1. NOTES: Immune Responses (UNIT 10 part 4)

2. PRIMARY IMMUNE RESPONSE
• PRIMARY IMMUNE RESPONSE: the first reaction / response to an antigen (first exposure)
 During this response, antibodies are produced for several weeks
 Antibodies first show up within 5-10 days
 As a result, some B cells will remain dormant as MEMORY CELLS

4. SECONDARY IMMUNE RESPONSE
• SECONDARY IMMUNE RESPONSE: the second response (exposure) to an antigen
Rapid response due to
memory cells produced
during the first exposure
 Antibodies produced within a day or two

7. CLASSIFICATION OF IMMUNITY
1) ACTIVE IMMUNITY
● A result of direct exposure to the antigen
● when the person produces an immune response (including memory cells) to the antigen
● Long-lasting (due to memory
cells)

8. ACTIVE IMMUNITY… NATURALLY ACQUIRED ACTIVE IMMUNITY: person
is directly exposed to the
pathogen, develops a disease,
survives, and therefore, acquires immunity
ARTIFICIALLY ACQUIRED
ACTIVE IMMUNITY:
person receives a vaccine

9. VACCINES… **A VACCINE consists of bacteria or
viruses that have been weakened or
killed so they a cannot cause a
serious infection; or could include
a toxoid or toxin that has been chemically altered to destroy its toxic effects
-Includes antigens that stimulate a primary immune response but does not produce the severe symptoms of disease

10. KEY: PRODUCE MEMORY CELLS TO THAT ANTIGEN!

11. 2) PASSIVE IMMUNITY ● Person receives antibodies produced by another
individual
● Since the person does not produce the immune response themselves, this is short-term only (as long as the antibodies remain in the blood)
● The person remains vulnerable to the antigen if exposed at a later date
 NO MEMORY CELLS

12. PASSIVE IMMUNITY: antibodies only
NATURALLY ACQUIRED PASSIVE IMMUNITY: fetus acquires limited immunity from mother through placenta and/or breast milk (including colostrum)
 ARTIFICIALLY ACQUIRED PASSIVE IMMUNITY: person receives an injection of antiserum (antibodies) collected from a person who has already developed immunity against a particular disease

14. REVIEW QUESTION:
Which of the following is naturally acquired active immunity?
person got sick & got better
person received a vaccination
person received antibodies (serum) in an injection
Fetus/baby received antibodies through placenta or in colostrum/breast milk

15. ORGAN TRANSPLANTATION and TISSUE REJECTION
● TISSUE REJECTION REACTION: when a transplant recipient’s immune system reacts against the donated tissue/organ
immune system functioning normally
Organ needed but isn’t “self”
Small triangles are “self”; transplant could have “squares”

17. BONE MARROW STEM CELL TRANSPLANTATION and “SELF” TISSUE REJECTION
● TISSUE REJECTION REACTION: when a bone marrow stem cell recipient’s new immune system reacts against all “self” body cells
immune system functioning normally
Donated stem cells have given recipient the donor’s immune system

18. Only go through transplant if absolutely necessary.
Donor will have bone marrow stem cells removed

19. Recipient will have their bone marrow cells destroyed by radiation
Recipient will receive donated cells through an IV
Stem cells will “seed” into bone marrow

20. ● to minimize tissue rejection:
Match donor and recipient tissues (“self” marker)
Use immunosuppressive drugs (help with transplant acceptance, but may increase the recipient’s risk of infection)

21. ALLERGIC REACTIONS
● Excessive and misdirected immune responses that may damage tissue (abnormal response)
● Triggered by antigens known as ALLERGENS
● The immune system attacks a nonharmful substance, such as chocolate or pollen

23. ALLERGIC REACTIONS
1) Delayed-reaction allergy: results from repeated exposure of the skin to certain chemicals (e.g. household chemicals, cosmetics)
-Activates T cells; T cells and macrophages collect in the skin and release chemicals that cause
eruptions and inflammation
(DERMATITIS)
-“Delayed” because it takes
about 48 hours to
develop

24. ALLERGIC REACTIONS 2) Immediate-reaction allergy:
An inborn ability to overproduce IgE antibodies in response to certain antigens/allergens
(i.e. pollen, pet dander, etc.)
Activates B-cells when 1st encountered & IgE antibodies attach to mast cells which contain histamine
-Occurs within minutes of contact with allergen

26. Immediate-reaction allergy
Subsequent (2nd +) exposure results in mast cells bursting and releasing allergy chemicals
such as HISTAMINE
Histamine causes blood vessels to dilate, tissues to swell, contraction of bronchial and intestinal smooth muscles, increased mucus production
 The released chemicals cause allergy symptoms such as: hives, hay fever, asthma, eczema, or gastric disturbances

29. Extreme allergies…
**Severe example of immediate-reaction allergy: ANAPHYLACTIC SHOCK!
-Mast cells throughout the body release histamine
-Severe drop in blood pressure (could lose consciousness and possibly die)
-Person must receive an injection of epinephrine (adrenaline) to restore blood pressure

30. AUTOIMMUNITY / AUTOIMMUNE DISORDERS:
● Abnormal Function
● The immune system manufactures autoantibodies (antibodies that attack a person’s own body tissues)
● May result from a previous viral infection, faulty T cell development, or reaction to a nonself antigen that resembles a self antigen

31. Examples of Autoimmune disorders:
Lupus erythematous: autoantibodies attack DNA (can affect whole body as result)
Rheumatoid arthritis: autoantibodies attack cartilage of joints

32. Examples of Autoimmune disorders:
 Insulin-dependent diabetes: T-cells cause destruction of insulin producing cells in pancreas

33. Examples of Autoimmune disorders:
Multiple sclerosis: T-cells destroy myelin sheath around neurons

34. Examples of Autoimmune disorders:
Grave’s disease- autoantibodies to thyroid stimulating receptor (overproduce thyroid stimulating hormone; involved in metabolism)

35. Examples of Autoimmune disorders:
Crohn’s Disease: immune system attacks alimentary canal (leading to chronic inflammation)

36. IMMUNODEFICIENCY DISEASE
Like autoimmune disorders, abnormal immune system function (compromised immune function)
Ex: HIV
Virus invades Helper T-cells, uses them to make more copies of the HIV virus, and then destroys the Helper T-cell
Newly made viruses from destroyed Helper T-cell infects other Helper T-cells
Without Helper T-cells, cannot activate Cytotoxic T-cells or B-cells  no immune system

37. HIV life cycle animation

38. REVIEW QUESTION:
If a person has an inborn allergy, what happens the FIRST time they are exposed to the allergen?
Histamine is released
White blood cells move into the area
B-cells produce antibodies that attach to mast cells
A and B

39. REVIEW QUESTION: Why is anaphylactic shock so dangerous?
Blood vessels constrict too much
Blood pressure drops dramatically
Blood pressure raises dramatically
Oxygen cannot release from hemoglobin in RBC’s

40. REVIEW QUESTION:
A person who had received a donated kidney may reject that kidney because
Their immune system only recognizes their type of blood
Their immune system cannot differentiate self from non-self.
The receptors on the kidney cells are non-self
The immune system cell receptors are non-self

41. REVIEW QUESTION: An autoimmune disorder is one where
All immune cells have the wrong receptors
B-cells have the wrong receptors
T-cells have the wrong receptors
One specific lymphocyte identifies a self receptor as non-self