Stuff I Don't Know

Question 1

Most B cells that come from the fetal liver are derived into what lineage?

Answer 1

B1

Question 2

Most B cells that come from the bone marrow are derived into what lineage?

Answer 2

B2

Question 3

Why do B1 cells exhibit a limited amount of diversity?

Answer 3

Because TdT is not expressed in the fetal liver

Question 4

What does TdT do?

Answer 4

TdT adds or removed nucleotides to the exposed ends of the V, D, and J genes before they are reuinted. Further increasing genetic diversity of the antibodies.

Question 5

Where is junctional diversity generated?

Answer 5

At the points between joining genes

Question 6

Junctional diversity results from what?

Answer 6

The loss of nucleotides at the ends of genes via exonucleases and the addition of P and N nucleotides.

Question 7

What are P nucleotides named for?

Answer 7

The palindromic appearance

Question 8

Where are large numbers of B1 cells found?

Answer 8

Self-renewing populations are found in the peritoneum and mucosal sites.

Question 9

What do B1 cells secrete?

Answer 9

They spontaneously secreted IgM antibodies that interact with polysaccharides, lipids, and oxidized lipids

Question 10

What is another name for B1 cells?

Answer 10

Natural antibodies, because they are present in individuals without overt immunity

Question 11

What do B1 cells mostly contribute?

Answer 11

IgM abs during early phases of infection

Question 12

Where do B2 cells develop?

Answer 12

From SC’s in the bone marrow

Question 13

Following rearrangement of their BCR chains, where do immature B2 cells relocate?

Answer 13

To the spleen

Question 14

What do immature B2 cells differentiate into?

Answer 14

Marginal Zone (MZ) and Mature Follicular (FO) cells

Question 15

Where are mature FO cells found?

Answer 15

They are recirculating lymphocytes

Question 16

Where are mature MZ B2 cells found?

Answer 16

In the spleen (splenic marginal zone), some in LNs

Question 17

FO B2 cells respond to antigens in what manner?

Answer 17

In a T cell dependent manner

Question 18

In order for a FO B2 cell to turn into a plasma cell, what needs to happen?

Answer 18

T cell dependent activation

Question 19

Are most MZ B cell responses dependent or independent of T cell activation?

Answer 19

Independent

Question 20

Where are MZ B cells predominantly located?

Answer 20

In the marginal sinus of the spleen

Question 21

Which immunoglobulin mediates the release of mediators from mast cells and basophils in response to an allergen?

Answer 21

IgE

Question 22

Which of the following cell types do NOT express MHC class I molecules?

Answer 22

RBC’s

Question 23

Where does loading occur in MHC class I?

Answer 23

The rough ER

Question 24

Where does loading occur in MHC class II?

Answer 24

acidified endosome

Question 25

What tonsil has no definitive capsule?

Answer 25

Lingual

Question 26

5 cells of the erythrocyte lineage

Answer 26

proerythroblasts, basophilic erythroblasts, polychromatophilic erythroblasts, orthochromatophilic erythroblasts, polychromatophilic erythroblasts

Question 27

Proerythroblasts

Answer 27

- Large (12-20 mm) - 1-2 nuclei - cytoplasm is basophilic

Question 28

basophilic erythroblasts

Answer 28

- small nucleus (10-16 mm) | - has polyribosomes which synthesize Hb (this is where Hb synthesis begins!

Question 29

polychromatophilic erythroblast

Answer 29

- acidophilic and basophilic staining | - can have distinct pink and purple areas

Question 30

orthochromatophilic erythroblast

Answer 30

- increasingly acidophilic | - gets rid of nucleus

Question 31

polychormatophilic erythrocyte

Answer 31

AKA reticulocyte

Question 32

5 steps of granulopoiesis

Answer 32

Myeloblast, promyelocyte, myelocyte, metamyelocyte, band cell

Question 33

Myeloblast

Answer 33

- large spherical nucleus, 3-5 nucleoli

Question 34

Promyelocyte

Answer 34

- contains primary granules (azurophilic)

Question 35

Myelocyte

Answer 35

- first to exhibit specific granules

Question 36

Metamyelocyte

Answer 36

- specific granules outnumber azurophilic granules

Question 37

What is another name for a band cell?

Answer 37

Stab cell

Question 38

What happens to immature neutrophils?

Answer 38

They enter a reserve pool in the bone marrow (5 days). Then, half will circulate as bands and the other half will stay in the marginated pool

Question 39

What happens in a left shift?

Answer 39

Myelocytes and metamyelocytes may be released

Question 40

What signaling molecules does the development of B cells require?

Answer 40

IL-1, IL-6, IL-7 & stromal cells

Question 41

What signaling molecules does the development of T cells require?

Answer 41

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