Immunology

Question 1

What is the importance of the immune system?

Answer 1

The immune system heavily invests in white blood cells and proteins to protect or defend the body from invading pathogens

Question 2

What are three layers of host defense?

Answer 2

1. Physical, chemical and microbiological (flora)
2. Innate immune system - recognition and destruction mechanisms of effector cells (macrophages and dendritic cells)
3. Adaptive immune system

Question 3

Compare and contrast: physical and chemical barriers

Answer 3

Physical barriers are the bodies’ first line of defense ex. flow of fluids in the skin (epithelium).

Chemical barriers are the also part of the body’s first line of defense where acidic, fatty or chemical secretions of the organs (with epithelia cells ex. digestive/respiratory tracts)

Question 4

Innate immune system

Answer 4

This refers to your body’s second life of defense system that is inherited from your parents.

It responds by causing inflammation at the sites of infection.

Question 5

Adaptive immune system

Answer 5

This is triggered by the innate immune system which was unsuccessful in protecting the body from infection, healing tissue damage and removing the threat quickly.

As the innate immune system continues to work on slowing the infection, the adaptive system has INCREASED POWER & responds SPECIFIC to the pathogen. It REMEBERS the pathogen after the infection has gone (immunological memory)

Question 6

How were vaccines discovered?

Answer 6

Edward Jenner found that immunization or vaccination with cowpox virus led to protection against other similar diseases; he called this procedure, vaccination

Question 7

What is the greatest triumph of immunology?

Answer 7

Vaccination using mRNA

Question 8

What is the success of vaccines in eradicating diseases? What did this reveal about vaccines?

Answer 8

Smallpox was GLOBALLY eradicated in 1977.
This revealed that vaccines are very effective in preventing severe disease and death

Question 9

What are novel vaccination strategies?

Answer 9

Using mRNA technology for vaccines and therapies improved delivery into host cells without being destroyed

Question 10

Describe the SARS-CoV-2 mRNA technology

Answer 10

SARS-CoV-2 mRNA vaccines are blueprints for the SPIKE PROTEINS associated with COVID-19 virus

Question 11

What is immunity?

Answer 11

Immunity describes a condition of a population that survives epidemic infections. This population is least likely or will not be affected when re-exposed to the same infection

Question 12

Name and describe hematopoietic cells of the immune system.

Answer 12

Leukocytes (white blood cells), red blood cells and megakaryocytes (makes platelets)

Question 13

What is the difference between hematopoiesis and Pluripotent hematopoietic stem cell?

Answer 13

Hematopoiesis refers to the development of all white blood cells while Pluripotent hematopoietic stem cells gives rise to blood cells and megakaryocytes in addition to white blood cells

Question 14

Which type of stem cells gives rise to all the hematopoietic cells? Where is it found?

Answer 14

Hemocytoblast or (multipotential hematopoietic stem cell) produces erythrocytes (red blood cells) - which can make megakaryocytes (platelets) - and leukocytes (white blood cells)

Question 15

Describe the “generation time” of pathogens or disease-causing microorganisms

Answer 15

Generation time is the time it takes for bacteria to double their population, which is usually 20 to 60 minutes (under optimal conditions).

Question 16

True or False; All microorganisms are pathogenic, especially commensal microorganisms

Answer 16

False; Commensal microorganisms a good microbiomes in our gut (~ 5lbs) which help us to digest foods for nutrients and protect against pathogenic microorganisms

Question 17

Why are commensal microorganisms sometimes referred to as opportunistic pathogens?

Answer 17

Commensal microorganisms may potentially cause disease if they move to the wrong area or the body’s defenses become weakened.

Question 18

Which bacteria can cause an infection of the large intestine (colon)? What factors promotes this opportunistic infection?

Answer 18

C. difficile (a germ) causes infection of the colon when antibiotics are digested. Antibiotics kill the commensal microorganisms (helpful bacteria) in our gut which gives rise to pathogenic bacteria namely, C. difficile.

Question 19

True of false; microbiological cells of the skin, gastrointestinal tract, respiratory tract and eyes are a part of the body’s first line of defense

Answer 19

True; normal flora in these organs help to initially protect against pathogenic bacteria

Question 20

Name the five pillars of inflammation.

Answer 20

Calor (warmth)
Rubor (redness)
Tumor (swelling)
Dolar (pain)
Functio laesa (loss of function)

Question 21

True/False; the innate immune system removes daily infections (rubbing eyes and nose, breathing polluted air and contaminated food ingestion) without the host noticing.

Answer 21

TRUE

Question 22

Explain the two main mechanisms that the innate immune system utilizes in responding to pathogenic bacteria that has breached mucosal membranes?

Answer 22

Recognition: protein and surface receptors bind to the pathogen’s associate molecular patterns (the pathogen or human host cell).

Destruction (indirect and direct attack on pathogens by EFFECTOR mechanisms)
- marking pathogens (molecular flags) or;
- directly attacking them using a membrane attack complex

Question 23

Explain innate immunity in surface wounds?

Answer 23

Health skin’s mucosal membrane is breached which introduces bacterial organisms to effectors cells (these cells secrete cytokines [proteins]).

Fluids and proteins enter infected tissue which becomes inflamed (innate response). There is warmth, redness, swelling and pain.

Question 24

What are cytokines?

Answer 24

Proteins released by DAMAGE cells & ACTIVATE IMMUNE cells

Question 25

What may happen in inflammation is chronic?

Answer 25

Acute/chronic inflammation may result in function laesa

Question 26

What are the two main cells of innate immunity?

Answer 26

Macrophages (neutrophils, basophils and Eosinophils) and;
Dendritic cells (Mast cells and Natural killer cells)

Question 27

Explain phagocytosis process in innate immunity>

Answer 27

Phagocytosis is the engulfing of bacteria or pathogens using pathogenic-recognition mechanisms & effector mechanisms.

The effector cells binds to the bacteria and engulfs it to kill it.

Question 28

What are macrophages?

Answer 28

Cells that are made up monocytes; its purpose is to engulf or consume a bacterium using ACTIVE SURVEILLANCE (foot and sensors that find and eat particles)

Question 29

What are the immune cells (lymphocytes) of adaptive immunity? Where are they located? How do they operate?

Answer 29

B-cells in Bone marrow and;
T-cells in Thymus
These cells operate like a lock and key mechanism (antigen (key) - receptor (T or B cell))

Question 30

What are the major lymphoid tissues?

Answer 30

1. Primary/central (where the B- and T-cells are located)
2. Secondary and;
3. Lymphatic

Question 31

How does the adaptive immune system work?

Answer 31

It works by using two mechanisms:
1. Clonal SELECTION: lymphocyte binds to specific pathogen
2. Clonal EXPANSION: creates an army of specific and potent immune cells for specific pathogen

Question 32

Which region of the antibody determines the antigen isotype and function? What is the mostly unknown antibody isotype? What is the most abundant antibody isotype

Answer 32

The constant region determines the type of isotype and antigen function.
IgD is the most unknown B-cell receptor
IgG is the most abundant because it has numerous functions

Question 33

How do antibodies aid in pathogen clearance?

Answer 33

Neutralization (binds to pathogen and renders it unfunctional)
Opsonization (opsonins tag pathogens to make them more recognizable to pathogens)

Question 34

Which lymphocyte creates a type of protein called antibodies?

Answer 34

B-cells create proteins (antibodies) which have many terminuses that create isotypes with different functions

Question 35

What chemical structures can antibodies bind to?

Answer 35

nucleic acids (which cause Lupus) and antibiotics (allergy)

Question 36

Briefly explain the T-cell response using key words, antigen representation and self antigens as well as viral antigens.

Answer 36

Requires antigen presentation (peptides) to become active; This is done through Major histocompatibility complexes (MHCs). MHC molecules exists in two forms: MHC I and MHC II.
MHC I presents INTRACELLULAR antigens like self and viral antigens.

Question 37

What are the two main sub-groups of T cells that mediate different
functions?

Answer 37

T-helper cells (“help” shape correct immune response) and;
Cytotoxic cells [CD8+ T cells] (releases cytotoxins to kill infected cells - makes sure healthy cells are not attacked)

Question 38

True or False; Vaccine development faces less public scrutiny than drug development.

Answer 38

False