THE EFFECT OF CYCLOPHOSPHAMIDE ON BURSAL AND SPLENIC DENDRITIC CELLS

The effect of in ovo and posthatch administration of cyclophosphamide, an immunosuppressive drug, on avian dendritic cells was examined in New Hampshire chickens. The Small Bursa line of New Hampshire chickens was more sensitive to the toxic effects of this drug than the line from which it was selected, the Lester J. Dreesen line. The bursal secretory dendritic cells, which may effect B cell differentiations, were left intact and appeared more prominent after treatment. The ellipsoid-associated cells, the dendritic cells of the spleen that bind and carry antigen, became vacuolated after treatment, but normal ellipsoid-associated cells were found within 1 wk. Ellipsoid-associated cells were able to bind and move carbon away from the ellipsoid areas of the spleen 5 wk after in ovo treatment with cyclophosphamide. However, the ability of treated birds to mount an antibody response to SRBC was compromised. The present study revealed that bursal dendritic cells were resistant to cyclophosphamide treatment during embryogenesis and the same embryonic treatment did not influence the migrating capability of ellipsoid-associated cells.