T Cell Activation and Differentiation (Exam 2)

______ cells are the key antigen presenting cell (APC).

Dendritic (DC)

DCs undergo antigen recognition through ______ or multiple surface _______.

phagocytosis, receptors

The uptake and processing of antigen triggers ______ upregulation and ______ molecule expression.

MHC (I and II), co-stimulatory

What interactions must occur for the activation of CD4 T cells?

- MHC: TCR/co-receptor

- Co-stimulator pair

- Cytokines

What are the co-stimulatory molecule interactions?

- B7:CD28

- CD40:CD40L

Which of these are found on the CD4/8 T cell?

CD28 and CD40L

Which of these are found on the APC?

B7 and CD40

What are the two types of CD4 T cells?

TH1 and TH2

What cytokine stimulates maturation of CD4 T cells into TH1?

IL-12

IL-12 is produced by ...

Macrophages, B cells, DCs

What do TH1 CD4 T cells secrete?

IFN-gamma and IL-2

IFN-gamma is a potent activator of ______.

macrophages

IFN-gamma increases ______ expression.

antigen

IL-2 is a T cell ______.

growth factor

Differentiation of CD4 T cells into TH1s is driven by what external factors?

- Intracellular pathogens

- Viruses

- Bacteria

- Some self antigens

What cytokine stimulates maturation of CD4 T cells into TH2?

IL-4

What do TH2 CD4 T cells secrete?

- IL-4, IL-13

- IL-5

IL-4 induces commitment to the ______ lineage.

TH2

IL-4 also induces class switching to ______.

IgE

IL-5 activates ______.

eosinophils

Differentiation of CD4 T cells into TH2s is driven by what external factors?

Parasitic worms and allergens

TH1 cytokine IFN-gamma inhibits ______ and ______.

TH2, TH17

TH2 cytokine IL-4 inhibits ______ and ______.

TH1 and TH17

Treg cytokine TGF-beta inhibits ...

TH1, TH2, TH17

TH and B cells work together to target a singular ______.

pathogen

How does this occur?

TH cells will bind to epitope A of the pathogen, while B cells will bind to epitope B of the same pathogen

CD8 cytotoxic T cells require what signals to be activated?

- Peptide/MHC:TCR

- Co-stimulation

- Cytokines

(similar to CD4 activation)

______ cells are the primary APCs for CD8 T cells.

Dendritic

CD8 T cells use ______ to bind to ______ on the virus-infected target cell.

FasL, Fas

CD8 T cells release ______ and ______ to induce apoptosis of the target cell.

perforin, granzymes

Perforin creates a ______ in the target cell membrane.

hole

______ then enters the cell through this hole and causes apoptosis.

Granzyme

CD8 T cells can kill any ______ cell in our body infected with a pathogen.

nucleated

CD4 T cells respond to ______ pathogens.

extracellular

CD8 T cells respond to ______ pathogens.

intracellular

Antigen is presented to CD4 T cells by ...

DCs, macrophages, B cells

Antigen is presented to CD8 T cells by any infected ______.

nucleated cell

CD4 T cell MHC restriction

MHCII

CD8 T cell MHC restriction

MHCI

The co-stimulatory signals for both CD4 and CD8 T cells are ...

CD28:B7

CD40L:CD40

CD4 T cells produce ______, while CD8 T cells produce ______.

cytokines, perforin/granzyme

At a certain point, T cell immune response is ______.

terminated

What are the two pairs responsible for termination of the T cell response?

CTLA-4:B7

PD-1:PDL1

CTLA-4 on the activated T cell fights ______ for B7 binding on the APC.

CD28

PD-1 on the activated T cell will bind to ______ on the APC.

PD-L1

Both of these signals will cause ______ of the activated T cell.

inhibition