Cell surface expression of 27C7 by neonatal rat olfactory ensheathing cells in situ and in vitro is independent of axonal contact

Abstract

Olfactory ensheathing cells (OECs) are Schwann cell-like glial cells of the olfactory system that promote neural regeneration after transplantation into the injured central nervous system. Compared to the closely related Schwann cells, however, the biological characterization of OECs has remained fragmentary. This is due to the fact that the expression of OEC-specific markers is subject to complex regulation and that intricate ultrastructural analysis is essential to determine their localization. The p75 neurotrophin receptor (p75(NTR)) as the prototype OEC marker, for example, is only expressed by a minor population of neonatal rat OECs in situ. The major population carries O4-positive axonal fragments on their surface after dissociation and up-regulates p75(NTR) during culturing (Wewetzer et al. in Glia 49:577-587, 2005). In the present study, we investigated whether the cell surface determinant 27C7, defined by a monoclonal antibody to Schwann cells, is also expressed by neonatal rat OECs in situ and in vitro. Primary cell suspensions of the olfactory bulb displayed 27C7 expression of both p75(NTR)-negative and p75(NTR)-positive OECs, while immature oligodendrocytes and astrocytes were devoid of any 27C7 labeling. This together with the finding that the intrafascicular OECs of the olfactory nerves in the mucosa expressed 27C7 but not p75(NTR), suggests that 27C7 was expressed by the entire OEC population in situ. Maintenance of OECs in the absence of olfactory neurons in organotypic slice culture up-regulated p75(NTR) but did not alter 27C7 expression. It is concluded that 27C7 unlike p75(NTR) is constitutively expressed by OECs and may, therefore, be a useful marker for characterization of neonatal OECs in situ and in vitro.

Increased p75 neurotrophin receptor expression in the canine distemper virus model of multiple sclerosis identifies aldynoglial schwann cells that emerge in response to axonal damage

“…Though it is well known that up-regulation of p75 NTR expression in cultured glial cells, e.g. olfactory ensheathing cells, only requires a short time interval of 2-4 days (Bock et al, 2007;Brandes et al, 2011;Wewetzer et al, 2005), NTR expression in cultures from adult canine brain is not detectable until 15 days in dissociation culture (Orlando et al, 2008) or until 10 days in organotypic slices as observed in the present study. Thus, the delayed initiation of p75 NTR expression argues for differentiation of precursor cells rather than for up-regulation of p75 NTR in mature glia.…”

“…Organotypic slice cultures were established according to Heimrich and Frotscher (1993) with modifications (Brandes et al, 2011;Omar et al, 2011). Briefly, the isolated olfactory bulb was placed on a plate of low-adhesive plastic (VulcolanÒ) and sections were cut (350 lm) using a tissue chopper (Mc Illwain, Mickle Lab, Engineering Surrey, UK).…”

Recent progress in histochemistry and cell biology

“…OECs display a changeable morphological and molecular phenotype (Alexander et al 2002;Vincent et al 2005), therefore, making it difficult to identify them. Brandes et al (2011) showed that the cell surface antigen 27C7, a marker for non-myelinating Schwann cells (Wewetzer et al 1997), is expressed constitutively in neonatal rat OECs and this expression remained stable in cultured OECs. Therefore, the authors regard the 27C7 antigen to be a valuable marker for the identification of OECs in different experimental setups.…”

Mucosal vaccination by the intranasal route. Nose-associated lymphoid tissue (NALT)—Structure, function and species differences

“…It is very likely that the entry of a virus into the brain during intranasal immigration happens via this route. Therefore, it is recommended to test potential life virus vaccines in vitro, because the olfactory ensheathing cells can be cultured [37].…”