XENOGENEIC (BOVINE) PERIPHERAL-BLOOD LEUKOCYTES ENGRAFTED INTO SEVERECOMBINED IMMUNODEFICIENT MICE RETAIN PRIMARY IMMUNE FUNCTION

The immune responsiveness of xenogeneic PBL engrafted into SCID mice w as investigated using the bovine PBL-reconstituted SCID mouse model sy stem (PBL-SCID-bo). Bovine PBL-reconstitution and B-cell activity were monitored by bovine serum Ig production. Bovine T-cell function was d emonstrated by an antigen-specific immune response to bovine transplan tation antigens provided by bovine skin allografts. Bovine allograft r ejection was clearly evident in > 65% PBL-SCID-bo that received a bovi ne PBL inoculum either 30 days after bovine skin grafting, or 7-52 day s before bovine skin grafting. Bovine allograft rejection was confirme d via histological examination and was characterized primarily by a ba nd of infiltrating bovine lymphocytes at the periphery of the graft an d tissue necrosis. A secondary immune response could be elicited if bo vine cells in the PBL inoculum were presensitized to Ag from the bovin e skin allograft donor. This study is the first to show that bovine ce lls engrafted in SCID mice after ip injection of bovine PBL retain som e aspects of immune competency. These results confirm the value of the xenogeneic PBL-reconstituted SCID mouse model in the study of primary immunity. (C) 1997 Elsevier Science B.V.