Immunogenicity
16 important questions on Immunogenicity
What are the 2 major mechanisms of immunogenicity?
2) breakdown of immune tolerance
- the formation of agregates. Here b-cells are stimulated to produce antibodies towards endogenous compounds.
What is the reaction to neo-antigens?
2) The APC will take it up and will show a fragment (peptide) on its MHC.
3) This signal is recognized by a T-helper cell.
4) The T-helper cell will become activated
5) The T-helper cell will activate a B-cell
6) B-cells start to produce antibodies
7) Memory T-cells and memory B-cells are formed.
How does the breakdown of immune-tolerance occur?
They are capable of crosslinking the B-cell receptor when:
- their molecular mass exceeds 100 kDa
- the valency of epitopes (the amount of epitopes that can be recognized by the B-cell) must be more than 10
- the spacing between epitopes is around 5-10 nm.
- Higher grades + faster learning
- Never study anything twice
- 100% sure, 100% understanding
For my 1st exam I got a C. Then, I started looking for ways to learn better and I came across Study Smart. Since then I have scored a A+, A, A- and another A. I highly recommend it to everyone who wants to hear it. I am so happy with it!!
I was struggling to finish all my first-year subjects for 3 years. Then I discovered Study Smart, which helped me to finish all of them within 3 months.
Because of StudySmart, things are going well in many ways. Before, I always had study stress and no time for anything. Now I feel calm and confident (because of the program). I used to score a B, now I usually score an A or A+.
Hey Chris, I really want to thank you very much for developing the platform, I usually got around C for my exams, now I scored an A+, an A and a A- !!
Since using Study Smart, my average has increased significantly. I even completed a statistics course with a A+ while I'm bad at statistics. I took on extra courses this year, because of Study Smart. Thanks so much!
Ever since I started studying with StudySmart I passed all my exams !!! No more re-sits!! At first, I was happy with a pass and now I only get good grades. Many thanks!
I aced all the courses I studied with Study Smart. For law, I first scored a D, and now an A! I’m 100% sure that I’ll pass all the courses I study with Study Smart.
I always thought I studied well. My grades were fine. I could never have imagined that applying these study skills would have such a huge and direct impact on my grades, my speed and the pleasure I have in learning.
For the first time, I finally feel totally confident about the way I learn. I have the perfect overview and make great progress in terms of speed and the grades I get. Thanks, Chris!
I immediately started to enjoy learning again, and my grades soared. All of a sudden, everything went better. I highly recommend Study Smart to all students..
Being able to create my materials online made the process of studying so much smoother and quicker. I no longer have to spend a huge amount of my time on creating my summaries.
At first, my notes were a mess. Now I use Study Smart to take my notes in a perfectly structured way. It helps me to save a lot of time and do other things I enjoy.
Students that study with Study Smart get better grades. The system applies all the learning methods in such a way that both well-performing students and students who struggle perform much better.
Hi Chris, I would like to thank you very much. Last year I scored C on a course, and this year I got an A+ thanks to your method! Thank you very much!
The largest effect is that my child is more enthusiastic about school! Every parent wants their children to be happy at school, Study Smart made it happen.
In high school, I failed several exams, and that has really changed now. I actually needed this tool very much back then. Since I started studying with StudySmart, I haven't had any D's. My average score is now an A and those are results I would have never had in the past
With my old method, I passed only 3 out of 8 courses. Since I started taking my notes digitally in Study Smart, I have passed all my courses on the first try. For me, StudySmart takes away the stress of wondering if I will pass or not.
Thanks to StudySmart, I passed all my exams, and with better grades than before! On top of that, I have mastered a very good study method now, which I am confident will help me earn my degree.
Which factors can contribute to the immunogenicity?
- glycosylation
- contaminants and impurities
- formulation
- application route
- dose
- length of the treatment
- assay technology
- patient features
- unknown factors.
In what way the application route can determine immunogenicity induction?
- inhalation: in the lung epithelium are a lot of immune cells.
What are the consequences of immunogenicity?
- antibodies bind to the administered compound. This will result into an altered PK (a shorter half-life) and if binding to the active site occurs as well it will lead to an inactivation of the compound.
For the immune reaction:
- There will be an immunological response; inflammation
- allergic response
- auto-immunity can be developed.
Why do we use large molecules if they can have such severe side effects?
- For certain diseases small molecules cannot help.
- The higher the need for a drug, the more risk will be acceptable.
- it is the biological approach; intervention in existing pathways which uses existing molecules. The replacement of defective or non-present proteins/peptides.
What is the classical example of EPO?
In patients with a destroyed EPO production a chronic anemia is the result. This can be overcome by giving EPO as a medicine.
However, the story goes that once there was a small difference in composition of EPO (formulation difference) due to wrong packaging. Therefore a wrong injection procedure was carried out. This induced an immunogenetic reaction.
It led to autoimmunity of the patients towards EPO and there was nothing there could be done for them. It was lethal.
What are the assay formats that can be used to determine immunogenicity?
- MSD (mesoscale discovery)
- immunoprecipitation
- surface plasmon resonance
What is the direct sandwich ELISA?
- You add the ADA (positive control; you use polyclonal antibodies)
- You add the detection antibody which is labeled with an enzyme e.g.
This one is species specific because the immune response will be polyclonal.
What is the bridging ELISA?
1) The capture antibody is the drug.
2) Then you add your sample (ADA)
3) Then again you add your drug but this time labelled.
The difference is that here the FAB part is used and not the FC part of the antibody.
What is the electrochemiluminescense assay (MSD)?
There is an electrode inside the plate. The more immunological trees the more light will be detected because the detection drug (antibody).
You first coat your plate with a biotin-labeled drug.
then you add the ADA
then you add the sulfo tag labeled drug.
What is the principle of the radioimmune precipitation assay?
2) add radioactive labeled drug.
3) ad protein A that can bind to the antibody. In this way the whole complex will be insoluble and the can centrifuge it and measure the radioactivity.
What is Surface plasmon resonance? (Biacore)
- immobilization of the drug
- addition of sample
- confirmation that the binding is an antibody
- inhibition of the binding with the drug.
This happens under a flow.
The more is added the higher the angle of the light that is reflected. This will be visible in a plot as a peak.
The height of the curve is an indication for the amount of antibody present.
An SPR immunoassay is labelfree unlike ELISA.
However this technique is hardly used anymore.
What is the strategy you use for immunogenicity?
- confirmation: Does the sample have a specific positive signal?
- titration: How much specific is that positive signal?
What are other parameters that you need to take into account regarding to sample storage?
- freeze/thaw
- short term/ long term
- The matrix effect (patient matrix)
1) you might have negative individuals
2) You can overcome this by spiking at a low and a high QC level for all samples.
3) this can be screened and confirmed.
The question on the page originate from the summary of the following study material:
- A unique study and practice tool
- Never study anything twice again
- Get the grades you hope for
- 100% sure, 100% understanding
