Antibodies

Question 1

Graves Disease

Answer 1

Antibodies to TSH, can cross placental barrier

Question 2

Allergies

Answer 2

Fc of IgE binds to mast cells and induces histamine/contents release

Question 3

Regulation of Transplant Rejection

Answer 3

Can use Abs to downregulate T cell response responsible for transplant rejection

Question 4

Ab Cancer Treatment

Answer 4

Can target Abs w/ toxin to specific cell markers, like HER2

Question 5

3 Serum Electrophoresis Results for Igs

Answer 5

Faint Ig bands - fine
Strong for all Ig bands - infection
Strong for 1 Ig band - tumor of plasma cells making 1 Ig

Question 6

Combining Sites (2)

Answer 6

End terminus of LC and HC where Ag binds; requires both HC and LC to come together/bind Ag

Question 7

2 Kinds of LCs (ratios and important point)

Answer 7

About 60:40 Kappa:Lambda

So if you saw only lambdas, know there’s a tumor producing lambda LCs

Question 8

Hypervariable Regions (2)

Answer 8

3 spots on V regions on each HC and LC that make up combining sites, accounting for Ag-binding diversity

Question 9

Variability Calculation Def

Answer 9

of AAs found at a given position/frequency of the most common AAs at that position

Question 10

Variability in Framework Regions

Answer 10

Still some so that superantigens can’t bind to EVERYTHING

Question 11

Average Size of Ag Combining Site (2)

Answer 11

6 saccharides or 4 AAs

Question 12

Ig Isotypes

Answer 12

Different region genes encode for different HC classes (effector function)

Question 13

IgM Notable Structure

Answer 13

Pentamer

Question 14

IgA Notable Structure

Answer 14

Dimer

Question 15

IgG Notable Feature (2)

Answer 15

Passes through placenta, so can cause problem’s w/ Grave’s disease but also transfer maternal immunity (so it’s the only one that doesn’t constantly increase through early life - starts off high, then drops and then steadily increases)

Question 16

IgA Production Areas

Answer 16

Lungs/intestines

Question 17

IgM Notable Feature

Answer 17

1st Ab made

Question 18

Ab Deficiency Time of Detection

Answer 18

Around 6 months

Question 19

Main 2 Points About Abs

Answer 19

Need HC and LC to make combining site for Ag binding

Effector function is in the HC

Question 20

Regions of Recombination for Igs

Answer 20

HCs have VDJ and LCs have VJ

Question 21

Ways to Separate Recomb for Different Chains (4)

Answer 21

All HC genes on 1 chrom, all kappa LC on a different chrome, and lambda LC on different chrom, and TCR chains (except alpha/delta) on different chroms

Question 22

HC Recombination

Answer 22

D and J recomb’d and moved adjacent to each other, then to V, then C

Question 23

LC Recombination

Answer 23

V and J recomb’d and moved adjacent toe ach other, then C

Question 24

Rag1/Rag2

Answer 24

Recombination activation endonucleases only in B and T cell precursors

Question 25

Somatic Hypermutation (3)

Answer 25

Continued mutations in hypervariable regions of B cells catalyzed by AID and selected for by Ag for stronger Ag binding

Question 26

Switch Recombination

Answer 26

Once Ig expressed and Ag selected for correct binding in B cells, AID catalyzes to switch the HCs for different effector functions

Question 27

Activation-Induced Cytidine Deaminase

Answer 27

Enzyme in B cells reponsible for somatic hypermutation and switch recombination

Question 28

3 Trends of Switch Memory B Cells/Vaccine Response (& major point)

Answer 28

Percentages of switch memory cells increase in young but not elderly as much after vaccination
Percentage of switched memory B cells correlates w/ vaccine response
AID positively correlated w/ vaccine response
*Class switch important because your higher affinity Ab can have better effector function. so vaccine response increases with class switching

Question 29

How to Target Ig for Secretion or Membrane Bound

Answer 29

Differential mRNA splicing

Question 30

How to Get IgD and IgM on Cell Surface at Same Time

Answer 30

Keep same VDJ (already specified towards Ag) and just splice mRNA differently to have Cmu or Cdelta

Question 31

Antibody Affinity

Answer 31

Can calculate like any other rxns, reversible and K = [AbAg]/([Ag][Ab])

Question 32

Avidity (3 long)

Answer 32

Multivalency, multiple binding sites on both Ag and Ab mean actually binding doesn’t follow thermodynamic equation so avidity is how well it actually binds
Greatly increases ability to bind uninterrupted over long period of time bc if one binding site deattaches, other one is still on
Even if IgM has lower affinity than another Ig, may actually bind better bc has higher avidity from 10 binding sites

Question 33

Primary and Secondary Interactions of Ab and Ag

Answer 33

Primary is fast rxn just controlled by diffusion

Secondary is slow reaction that results in cross linking and precipitation

Question 34

Immunoprecipitation and Ab/Ag Concentrations

Answer 34

Too much Ab: Epitopes bound but still small complex, nothing else for Abs to bind to
Too much Ag: All Abs bound, but to just 2 epitopes each. Small complex
Equal: Formation of a large precipitate lattice

Question 35

7 Clinical Uses for Abs (& examples)

Answer 35

Detection of Viral Antigens (HIV testing)
Detection of Cancer Antigens (PSA, prostate)
Typing of Tissues for Transplantation (see relatedness and likelihood of rejection)
Typing of Blood for Transfusion
Pregnancy Testing
Anti-Cell Therapy - Rituximab stops B lymphocyte tumors
Detection of Autoantibodies (like SLE on dsDNA)

Question 36

Flow Cytometry (2)

Answer 36

Tag target of interest w/ fluorescent antibodies, it counts cells in blood individually and gives reading on #
Can be used for lambda/kappa LC comparisons or T cell counts for HIV

Question 37

Enzyme Linked Immunosorbent Assay (ELISA) (reason and process)

Answer 37

To see if person has Abs to something
Put target of interest on plate, add pt Ab, add ezyme-linked secondary Ab to tag those Abs to see if it bound and will turn medium from clear to colored

Question 38

Direct Coombs Test (reason and process)

Answer 38

To test autoimmunity to RBCs
Take blood sample and wash RBCs, then add secondary antibody and crosslinking will cause
“pallet” of RBCs

Question 39

Agglutination

Answer 39

Measuring Ab to RBC in hemolytic anemia

Question 40

Indirect Coombs Test (reason and process)

Answer 40

To test blood recipient match

Take recipient serum, add to donor blood, and do direct coombs test to see if Abs bind