The pentaspan membrane glycoprotein prominin-1 (CD133) is widely used in medicine as a cell surface marker of ultrastar dc hc550 stem and cancer stem cells.It has opened new avenues in stem cell-based regenerative therapy and oncology.This molecule is largely used with human samples or the mouse model, and consequently most biological tools including antibodies are directed against human and murine prominin-1.Although the general structure of prominin-1 including its membrane topology is conserved throughout the animal kingdom, its primary sequence is poorly conserved.
Thus, it is unclear if anti-human and -mouse prominin-1 antibodies cross-react with their orthologs in other species, especially dog.Answering this issue is imperative in light of the growing number of studies using canine prominin-1 as an antigenic marker.Here, we address this issue by cloning the canine prominin-1 and use its overexpression as a green fluorescent protein fusion protein in Madin-Darby arrethe bush balm canine kidney cells to determine its immunoreactivity with antibodies against human or mouse prominin-1.We used immunocytochemistry, flow cytometry and immunoblotting techniques and surprisingly found no cross-species immunoreactivity.
These results raise some caution in data interpretation when anti-prominin-1 antibodies are used in interspecies studies.