I&I Introduction to Immune Responses

Question 1

What are physical barriers to infection and how do organisms overcome this?

Answer 1

-Skin provides a protective cover
-Organisms can overcome this barrier
-Cuts or damaged skin
-Insect bites
-Animal bites

Question 2

What are mucus linings and what do they do?

Answer 2

-There are areas of the body that are not covered by skin
-Mucus traps organisms

Question 3

What does bacteria in genital tract always cause?

Answer 3

-Commensal organisms present in genital tract which always causes competition

Question 4

What can happen if antibiotics used for treatment kill commensal organism that usuallt reside in genital tract?

Answer 4

-If antibiotics used for treatment result in the death of bacteria that normally resides in genital tract, this can cause less competition and increase likelihood to get infection

Question 5

What is the innate immune system also known as anad what is it?

Answer 5

-Also known as non-specific immunity and is the first line of defence in the immune response

Question 6

What is the main cell which makes up innate immune system and what does it include?

Answer 6

-Includes Phagocytes(effector cells):
-neutrophils
-Macrophages
-dendritic cells

Question 7

What is the origin of phagocytes?

Answer 7

-Origin of phagocytes is generated in the bone marrow

Question 8

What are other type of cells involved in innate immune system?

Answer 8

-Also include:
-Mast cells
-Eosinophils
-Basophils
-Natural killer cells

Question 9

What do macrophages start as and where are they activated?

Answer 9

-They start as monocytes then they are activated in the tissue and become macrophages

Question 10

How do macrophages work?

Answer 10

-Microbe must attach to phagocyte
-Ingestion initiated
-Organism enters the phagocyte in a vacuole
-Destroyed within this vacuole

Question 11

What do dendritic cells enter?

Answer 11

-They enter skin, mucosa, tissues

Question 12

How do dendritic cells work?

Answer 12

-How it works
-Capture microbes
-Phagocytosis
-eliminate the microbe
- they also present the microbes as antigens to T cells

Question 13

What do phagocytes present microbe as and to what?

Answer 13

-Phagocytes present the microbe as antigens to T cells

Question 14

What protein do phagocytes work with in order to destroy an organism

Answer 14

-Complement and phagocytes work together in destroying an organism

Question 15

What is complement?

Answer 15

-Complement are a group of proteins that assist with the attachment of micro-organisms and phagocytes

Question 16

What does complement act as?

Answer 16

-Complement also act as an enzyme cascade system

Question 17

What does complement enhance?

Answer 17

-Complement enhance phagocytic function

Question 18

What do phagocytes aslo produce?

Answer 18

-Phagocytes also produce substances that attract other cells to the site
-Chemotactic substances

Question 19

What permeability does do phagocytes increase?

Answer 19

Phagocytes also increase vascular permeability to allow immune cells to get in

Question 20

What does inflammation attract and help with?

Answer 20

-Attract cells to site
-Help killing and clearance of organisms

Question 21

What do interferons intefere with?

Answer 21

-Interferons interfere with viruses infecting other cells

Question 22

What do natural killer cells play a role of and how so?

Answer 22

-Play a role of surveillance
-Any cell that has changed is a target for killing

Question 23

What are other examples of innate immune system defences

Answer 23

-Inflammation (CRP, Acute phase proteins APP)
-Interferons
-Natural killer cells

Question 24

What type of response is the adaptive immune system and what does it include?

Answer 24

-Highly specific immune response
-Includes B and T lymphocytes

Question 25

How do B lymphocytes recognise an antigen?

Answer 25

-B lymphocytes recognise antigen through immunoglobulin receptors on their surface

Question 26

How do T lymphocytes recognise an antigen?

Answer 26

-T lymphocytes recognise antigen through T cell receptors

Question 27

What happens when lymphocytes bind to antigens?

Answer 27

-When their receptor bind to an antigen, they proliferate and form clones

Question 28

What is the response of memory lymphocytes in response to an antigen and what are 2 characteristics of memory lymphocytes?

Answer 28

Memory lymphocytes will return to patrol
-They are non-dividing and long lived

Question 29

What do effector cells remove?

Answer 29

-Effector cells
-These remove the virally infected cells lysed by T-lymphocytes
-Bacteria covered by antibodies

Question 30

What do B cells make?

Answer 30

B cells make antibodies

Question 31

What are antibodies and which one is made before the other?

Answer 31

-Antibodies are immunoglobulins
-IgM is made first and then IgG

Question 32

What is a characteristic of B cells and what happens when they’re acativated?

Answer 32

-B cells are very specific and when activated, they cause proliferation of clone and make correct antibodies

Question 33

What are 2 ways antibodies work?

Answer 33

1. Work by neutralsation
2. Opsonization

Question 34

How does neutralisation by antibodies occur?

Answer 34

-E.g. they coat virus with antibody and stop it from entering cells

Question 35

How does opsonization by antibodies occur?

Answer 35

-Opsonin’s tag foreign pathogens for elimination by phagocytes

Question 36

What do T helper cells aid with and how is this done?

Answer 36

-T helper cells aid B cells make antibodies once they are activated
-This is by releasing cytokines that promote B cells to produce antibodies

Question 37

How are T helper cells activated?

Answer 37

-Phagocytes present antigen of the infectious agent to T helper cells in order to activate them

Question 38

What are T cytotoxic cells?

Answer 38

Cells that kill

Question 39

How do T-cytotoxic cells work?

Answer 39

-They work by attaching to MHC and virus protein on surface of infected cell
-Viruses produce protein which are attached to a cell protein called major histocompatibility complex(MHC) and appears on the cell surface