A novel monoclonal antibody inhibits the immune response of human cells against porcine cells: identification of a porcine antigen homologous to CD58.
BACKGROUND
Human CD58 is an adhesion molecule that interacts with CD2 on lymphocytes. We describe here an antibody that blocks responses of human peripheral blood mononuclear cells (PBMCs) to porcine cells and reacts with a porcine protein with homology to CD58.


METHODS
Antibodies were isolated with a screen for inhibition of the human antiporcine response. One of these antibodies was used for immunoaffinity purification of a protein that was identified by molecular weight determination, endoglycosidase sensitivity, and microsequencing analysis as a porcine homologue of CD58.


RESULTS
The antigen recognized by this antibody was a cell surface protein of relative molecular mass (Mr)=45,000 containing N-linked carbohydrate chains. Immunoaffinity purification of this protein and microsequencing revealed homology to sheep CD58 as well as sequences that were common to this protein and both sheep and human CD58. The protein was widely distributed on porcine cells, including lymphocytes, endothelial cells, muscle cells, and neuronal cells. This antibody efficiently inhibited lysis of porcine targets by human PBMCs in addition to preventing proliferation of the human PBMCs in response to the porcine cells.


CONCLUSIONS
The CD2 interaction with porcine cells is important for the efficient recognition of porcine tissue, and inhibition of the human antiporcine immune response with the antibody is likely to be caused by the disruption of the human CD2 interaction with this porcine homologue of CD58. The antibody may prove to be useful for the blocking of this interaction without interfering with other functions of T cells.
Crosby
Katherine
K
Diacrin, Inc. Charlestown, MA, USA.
Yatko
Chris
C
Dersimonian
Harout
H
Pan
Luying
L
Edge
Albert S B
AS
D000595:Amino Acid Sequence; D000818:Animals; D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D018968:CD58 Antigens / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification*; D002846:Chromatography, Affinity; D003601:Cytotoxicity Tests, Immunologic; D006801:Humans; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D051379:Mice; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D012756:Sheep; D013045:Species Specificity; D034421:Sus scrofa / Q000235:genetics / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology; D014018:Tissue Distribution
D000911:Antibodies, Monoclonal; D018968:CD58 Antigens; D007166:Immunosuppressive Agents