Lymphocytes Flashcards
2 types of immune response
- innate
2. adaptive
time for 2 different immune responses
- innate - hour to days
2. adaptive > 5 days
cells for 2 different immune responses
- innate - WBC’s phagocytose
2. adaptive - lymphocytes - antigen antibodies
2 main types of lymphocytes and where from
- B cells - bone marrow
2. T- cells - marrow, but mature in thymus
where do 2 different cells exist in lymph nodes
- B cells - follicles
2. T- cells - paracortical
where do lymphocytes exist in spleen
white pulp
- B cells - lymphoid follicle
- T- cells - periarteriole sheath
what are markers for 2 different lymphocytes dev.
- B cells - CD19
2. T- cells - CD3
2 key reactions during lymphocyte differentiation
- T-cell receptor gene rearrangment
2. selection and apop.
2 function of antigen receptors
- antigen recognition
2. cell signaling
what is rearranged in each lympho to make antigenreceptor
- B cells - immunoglobulin genes
2. T- cells - T-cell receptor genes
3 possible outcomes of rearrangments
- positive selection - responds well to antigens
- neg. selections - death bc too stongly self-reactive
- (90%) cel death - bad rearrangements
path of t-cell dev.
common precursor>to thymus>signal for precursors to commit to T>massive cell death
marker for increased B and T cell diversity
TdT
features of ALL B-cell precursors
- bone marrow infiltration
- pancytopenia
- bone pain
- splenomegaly
- CD19 and Tdt
signs of burkit lymphoma
- lymphoid masses in small bowel
- rapid cell turnover
- mature B cells
signs of lymphoblastic lymphoma
- thymus ant. mediastinal mass
- CD3 and Tdt
** 3 causes of malignant transformation
- abnormal cell proliferation
- impaired cell death
- blocked differentiation
2 major times of mutations to occur
- DNA breaks during rearragment for antigens
2. clonal expansion- after contact antigen
Aprox. number of mutations required for malignant transformation in ALL
6
when do most mutations occur for ALL
before birth
better target to identify residual blasts in blood
immunoglobulin or T-cell markers - more precise that microscolpy (5%)
what does chromosomal translocation do to cause ALL
overexpression of oncogenes at breakpoint
