Cmbm- Exam 3- Activation Of B And T Cells By Antigen

Front 1

What is the first step in any adaptive immune response?

Back 1

Naive T cell encounters it's specific antigen and it is stimulated to differentiate into an effector T cell

Front 2

Where is the adaptive immune response initiated?

Back 2

Secondary lymphoid tissue

*Regional lymph nodes, spleen, tonsils, Peyer's patches, GALT, appendix

Front 3

What cell takes up pathogens and carries antigen to lymphoid tissue to activate T cells?

Back 3

Dendritic cells

Front 4

What type of cell can process and present antigen that is carried passively into lymph?

Back 4

Macrophage

*Resident in tissues (don't migrate)

Front 5

What occurs after a T cell encounters a specific antigen?

Back 5

T cell proliferates and differentiates into effector cells

Front 6

What two endothelial molecules do naive T cell L-selectins bind?

Back 6

1) CD34
2) GlyCAM-1

*Binding to these sugar residues allows for "rolling"

Front 7

What T cell molecule do ICAM-1 and ICAM-2 bind?

Back 7

LFA-1 (Integrin)

*LFA-1 activated by cytokines bound to extracellular matrix

Front 8

What molecular interaction increases the LFA-1:ICAM-1 interaction between T cell and dendritic cell?

Back 8

Binding of T-cell receptor to MHC complex

Front 9

Which two signals activate T cells?

Back 9

1) TCR (naive T cell) interacts with antigen bound in MHC II molecule (APC)
2) B7 (APC) interacts with CD28 (naive T cell)

Front 10

What occurs to the T cell if no B7 is located on the APC?

Back 10

T cell inactivation (anergy)

*With B7 present, T cell proliferation and differentiation

Front 11

Name two helper T lymphocyte molecules that are involved in signal transduction?

Back 11

1) CD28 (binds B7 on APC)
2) CD3

Front 12

What is the most important surface protein involved in CD4+ effector function?

Back 12

CD40L

*Binding of CD40L (T cell) to CD40 activates the cell bearing CD40 (macrophages, dendritic cells, B cells)

Front 13

What are the two helper T-cell activation markers?

Back 13

1) CD40L
2) IL-2R

Front 14

In a resting T-cell, which IL-2 peptide chains are expressed?

Back 14

Beta and gamma (always expressed)

*Alpha chain is expressed in ACTIVE T cell (need all 3 chains for highest affinity and T cell proliferation)

Front 15

Which cytokines favor the development of Th0 into Th1 cells?

Back 15

IFN-y or IL-12

Front 16

Which cytokine favors the development of Th0 into a Th2 cell?

Back 16

IL-4

Front 17

What are the properties of Th1 cells?

Back 17

1) Make IFN-y
2) Host defense against intracellular microbes (Activates macrophages for KILLING)
3) Inflammation (CHRONIC)

Front 18

What cell drives chronic inflammation?

Back 18

Th1 cells

Front 19

What are the properties of Th2 cells?

Back 19

1) Secrete IL4,5,13
2) Host defense against helminths
3) Parasitic and allergic reactions

Front 20

What are the properties of Th17 cells?

Back 20

1) Secrete IL-17
2) Host defense against some bacteria
3) Inflammatory disorders

Front 21

What are 3 functions of antibodies?

Back 21

1) Neutralization
2) Opsonization (promote phagocytosis)
3) Target for complement

Front 22

Which molecule promotes B cell class switching?

Back 22

CD40

*CD40L on T cell binds to CD40 on B cell surface

Front 23

Why don't you see IgM in a patient who has had a primary bacterial infection for 2 days?

Back 23

Primary response takes 5-10 days!

Front 24

How long would it take to detect IgG in a patient who has a secondary rubella infection?

Back 24

1-3 days

Front 25

What are the consequences of T-independent antigens having no T cell help?

Back 25

1) Little to no class switching (no CD40)
2) Little to no memory

*T-ind antigents cause proliferation and IgM secretion in absence of T cell help