In vitro organ culture of embryonic bursa of Fabricius.

An in vitro method for organ culture of embryonic bursa of Fabricius is presented. It is shown that bursa cells proliferate in in vitro culture as evidenced by [3H]-thymidine incorporation. We assessed the expression of B-cell alloantigen (Bu-la and Bu-lb), class I (B-F) and class II (B-L) antigens of chicken major histocompatibility complex (MHC), and surface immunoglobulin (sIg) on cultured bursa cells using specific monoclonal antibodies (mAb). Cells from 13-day and 14-day embryonic bursae incubated in organ culture for 1 to 2 weeks developed characteristic patterns of surface phenotype observed in adult chicken except for B-F antigen, whose expression was much lower than in vivo. These results indicate that the maturation of bursa cells in organ culture follows the in vivo development, except for the expression of MHC class I antigens. Furthermore, we demonstrate the in vitro repopulation of bursae from cyclophosphamide(cy)-treated chickens by cells from Bu-l antigen disparate normal bursae.