Lecture 2

Question 0

Myeloid lineage?

Answer 0

Everything else

ie. DC, Mono, Neutr, Eosin, Basos, Erythrocytes, platelets, phagos

Question 1

Lymphoid lineage?

Answer 1

Big Ten Network

B lymphocytes, T lymphocytes, NK cells

Question 2

which cytokines help T cells become T lymphocytes?

Answer 2

IL-1, IL-2, IL-6, IL-7

IL-2 unique to T cells

Question 3

Which cytokines help B cells become B lymphocytes?

Answer 3

IL-1, IL-6, IL-7

Question 4

what are the primary lymphoid organs?

Answer 4

thymus, bone marrow

Question 5

secondary lymphoid organs?

Answer 5

spleen, lymph nodes, lymphoid tissues

Question 6

what are some characteristics of small lymphocytes?

Answer 6

8-10 microm in diameter
naive B and T lymphocytes are in a state of rest (G0)
when stimulated they enter G1 stage

Question 7

what are large lymphocytes?

Answer 7

10-12 microm in diameter

they are activated lymphocytes and called large lymphocytes/lymphoblasts

Question 8

what is the most important cytokine for survival of naive T cell, which promotes low-level cycling of naive T cells?

Answer 8

IL-7

Question 9

what is required for naive B cell survival?

Answer 9

BAFF, a cytokine that belongs to TNF family

Question 10

T lymphocyte characteristics

ie. what do they make contact with, what are their #s like?

Answer 10

immature T cells make contact with epithelial cells, DCs, and macrophages in the thymus and these interactions determine diff

naive T cells maintained in periphery and their # remains constant
functionally mature T cells migrate to 2ndary lymphoid tissues

Question 11

what are 2 kinds of T cells and what do they do?

Answer 11

T helper (CD4) - help B cell growth and diff

Cytotoxic T lymphocyte (CD8) - recognize and kill virus-infected cells

Question 12

Where do B lymphocytes develop from and where does differentiation occur?

Answer 12

stem cells around 14th week of gestation within the fetal liver, after birht the bone marrow after contact w/stromal cells

Question 13

what antibodies are expressed on B cells as the BCRs?

Answer 13

IgM then IgD

Question 14

what are the 2 types of B cells?

Answer 14

B1 - fetal stage that self-renew

B2 - made in bone marrow

Question 15

What is a plasma cell?

Answer 15

terminally differentiated B cell which produces and secretes large amounts of Abs

comprise < 3% of bone marrow white cell count

Question 16

What do B cells do and where do they migrate to?

Answer 16

present Ags to helper T cellssss and mature B cells migrate to secondary lymphoid tissues to respond to foreign Ags

Question 17

where are lymphocytes unable to reach?

Answer 17

eye, brain, testes

Question 18

Lymphocytes use HEVs (endothelium of postcapillary venules) to reach where?

Answer 18

lymph nodes, skin, intestine

Question 19

how do lymphocytes reenter circulation?

Answer 19

efferent lymph vessels that merge into the thoracic duct

Question 20

Lymphocyte activation steps

Answer 20

full mature, naive T cells and immature B cells migrate to LN and spleen
B cells mature in LN and spleen
naive B and T cells activated by Ags diff. into effector or memory lymphocytes
some migrate to infection sites and Abs secreted by effector B cells go to infection sites

Question 21

what are antigen presenting cells? (APCs)

Answer 21

cells that capture, display, and process microbial Ags to lymphocytes and provide signals that stimulate proliferation and differentiation of the lymphocytes

Question 22

What is the major type of APC involved in initiating a T cell response?

Answer 22

DC - activates naive T cells

Question 23

what response do macrophages and B cells act as APCs?

Answer 23

cell mediated and humoral respectively

Question 24

what does a follicular DC do?

Answer 24

displays Ags to B lymphocytes during humoral immune response

Question 25

what provides the link between innate and humoral immunity?

Answer 25

DCs and macrophages

Question 26

what does maturation of DCs depend on?

Answer 26

Flt3 ligand which binds to the Flt3 Tyr kinase receptor on precursor cells

Question 27

what do activated DCs secrete?

Answer 27

cytokines

Question 28

what migrates to LNs where they display microbial protein Ags to T lymphocytes upon activation by microbes?

Answer 28

classical DCs

Question 29

what has potent antiviral activity?

Answer 29

type 1 interferons aka IFN alpha/beta

Question 30

where are FDCs located and what do they bind to and display

Answer 30

found in secondary lymphoid tissue

bind Ags on surface for B lymphocyte recognition

Question 31

What are Innate Lymphoid Cells (ILCs) and what do they lack?

Answer 31

subsets of bone marrow derived cells with lymphoid morphology

lack T cell Ag receptors

Question 32

what are the 3 major functions of ILCs?

Answer 32

early defense against infectious pathogens, recognize stressed/damaged host cells and help eliminate them, influence subsequent adaptive immune response

Question 33

what is the 1st ILC and what does it secrete?

Answer 33

NK secretes IFN-gamma to kill infected cells

Question 34

What is the path of naive T and B lymphocytes through the LN?

Answer 34

enter LN via artery, leave circulation through wall of HEV

B and T cells migrate to diff. zones of LN based on chemokines

Question 35

What is the DC path through LN

Answer 35

DCs pick up Ags from entry site and enter through afferent lymphatic vessels

Migrate to T-cell rich areas of the node