2 Immuno: Adaptive Immunity: Lymphocytes

Front 1

types

Back 1

- acquired immune response
1. T cells: cell-mediated
2. B cells: humoral immunity
3. NK cells: no receptors specific for Ag, largest, probably from same stem cells as T cells

Front 2

TCR and BCR structure

Back 2

TCR and BCR:
- expressed on surface
- contain several different proteins
- parts:
1. Ag binding
2. signal transduction to cell: eg CD3 of TCR, CD79 of BCR

Front 3

affinity

Back 3

affinity:
- strength of binding between Ag and R
- below threshold: encounter insufficient to activate lymphocytes

Front 4

TCR

Back 4

TCR:
- recognizes Ag ONLY when presented by APC in context of MHC
- never secreted, always attached

Front 5

BCR

Back 5

BCR:
- see linear epitopes on unprocessed Ag free in solution
- Ab identical to BCR minus membrane anchoring portion

Front 6

somatic gene rearrangement fx

Back 6

somatic gene rearrangement:
- during maturation allows R recognition and response to diversity of Ag
1. T cells: thymus
2. B cells: marrow, peyer's, bursa

Front 7

_CR specificity

Back 7

_CR specificity:
- for single, or very closely related, epitope
- greater than MHC which can bind multiple Ag
- diversity allows animal to recognize any foreign Ag encountered

Front 8

somatic recombination process

Back 8

somatic recombination:
1. receptor genes exist as segments in the germ line
2. maturation: segments rearrange with help of recombinases
3. transcription: DNA to mRNA
4. translation: mRNA to receptor protein chains
5. separate chains bound together= receptor
6. diversity: different combinations of V, D and K segments

Front 9

immunodeficiencies and recombination

Back 9

somatic gene rearrangement leading to dyfunctional Ag receptors= lack of immune response= immunodeficiency

Front 10

Ig light chain construction

Back 10

Ig light chain construction:
- DNA rearrangement occurs during early B cell development
- each B cell committed to making a single form of light chain for its Ag receptor

Front 11

receptor molecules

Back 11

receptor molecules:
- communicate with environment or other cells
- also expressed on othe cell types, eg AbR and complement R on macs
1. Ag
2. cytokine
3. Ab
4. complement

Front 12

Ag receptors

Back 12

Ag receptors: TCR, BCR
- TCR recognized Ag being presented by MHC molecules
- TCR must also recognize MHC

Front 13

cytokine receptors

Back 13

cytokine receptors:
- also in some non-lymphocytes
- CD25 receptor for IL2

Front 14

Ab receptors

Back 14

Ab receptors (FcR):
- also in some non-lymphocytes
- bind Fc region of particular Ab

Front 15

complement receptors

Back 15

complement receptors:
- also in some non-lymphocytes

Front 16

other receptors

Back 16

receptors needed to recognize molecules on the surface of cells that help with co-stimulation
- CD40L, CD28, CTLA-4

Front 17

adherence molecules

Back 17

adherence molecules:
- integrins
- selectins

Front 18

MHC

Back 18

1. MHC I: all nucleated cells
2. MHC II: only APC B cells that present to T cells (need cytokine signal)

Front 19

CD

Back 19

CD= cluster differentiation:
- naming lymphocyte cell surface molecules
- ID: MoAbs, fluorescent Ab
- expressed by different subsets: eg CD4 Th and CD8 CTLs
- immunophenotyping lymphocytes