Immune SystemImmune SystemIntroductionIntroduction

• System that helps fight off System that helps fight off and destroy Cancer cells and destroy Cancer cells and pathogensand pathogens

• Composed of many parts:Composed of many parts: * Spleen* Spleen * Lymph nodes* Lymph nodes * Thymus* Thymus * Bone marrow* Bone marrow * Lymphatic vessels* Lymphatic vessels * Lymphocytes or White* Lymphocytes or White Blood cellsBlood cells

PathogensPathogens• What are Pathogens?What are Pathogens?

Organisms that cause Organisms that cause diseasedisease

• Infectious diseases are?Infectious diseases are?

Diseases that are caused by Diseases that are caused by pathogens .pathogens .

• When you have an When you have an infectious disease infectious disease pathogens are inside your pathogens are inside your body causing harmbody causing harm

• Staphyloccocus Staphyloccocus aureusaureus

• Magnified 20,000XMagnified 20,000X• About 1 um in sizeAbout 1 um in size

• What type of What type of pathogen is Staph?pathogen is Staph?

BACTERIABACTERIA

44 TYPES OF COMMON PATHOGENS TYPES OF COMMON PATHOGENS

• Can you guess what they are?Can you guess what they are?

* * Viruses Viruses

* Fungi * Fungi BacillusBacillus

* Bacteria * Bacteria

* * Protists/ParasitesProtists/Parasites FungusFungus

Immune SystemImmune System• Made of different types of cells Made of different types of cells each with a specific jobeach with a specific job• These cells are called These cells are called LymphocytesLymphocytes or or White White

bloodblood cellscells or or WBC’sWBC’s • Target specificTarget specific Pathogens, Infected cells and Pathogens, Infected cells and

Cancer cellsCancer cells• Sometimes the Immune system attacks its body:Sometimes the Immune system attacks its body: * This is called * This is called Autoimmune DiseaseAutoimmune Disease Example:Example: Lupus Erythematosus Lupus Erythematosus

Arthritis Arthritis

Types ofTypes of LymphocytesLymphocytes 1. 1. T - cellsT - cells

Identify Identify PathogensPathogens by recognizing by recognizing

their their AntigensAntigens

What is their job?What is their job?

To activateTo activate B-cellsB-cells

2. 2. B cellsB cells Produce chemicals called Produce chemicals called AntibodiesAntibodies

Types ofTypes of LymphocytesLymphocytes

3. 3. Macrophages Macrophages – – Surround pathogen and Surround pathogen and

digest or eat itdigest or eat it

Also called PhagocytesAlso called Phagocytes

Types ofTypes of T – cellsT – cells• There are the Two Types of special T– CellsThere are the Two Types of special T– Cells

1. Natural Killers Cells 1. Natural Killers Cells

2. Cytotoxic Cells 2. Cytotoxic Cells

* Destroy pathogens after they are marked by* Destroy pathogens after they are marked by

antibodiesantibodies

* Destroy cells that are infected with a virus* Destroy cells that are infected with a virus

* Also recognize cancer cells and destroy them* Also recognize cancer cells and destroy them

Types ofTypes of T – cellsT – cells• What are Memory T- Cells ?What are Memory T- Cells ? They remember what type of antigens They remember what type of antigens are on a pathogen!!!are on a pathogen!!! Help immune system recognize the Help immune system recognize the

pathogen if it pathogen if it invadesinvades our body again!! our body again!! AMAZING ! ! !AMAZING ! ! !

ANTIGENS AND ANTIBODIESANTIGENS AND ANTIBODIES

• What are What are AntigensAntigens??

Special proteins on the surface of pathogens and Special proteins on the surface of pathogens and

surface of our cells cells surface of our cells cells

They are recognized by the They are recognized by the Immune SystemImmune System• Why?Why?

So the White blood cells know which pathogens So the White blood cells know which pathogens

they need to destroy!!!they need to destroy!!!

ANTIGENS AND ANTIBODIESANTIGENS AND ANTIBODIES

• What are What are AntibodiesAntibodies? ?

Special proteins that recognize Special proteins that recognize specific specific AntigensAntigens on on PathogensPathogens

Mark the pathogens for Mark the pathogens for destruction by WBC’sdestruction by WBC’s

The Immune SystemThe Immune System• How do How do T- cellsT- cells and and B - cellsB - cells work together work together to fight off pathogens and destroy infected cells?to fight off pathogens and destroy infected cells?

What happens when a virus infects a cell?What happens when a virus infects a cell?What do What do T-cellsT-cells do?do?

What is another job of theWhat is another job of the T- cells? T- cells?

So, why do So, why do B – cellsB – cells produce produce antibodies?antibodies?BecauseBecause…………

How does the Immune System workHow does the Immune System work

T- cells recognize bacterial or viral T- cells recognize bacterial or viral antigen.antigen.

Some T- cells attack cells infected with Some T- cells attack cells infected with pathogenspathogens

Other T-cells signal B cells to produce Other T-cells signal B cells to produce antibodiesantibodies .

Antibodies attach to the antigens on virus or Antibodies attach to the antigens on virus or bacteria bacteria (Lock & Key)Lock & Key)

Antibodies help phagocytes destroy the bacteria Antibodies help phagocytes destroy the bacteria or virusor virus

ImmunityImmunityHow does a person become immunized?How does a person become immunized?

Two Types of ImmunityTwo Types of Immunity• Active ImmunityActive Immunity Immune system produces antibodiesImmune system produces antibodies on its own in response to a pathogenon its own in response to a pathogen• Passive ImmunityPassive Immunity Antibodies are injected into a patient to Antibodies are injected into a patient to help prevent a disease from a pathogenhelp prevent a disease from a pathogen

VaccinesVaccinesHow do vaccines work?How do vaccines work?

1.1. They contain a weakened pathogen They contain a weakened pathogen that stimulates production of that stimulates production of

antibodies without causing the antibodies without causing the actual diseaseactual disease ExampleExample: The Flu shot: The Flu shot2. Antibodies are already in the vaccine2. Antibodies are already in the vaccine Your immune system doesn’t need toYour immune system doesn’t need to produce themproduce them

Active Immunity Both Passive ImmunityActive Immunity Both Passive Immunity

The body The body makes makes

antibodies.antibodies.

Memory cells Memory cells recognize recognize antigensantigensfrom the from the

pathogenpathogen.Immunity Immunity

may last for may last for years or a years or a lifetime.lifetime.

Antibodies Antibodies are given, are given, the body the body does not does not

make make antibodies.antibodies.Immunity can be Immunity can be

acquired from the acquired from the mother during mother during

pregnancy.pregnancy.

Immunity Immunity lasts only a lasts only a few monthsfew months..

Can Can prevent prevent diseasesdiseases

May May involve involve

an an injectioninjection

Systemic Lupus erythematosus • Chronic inflammatory conditionChronic inflammatory condition• Occurs when the body's tissues are attacked by its Occurs when the body's tissues are attacked by its

own immune systemown immune system• People with lupus have unusual antibodies in People with lupus have unusual antibodies in

their blood that attack their own body their blood that attack their own body • Lupus can cause disease of the skin, heart, lungs, Lupus can cause disease of the skin, heart, lungs,

kidneys, joints, and nervous systemkidneys, joints, and nervous system• Eight times more common in women than in menEight times more common in women than in men

Who Gets Lupus?• Anyone can get lupusAnyone can get lupus

• But, But, more than 90%more than 90% of people with lupus are women of people with lupus are women

• Your odds of getting the disease are higher if you are:Your odds of getting the disease are higher if you are:

* African-American, Latino, or Asian * African-American, Latino, or Asian

* Aged 15 to 45 * Aged 15 to 45

* Related to someone with lupus* Related to someone with lupus

Classic symptoms of Lupus• Butterfly-shaped rash across theButterfly-shaped rash across the cheeks and bridge of the nosecheeks and bridge of the nose• Nails crack or fall offNails crack or fall off • Fever and FatigueFever and Fatigue• Light SensitivityLight Sensitivity• Hair LossHair Loss

Which Organs are affected by Lupus?Which Organs are affected by Lupus?

• Heart Heart

Lung

Which Organs are affected by Lupus?Which Organs are affected by Lupus?

• LungsLungs

Which Organs are affected by Lupus?Which Organs are affected by Lupus?

• KidneysKidneys

Which Organs are affected by Lupus?Which Organs are affected by Lupus?

• LiverLiver

JOINTSJOINTS

• Connective tissue in joints is also affected• What type of Connective tissue? * Tendons – Attach muscles to bones * Ligaments – Attach bone to bone

Review QuestionsReview Questions

1.1. Question Question: What is the : What is the functionfunction of the immune system? of the immune system?

Answer: Helps fight off pathogens.Answer: Helps fight off pathogens.

22. . QuestionQuestion: Which 4 : Which 4 white blood cellswhite blood cells or lymphocytes or lymphocytes

help destroy pathogens?help destroy pathogens?

Answer: Macrophages, B cells and T cellsAnswer: Macrophages, B cells and T cells

3. 3. QuestionQuestion: What is an antigen?: What is an antigen?

Answer: Answer: Special proteinSpecial protein on surface of pathogens on surface of pathogens

recognized by the immune system recognized by the immune system

4. 4. QuestionQuestion: What is an antibody?: What is an antibody?

Answer: Answer: Special Special proteinprotein in the immune system in the immune system

that recognizes and attaches to a that recognizes and attaches to a

specific antigen on a pathogen and specific antigen on a pathogen and

marks the pathogen for destruction.marks the pathogen for destruction.

5.5. QuestionQuestion: Explain the difference between : Explain the difference between Active Active

and and Passive ImmunityPassive Immunity??

Answer: Answer: * In * In Active immunityActive immunity the immune the immune

system produces the antibodiessystem produces the antibodies

* In * In Passive immunityPassive immunity the antibodies the antibodies

are injected into a patient to destroyare injected into a patient to destroy

the pathogensthe pathogens

6. 6. QuestionQuestion: Which cells of the immune system : Which cells of the immune system produce antibodies?produce antibodies? Answer: B cellsAnswer: B cells7. 7. QuestionQuestion: Which cells produce B cells?: Which cells produce B cells? Answer: T cellsAnswer: T cells8. 8. QuestionQuestion: Name the 2 types of T- cells: Name the 2 types of T- cells Answer: 1) Answer: 1) Natural Killer cellsNatural Killer cells 2) 2) Cytotoxic cellsCytotoxic cells9. 9. QuestionQuestion: What are memory T - cells? : What are memory T - cells? Answer: Answer: * They remember what type of antigens are on the * They remember what type of antigens are on the surface of a pathogensurface of a pathogen * Help immune system recognize the pathogen if it * Help immune system recognize the pathogen if it invades our body again!!invades our body again!!

10. 10. QuestionQuestion: What are the 4 main functions of : What are the 4 main functions of

T- cellsT- cells

Answer:Answer:

1. Stimulate B-cells to produce antibodies1. Stimulate B-cells to produce antibodies

2. Destroy pathogens after they are marked 2. Destroy pathogens after they are marked

by antibodiesby antibodies

3. Destroy cells that are infected with a virus3. Destroy cells that are infected with a virus

4. Also recognize cancer cells and destroy 4. Also recognize cancer cells and destroy themthem

11. 11. QuestionQuestion: What are the : What are the 4 common4 common pathogens? pathogens?

Answer: Answer:

Virus Bacteria Fungi Protists/parasitesVirus Bacteria Fungi Protists/parasites

::

12. 12. QuestionQuestion: Name 2 ways a vaccine works!: Name 2 ways a vaccine works!

Answer:Answer:

1. Contains a weakened pathogen that stimulates 1. Contains a weakened pathogen that stimulates

production of antibodies without causing the production of antibodies without causing the

actual disease, or…………?actual disease, or…………?

2. Antibodies are already in the vaccine to 2. Antibodies are already in the vaccine to

destroy pathogens, body doesn’t need to make destroy pathogens, body doesn’t need to make

antibodiesantibodies

13. 13. QuestionQuestion: Why : Why can’tcan’t scientists produce an scientists produce an

effective vaccine against effective vaccine against HIVHIV??

Answer: Because the virus mutates or changes Answer: Because the virus mutates or changes

and the vaccine no longer works!!!!!and the vaccine no longer works!!!!!