Immune System, Vaccines, and Antibiotics Part 2Biology EOC ReviewSC.912.L14.52

By M. Donohue

• Brainstorm!• Raise Your Hand!

•What is Immunity???

• Disease disrupts stability of an organisms STABLE INTERNAL environment

• Immune systems helps MAINTAIN stability…AKA HOMEOSTASIS

• Immune System:• The organ system that

protects the body from disease

• Made up of specialized cells and organs that work together to protect you from pathogens

• Infection- the multiplication of a pathogen in body tissue

• Three different lines of defense…we will get to these in a bit…

•The Immune SystemWhat is homeostasis? Why do you think the immune system plays a role in homeostasis?

Your Body Fighting Against Evil Invaders!

• You have to make ANTIBODIES!!!• Remember those?• Definition: protein produced by

white blood cells (WBCS)• Attaches to antigens of invaders

using ”lock and key” mechanism

• Antigens are proteins on the surface of call cells and viruses…their id card

• Antibodies cause antigens to clump together=easier for your body to attack and destroy

• Antibodies in a nutshell Mark invader and herd them together so they can be easily destroyed by other WBCs (white blood cells)

• Well how does our body do that?• Two different ways….

• Active Immunity• Passive Immunity

•How Do We Build Immunity?Your body marks the

attackers, herds them together, and

DESTROYS them!

• Active Immunity• Results from exposure to

pathogen • Can occur naturally…

• Pathogen enters body• immune system makes antibodies…AKA you get sick

• Can occur by VACCINATION

• Weakened or deactivated virus introduced to body to make antigens• Doesn’t usually make you sick• Next time a person gets infected, their body rapidly makes antibodies to destroy pathogen

• Passive Immunity• Created by transferring antibodies made by one organism into another organism

• Ex. Rabies• Often acquired before birth during fetal development

• Newborns receive antibodies through their mother’s milk

•Two Major Types of Immune Responses

INNATE Immunity-Rapid responses to a broad range of microbes

ACQUIRED immunity-Slower responses to specific microbes

External Defenses Internal Defenses

•Skin•Mucous membranes•Secretions

•Phagocytic cells•Antimicrobial proteins•Inflammatory response•Natural Killer cells

•Humoral response (antibodies)•Cell-mediated response (cytotoxic lymphocytes)

•Overview of Vertebrate Defenses against pathogens

Introducing Your Immune Systems

3 Lines of Defense!

•The Immune Systems 3 Lines of Defense

#1: Barriers!

#2: Inflammatory Response!

#3: Immune response!

Non-specific

SPECIFIC

• #1: Barriers to Infection (nonspecific)

• Function-keep invaders (pathogens) OUT of your body

• Skin• Mucous membranes (respiratory tract)• mucus traps pathogens • cilia moves it out of your throat and nose or into stomach (sneeze, cough, swallow)

• Mucus, Saliva and tears• contain enzyme lysozyme (enzyme that breaks down cell walls of bacteria)

• Perspiring (sweat and oil)• liquid waste secreted from pores that contains acids, salts and enzymes that kill bacteria on surface of skin

•The Immune Systems 3 Lines of Defense

•The Immune Systems 3 Lines of Defense• #2 Inflammatory Response (nonspecific)• Function- respond to the invaders that have entered the body and have started to damage precious tissue

• White Blood Cells WBCs• Several different types

specialized to fight disease• Blood vessels near injury WIDEN(dilate) to let more blood flow to area of injury• Plasma fills spaces between cells • Plasma carries WBCs called MACROPHAGES to injury site

• MACROPHAGES- large WBCs that engulf and destroy pathogens and alert other immune cells

• Area is swollen b/c of increased blood flow• Fever- increase in temp. makes more less suitable for growth of bacteria and MACROPHAGES work more efficiently

•The Immune Systems 3 Lines of Defense

• #3: Immune Response (specific)

• Function-specialized attack on SPECIFIC pathogens that have invaded the body

• Many WBCs involved• Macrophages, T cells, and B cells

• WBCs secrete antibodies, a protein that attaches to specific region of foreign substance called the antigen

• Phagocytes• cells specialized in finding and "eating"

bacteria, viruses, and dead or injured body cells.

• There are three main types

1) the granulocyte

2) the macrophage

3) the dendritic cell• Lymphocytes

• migrate to parts of the lymphatic system

• T cells and B cells

• Who are the warriors saving our bodies?•Meet the Troops

• The granulocytes often take the first stand during an infection.

• Sacrifice them selves in battle…gobble up invaders until they die (thank you brave warriors…)

• The macrophages ("big eaters") • slower to respond to invaders than the

granulocyte but they are larger, live longer, and have far greater capacities

• ALERT the rest of the immune system of invaders.

• The dendritic cells are "eater" cells and devour intruders

• Helps ACTIVATE rest of immune system• filter body fluids

•Phagocytes

• On the surface of each lymphatic cell are receptors that enable them to recognize foreign substances.

• very specialized receptors- each can match only one specific Antigen- • protein on the surface of a cell (good or bad) that signals to other

cells what it is• T cells

• T cells come in two different types, helper cells and killer cells.

• B cells• JOB: search for antigens matching its receptors, connect and

become PRATIALLY ACTIVATED• FULL ACTIVATION require proteins from helper T cells• Once FULLY ACTIVATED:

• the B cell starts to divide to produce clones of itself called plasma cells and B memory cells.

•Lymphocytes (specialized attackers)

• Helper T cells main regulators of the immune defense

• JOB: activate B cells and killer T cells.

• must be activated by antigen presentation

• ACTIVATED Helper divides and to produces PROTEINS that activate B and T cells

• Killer T cells • specialized in attacking cells of

the body infected by viruses and by bacteria (and sometimes cancer cells)

• Recognize antigens on invaders and swiftly kill the EVIL invader

• Two types•T Cells

  

• The plasma cell

• Job: Make antibodies that search for other similar

invaders

• Antibody finds invader, attaches to it and attracts

macrophages to come over and gobble up the invader

• Some Antibodies also neutralize toxins and incapacitate

viruses, preventing them from infecting new cells.

• The Memory Cells

• Prolonged life span and can thereby "remember"

specific intruders (T cells produce even better ones)

• The next time the same invader comes into body, B

and T memory cells help the immune system to

activate much faster

• Invaders are wiped out before the infected human feels

any symptoms

• Immunity against the invader has been achieved

•B Cells (2 types)

 

Once the battle is done, the T-suppressor cell calls off the troops so they can rest up for the

next battle!

•Nonspecific vs. specific defenses

•Nonspecific defenses do not distinguish one infectious microbe from another•Specific defenses recognize and defend against invading microbes and cancer cells• Involves presence of an antigen

•Nonspecific defenses• Skin • Mucus• Macrophages• Inflammatory Response• Interferons and complement proteins

• attack microbes either directly or indirectly by impeding their reproduction• Interferons are produced by infected cells • Diffuse to healthy cells where they cause the cell to inhibit viral production• Complement proteins are activated by microbes or immune system•Coat infected cells –easier to eat•Can amplify inflammatory response

•Nonspecific defenses: inflammatory response

•Nonspecific defenses: inflammatory response

•Redness, heat, and swelling caused by• Increase in blood flow, fluid, and cells

• Inflammatory response disinfects and cleans injured tissues• Pus = dead white cells and fluid

• Systemic response is widespread• Toxins or microorganisms released in bloodstream

•Circulates through body• Inflammatory weapons

• increase white blood cells, •Fever

• Low-grade fever can stimulate phagocytosis and inhibit growth of many microorganisms

•Specific immunity

• Often more effective than nonspecific response• It also amplifies nonspecific response

• Specific response begins due to presence of an antigen• Can either increase # of cells that attack invader directly OR

• Produce antibodies• Immune system “remembers” antigens it has previously encountered• Responds immediately and vigorously • Is adaptive

•Antibiotics

• Must call for extra help…Medicine/drugs called ANTIBIOTICS

• Drugs used to either kill bacterial or prevent reproduction

• Penicillin-1st antibiotic• 1928• Used to be effective against many bacterial

infections• Today, it is the least effective antibiotic

against many of the infections it fought• Why???• See next slide….

• What happens when your body can’t fight off infection?

• Antibiotic usually kills entire colony of bacteria

• Sometimes a few little suckers survive• They develop their own

immunity/resistance to the antibiotic (it’s in their simple DNA)…EVOLUTION!

• These resistant bacteria reproduce ASEXUALLY and pass off instructions for resistance to offspring

• Their little super army of resistant bacterial clones grows quickly over time and occurs every time antibiotic is used

• Eventually there may be so many resistant bacteria that the antibiotic won’t work…BIG PROBLEMS!

• Need to find a new strategy of attack• SOOOOO…do NOT use antibiotics

every time you feel sick…only use when they are prescribed by your Doc!

• Why do some antibiotics stop working???

•Bacterial Resistance to Antibiotics

Explain why

this is true…

• Let's see exactly how this all works...CLICK ME!!!!

• Nonspecific vs. specific Immunity• As organisms have become more evolved, SPECIFIC

Immunity has developed (helps in survival and reproduction)

• Active vs. passive immunity• Antibodies

• Protein that attaches to the antigens of invaders and signals to immune cells that it needs to be destroyed

• Antigens• Proteins on the surface of cells that indicate to other cells

what it is• Macrophages

• First ones to Gobble up invaders• T Cells

• Attack specific invaders and kill them• B Cells

• Produces Antibodies against the invader

•Summary (What you need to know)

Test Your Skills!

Fold you paper long ways (hotdog)

Title column on the left Answers

Title the second column Explanations

Answers Explanation

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2.

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5.

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Test Your Skills!

1.What is your body’s first line of defense?

a)Skinb)Antibodiesc)Red blood cellsd)White blood cells

Test Your Skills!

2. Scientists from different fields work together to continually modify the chemical composition of antibiotic medicines. This is to keep up with the adaptive abilities of the pathogens antibiotics are intended to treat. Antibiotics inhibit the formation of membranes in certain prokaryotes. Which of the following would most likely be treated with antibiotics?

a. Body cellsb. Foreign pathogensc. Inherited risk factorsd. Cells that carry mutations

Test Your Skills!

3. Rather than use a whole virus, some vaccines use only parts of the protein coat of the virus. Why does this method work?

a. The viral protein coat is what causes the viral disease

b. The viral protein coat carries the antibodies needed to fight the disease

c. The viral protein coat carries the antigens that provoke the immune response

d. The viral protein coat provides a food source for viruses that enter the infected host cell

Test Your Skills!

4. An antibiotic is advertised as being able to kill 95% of all bacteria it is meant to treat. What can happen with prolonged or repeated use of this antibiotic?

a. That type of bacteria may become extinct

b. That type of bacteria may become resistant to the antibiotic

c. The bodies of the patients may become resistant to the antibiotic.

d. A lower does of the antibiotic may be needed to treat the next outbreak of the bacteria

Test Your Skills!

5. Which of these statements best describes how a vaccine can protect a person from an infectious virus?

a. The vaccine stimulates platelet production, which kills the virus.

b. A small dose of the weakened virus is given to the patient so antibodies can form.

c. The vaccine stimulates chemical blockers that do not allow the virus to enter the blood stream.

d. A small dose of the weakened virus is given to the patient in order to prevent wall synthesis and repair.

Test Your Skills!6. Some forms of vaccination consist of injecting a person with inactive viruses. How do the proteins from the inactive virus protect the person from later infections by those viruses?

a. They cause a mild infection that prevents the person's body from responding to later infections.

b. They bond with receptors on the cells of the person so that later active viruses cannot bind with them.

c. They stimulate an immune response that produces memory cells. These cells can produce antibodies when a new active virus infects the cell.

d. They remain in the body and serve as a food source for later active viruses instead of feeding on the person’s tissues and causing infection

Test Your Skills!

7. Biologically produced proteins called antibodies help the body fight infection in which of these ways?

a. Antibodies destroy pathogens by engulfing and digesting them

b. Antibodies are found in the antibiotic medications that can be used to help the body fight off infections that have occurred.

c. Antibodies identify and destroy foreign material s and pathogens by producing powerful chemicals that dissolve them, making them harmless.

d. Antibodies attach to the surface proteins of antigens, inactivating the pathogen or signaling other immune cells to destroy the foreign protein material

Test Your Skills!

8. Certain cells are activated by the immune system to find and destroy pathogenic cells that make their way into the body. T cells are affected by the macrophages as a step in what type of the immune system response?

a. A specific, general responseb. A specific, targeted

responsec. A nonspecific, general

responsed. A nonspecific, targeted

response

X YEvolutionary Early

(vertebrates)Recent

(mammals)

Types of response General response

Targeted, specific antigen response

Timing of response Early line of defense, largely

unchanging

Slow, development

becomes stronger in time, has

memory

Examples Natural killer cells,

interferon, inflammation

Antibodies made by body in

response to antigen

Test Your Skills!9. The human immune system is made up of special cells, proteins, tissues, and organs that defend against viruses and microorganisms everyday. In the human body there area two different types of response systems (as describe in the table below). Which choice correctly identifies X and Y??

a. X=active , Y= passiveb. X= acquired, Y= inbornc. X=inborn , Y= acquiredd. X=Antibodies , Y= White blood cells

10. The p53 gene codes for the p53 protein that locates errors on the DNA for cellular repair. The diagram below shows the relationship among possible environmental influences, the p53 gene, and cancer.

Which of the following statements best describes the relationships among possible environmental influences, the p53 gene, and cancer?a. Environmental influences can lead to mutations in the p53

gene, which can cause certain cancers.b. Increased levels of p53 protein, rather than environmental

influences, can cause certain cancers.c. Mutations in the p53 gene increase environmental

influences that can cause certain cancers.d. Genes such as p53 are less causal than environmental

influences in stimulating certain cancers.

1. A2. B3. C4. B5. B6. C7. D8. B9. C10. A

•Answers to #1-10