Introduction to Immunology

Which ABY is produced in the primary immune response?

IgM

What is the CD marker that has receptor sheep RBCs (rosettes are formed)?

CD2

Which CD marker transmits signals to activate T cells?

CD3

Which CD marker is a T helper cell co-receptor that binds MHC class 2 molecules?

CD4

Which CD marker is a T cytotoxic cell co-receptor that binds MHC class 1 molecules?

CD8

Which CD marker signals to regulate B cell development and maturation?

CD19

Which CD marker is a NK cell receptor for the Fc portion of IgG?

CD16

Which CD marker is a NK cell marker that helps support antibody production?

CD56

B cell maturation line

Pro B Pre B Immature B Mature B Plasma cell Memory B cell

In T cell maturation, is CD4 or CD8 present in the double negative stage?

No, neither are present

Which two CD markers are present in the double positive stage in T cell maturation?

CD4 & CD8

What is the function of T helper cells?

Effector cells produce cytokines

What is the function of B cells & plasma cells?

Antibody production

What is the function of cytotoxic T cell?

Effector cells kill diseased cells

What is the function of natural killer cells?

Kills diseased cells without prior exposure

What are the two methods of killing for NK cells?

ABY independent cytotoxicity: occurs with decreased MHC Class 1 expression ABY dependent cytotoxicity: recognition of Fc portion of the ABY

T cells interact with antigens with what?

TCR

B cells interact with antigens with what?

BCR

What are the antigen presenting cells?

B cells, macrophages, monocytes, dendritic cells

What are glycoproteins made by B cells?

Immunoglobulins

Where are B cells located?

Lymph nodes: cortex Spleen: PALS region

What is the phagocyte binding region of IgG?

Fc

Where does antigen independent lymphopoieses occur?

Bone marrow

Which immunoglobulins have J chains?

IgA

What portion of immunoglobulins is called Bence jones proteins?

Light chain

Which antibody heavy chain classes have subtypes?

IgA & IgG

What immunoglobulin incorporates a secretory component to facilitate transport to mucosal surfaces?

IgA

What is the most common vaccine type that contains the treated complete antigen that is no longer infective but can help generate antibody response?

Attenuated

What vaccine type has a partial component, protein or polysaccharides, from antigens that helps generate antibody response to that particular component?

Acellular/subunit

What vaccine type is genetically made using recombinant DNA technology; it uses viral proteins cultured inside yeast?

Synthetic

What vaccine type is a microbial polysaccharide that is chemically coupled proteins facilitate response of T helper cells?`

Conjugate

Which maturation stage of B cells where recombination of genes that produce heavy chains takes place under the influence of stromal cell cytokines, and CD19 can be detected?

Pro-B

Which maturation stage of B cells where affinity maturation is tested and self-reacting cells are eliminated?

Immature B cell

Which T helper cell subset can enhance activities of the immune system such as antibody formation, allergic response, anti-parasite response and antigen presentation?

Th2

Only one kind of light chain is made; either kappa or lambda?

Allelic exclusion

What is the class, subclass and light chain type of a molecule?

Isotype

What are 2 subunits of IgA joined by J chain?

Dimer

What is it called when complement deposits on host cells causing them to be a target for destruction?

Innocent bystander lysis

Activation unit

C4, C2, C3

Membrane attack unit

C5b, C6, C7, C8, C9

What is the light and heavy chain determinants that make an antibody unique?

Idiotype

What is genetic variations in the constant region of antibody between individuals within the same species?

Allotype

What is 5 subunits of IgM joined by J chain?

IgM

Recognition unit

C1

What is one subunit with 2 light chains and 2 heavy chains?

Monomer

What are the names of the light chains?

Kappa & Lambda

Which antibody can cross the placenta?

IgG

Which antibody is great at activating complement & agglutination?

IgM

Which antibody is a great opsonin?

IgG

Which antibody is involved in allergic reactions?

IgE

Which antibody is associated with mucosal membranes?

IgA

Which antibody is important in parasitic infections?

IgE

How is the large number of antibody specificities derived?

Mixing of different genes on chromosomes 14, 2, & 22

What type of antibody will be most likely used in a clinical lab?

Monoclonal

Why do we use monoclonal antibodies in the lab?

Results are permanent, reproducibility, & defined specificity

What cell occurs in response to intracellular pathogens?

Th1

What cell occurs in response to extracellular pathogens, like helminths and allergens?

Th2

What is the role of MHC molecules (antigens)?

Bind to peptides within the cell & transport to cell surface

What does the TCR recognize?

Antigens

What links TCR to MHC class II molecules and results in release of massive amounts of cytokines? (Toxic Shock Syndrome)

Superantigen

Primary response

Slow, low levels & IgM produced

Secondary response

Rapid, high levels & IgG produced

How many subtypes of IgG are there?

4

How many subtypes of IgA are there?

2

What is the total approximate amount of IgG in serum?

75-80%

What is the total approximate amount of IgM in serum?

10%

Which antibodies have J chains?

IgM & IgA

What is the total approximate amount of IgD in serum?

<.001%

What is the total approximate amount of IgE in serum?

.0005%

What is the Fab portion on an immunoglobulin?

Antigen binding fragment

What are the three processes that B & T cell maturation consist of?

Proliferation, expression, selection

Where do B cells develop and mature?

Bone marrow

What kind of lymphopoiesis are B cells involved in?

Antigen-independent

Which CD marker is thought to be involved in B cell activation?

CD20

Which CD marker is found on activated T & B cells & is a receptor for interleukin-2?

CD25

Which CD marker is a receptor for complement breakdown component?

CD21

Which CD marker is a membrane glycoprotein present on all hematopoietic cells?

CD45R

Which class is found on all nucleated cells?

MHC class I

Which class interacts with Th cells and is present on all stages of B cells except plasma cells?

MHC class II

What is the initial force of attraction between an antibody Fab site and an epitope?

Affinity

What is the sum of all antibody-epitope pairs?

Avidity

What is the function of the Fc portion of the antibody?

Binding site for phagocytes and complement

What are the advantages for the acquired immune system when the T helper cell "helps" the B cell?

Class switching, affinity maturation of antibody & memory cells

Antibodies that interact with structurally similar antigens can cause false-positive reactions due to what?

Cross reactivity

What does the term agammaglobulinemia mean?

Deficiency of immunoglobulins

What is the source & what are the characteristics of polyclonal antibodies?

Derived from injecting animals; diverse antibodies from many B cell clones

What is the source & what are the characteristics of monoclonal antibodies?

Derived in laboratory setting; one type of antibody from one B cell clone

Which pathway is activated by antigen-antibody complexes?

Classical pathway

Which pathway is activated on microbial surfaces?

Alternative pathway

Which pathway is activated by microbial polysaccharides?

Lectin pathway

Which complement is a very strong opsonin?

C3b

Which complements are anaphylotoxins?

C4a (least effective), C3a (weaker), C5a (very strong)

Which complement is a major attractant and strong anaphylotoxin?

C5a

What does tickover mean?

Spontaneous hydrolysis

What four serum proteins are involved in the activation of the alternative pathway?

C3, factor D, factor B, & properdin

What is the function of properdin?

Stabilizes C3bBb

Where do the classical and alternative pathways intersect?

C5 convertase

What are lectins?

Proteins that bind to carbohydrates

What is the primary lectin involved in activation?

MBL

Where does the lectin pathway intersect the classical pathway?

C3 convertase

What blocks the initiation of classical and lectin pathways?

C1 inhibitor (C1INH)

What is a deficiency of C1INH?

Hereditary angioendema

What inactivates C3b & C4b with help from C4BP, CR1, DAF, & Factor H?

Factor I (inactivator)

What interacts with C5b67 in fluid phase to prevent bystander lysis?

S protein (vitronectin)

What is a deficiency of DAF?

Paroxysmal nocturnal hemoglobinuria

What protects cells from bystander lysis and dissociates C3 convertase?

DAF (CD55)

What blocks the insertion of C9 into the membrane?

MAC-INH (CD59)

What is the function of CR-1?

Mediates transport of immune complexes to liver/spleen

What is a receptor for Epstein-Barr virus?

CR-2

What prevents binding to Factor B and accelerates the decay of C3bBb?

Factor H

What is the function of CR2?

Found on B cells & dendritic cells; involved in B cell stimulation

What measures the total complement activity?

CH50 (Total hemolytic complement)

Which immunoglobulin is called a macroglobulin?

IgM

If a baby has an infection at birth (congenital infection), which antibody will be present?

IgM

Which is the largest antibody?

IgM

Which antibody reacts best in the cold?

IgM

Which ABY is best at binding to complement?

IgM

What are the relative concentrations of ABYs in serum?

IgG>IgM=IgA>IgD>IgE

Which ABY reacts best in warm temperatures?

IgG

What deficiency is responsible for anaphylactic reactions following blood transfusions?

IgA

What is a cryoglobulin?

Ig (IgM class) that precipitates at cold temperatures

What have variable portions in the light & heavy chains that give individual molecule antibodies specificity?

Idiotype antibodies