Illustration of cell surface markers in peripheral blood mononuclear cells (PBMC) and bone marrow haematopoietic cells (BMHC) from CSFV persistently infected and naïve animals at 6 weeks of age. (A) Comparative expression of CD172a (myelomonocytic cells) and 6D10 (granulocyte lineage) cell surface markers in PBMCs and BMHCs from CSFV persistently infected (black dots) and naïve (white dots) animals. Mean values for each group are indicated (triangle symbol). (B) Comparative expression of MDSC surface markers labelled by single (6D10), double (6D10/CD33 and 6D10/CD11b), and triple (6D10/CD33/CD11b) staining in different cell populations (in the bottom panels, 6D10+ cells were gated and the expression of CD33vs CD11b analysed). The cell populations evaluated were: I) BMHC from a naïve animal, II) BMHC from a CSFV persistently infected animal, III) PBMC from a naïve animal, and IV) PBMC from a CSFV persistently infected animal. The experiments were repeated twice under the same conditions.