenzavirusactas antigens,triggeringthe immunesystem  These antigenscan change regularly,formingnew strainsof the virus  Memorycellsproducedfrominfectionwithone strainof lfuwill notrecogniseotherstrainswithdifferent antigens  Thismeansyour immune systemproducesaprimaryresponse everytimeyouare infectedwithanewstrain (carryingdifferentantigens)  So thismeansyoucan sufferfromflumore than one-eachtime youare infectedwithanew strain MONOCLONALANTIBODIES THE USE OF MONOCLONALANTIBODIES  Monoclonal antibodiesare antibodiesproducedformasingle groupof geneticallyidentical B-cells(plasma cells)- Basicallycollectedfromone ancestral B-cell  Thismeansthat theyare all identical instructure  You can make monoclonal antibodiesthatbindtoanythingyouwante.g.a cell antigenorothersubstance, and theywill onlybindto(target) thismolecule FIGHTING CANCER  Cancer cellshave differentantigenscomparedtonormal cells  Monoclonal antibodies thatcomplementthese antigenswillbe harvestedandhave acytotoxicdrug attachedto it  However,there have beenissueswiththe actionof the antibodiesandthishasnotbeenassuccessful as previouslyhoped