Therapeutic Proteins Flashcards
What does the addition of a polyethylene gylcol moietie do for the half life of a therapeutic protein
it increases half-life and masks the drug from the immune system, resultin gin decreased immunogenicity and antigenicity
What sort of tag can you add to increase the cell kill induced by antineoplastic antibodies and to allow visualization of the extent of malignancy?
radiolabelled tags
Why are peptibodies special?
they are the newest modification - they will interact with a receptor, but will not activate the immune system
What are some issues with using native peptides?
- lack of receptor specificity
- lack of oral bioavailability
- generation of neutralizing antibodies
- short during of action due to - degradation and renal clearance
What are the five advantaes of antibody therapy?
- specificity
- number of potential targets - so many targets = so many drugs options
- long term benefit to short term therapy
- diagnostic reagents - can be used tot est to see if cells will respond before administering the drug
- definition of disease process - so using radiolavels to ID cancer metastases
What are the 4 characteristics of an ideal therapeutic antibody?
- high degree of affinity and specificity
- adequate recruitment of effector functions
- long half life
- reduced SYSTEMIC immunogenicity
How are antibody antineoplastics made?
They are antibodies grown in cell culture following fusion of mouse plsnic cells with tumor cells grown in cultrue
What is the difference between a humanized and a chimeric antibody
the chimeric has all of the Fv from a mouse and only the Fc from a human.
The humanized is mostly human - only the complementarity-determining region is from a mouse
If the goal is to label a tumor cell and recruit the immune system to kill it, which would be better - a mouse or a human antibody?
mouse - because it will be more likely to recruit a more severe immune response
How are antibodies administered?
always IV - they’re proteins, so they’ll be broken down in the gut
For the antibodies, is the half life generally long or short?
extremely long
What are the two types of infusion reactions you can get with antibodies?
Type 1 and Type 3 hypersensitivity reactions
What are the timing considerations for whether someone has a type 1 or a type 3 HS?
type 1 occurs within seconds to minutes, type 3 takes a lot longer - lik 7-10 days.
Of the two HS reactions, which gets better and which gets worse with repeat aadministration?
Type 1 gets worse with repeat administration, Type 3 tends to improve
What is the serum sickness (type 3 HS) that can occur with antibody use, especially with mouse or chimeric antibody use?
Human anti-mouse antibody (HAMA) - you get a severe reaction that results in kidney damage
What is cytokine release syndrome and why does it occur?
One of the things antibody treatments do it increase release of cytokines. If this goes overboard, you get this syndrome - you basically feel like crap.
Why do you always do a skin mantoux test before putting someone on an antibody treatment?
Some antibodies decrease immune function (and are often given with other immunosuppressive agents), so reactivation of TB is a possibility