antibodies Flashcards
antibodies are
immune globulins (make your body stronger)
what should you consider in regards to affinity and Ab
Ab affinity for Ag
shape and structure of Ab
y shaped protein
-upper tips pf Y are rxn sites with certain Ag
5 types of Ab
IgG, IgD, IgA, IgF, IgM
which Ab is the main type and where is it found and whats its role
IgG
found in blood and extracellular fluid
controls infection
roles and parts of Ab (label Y)
variable region-react with Ag (two tips of Y)
Fc region- constant but mediates downstream effetc of rxn of Fab
what can divide IgG molecule
pepsin and papain
plasma clearence of IgG
T1/2 is 40 hours
(slow moving so it divides to break down and move to tumor sites)
size of IgG
relatively immobile (can travel to sites of tumor) and large
what major antibody class is found in normal human serum
IgG
what does digestion of antibody with pepsin enzyme result in
a smaller bivalent antibody fragement with a loss of lower end of Fab 2
what does digestion of antibody with papain enzyme result in
produces two smaller antibody fragments each having a single variable or antigenic recognition site (Fab)
T1/2 of papain digestion
1 hr
T1/2 of pepsin digestion
20 hr
5 steps of MoAb productiom
1- immunize mouse with an antigen (injecting antigen)
2- remove spleen when mouse begins to produce antibodies
3- fuse Ab producing cells with myeloma cell line (cell line that is not Ab producing)
4- new line reinjected into different mouses peritoneum
5- harvest ascites fluid from mouse to get MoAbs
what factors affect MoAb production
-purity of antigen
-mouse strain used
-age and sex of mouse
-tolerance of individual mouse
-use of adjuvant (maximisez animals immune response=incr prod of Ab)
what is a HAMA rxn
Human Anti Mouse Antibody
HAMA rxn inactivates mouse antibodies in severe allergic rxns bc the body overrecognizes it as a foreign particle
how do we make a HAMA rxn less likely to occur when in lab
humanize mouse MoAb by using chimeric
what is chimeric MoAb
regions of human myeloma protien joined to variable regions of mouse Ab
why do we inject MoAb slowly and how slow
over 5 min to decr HAMA rxn chance
symptoms of HAMA rxn
fever, rash, hypotension, nausea, death (rare)
HAMA rxn in depth
1-human immune systems sees mouse Ab as foreign so human makes Ab againts mouse Ab
2-2nd injection given of MoAb and human immune system activates and creates anti mouse (murine) Ab
3-HAMAs remove mouse Ab but this also breaks bond with radionuclide
HAMA rxns are ____in first injection and ______in second
created; react
what are radioactive labeled MoAbs used for
find specific antigens on tumor cell surface and demonstrate tumor location
-can image and treat with MoAbs
In-111 is best used for….
whole Abs
Tc-99m is best used for…
Ab fragments
what isotopes can be used
In-111, Tc-99m, I-131, I-123
how many cases of prostate cx each year, survival rate
180,400
-5 year surv rate-99% confined, 30% in unconfined
-2nd leading cause of death in men
-most noncutaneous type pf cx
what tests are used to dx prostate cx
-digital rectal exam (DRE)
-prostate specific antigen (PSA)
-gleason score (GS)
-trans-rectal US (can include bx)
prostae cx treatments
-brachytherapy=internal radioactive seeds
-cyroablation=freeze gland/remove tissue
-radiation therapy
-surgery=remove gland
-hormone therapy=remove testosterone/reduce via injection/pill
Prstate cx dx tests
bone scan, PET scan, MRI, CT, Prostascint
what does prostate gland do and location
chestnut structure about 4 cm across and 3 cm thick that surrounds beginning of urethra, inferior to bladder
-helps control urination and forms part of content of semen
what is prostasinct and how does it work
-IgG murine Moab also called Capromab pendetide
-0.5 mg conjugated with In-111 chloride
-increased PSA, directed agaisnt PSMA
-recognizes protein on both prostae and tumor cell
-off market
