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Human xenoreactive natural antibodies of the IgM isotype activate pig endothelial cells
Author(s) -
Vanhove Bernard,
Martin Rainer,
Lipp Joachim,
Bach Fritz H.
Publication year - 1994
Publication title -
xenotransplantation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.052
H-Index - 61
eISSN - 1399-3089
pISSN - 0908-665X
DOI - 10.1111/j.1399-3089.1994.tb00046.x
Subject(s) - antibody , complement system , biology , microbiology and biotechnology , isotype , gene , immunology , biochemistry , monoclonal antibody
Preformed, xenoreactive natural antibodies (XNA) and complement (C) are involved in the initiation of vascular rejection of organs transplanted between discordant species, presumably by stimulating donor organ endothelial cells (EC). Although C is known to play a role in the activation of EC, it has not been clear whether the antibodies serve only to anchor the initial components of C, and thus permit the C cascade to proceed, or whether the antibodies themselves deliver a signal to the EC. We have tested affinity‐purified human IgM containing XNA (IgM‐XNA) for its ability to stimulate in vitro the up‐regulation of genes in pig EC. Northern blot analysis shows that IgM, which contains XNA, stimulates mRNA accumulation for certain genes (including IL‐8, PAI‐1, and ECI‐7, a new gene that we have found is associated with EC activation), but not others known to be up‐regulated in response to TNF, IL‐1 or LPS. Our results show that XNA provide a signal to EC, and thus may themselves participate in activation of EC and consequent vascular rejection.