B Cell Development and Application of Antibodies

Question 1

What are the primary lymphoid organs for T and B cells?

Answer 1

-T cells :thymus

-B cells: the red bone marrow
(primates and rodents)
* the ileocecal Peyer’s patches (ruminants, pigs, horses
and dogs)
*bursa of Fabricius (birds).

Question 2

what happens to lymphocytes in the primary lymphoid organs?

Answer 2

-lymphocytes develop and express their antigen-specific receptors, and V(D)J recombination takes place here

Question 3

What are the secondary lymphoid organs?

Answer 3

lymph nodes, spleen, MALT, Bone marrow

Question 4

What are the steps involved in the development of B lymphocytes?

Answer 4

start primary lymphoid organs (antigent independent):

1.Pro-B cell
2. Pre-B cell
3.Immature B cell
4. Mature B cell

then move on to the SLO (ARE ANTIGENT DEPENDENT)

5. memory B cells
   6.Plasma cells

Question 5

describe the Pro-B cell stage

Answer 5

B lymphocytes arise from hematopoietic stem cells that commit to the B cell lineage.

earliest distinguishable cell in the B cell lineage

have undergone D-J segment heavy chain rearrangement but have NOT produced immunoglobin (Ig) for expression on their cell surface

Question 6

Describe the Pre-B cell stage

Answer 6

cell makes μ HEAVY CHAINS BUT NO LIGHT CHAINS.

have undergone COMPLETE V-D-J segment HEAVY CHAIN rearrangement.

This rearranged V-D-J unit is put next to the Cμ gene, and the pre-B cell produces a μ heavy chain

μ heavy chain is paired with SURROGATE light chain to form a molecule that can be expressed at the cell surface

Ig-ALPHA and Ig-BETA are obtained on this stage as well

Question 7

what is a surrogate light chain, which is seen in Pre-B cells? and what is therefore the Pre-BRC?

Answer 7

product of two non-rearranging genes

μ heavy chain PLUS surrogates light chain are known as Pre-BCR

Question 8

plasma cells created first in the primary response will secrete _________, UNTIL TJE IMMUNE SYSTEM PROCEEDS and the TH CELLS BECOME AVAILABLE FOR CLASS SWITCHING

Answer 8

IgM.

Question 9

_______ are necessary to carry out class switching , Where class switching prodigy will yield______

Answer 9

Th cells

plasma B cells (G,A or E) AND memory cells (G,A or E) that secrete their immunoglobulins on the cell surface.

Question 10

describe the Immature B cells stage

Answer 10

have undergone a
COMPLETE V-J LIGHT CHAIN rearrangement

actual light chains are paired with μ heavy chain

EXPRESS IgM (with two FULL light chains, and two FULL left chains)

Question 11

What are the possible outcomes of an immature B cell the tissue exposed to an antigen?

Answer 11

1. Deletion-death of that cell by apoptosis
2. anergy- or the cell
   is inactivated
3. receptor editing-the cell’s Ig L chain genes undergo rearrangement using unrearranged V or J elements (generate new specificity for IgM)