Adaptive immunity and vaccination

Question 1

Gibe 4 adaptive immune responses:

Answer 1

antigenic specificity
diversity
immunological memory
self/non-self destruction

Question 2

How does the grade of response differ in innate and adaptive immunity?

Answer 2

innate: invariant, the number of times we have encountered the organism doesn’t matter
adaptive: modulated by memory, where response is quicker the second time

Question 3

How are lymphoid cells split?

Answer 3

into T (thymus gland) cells (helper and cytotoxic) and B (bone marrow) cells (plasma cells - produce antibodies)

Question 4

What is the difference between T cells and B cells?

Answer 4

T cells: cell mediated immunity, responds to foreign material INSIDE body cells
B cells: humoural immunity, produces antibodies, responds to foreign material OUTSIDE body cells

Question 5

What is the difference between T cells and B cells?

Answer 5

T cells: cell mediated immunity, responds to foreign material INSIDE body cells
B cells: humoural immunity, produces antibodies, responds to foreign material OUTSIDE body cells

Question 6

Describe CD4 T helper cells:

Answer 6

recognise APCs on MHS class II (macrophages, not any cell)
2 categories:
a) Th 1 cells: stimulate cell mediated immunity
b) Th2 cells: stimulate growth of specific plasma cell and antibody secretion
Stimulates humoural immunity and secrete cytokines

Question 7

Describe CD8 T cytotoxic cells:

Answer 7

recognise APCs on MHS class I 
triggers cytotoxicity (cell mediated immunity)

Question 8

What are the three types of APCs?

Answer 8

• B cells
• Macrophages
• Dendritic cells
  these 3 are the only cell type that express MHC class II proteins (all WBCs)

Question 9

What is the role of B lymphocytes?

Answer 9

they function in humoural immunity of the adaptive immune system by secreting antibodies (e.g. IgG, IgE)

Question 10

How do T cells ‘help’ B cells?

Answer 10

before the B cell can produce antibodies, the Th cell releases cytokines that signal the B cells to divide and secrete the antibodies

Question 11

What is the structure of an immunoglobulin/antibody?

Answer 11

2 light chains with an antigen attaching site (N terminal) and 2 heavy chains which direct the antibody to the right cell in the immune system (C terminal)

Question 12

What are the 4 functions of antibodies?

Answer 12

1. opsonisation - coats antigen with proteins that can be detected
2. neutralisation - of the toxin produced by the bacteria
3. activation of complement proteins
4. Antibody dependent cytotoxicity - destruction of antibody coated target cells by NK cells

Question 13

Where are dendritic cells located?

Answer 13

in the structural component of the lymphoid organs such as the thymus, lymph nodes and spleen

Question 14

What is the role of dendritic cells?

Answer 14

They capture the antigen or bring it to the lymphoid organs where an immune response is initiated by presenting the antigen to the T cells

Question 15

What are the 2 types of specific acquired immunity?

Answer 15

• humoural (B cells) and cell mediated (T cells)

Question 16

How do memory cells work?

Answer 16

they lay dormant in the lymphatic system for years, if they detect a pathogen with the specific antigen, they can clone rapidly and secrete antibodies

Question 17

What do vaccines do?

Answer 17

upon infection, rapidly secrete antigen specific antibodies

Question 18

Define vaccine immunogenicity:

Answer 18

ability of a vaccine to induce antibodies

Question 19

Define vaccine efficacy:

Answer 19

reduction in the incidence of a disease around people who have received a vaccine compared to unvaccinated people

Question 20

Define vaccine effectiveness:

Answer 20

Ability of a vaccine to protect the community and is revealed after a vaccine is introduced in a vaccination programme

Question 21

What is the difference between active and passive immunity?

Answer 21

Active: acquired through natural infection/immunisation and is long lasting
Passive: conferred by maternal antibodies/immunoglobulin preparations and is short lasting

Question 22

Which disease has a vaccine which is of killed virulent organisms?

Answer 22

whooping cough

Question 23

Which disease has a vaccine which is of live, non-virulent strains?

Answer 23

Rubella

Question 24

Which disease has a vaccine which is of modified toxins?

Answer 24

Diptheria

Question 25

Which disease has a vaccine which is of isolated antigens from a pathogen?

Answer 25

Influenza

Question 26

Which disease has a vaccine which is of genetically engineered antigens?

Answer 26

HepB

Question 27

What is an adjuvant vaccine?

Answer 27

substance added to increase body’s immune response