Exam 2 - Combined Set

Immunology exam 2: diagnostic immunology - chapter 11

what is diagnostic serology used to test for

antibodies and/or antigens in a patient

What are the 5 different tests for diagnostic serology

serial dilution

agglutination reactions

flow cytometry

elisa

western blot

what test involves a series of dilutions of a patient sample to test for a variety of antibodies or antigens

serial dilution

what is measured by serial dilution

antibody titer (blood test for antibodies)

what kind of information does a serial dilution provide

exposure to antigen

strength of immune response

vaccine memory

which diagnostic serology test uses antibodies to clump antigens

agglutination reactions

what are agglutination reactions used to determine

ABO blood type

clump = positive

which test uses fluorescent labeled antibody to distinguish cells from one another using lasers, scatter, and optics

flow cytometry

what information does flow cytometry provide

CBC

What is first added to the well of a direct ELISA test? what is added to the indirect?

antibody

antigen

what is added to both direct and indirect ELISA tests to determine if the patient has the antibody or antigen

enzyme-linked antibody

in both direct and indirect ELISA tests, a substrate is added at the end, what does it mean if it changes color

positive test to detect antigen (direct) or antibody (indirect)

what is the main difference between direct ELISA and indirect ELISA

d: look for antigen, forms antibody sandwich

i: look for antibody

what are the two main things used to run a Western Blot test

gel electrophoresis

immunoblotting

what does gel electrophoresis separate

proteins, DNA, RNA according to size, shape, and change

what is immunoblotting

antibodies are used to detect specific antigens in patient serum

what type of information does a western blot test give?

identification of a protein and molecular weight

what tests are required to determine if one has HIV? which one or ones have to be positive? what is each test looking for?

indirect ELISA (antibodies) and Western Blot (antigens)

both

during the initial, acute infection of HIV, what happens to the virus? will you see more antigen or antibody at this point?

spikes, antigen

during the chronic stage of HIV infection, what happens to the viral load? will you see more antigen or antibodies?

drops drastically, antibodies

Which of the following tests is used to measure the concentration of antibodies in a patient sample?

a. western blot

b. antibody titer

c. serial dilution

d. agglutination reaction

b

what two jobs do helper t cells have

1. remain in blood and lymph to help B and CTLs

2. leave blood and enter battle sites

how do helper t cells "help" b cells and CTLs

they omit cytokines

what is the importance of cytokines

they drive the immune response

give the address for anatomical location and pathogen identity

what cells provide helper t cells with "education" to tell them what type of invader and the location of the invader

dendritic

how do dendritic cells identify a pathogen in order to inform the helper t cells

TLR on dendritic cell recognizes PAMP on invader

how do dendritic cells provide the helper t cells with the pathogen's regional identity

they recognize the cytokines being omitted

what two factors influence which fate a helper t cell will fall into

1. cytokines released by APDC

2. strength of MHC II-peptide interaction

what defense are TH1 cells used for

viral or bacterial attack inside cells (intracellular pathogen)

what are the effector cytokines of a TH1 (the cytokines omitted by Th1)

TNF, IFN-gamma, IL-2

what cytokine does and APDC release at the time of activation in order for a TH1 bias to occur

IL-12

what is the role of TNF

activate macrophages and natural killer cells

what is role of IFN-gamma

activate macrophages and keep them active

what antibodies do IFN-gamma cytokines tell B cells to make

IgG

what does IL-2 do

proliferation of CTLs, NK cells, and more Th1

recharge NK cells

what defense are Th2 used for

parasitic/helminths attack or food contaminated with pathogenic bacteria (GI system)

what cytokine does APDC omit to produce a Th2 bias

none, IL-4 comes from the GI system and has this role

what are the effector cytokines for a Th2 bias (the ones omitted by the Th2 celll)

IL-4, IL-5, IL-13

what is role of IL-4

growth factor to proliferate T cells and B cells making IgE

IL-5 acts on B cells to tell them to produce what antibody? where?

IgA, peyers patches

what does IL-13 stimulate

mucus in intestine

do Th11 or Th2 cells receive a stronger stimulus before undergoing differentiation

th1

is IgA anti- or pro-inflammatory

anti

low affinity IgA antibodies are important to confine what to the intestinal lumen

commensal bacteria

in the case of a bacteria replicating in a macrophage, such as Mycobacterium Leprae, would you want a th1 bias or th2 bias? why?

th1

keeps macrophage activated from IFN-gamma so they can present antigen

What defense are Th17 cells used for

fungal attack and bacteria in mucosal barriers (extracellular)

what cytokines are released by APDC to produce a Th17 bias

TGF-beta, IL-6, IL-23

what are the effector cytokines of a th17 cell

IL-17

IL-21

IL-23

what cells does IL-17 recruit in large numbers

neutrophils

what does IL-21 promote growth of

more th17 cells

what are the non-committed t cells that change based on the cytokine environment

Th0

what are Tfh helper t cells

follicular helper t

what pathogens do Tfh defend against? what is the immune reaction of these cells?

extracellular pathogens

antibody production

what do Tfh cells require for activation

1. APDC activate T cell (B7/CD28)

2. Activated B cell has ICOS-L which binds with ICOS on the activated T cell causing the T cell to differentiate into a Tfh

where do Tfh cells travel to in a lymph node, what occurs here?

germinal center, activates naive b cells to allow class switching and somatic hypermutation

what cytokine do follicular helper t cells release

IL-21

what are the target cells of each bias respectively

th1

th2

th17

tfh

macrophage

eosinophil

neutrophil

b cells

Th9 cell produces what cytokine? what is it used to defend against?

IL-9

worms

Th22 cell produces what cytokine? what is it used to defend against?

IL-22

skin

t/f

cytokines have a very limited range and only have a local impact

true

what is cross regulation

helper t cells omit cytokines which inhibit other biases

Th1 makes IFN gamma which inhibits production of what bias

th2

iTreg/pTreg makes IL-10 which inhibits production of what bias

th1

what do superantigens (sag) do

- attack to MHC II and TCR to bypass need for TCR to recognize an antigen

- forces t cell into activation

- could be against self or foreign

- increase cytokine release

what is an example of an exogenous superantigen exotoxin that is caused by our own immune response against ourselves

toxic shock syndrome toxin

what does a naive CTL need for activation

activated dendritic cell

when an activated dendritic cell and Th cell bind, they emit cytokines which attract what cells

CTLs

once the CTL is activated, it leaves the lymph organ and enters the tissue to be ____ by a macrophage. The CTL can then scan any call it finds

reactivated

how do CTLs kill

- deliver package with perforin and granzyme B

- Fas Ligand on CTL bind to Fas Protein on target = apoptosis

what is known as the death receptor and is found on target cells

fas protein

what are the primary lymphoid organs

bone marrow

thymus

what cells originate in the bone marrow?

b and t

where do t cells develop

thymus

what are the secondary lymphoid organs

lymph nodes

spleen

mucosal-associated tissue (MALT)

where are B and T cells activated

secondary lymphoid organs

what area of secondary lymphoid organs are T cells located in both the lymph node and spleen? where are B cells located?

lymph node: paracortex

spleen: PALS

b cells: lymphoid follicle

t/f

lymphoid follicles are within every secondary lymphoid organ

true

what cells occupy the primary lymphoid follicles?

follicular dendritic cells

naive B ells or memory b cells

when does a primary lymphoid follicle become a secondary lymphoid follicle (germinal center)

when B cells are activated

after there is antigen stimulation in the secondary lymphoid follicle, replication and differentiation of B cells takes place. What is this known as?

clonal expansion

a secondary lymphoid follicle is made of a light and dark zone, what cells make up each zone?

light: B cell, FDC

dark: proliferated B cells

what three processes of B cells occur in the Germinal center (secondary lymphoid follicle) following activation and proliferation

somatic hypermutation (dark zone), travel to light zone to test affinity

career decision (plasma or memory cell)

class switching (dark zone)

APDCs are WBCs made in ___ ___ and migrate to tissue to become ____. They then travel to ___ lymphoid organs and present antigen to ___ cells

bone marrow, activated, secondary, T

follicular dendritic cells (FDC) are regular cells that are in ____ lymphoid organs and display antigen to ___ cells

secondary, B

what is the normal function of FDCs

catch and display opsonized antigen to B cell

do FDCs kill or opsonize antigens

no, they just hold onto it

what receptors do FDCs have in order to bind to an opsonized antigen

complement and antibody

for B cell activation, what must be holding onto the antigen in order for a B cell to recognize it?

follicular dendritic cell

when the FDC holding an opsonized antigen comes in contact with a B cell, the B cell and antigen bind, B cell MHC II presents antigen to Follicular helper t cell, CD40/CD40L co-stimulation occurs and the B cell is ____

activated

MALT in the peyers patches and appendix is known as

GALT - gut associated lymphoid tissue

what components do Peyer's patches (GALT) have for lymphocytes to enter/exit?

HEV, efferent lymph vessels

what components do Peyer's Patches (GALT) have for antigen to enter?

m cells/microfold cells

what do M cells of the peyers patches do

enclose selective intestinal antigens in vesicles to release into surrounding tissue

in peyer's patches, helper t cells with ___ bias are made to tell B cells to make which antibody

Th2, IgA

MALT in the tonsils and adenoids are known as

NALT - nasal associated lymphoid tissue

MALT in the bronchi is known as

BALT - bronchus associated lymphoid tissue

describe the layers of a lymph node from outer to inner

capsule, subcapsular sinus/marginal sinus, cortex/B cell zone, paracortex, medulla, afferent and efferent lymph vessels

where does lymph first enter the node? what cells line this area

marginal sinus/subcapsular sinus

macrophages

what cells are found in the cortex of a lymph node

B cells and FDC

what cells are in the paracortex of lymph node

T cells