Cellular Immunity III

Created by nbecketti 

Upgrade to
remove ads

What are the three types of professional antigen presenting cells

Dendritic cells, macrophages, B cells

How do dendritic cells take up antigens

pinocytosis and phagocytosis

What kind of antigens do dendritic cells present

Peptides, viral antigens, allergens

How do macrophages take up antigens

Phagocytosis

What kind of antigens do macrophages present

Particulate antigens, intracellular and extracellular pathogens

How do B cells take up antigens

Through antigens specific receptors Ig

What kind of antigens do B cells present

Soluble antigens, toxins, viruses

Where most dendritic cells found

In the skin or mucosal tissues as Langerhans cells

What is the best APC

Dendritic cells

Once a dendritic cell or macrophage presents a specific antigen a T cell recognizes what happens to the T cell

It begins to proliferate and differentiate to effector cells

How do T cells enter lymph nodes or regular tissues

The of the same mechanism of neutrophils that is rolling tight adhesion diapedesis and tissue migration

What do selectins do

They allow lymphocytes to home to lymph nodes or to sites of infection

What do ICAMS do

They allow T cells to talk to APC's

Where can Naïve T cells enter lymph nodes

afferent lymphatics or the blood

What happens to the the adhesion molecules of T cells once they become activated

They change

Describe the intracellular signaling pathway that turns on inside an activated T cell

Tyrosine kinases activate Phospholipase Cg. This cleaves PIP2 to DAG and IP3. Dag and calcium activate Protein Kinase C (PKC). IP3 causes the release of calcium. The release of calcium activates the phosphatase calcineurin. PKC and calcineurin activate transcription factors NFkB and NFAT which induce the cell to divide.

What does receptor associated tyrosine kinase activate

PLCg

What does PLCg do

cleaves PIP2 to DAG and IP3

What does DAG and calcium activate

PKC or protein kinase C

What does IP3 do

causes the release of calcium from the ER

What does the release of calcium do

activates calcineurin

What do PKC and calcineurin do

activates transcription factors NFkB and NFAT

What do the transcription factors NFkB and NFAT do

induce the T cell to divide

What transcription factors induce the t cell to divide

NFkB and NFAT

Is engagement of the T cell via the TcR enough to turn on the T cell

No, it requires co stimulation

What is co stimulation mediated by

CD80 and CD86 on the APC which binds to CD28 on naïve T cells to deliver the costimulation

What co stimulatory molecules are on the T cell

CD28

What costimulatory molecues are on the APC

CD80 and CD86

What happes to the T cell once the response to the non self antigen is complete

The T cell upregulates expression of CTLA4

What does CTLA4 do

It binds to CD80 and CD86 better and shuts down the T cell response

What happens to the T cell in the absence of costimulation

It becomes anergic or permanently inactive

What is the source and effects of IL1

APCs and Inflammation

What is the source and effects of IL2 and IL12

Th1 and T cell growth

What is the source and effects of IL4 and IL5

TH2 and humoral immune response such as IgA, IgG1, IgE antibody production and class switching

What is the source and effects of IL 10

Th2 (Treg) inhibits Th1 and upregulates MHC class II

What is the source and effects of IFN gamma

Th1 and inhibits Th2, upregulates MHC class I and II

What is the source and effects of TNF

Th1 and inflammation

What is the IL2 receptor

CD25

What happens to activated T cells with regards to IL2

they begin to make their own IL2 and change receptors from a low affinty dimer to a high affinty trimer

What pathway is the signaling for IL2 mediated by

PI3

What is a crucial signaling molecule in the PI3 pathway

mTOR

What are the two subsets of effector T cells

CD8 and CD4

What do CD8 t cells make

perforin and granzymes and Fas

What is the function of CD8 t cells

cytotoxic

What is the function of perforin

it perforates cells

What is the funciton of Granzymes

it is injected into a cell and begins the cell death pathway

What is the funciton of Fas

interacts with the Fas ligand and also begins the cell death pathway

What are the three subsets of CD4 cells

Tregs, Th1 and Th2

What do Treg T cells do

down regulates th1 via IL10

What do TH1 cells do

inflammatory and cellular immune response by making TNF and IL12 and INF gamma secretion. Host defense against intracellular microbes

What do th2 cells do

humoral antibody immune response IL4 il5 il13 secretion, host defense against helminths and allergic reactions

What drives naïve cd4 tcells down the th1 pathway

IL12, IFN gamma

what driives naïve cd4 tcells down the th2 pathway

il4

What happens do down or upregulate the th1 or th2 responses

th2 secretes TGF beta and IL10 which inhibit activation and growth of TH1, th1 secretes IFN gamma which inhibits proliferation of th2 cells

Why do cd8 cells not require further costimulation after being stimulates

the IL2 they produce is an autocrine growth factor

how do ctl's kill their targets

inducing apoptosis via perforins and granzymes

How else can apoptosis be triggered via CTl's

interaction of CTL FASL with the Fas in the target cell

what is the function of Th1 cells

cellular immunity

what is the funciton of the th2 cells

humoral imminity

what do th1 cells talk to

cd8 cells and macrophages

what do th2 cells talk to

b cells

What do th1 cd4 cells activate

they activate macrophages to become highly microbiocidal

how do th1 cd4 cells accomphlish this microbiocidality

the interaction between cd40 on the macrophage and cd40L on the t cell and via th1 cytokines

what happens when intracellular pathogens cannot be totally eliminated

th1 cells induce granuloma formation

where are granulomas commonly seen and why

tuberculosis, parasitic infections and granulomatous disease. The pathogens have evolved mechanisms to resists macrophage mediated killing

How do th2 cells talk to b cells

through the CD40L and CD40 interaction along with IL4 and IL5

what interaction is required for class switching

CD40-CD40L

What happens when th2 cells talk to B cells

B cell proliferation and differention into antibody secreting plasma cells

Where does the B cell proliferation occur

germinal center

what antibodies are produced when IL4 is released from th2 cells to the b cells

IgG4 and IgE

What does IgE cause

mast cell degranulation

what does IL5 do

recruits eosinophils to activate to kill helminths

what is the difference between protective immunity and immunological memory

protective immunity is due to recent infections that have induced antibodies, immunological memory is due to a memory response from a previous infection from a while ago

Which is better the primary or secondary immune response

the secondary due to the affinty of the antibodies and and the freguency of the antigen specific b cells

Please allow access to your computer’s microphone to use Voice Recording.

Having trouble? Click here for help.

We can’t access your microphone!

Click the icon above to update your browser permissions above and try again

Example:

Reload the page to try again!

Reload

Press Cmd-0 to reset your zoom

Press Ctrl-0 to reset your zoom

It looks like your browser might be zoomed in or out. Your browser needs to be zoomed to a normal size to record audio.

Please upgrade Flash or install Chrome
to use Voice Recording.

For more help, see our troubleshooting page.

Your microphone is muted

For help fixing this issue, see this FAQ.

Star this term

You can study starred terms together

NEW! Voice Recording

Create Set