Phenotypic behavior of PBMCs from irradiated dogs based on flow cytometry.

: The present paper investigates the phenotypic parameters of stimulation markers and cell immunosuppression markers in an animal model using flow cytometry analysis. Six dogs were exposed to 2, 4 or 6 Gy following a head and neck protocol. Samples of peripheral blood mononuclear cells (PBMCs) were collected before irradiation, representing standard values for all dogs (control), and at 2 h, 18 h and 30 d after irradiation. Such samples were separately assessed for surface markers with the monoclonal antibodies anti-CD5, anti-CD4 and anti-CTLA-4 by flow cytometry. A reduction in Tcell expression of CD5 and in the subpopulation expressing CD4 and an increase in CTLA-4 expression were found. No statistically significant differences were observed for the absorbed dose grouping, although the time kinetics were recorded. Radiation induced phenotypic differences between the lymphocyte lineages, reducing the CD5 and CD4 Tcell subpopulations and increasing CTLA-4 expression. The findings demonstrate the relevance of investigating the immunophenotype of irradiated subjects by examining the peripheral cell lineage.