Is this a therapeutic or prophylactic regimen? Do you implant the tumor, treat with the vaccine or do you vaccinate and then implant the tumor? I am assuming you think your VLP is functioning through neutrophils and would like to deplete them and see if the protection disappears. I do not think increasing the antibody dose would help; the dose you use is pretty standard. You could try starting the depletion treatment earlier and/or doing injections every day. This may help prevent circulating neutrophils from reaching the tumor but might not deplete infiltrated neutrophils if already present in the tumor. You can never achieve total depletion with antibodies.

You could try to set up your tumor model in neutrophil knockout mice and see if these are protected or not. Simplistically speaking, if your VLPs can prevent/cure tumor in neutrophil sufficient mice but cannot do this in neutrophil deficient mice, that says something. However, it is never that simple. Neutrophil knockout mice may come with their own problems.

Thanks, it is a therapeutic vaccine , i transplanted the tumour and then depleted the neutrophils one day before inta TUMOUR vaccination. I start vaccination 4 or 5 days after tumour trsnsplantation. It is weired that the neutrophils were depleted from blood during the experiment‘s time (14 days) but they were infiltrating the tumour !!

That explains it. Neutrophils might have infiltrated the tumor during the 4-5 days after tumor implantation and before you started injecting them with the antibody. It could be that your antibody is reaching the circulation but not the tumor (big tumors are hypoxic). You could either start the antibody treatment a couple of days prior to tumor implantation (might change the kinetic of tumor growth) or you could try intratumor injection of antibody (in place of or on top of the current mode of administration) a couple of days after implantation/before vaccination.

Thanks Julie.