Hello,

My first point is that many treatments in mice are done using non-mouse antibodies. The reason for this is that it takes time for the mice to develop an anti-Ig immunity, which would block your antibody. My advice would be that unless you aim at repeated injections over extended time, you might still use rabbit antibody. Also, consider that rabbit and more so rat/hamster are closely related to mouse and less likely to generate a response than rabbit antibodies in human.

A second point is that given strong adjuvant, you can overcome tolerance in mouse and generate antibodies against self-antigen. If you plan to use a peptide for immunization, you can also use a foreign carrier protein which will generate immunogenic peptides to better stimulate T cells. You can then select B cell clones specific for your antigen and go for hybridomas.

In general, consider that it might take a lot of time until you get a clone with good specificity and affinity, and which has the effect you want (agonist antagonist, cell depleting etc..) this has to be validated: different clones for the same protein can have very different effects! Isotype is also important has it defines interaction with Fc receptors!

Good luck!

Rat antibodies are quite often used for experiments in mice. But if you still need a mouse antibody, I agree with the previous answer. A potent adjuvant and a good carrier can produce nice responses against self-antigens.

Thanks Fluorian and Gertrudis, this is quite helpful! I will choose rat for Ab making.

btw, what is the best way to immunize the animal to make a blocking antibody against a cell surface ligand? Should I use the whole ligand protein or just a small peptide binding to a foreign carrier?

If using whole ligand protein, should I still add foreign peptide? If I use small peptide, will the antibody against that peptide not have blocking effect? 

I f you already know a small peptide that actually reproduces the relevant binding site, this could be used. But bear in mind that sometimes small molecules, even when binding to a receptor do not mimic all the features of the natural ligand, so are not able to produce cross-reactive responses. you will have to titrate the antisera against both the immunizing peptide and the original ligand you want to block.

 If you immunize with a large protein, just the adjuvant is often required, but if the immunogenicity results to be low in mice or in a related species (rat, for instance), a carrier can help.

Thanks Gertrudis! The small peptide is predicted by some online software based on immunogenicity and hydrophilicity, which may not suit for antibody work in vivo. Also, I do not know the binding site for this ligand, so a large protein with adjuvant would be the best choice. Thanks a lot!