Characterization of novel monoclonal antibodies able to identify neurogenic niches and arrest neurosphere proliferation and differentiation.

Two monoclonal antibodies (Nilo1 and Nilo2) were generated after immunization of hamsters with E13.5 olfactory bulb-derived mouse neurospheres. They are highly specific for neural stem and early progenitor cell surface antigens. Nilo positive cells present in the adult mouse subventricular zone (SVZ) were able to initiate primary neural stem cell cultures. Moreover, these antibodies added to neurosphere cultures induced proliferation arrest and interfered with their differentiation. In the lateral ventricles of adult mice, Nilo1 stained a cell subpopulation lining the ventricle and cells located in the SVZ, whereas Nilo2 stained a small population associated with the anterior horn of the SVZ at the beginning of the rostral migratory stream. Co-staining of Nilo1 or Nilo2 and neural markers demonstrated that Nilo1 identifies an early neural precursor subpopulation, whereas Nilo2 detects more differentiated neural progenitors. Thus, these antibodies identify distinct neurogenic populations within the SVZ of the lateral ventricle.