Organization of the Animal BodyOrganization of the Animal Body

Cell and Tissue TypesCell and Tissue Types

Organ SystemsOrgan Systems

Organizational Hierarchy of LifeOrganizational Hierarchy of Life

Most ComplexMost Complex

Least ComplexLeast Complex

Non-livingNon-living

LivingLiving

sub-atomic particlessub-atomic particles

atomatom

moleculemolecule

macromoleculemacromolecule

organelleorganelle

cellcell

tissuetissue

organorgan

organ systemorgan system

organismorganism

Immune SystemImmune System

Cells, Cell Cells, Cell Products Products and Organs and Organs That Protect That Protect the Body the Body Against DiseaseAgainst Disease

Properties of the Immune Properties of the Immune ResponseResponse

A.A. Specificity: Unique response Specificity: Unique response against each each invaderagainst each each invader

B. Memory: Increased response at next B. Memory: Increased response at next invasioninvasion

C. Discrimination: Ability to distinguish C. Discrimination: Ability to distinguish “self” from “non-self” “self” from “non-self”

Applying Your KnowledgeApplying Your Knowledge

Which property of the immune response: Which property of the immune response:

A.A. keeps you from developing chicken pox a keeps you from developing chicken pox a second time? (Assume you had a severe second time? (Assume you had a severe case at age six.)case at age six.)

B.B. helps you successfully recover from a cold?helps you successfully recover from a cold?

C.C. causes you to reject a donated organ?causes you to reject a donated organ?

1.1. SpecificitySpecificity2.2. MemoryMemory3.3. Discrimination between self and non-selfDiscrimination between self and non-self

Components of the Immune SystemComponents of the Immune System

• Organs Organs – Bone MarrowBone Marrow– SpleenSpleen– ThymusThymus– TonsilsTonsils– Lymphatic vesselsLymphatic vessels– Lymph NodesLymph Nodes

• CellsCells– Macrophages: Macrophages: engulf invadersengulf invaders

– B cells: B cells: humoral immunityhumoral immunity

– T cells: T cells: cell-mediated immunitycell-mediated immunity

Macrophages Engulf the Invader and Macrophages Engulf the Invader and

Signal Other Immune System CellsSignal Other Immune System Cells

Viral Invader

Antigens

Macrophage

Macrophage engulfs invader

Macrophage displays

“processed” antigen

Macrophage releases cytokines to influence

T and B cells

T Cells Become Activated, Leading to T Cells Become Activated, Leading to Cell-mediated and Humoral ResponsesCell-mediated and Humoral Responses

Macrophage secretes

cytokines to activate T cell

Helper T Cell binds to

Macrophage

Helper T Cell

T Cell ReceptorMacrophage

Humoral Humoral ResponseResponse

Invader binds to B cell that carries

antibody matching the

antigen

Antibody

Activated Helper T cell stimulates

division of selected B cell

Dividing B cell gives rise to

memory B cells and plasma cells

Memory B cells respond in future

invasions

Plasma cells secrete

antibodies into bloodstream

B cellsB cells

Antibody Structure: Y-Shaped ProteinAntibody Structure: Y-Shaped Protein

ss ss

ss ssss ssss ss

Cons

tant

Cons

tant

Cons

tant

Cons

tant

Variab

le

Variab

le

Variab

le

Variab

le

Constant

Constant

Varia

ble

Varia

ble

Con

stan

tC

onst

ant Va

riabl

eVa

riabl

e

BAD AntigenBAD Antigen

Antibody has 2 heavy chainsAntibody has 2 heavy chains and 2 light chains. and 2 light chains.Variable regions bind to antigen.Variable regions bind to antigen.Constant regions bind to cellsConstant regions bind to cells or other antibodies. or other antibodies.

Three-Dimensional Three-Dimensional Antibody StructureAntibody Structure

Gene forGene forconstant regionconstant regionof light chainof light chain

Genes forGenes forvariable regionvariable regionof light chainof light chainGene forGene for

constant regionconstant regionof heavy chainof heavy chain

Genes forGenes forvariable regionvariable regionof heavy chainof heavy chain

Recombination during Recombination during Construction of Antibody GenesConstruction of Antibody Genes

Antibodies Mark Invaders for DestructionAntibodies Mark Invaders for Destruction

Phagocytosis by Phagocytosis by a Macrophagea Macrophage

Applying Your KnowledgeApplying Your Knowledge

A.A. Which part of the antibody binds to the Which part of the antibody binds to the antigen? (choices on left)antigen? (choices on left)

B.B. Which type of protein structure is seen Which type of protein structure is seen in a functional antibody molecule? in a functional antibody molecule? (choices on right)(choices on right)

1.1. Light ChainLight Chain2.2. Heavy ChainHeavy Chain3.3. Variable RegionVariable Region4.4. Constant RegionConstant Region

1.1. Primary StructurePrimary Structure2.2. Secondary StructureSecondary Structure3.3. Tertiary StructureTertiary Structure4.4. Quaternary StructureQuaternary Structure

Memory Cells and the Immune Response

Cell-Mediated ResponseCell-Mediated Response

Activated Helper T cell stimulates

activity of Cytotoxic T cells

Cytotoxic T cell destroys

infected body cells by forming

pores in cell membrane

Memory T cell responds in

future infections

Division of T cells gives rise to

memory T cells

Applying Your KnowledgeApplying Your Knowledge

Which immune system cell: Which immune system cell:

A.A. keeps you from developing chicken pox a keeps you from developing chicken pox a second time? (Assume you had a severe second time? (Assume you had a severe case at age six.)case at age six.)

B.B. helps you successfully recover from a cold?helps you successfully recover from a cold?

C.C. causes you to reject a donated organ?causes you to reject a donated organ?

1.1. MacrophageMacrophage2.2. Plasma CellPlasma Cell3.3. Memory B CellMemory B Cell4.4. Helper T CellHelper T Cell5.5. Cytotoxic T CellCytotoxic T Cell

Humoral and Cellular ImmunityHumoral and Cellular Immunity

Humoral Humoral

(Antibody-mediated)(Antibody-mediated)

CellularCellular

(T-cell mediated)(T-cell mediated)

Hay feverHay fever Reaction to poison ivyReaction to poison ivy

Transfusion reactionsTransfusion reactions Tuberculin TestTuberculin Test

Rh diseaseRh disease Reaction to bee stingsReaction to bee stings

ImmunizationImmunization Graft (organ) rejectionGraft (organ) rejection

Viral and Bacterial Viral and Bacterial infectionsinfections

Cancer PreventionCancer Prevention

Cell-Mediated Immunity at WorkCell-Mediated Immunity at Work

Cytotoxic T CellsCytotoxic T Cells

Cancer CellCancer Cell

Diseases of the Immune SystemDiseases of the Immune System

A.A. Inherited Immune DeficienciesInherited Immune Deficiencieseg. SCID: eg. SCID: Severe Combined Immune DeficiencySevere Combined Immune Deficiency

B. AIDS: B. AIDS: Acquired Immune Deficiency SyndromeAcquired Immune Deficiency Syndrome HIV infects Helper T Cells HIV infects Helper T Cells

C. Autoimmune diseasesC. Autoimmune diseases1. Autoimmune ulcerative colitis1. Autoimmune ulcerative colitis2. Rheumatiod arthritis2. Rheumatiod arthritis

D. Allergies D. Allergies

Allergic ReactionsAllergic Reactions

Pollen grains enterPollen grains enterrespiratory tractrespiratory tract

Pollen grains enterPollen grains enterrespiratory tractrespiratory tract

Pollen binds toPollen binds toallergy antibodyallergy antibodyPollen binds toPollen binds toallergy antibodyallergy antibody

Causes releaseCauses releaseof histamine,of histamine,which causeswhich causes

symptomssymptoms

Causes releaseCauses releaseof histamine,of histamine,which causeswhich causes

symptomssymptoms

Mast CellMast CellMast CellMast Cell

““Allergy” plasma cell releasesAllergy” plasma cell releases“allergy” antibodies“allergy” antibodies

““Allergy” plasma cell releasesAllergy” plasma cell releases“allergy” antibodies“allergy” antibodies

Binding site forBinding site for“allergy” antibodies“allergy” antibodies

Binding site forBinding site for“allergy” antibodies“allergy” antibodies

Histamine vesicleHistamine vesicleHistamine vesicleHistamine vesicle

HIVHIV

GlycoproteinsGlycoproteinsGlycoproteinsGlycoproteins

EnvelopeEnvelope(lipid bilayer)(lipid bilayer)

EnvelopeEnvelope(lipid bilayer)(lipid bilayer)

ProteinProteinCoatCoat

ProteinProteinCoatCoat

CoreCoreProteinsProteins

CoreCoreProteinsProteins

ReverseReverseTranscriptaseTranscriptase

ReverseReverseTranscriptaseTranscriptase

Viral RNA inViral RNA inprotein coatprotein coatViral RNA inViral RNA inprotein coatprotein coat

HIV InfectionHIV Infection

Helper T Cell (green)Helper T Cell (green)Helper T Cell (green)Helper T Cell (green)

Recently emergedRecently emergedHIV particles (red)HIV particles (red)Recently emergedRecently emergedHIV particles (red)HIV particles (red)

EmergingEmergingHIV particlesHIV particles

EmergingEmergingHIV particlesHIV particles

Envelope acquiredEnvelope acquiredfrom helper T cellfrom helper T cell

Envelope acquiredEnvelope acquiredfrom helper T cellfrom helper T cell