Mod 3 - Cells of Adaptive Immunity and Overview

Question 1

List the cells of adaptive immunity

Answer 1

Dentrites
Macrophages
B Cells –> Plasma cell
T Cells –> Cytotoxic cell, Helper Cell

Question 2

What is adaptive immunity?

Answer 2

Adaptive immunity is a complex network of specialized cells that serves to eliminate pathogens causing an infecction.

Question 3

Name the five characteristics of adaptive immunity?

Answer 3

1. Elimination
2. Specific
3. Adaptive
4. Delay in Response
5. Memory

Question 4

Describe the characteristic of elimination of adaptive immunity.

Answer 4

Adaptive Immunity:

1. Acts to eliminates particular pathogens that have breached the innate system.
2. May be exhibiting symptoms at this point if 1st time with pathogen.

Question 5

Describe the specific characteristic of adaptive immunity.

Answer 5

B and T cells act specifically to fight a particular pathogen.

Question 6

Describe the adaptive characteristic of adaptive immunity.

Answer 6

Not born with it; develops over lifetime. Response increases, more efficient with each subsequent exposure (to same pathogen?).

Question 7

Describe the “delay in response” characteristic of adaptive immunity.

Answer 7

Takes time to be initiated, typ. 3-4 days the 1st time a pathogen is encountered.
If memory –> response is sooner.

Question 8

Describe the memory characteristic of adaptive immunity.

Answer 8

Develops memory once pathogen is encountered. Upon subsequent exposures it quickly eradicates infection w/o individual feeling sick or even being aware of exposure.

Question 9

The adaptive immune system are performed by cells and their actions are mediated by what kind of molecular elements?

Answer 9

Cytokines and Proteins.

Question 10

Which two cells of the adaptive immunity are considered professional antigen presenting cells (APCs)?

Answer 10

Dendrites and Macrophages

Question 11

To what cells do dendrite and macrophages cells present antigens to primarily? They act like a messenger for what?

Answer 11

T Cells

They act like a messenger for pathogen peptides.

Question 12

What do dendrites engulf?

Answer 12

? Clarify

Question 13

A phagocytic cell of the Adaptive Immune system is a ?

Answer 13

Macrophage

Removes particulates (bacteria, debris, dying cells, etc.)

Question 14

What is another name for a macrophage in the lungs (besides alveolar macrophage)?

Answer 14

Dust Cell

Question 15

What cell is dedicated to the production of immunoglobulins and antibodies?

Answer 15

B cells

Question 16

What cell secretes antibodies?

Answer 16

Plasma cells are mature B cells that function to secrete antibodies.

Question 17

What is the percentage of lymphocytes that are circulating as B cells?

Answer 17

5-15%

Question 18

What do T cells become once activated by the presence of a pathogen?

Answer 18

Effector Cells: Cytotoxic or Helper Cells.

Question 19

What is the percentage of lymphocytes that circulate as T cells?

Answer 19

80%

Question 20

What effector T cell removes intracellular pathogens and which one removes extracellular pathogens?

Answer 20

Cytotoxic Cells, removes intracellular pathogens (i.e. viruses and tumor cells).
Helper Cells, remove extracellular pathogens (i.e. bacteria) by activating other cells of the immune system.

Question 21

What are the four categories of adaptive immunity?

Answer 21

1. Artificial active, i.e. vaccinations
2. Artificial passive, i.e. hepatitis immunoglobulin, inject antibodies made, deteriorates over time.
3. Natural active, from infection, e.g. chicken pox
4. Natural passive, e.g. antibodies transferred from breast milk

Question 22

What does “artificial” mean in terms of immunity?

Answer 22

Means created as a result of commercial or manufactured product.

Question 23

What does natural immunity mean?

Answer 23

Means created from having the disease or passed from mother to baby.

Question 24

What does active immunity mean?

Answer 24

Means a person’s immune system is stimulated to create immunological memory.

Question 25

What does passive immunity mean?

Answer 25

Receiving antibodies from Mom or medication and so it will deteriorate over time (i.e. think antibiotics for UTIs).

Question 26

What does a B cell required to attack a pathogen specifically?

Answer 26

Requires RECEPTORS on its surface. B cell receptor is called an IMMUNOGLOBULIN. Interacts directly with pathogen surface which activates it to mature into a PLASMA CELL that will secrete ANTIBODIES.

Question 27

What happens to antibodies after they are secreted by plasma cells?

Answer 27

Available within site of infection and also carried through the peripheral circulation to prevent wide spread infection.

Question 28

What are the two main functions of antibodies?

Answer 28

1. Opsonize pathogen by marking it for removal (... for removal by classical pathway/compliment cascade). 2. Neutralizes pathogen or toxin so it cannot interact with healthy tissue.

Question 29

Each lymphocyte carries a receptor for ___ specificity.

Answer 29

one Therefore, need a variety of lymphocytes with different specificities.

Question 30

If each B cell only contains a receptor with one specificity, how does it defined the body against a variety of invading pathogens?

Answer 30

The overall population of B cells within circulation must contain different specificities to defend against the variety of pathogens.

Question 31

How many different antibodies is it estimated the body has?

Answer 31

10^9 different antibodies at any one time!!

Question 32

What is the molecular component on the pathogen surface that the antibody will bind to?

Answer 32

Epitope, also called antigenic determinant.

Question 33

What type of molecule is an epitope typically?

Answer 33

A branched carbohydrate or a protein molecule, since these substances exhibits higher antigenicities.

Question 34

What does it mean when an cell (pathogen) is referred to as a multivalent? Implications?

Answer 34

Has more than on epitope. Means more than one antibody can fight against the pathogen, since antibodies are specific for one epitope.

Question 35

What is the term for the strength of binding at one site between the epitope and the antibody?

Answer 35

Affinity

Question 36

What is overall binding strength called?

Answer 36

Avidity

Question 37

What characteristic is utilized within the laboratory for identification of specific hormones within the circulation of patients?

Answer 37

Affinity, the higher it is the better the binding strength of that antibody to the desired epitope.

Question 38

What happens if affinity is too high or if it is too low?

Answer 38

If too high --> antibody will have difficulty identifying the hormone (degree of tolerance is not acceptable). If too low --> antibody will bind to other hormones other than the target. Delicate balance to ensure false negatives and false positives test results are not obtained.