Radiosensitivity of peripheral blood B cells in pigs

Swine are here introduced to biodosimetry in an attempt to develop a large animal model allowing for comparison of in vitro experiments with the in vivo processes occurring after exposure to gamma radiation. This work investigates the radiosensitivity of the B cell compartment in peripheral blood. Four-week-old piglets were irradiated using the whole body protocol or full blood samples were irradiated in vitro in the dose range of 0-10 Gy. Relative radioresistance of B cell subpopulations and subsets was determined by measuring their relative numbers in leukocyte preparations at selected time intervals after irradiation using two color immunophenotyp-ing and flow cytometry. Porcine B cells represent the most radiosensitive lymphocyte population in peripheral blood. Among B cell subpopulations and subsets investigated, the CD21+SWC7+ and CD21+CD1+ cells are highly radiosensitive and possess biodosimetric potential, at least in the range of low doses. Differences between cultures irradiated in vitro and lymphocyte dynamics in peripheral blood of irradiated animals clearly document the limits of in vitro data extrapolation in biodosimetry. We have shown that pigs can successfully be used in radiobiology and experimental biodosimetry due mainly to their availability, size and a relatively broad spectrum of available immunoreagents for lymphocyte classification