0403 - Introduction to Immunology -BX

Question 1

Name the 3 components of the immune system (think broad)

Answer 1

organs and tissues

cells

molecules

Question 2

Name the two types of lymphoid organs and their constituents

Answer 2

Primary: Thymus, Bone Marrow

Secondary:

Lymph nodes,

Tonsils,

Spleen,

Lymphatic Vessels,

Mucosal Associated Lymphoid Tissue

Question 3

What is the distinction between primary and secondary lymphoid organs?

Answer 3

Primary: where immune cells are produced

Secondary: areas where immune interactions are carried out

Question 4

What are lymphocytes? Name the 3 types.

Answer 4

lymphocytes are immune cells (granulocytes) founds in lymph nodes

T-cell - matures in thymus

B-cell - matures in bone marrow

NK-cell - multiple locations

Lymphocytes relocate to lymph nodes upon maturation.

Question 5

Where are blood cells created? What are they created by and what 3 types of cells are created?

Answer 5

Created in the bone marrow, by PHSC (pleuripotent hematopoietic stem cells)

3 types:

common lymphoid progenitor (lymphocytes)

common myeloid progenitor (granulocytes, platelets and RBCs)

immature dendritic cells (unknown origin)

Question 6

What is a lymph node? what is the importance?

Answer 6

secondary lymphoid organ

acts as an immune organ to constantly check incoming fluids for foreign material (antigens).

contains lymphocytes and macrophages

Question 7

What is the spleen? What is its importance?

Answer 7

secondary lymphoid organ

breaks down old RBCs

contains T and B cells

collects antigens from blood

Question 8

what are peyer’s patches?

Answer 8

analogous structure to lymph nodes, but located in the bowels

contains segregated B and T cell compartments (just like lymph nodes)

Question 9

what is the lymphatic system?

Answer 9

Lymph vessels + nodes

not in the CNS, eyes, ears, skin, or bone + cartilage

follow course of veins (developmentally similar)

fluid movement driven by muscle contraction

contains valve system

important for lipid metabolism

Question 10

What are the cellular components of the innate response?

Answer 10

Innate immunity involve cells that are not lymphocytes

granulocytes (neutrophils, basophils, eosinophils)

mast cells

macrophages

NK cells

Dendritic cells

Question 11

Describe features of the innate response. (4)

Answer 11

as a first line of defense, it is immediate

it does not have memory (therefore not graded in response)

it is the same for all humans (preserved from evolution)

specific molecules and patterns are recognized (ex. lipopolysaccarides in bacteria, but not the species of bacterium)

Question 12

Describe features of the adaptive response (4)

Answer 12

only present in higher vertebrates

unique receptors on lymphocytes that recognize unique antigens

has memory (therefore graded in response), but slower

T and B cells are uniquely different in each person.

Question 13

How does the innate reponse work?

Answer 13

Toll-like receptors on cells present foreign molecules on cells surface

(carried out by endosomes in cells)

innate response molescules (DAMP and PAMP) will trigger innate response (pattern recognition of immune cells)

Question 14

What is an antigen?

Answer 14

Antigen is anything that is recognized by the immune cells

could also be a change in appearance of host cells

Question 15

What are APC’s?

Answer 15

APC’s are antigen presenting cells

They digest foreign material and present broken down molecules as antigens on cell surface

uses MHC-II complex (complements CD-4)

(all other cells have MHC-I, using CD-8)

macrophages, dendritic cells, and B cells are involved

Question 16

Which two type of cells participate in phagocytosis?

Answer 16

macrophages and neutrophils

Question 17

How are immune cells activated once an antigen is recognized?

Answer 17

Dendritic cells (APC) becomes activated once a T-cell binds to the antigen. T-cell also gets activated (co-activation)

T-cells can also recognize B-cell antigens, and once bound, T-cells will also activate B-cells.

(both describe activation to achieve effector function)

Question 18

What are lymphocytes? What cells are involved, what do they do?

Answer 18

lymphocytes are the T, B, and NK cells.

they are part of the adaptive response

B cell: APC, detects and displays 3D structures (antigens)

humoral immunity

T cell: recognize antigens on APCs using the MHC complexes

cellular immunity

NOTE: (NK cells are a bit of both)

Question 19

What are cytokines?

Answer 19

low molecular weight proteins

signal molecules that induce movement of immune cells

use cytokine receptors

activates both innate and adaptive responses

Question 20

describe the concept of tolerance

Answer 20

attenuated immune response because:

antigen presented is considered to be “self”

Central tolerance: removal of self-recognizing lymphocytes

Peripheral: prevent activation of lymphocytes through self antigen recognition