Contribution of donor-specific antibodies to acute allograft rejection: evidence from B cell-deficient mice

D Brändle, J Joergensen, G Zenke, K Bürki… - Transplantation, 1998 - journals.lww.com
D Brändle, J Joergensen, G Zenke, K Bürki, RP Hof
Transplantation, 1998journals.lww.com
Background. The role of T lymphocytes in acute allograft rejection is well established. The
involvement of B lymphocytes in this process, however, is more controversial. A series of
reports showed that mice without a functional B-cell compartment rejected allografts with the
same kinetics as control animals. In rats, however, alloantibodies were found to play a
decisive role in allograft rejection. To provide an explanation for the discrepant results, we
readdressed the role of B cells and antibodies in mice with disrupted immunoglobulin µ …
Abstract
Background.
The role of T lymphocytes in acute allograft rejection is well established. The involvement of B lymphocytes in this process, however, is more controversial. A series of reports showed that mice without a functional B-cell compartment rejected allografts with the same kinetics as control animals. In rats, however, alloantibodies were found to play a decisive role in allograft rejection. To provide an explanation for the discrepant results, we readdressed the role of B cells and antibodies in mice with disrupted immunoglobulin µ chain genes. The use of cyclosporine (CsA), which strongly suppresses T cells, allowed us to focus specifically on the function of B cells.
Methods.
C57BL/6 mice rendered B cell deficient by targeted disruption of the immunoglobulin µ chain gene (referred to as µMT/µMT mice) and µMT/+ control mice with one functional µ chain were heterotopically transplanted with fully MHC-disparate BALB/c hearts. CsA was administered subcutaneously by Alzet osmotic pumps. Normal and immune serum specific for donor hearts was given to assess the role of antibodies in the rejection process.
Results.
Both B cell-deficient µMT/µMT and heterozygous µMT/+ mice were found to reject transplanted hearts within a similar period of time. In contrast, when T cells were partially suppressed with CsA, graft survival was significantly prolonged in µMT/µMT mice as compared with heterozygous controls. Passive transfer of donor-specific immune serum, obtained from µMT/+ animals rejecting allogeneic hearts, to CsA-treatedµMT/µMT mice significantly accelerated allograft rejection as opposed to recipients treated with normal serum.
Conclusions.
B lymphocytes and antibodies play an important role in acute allograft rejection particularly when the dominant T-cell compartment is partially suppressed.
Lippincott Williams & Wilkins