Method preventing depletion of non-autologous hematopoietic cells and animal model systems for use thereof

Patent Number: 6770260

This patent teaches depletion or inactivation of recipient macrophages using dichloromethylene diphosphonate in order to allow allogeneic or xenogeneic stem cell transplants and progeny of the stem cell transplants not to be rejected.

The patent is very interesting since the inactivation of macrophages theoretically may also allow for inactivation of dendritic cells. If this occurs, then the indirect pathway of antigen presentation may be blocked.

Blocking the indirect pathway of antigen presentation would be very important in xenotransplantation, particularly islet xenotransplantation, where the rejection is mediated primarily by activation of the indirect pathway of antigen presentation.

This was demonstrated clearly in experiments in which mouse recipients lacking MHC II were not able to reject pig islets but rejected allogeneic mouse and rat islets.

View this patent on the USPTO website.