i know that production of mAbs in display system is easier and faster than transgenic mice but immunogenicity may be occur in display systems and ......
please help
First both methods are protected by multiple patents.
These are methods that require obvious technical skills.
Phage display, the oldest and most widely used, allows to clone human antibodies priori true. This relatively rapid technique, but there are at least two limitations in the technology: cloning is done on parts of VH and VL antibody independently. Recombination between VH and VL is random and selection of the isotype is imposed. Two actions that have a real impact on the future of the antibody that is well built.
The selection is also limiting because it targets mainly linear epitopes. By cons it does not seem to have the limitation in terms of recombination.
This is quite the opposite to the transgenic mouse, wherein a humanized antibody is obtained includes, where the targeted epitope may be conformational, and where there is obtained an antibody which does not require genetic manipulation.
The limit lies mainly in the number of genetic recombination of VDJ, which is 100 times smaller.
A final limitation concerns the presentation of the antigen that is very different between human and mouse.
However there is a third strategy that can combine the performance of two previous methods.
The technique oftransformation ofcirculating Bcellswith EBV: atvery loworiginallythis strategyhas completely changed with the stimulation and activation via CD40 system.Several variants have been made by some seven laboratories worldwide: cell sorting, activation CpG, Isaac selection,HuBBB...But generally all these developments going in the same direction: unlimited performance to give perfect antibody without any modifications or recognition restriction.
To the above I would also add that using transgenic mice and immunising in a more natural setting you are more likely to obtain high affinity clones due to affinity maturation occurring in vivo. Using phage display you can generally obtain antibody clones in the range of the nM affinity.
thanks Dr Pin
and this sentence "selection of the isotype is imposed" what do you mean?
thanks mathieu..
and generally the range of affinity for transgenic mice derived mAb?
in the phage display technique, genes of immunoglobulins were amplified by PCR; For this we only target the VH and VL. DJ and Fc are then added to VH and VL after selection of clones of interest. This is done so imposed because we choose isotype (Fc) that will add.
In transgenic mice, it is a bit the same, as it requires the human gene encoding the Fc (IgG1 or IgA, for example).
Apart from the pros and cons discussed above, we have to realize that a fit-for-purpose antibody (classical mab or phage display) will have to be screened in the application it is required for, an approach that is not common practice yet. The reason is a practical one: You first try the reagents that are already out there and hope one will work. Both the classical approach and the phage display screens remain expensive, and it only makes sense going through the trouble once the required assay has been fully validated with a polyclonal antibody, and long term use requires replacement with a mirroring "immortal" antibody (for example in diagnostics). A cost-effective alternative might be the use of peptide-generated antibodies from large animals, so the batch-to-batch variations (main argument to switch from poly- to monoclonal) is kept to a minimum.
if you dont have phage display up-and-running i wouldnt advise you to go down this route, there are a lot of caveats and artefacts you can encounter in phage display. If you have access to transgenic mice, this will in most cases give you better results, especially if you get good titers against your antigen.
BTW key patents for phage display have / are about to expire, the same is true for the transgenic mouse technology. But there are a lot of follow up patents so if IP is imporant watch ourt.
In terms of timeline, which method (phage or transgenic mice) is faster?
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