cell and antibody mediated immunity

Question 1

what happens within secondary lymphoid organs

Answer 1

dendritic antigen presentation

naitve t cells

Question 2

what happends to naive t cells in the secondary lymphoid organs

Answer 2

antigen recognition via TCR- signal 1

co-stimulation via CD28- signal 2

induction of cell division and differentiation into effector cells

Question 3

CD8 T cells job is

Answer 3

target cell killing
cytokine production

Question 4

CD4 T cells job is

Answer 4

cytokine production
T cell subsets ( helper and regulatory cells)

Question 5

what are CTL

Answer 5

Cytotoxic T lymphocytes

Question 6

how do CD8 T cells kill target cells

Answer 6

encounter and adhere to target cell

antigen recognition redistributes cytoskeleton and cytoplasmic components of T cell

releases lytic granules that contain perforin at the site of cell contact poking holes into the cells

Question 7

what differentiates T cell subsets

Answer 7

directed by environmental cytokines

Question 8

what do CD4 T cells induces

Answer 8

transcription factors

Question 9

how do Th1 cells activate macrophages

Answer 9

naive t cells are activated in presence of IL-12

differentiation into Th1 effector CD4 cells

effector CD4 t reginizes peptide-HLA class 2

IFN-y is produced by CD4

IFN-y binds receptor on macrophage causing cell to become engulfed

Question 10

what is the process of follicular helper cd4 cells

Answer 10

naive t cells activiated in presence of IL-6/ IL-21

differentiation into Tfh cells

effector CD4 tfh cell recognizes HLA class 2 on b cell

production of cytokines and expression of CD40L

actives B cell to differentiate into plasma cell

Question 11

Regulatory t cells control of other cells steps

Answer 11

t cell activated in prescence of TGF-B

differentiation into Threg

CD4Treg cell regonition of peptide HLA class 2 antigen presenting cell ( APC)

CD4Treg cell regulates/supresses effection CD4 T cell

cytokines like IL-10, cell-cell interactions, signaling

Question 12

what activates naive B cells

Answer 12

unprocessed antigen

Question 13

steps of initial activation of antigen specific b cell

Answer 13

b cell recognizes antigen ( soluble or captured on follicular dendritic cell)

b cell is activated

expression of peptide HLA class 2 complex

interaction with effector CD4 T cell

B cell activation ( maturation into antibody producing plasma cells) ( formation of germinal center)

Question 14

antibody neutralization of pathogens in non-immune individuals

Answer 14

• pathogen enters the body
• pathogen binds to receptor on host cell
• internalization/ infection

Question 15

antibody neutralization of pathogens in immune individuals

Answer 15

• pathogen enters the body

-pathogen-specific antibodies bind the pathogen

• blocks pathogen binding to host receptor cause NO infections

Question 16

Antibodies can recruit..
what are the steps of ADCC

Answer 16

immune cells

-target cells bound by IG1/IG3 antibodies

• FC/R111 on natural killer cells recognize IgG on target cell

activation of NK cells

killing of target cells

Question 17

steps of mucosal secretion of IgA

Answer 17

• binding of IgA to poly-Ig receptor on basolateral face of epithelial cell
• receptor-mediated endocytes of IgA
• Receptor is cleaved, IgA bings to mucus with secretory place

Question 18

IgE antibodies can

Answer 18

arm mast cells

Question 19

steps of arming mast cells

Answer 19

• plasma cells produce IgE antibody
• IgE antibody binds high affinity IgE Fc receptors on mast cell
• antigen binds FceR bound IgE on surface of mast cell
• ITAM- based signaling via FceR
• activation of mast cell is done