We meet again in cyberspace. Thanks for the suggestion!

Hi Clive,

You need to check your system for MHC alleles compatible with presenting these specific Ova peptides before starting.

If compatible:

Overexpressed cytosolic protein would yield presentation of MHC-I bound SIINFEKL.

For MHC-II presentation you may want your OVA to be phagocytozed, this would lead to presentation of peptides on both class I and II MHC.

I don’t know about peptide expressed in the cytosol and if it can pass the TAP and bind to naïve MHC but as for MHC-I it is quite possible.

I am not so optimistic about class II presentation, but there is some work published showing the presentation of inner peptides on MHC-II of APCs

If you want strong peptide presentation on both MHCs, check out the attached work on chimeric B2M-peptides, and the also have done chimeric peptides bound to MHC-II (If I recall correctly) Beta chain:

Margalit, A., Migalovich Sheikhet, H., Carmi, Y., Berko, D., Tzehoval, E., Eisenbach, L. & Gross, G. (2006). Induction of anti-tumor immunity by CTL epitopes genetically linked to membrane- anchored b2 microglobulin. J. Immunol. 176, 217-224

Good luck.

Ehud. Thanks for the info. I am going to use the virus in vivo (mice). I don't want to force any particular type of presentation, but rather observe what happens naturally. My understanding is that, as would occur during most virus infections, there should be three types of antigen presentation; 1.) MHC-I presentation of cytosolic-derived OVA, 2.) cross presentation of OVA in some cells eg CD103+ DC, and 3.) exclusive MHC-II presentation by phagoyctes that have consumed infected cellular debris. My main question was concerning whether I can express those peptides alone, or if it is best to engineer a virus that makes the whole OVA protein. Many thanks!!

Hi Clive,

You would need some kind of detection system for any OVA peptide presented such as T cell clone with TCR directed at OVA peptides (such as B3Z cellls for SIINFEKL) or antibodies for MHC-OVApetide combination.

If you direct your detection to the above peptides notice my first remark about compatibility since SIINFEKL is presented on H-2-Kb of C57BL6 mice while ISQAVHAAHAEINEAGR as far( as I know) is presented on H-2-IAd from Balb/c

Regards,