Figure 1. Confocal microscopy images showing expression of the phenotypic marker p75^NRT in olfactory ensheathing cells (OECs) infected by Streptococcus pneumoniae.

(a) Optical section showing OEC cultures infected by S. pneumoniae for 3 h and immunolabeled for p75^NRT and Alexa 488-labeled secondary antibody. The nuclei of OECs and/or bacterial DNA (blue dots) were stained with DAPI. The DAPI counterstaining shows the bacterial DNA surrounded by intense labeling of the pneumococcal capsule by the anti-pneumococcal antiserum and Cy3-tagged secondary antibody (arrows in a,b). (b) Orthogonal plane image cut at the maximum nucleus diameter of a shows details of internalized S. pneumoniae (thick arrows). The data are representative of three separate experiments, each conducted in triplicate. Scale bar = 12 μm (a); 8 μm (b).