Exam 2 - Chapter 8, immune system regulation

what percentage of CD4+ cells are helper t, what percent are regulatory t cells

95

5

what are the two kinds of regulatory t cells

inducible Tregs (iTreg)/peripheral Tregs (pTreg)

natural Tregs (nTreg)/Thymus Tregs (tTreg)

what do activated regulatory t cells secrete? why?

anti-inflammatory cytokines

restrain the immune system

what is the function of iTreg

regulate the immune system

what are the effector cytokines of an inducible regulatory t cell

TGF beta, IL-10

what stimulates the iTreg to make its anti-inflammatory cytokines

IL-2 and TGF beta

what does TGF beta bind to? what functions does it have

t cells

reduce proliferation of t cells, reduce CTL killing power, reduce Th1 and Th2 cell differentiation, regulate innate-like lymphoid cells

what is the function of IL-10

block co-stimulatory signals (CD28), reduce proliferation of t cells

IL-6 and TGF-Beta when combined will produce which Th bias

Th17

what produces the TGF beta that will combine with IL-2 to produce an iTreg

endothelium

what produces the TGF beta that will combine with IL-6 to form a Th17 bias

APDC

a Th17 cell produces IL-23, this cytokine is ____-inflammatory because it reduces the ability of _____ cells to regulate the immune system

pro, iTreg

where do iTreg/pTreg cells develop

in MALT (secondary lymphoid organ)

where do nTreg/tTreg cells develop

thymus

what is the function of nTreg cells

protection against autoreactive t cells from leaving thymus

which type of regulatory t cell is antigen specific

nTreg/tTreg

how do iTregs affect allergies

they control mast cell degranulation

more experienced t cells make a negative regulator that is on their surface. This regulator is called _____ and it binds to ___ on the APDC which prevents ___ from binding and causing co-stimulation. This negative regulator has an affinity that is much higher than that of CD28 meaning it can outcompete and cause the t cell to enter into _____

CTLA-4, B7, CD28, anergy

in regards to the negative regulator PD1/PDL-1, which is found on the T cells and which is found on WBCs

T: PD1

WBC: PDL-1

what does PD1/PDL-1 cause

apoptosis, slow proliferation

AICD is another form of negative t cell regulator. what does this stand for? what is the mechanism of action?

activation-induced cell death

Fas receptor protein bind to Fas Ligand = apoptosis

which is susceptible to killing, which does the killing:

Fas protein and fas ligand

does killing: fas ligand

can be killed: fas protein

t/f

CTLs have both fas protein and fas ligand

true

what makes a t cell more prone to being killed via AICD

experience, more reactivations = more likely death from increased sensitization

which immune cells live the longest

macrophage

what is the longest lived antibody

IgG