W4: The life cycle of b- lymphocytes

Question 1

what is lymphomagenesis?

Answer 1

Lymphomagenesis is the process through which normal lymphocytes (a type of white blood cell) transform into lymphoma cells, which are cancerous.
Essentially, it describes how lymphoma, a type of cancer that affects the lymphatic system, develops and progresses.

Question 2

what is the innate immunity?

Answer 2

• instant/ immediate reponse
• integrates with adaptive immune system
  -e.g. barriers (skin), antibacterial substances
  (saliva, tears), CRP, phagocytes (neutrophils)

Question 3

what is the adaptive system?

Answer 3

• acquired and slower
• await days_ 4 weeks
• accurate= specific autoregulation autoimmunity
• e.g. lymphocytes: T, B, NK

Question 4

what is the functions of adaptive system?

Answer 4

1. Specificity
2. Memory
3. Diversity
4. Self-tolerance
5. Clonal Expansion

Question 5

what are the areas involved in b cell development?

Answer 5

1. Bone marrow
   – VDJ recombination
2. Lymph node
   – Germinal center formation
   – Somatic Hypermutation
   – Class switch recombination
3. Plasma and Memory cells

Question 6

how is the BCR made?

Answer 6

• DNA (gene) level: chromosome 14 [Multiple segments for V, D and J]
  1. D to J recombination
  2. V to DJ recombination
  3. transcription & splicing
  4. translation and assembly

Question 7

what will happen if a segment is not joined up correctly?

Answer 7

• If segments are joined up correctly (productive gene
  rearrangement), the heavy chain protein is produced and
  goes to the B-cell surface

Question 8

why does b cell require a functional bcr?

Answer 8

1. Productive rearrangement of heavy chain
   VDJ segments
2. Productive rearrangement of light chain
   VJ segments
3. Heavy and light chains must fit together

Question 9

what is a mature b cell?

Answer 9

fully formed bcr sitting on the b-cell surface but having not met its antigen (naive)

Question 10

where do b cell fine tune their bcr to their specific antigen?

Answer 10

They
do this in the dark zone
by a process called
Somatic Hypermutation
* aim is to increase the antibody’s affinity to its antigen

Question 11

where do mutations occur?

Answer 11

variable regions of the
light and heavy chains
* But these mutations are
RANDOM so there are
three possible outcomes:
* Increased BCR affinity to its
antigen
* Decreased BCR affinity to its
antigen
* BCR affinity unchanged

Question 12

what are the options when B cell leave the GC?

Answer 12

• become memory cells
• become plasma cells

Question 13

what are plasma cells?

Answer 13

• Are antibody factories
• Reside in bone marrow and produce
  secreted form of BCR

Question 14

what are memory cells?

Answer 14

• Remember first exposure to pathogen
• Help defend against subsequent exposure
• Live in marginal zone, peripheral blood
  and spleen

Question 15

identify:
1. what is the cancer of BM?
2. Pre GC
3. GC dark
4. GC light zone
5. post GC

Answer 15

1. BM:
   Acute lymphoblastic leukaemia
2. Pre GC:
   Mantle cell
   lymphoma
3. GC(dark zone):
   Burkitt lymphoma
   Diffuse large B-cell lymphoma
4. GC (light zone):
   Follicular lymphoma
5. Post-GC:
   Chronic lymphocytic leukaemia
   Marginal zone lymphoma
   Multiple myeloma
   Hairy cell leukaemia