W4.1

Question 1

Innate immunity review

Answer 1

“(Natural, Native)

• evolutionarily less advanced
• same response regardless of stimuli
• first line of defense
• rapid response
• no memory - same response every time
• pattern recognition receptors “

Question 2

Adaptive immunity review

Answer 2

“(Specific)

• more advanced
• each response is tailored to stimulus
• take longer to develop initially, but are much more effective
• stronger responses with each exposure
• Ability to remember previous infections “

Question 3

The goal of the immune system

Answer 3

to survey the body for potential pathogens, find cells that can recognize that pathogen, and kill/remove it

Question 4

Adaptive immune system (humoral vs cell mediated immunity)

Answer 4

“H - B lymphocyte

CM - Helper and Cytotoxic T cell”

Question 5

Antigen

Answer 5

any substance that can be specifically bound by an antibody or T cell receptor

Question 6

Lymphocytes

Answer 6

“A subset of WBCs that can be distinguished on the basis of

morphology, histologic staining, immunologic functions, and extracellular/surface markers “

Question 7

how to identify T cells

Answer 7

Flow cytometry recognizes CD2, CD3, CD4, CD8

Question 8

how to identify B cells

Answer 8

Flow cytometry recognizes CD19, CD20, CD22, and surface immunoglobulin

Question 9

how to identify NK cells

Answer 9

Flow cytometry recognizes CD16 and CD56

Question 10

Lymphocytes importance and size

Answer 10

”- primary importance in the adaptive immune system

• 7-10 um diameter
• rounded, indented nucleus; chromatin stains deep blue
• rise from hematopoietic stem cell in the bone marrow, differentiate in primary lymphoid organs “

Question 11

Lymphocytes percentage(s) of the WCBs and peripheral blood

Answer 11

”- 20-40% of circulating WBCs

- B cells (10-20%, T cells (61-89%), NK (22%)”

Question 12

Flow Cytometry

Question 13

How cells are identified

Answer 13

“by size, densitiy, and expression of surface proteins

B (CD19, CD20), T (CD3), Monocytes (CD14), NK (CD16, CD56) “

Question 14

Secondary Lymphoid Tissue

Answer 14

“includes : spleen, lymph nodes, appendix, tonsils, other mucosal associated lymphoid tissue

• main contact with foreign antigens takes place
• spleen filters for antigens”

Question 15

similarity of T and B lymphocytes in the lymphoid system

Answer 15

recirculate continuously from the bloodstream to the secondary lymphoid organs and back

Question 16

APC

Answer 16

antigen presentation cell

Question 17

Lymph Node (lymph flows in through)

Answer 17

“Lymph flows into the node from surrounding tissue through the afferent vessel
(includes fluid and cell from the tissues, especially APCs that hange out in these tissues looking for antigen) “

Question 18

Lymph Node (lymph fluid is inspected by, ->?)

Answer 18

“Once in the lymph node, the lymph fluid is inspected by lymph node resident APCs;
- debris, antigen, dead/dying cells are taken up by lymph node APCs and are presented to naive T and B cells that circulate via the blood) “

Question 19

Lymph Node (inspection results in no infection)

Answer 19

“The APCs will display ““self peptide”” and not express costimulatory molecules
(naive lymphocytes signaled “” everything is ok, live, recirculate throughout the body and be happy””)

Question 20

Lymph Node (inspection results in foreign material)

Answer 20

”- Tissue APCs likely have already taken it up
- (in the lymph) lymph node APCs recognize foreign antigen, become activated, express costimulatory molecules -> ““activation signals”” to lymphocytes

Question 21

Lymph Node (lymph leaving the node)

Answer 21

inspected/filtered lymph and cells leave the node through the efferent vessels and eventually into the bloodstream

Question 22

Immune repertoire

Answer 22

“Total collection of specificities

• T and B cells diverse specificites
• 10 bill receptors to recognition “

Question 23

ideal immune repertoire

Answer 23

”- large enough to recognize any potential microbe/invader/antigen/pathogen
- specific enough to only respond to microbes/pathogens/antigens/ that are present