- Email: [email protected]
Human natural killer cells augment B cell responses to porcine xenoantigens
Human Natural Killer Cells Augment B Cell Responses to Porcine Xenoantigens R. John, P. Kwiatkowski, N. Edwards, S.F. Wang, and S. Itescu
P
ORCINE xenografts that are transplanted into primate recipients and survive beyond the hyperacute period subsequently succumb to a rejection process at days 3 through 6 which is characterized by vascular deposition of immunoglobulin G (IgG) and complement, and by tissue infiltration with natural killer (NK) cells and macrophages.1 Because human NK cells have been shown to bind gal ␣ (1,3)-gal,2,3 the principal porcine xenoantigen recognized by human antibodies,4,5 we investigated whether NK cells could augment the human anti-porcine B-cell antibody response.
DISCUSSION
These results show that human NK cells augment B cell anti-porcine IgG responses via CD40-CD40 ligand interactions and specific cytokines, and that this process is dependent on NK cell recognition of gal ␣ 1,3-gal. This T-cell– independent pathway of induced humoral immunity to carbohydrate antigens6 could be a major barrier to acceptance of discordant xenografts. Inhibition of NK-B cell interactions may be required for prevention of vascular rejection in pig-to-primate xenotransplantation.
METHODS
REFERENCES
Human B cells and NK cells were isolated by immunomagnetic beads to more than 95% purity. Proliferation of B cells cultured with porcine aortic endothelial cells (PAEC) was measured in the presence or absence of irradiated NK cells, monoclonal antibodies, (MAb) against human CD40 and CD40 ligand, and various cytokines. Anti-porcine antibodies were measured in enzyme-linked immunosorbent assay using PAEC targets.
1. Itescu S, Kwiatkowski P, Artrip JH, et al: Human Immunol 59:275, 1998
RESULTS
5. Cooper DKC, Good AH, Koren E, et al: Transplant Immunol 1:198, 1993
Addition of irradiated NK cells significantly increased B cell proliferation to PAEC and induced anti-pig antibody isotype switching, with reversal in the ratio of anti-pig IgM/IgG antibodies. These effects required NK cell preactivation, and were mediated via CD40-CD40 ligand interactions and specific cytokines produced by the NK cells. NK-driven B cell proliferation was significantly reduced by IB4, a lectin with specific binding affinity for gal ␣ 1,3-gal, but not by a lectin with specificity for sialic acid.
0041-1345/00/$–see front matter PII S0041-1345(00)01041-1 928
2. Inverardi L, Clissi B, Stolzer AL, et al: Transplantation 63:1318, 1997 3. Artrip JH, Kwiatkowski P, Michler RE, et al: J Biol Chem 16:10717, 1999 4. Sandrin MS, Vaughan HA, Dabkowski PL, et al: Proc Natl Acad Sci USA 90:11391, 1993
6. Snapper CM, Mond JJ: J Immunol 157:2229, 1996
From Transplantation Immunology, Department of Surgery, Columbia University, New York, New York. Address reprint requests to Silviu Itescu, MD, ColumbiaPresbyterian Medical Center, 630 W 168th St, PH 14-1485, New York, NY 10032.
© 2000 by Elsevier Science Inc. 655 Avenue of the Americas, New York, NY 10010 Transplantation Proceedings, 32, 928 (2000)
P
ORCINE xenografts that are transplanted into primate recipients and survive beyond the hyperacute period subsequently succumb to a rejection process at days 3 through 6 which is characterized by vascular deposition of immunoglobulin G (IgG) and complement, and by tissue infiltration with natural killer (NK) cells and macrophages.1 Because human NK cells have been shown to bind gal ␣ (1,3)-gal,2,3 the principal porcine xenoantigen recognized by human antibodies,4,5 we investigated whether NK cells could augment the human anti-porcine B-cell antibody response.
DISCUSSION
These results show that human NK cells augment B cell anti-porcine IgG responses via CD40-CD40 ligand interactions and specific cytokines, and that this process is dependent on NK cell recognition of gal ␣ 1,3-gal. This T-cell– independent pathway of induced humoral immunity to carbohydrate antigens6 could be a major barrier to acceptance of discordant xenografts. Inhibition of NK-B cell interactions may be required for prevention of vascular rejection in pig-to-primate xenotransplantation.
METHODS
REFERENCES
Human B cells and NK cells were isolated by immunomagnetic beads to more than 95% purity. Proliferation of B cells cultured with porcine aortic endothelial cells (PAEC) was measured in the presence or absence of irradiated NK cells, monoclonal antibodies, (MAb) against human CD40 and CD40 ligand, and various cytokines. Anti-porcine antibodies were measured in enzyme-linked immunosorbent assay using PAEC targets.
1. Itescu S, Kwiatkowski P, Artrip JH, et al: Human Immunol 59:275, 1998
RESULTS
5. Cooper DKC, Good AH, Koren E, et al: Transplant Immunol 1:198, 1993
Addition of irradiated NK cells significantly increased B cell proliferation to PAEC and induced anti-pig antibody isotype switching, with reversal in the ratio of anti-pig IgM/IgG antibodies. These effects required NK cell preactivation, and were mediated via CD40-CD40 ligand interactions and specific cytokines produced by the NK cells. NK-driven B cell proliferation was significantly reduced by IB4, a lectin with specific binding affinity for gal ␣ 1,3-gal, but not by a lectin with specificity for sialic acid.
0041-1345/00/$–see front matter PII S0041-1345(00)01041-1 928
2. Inverardi L, Clissi B, Stolzer AL, et al: Transplantation 63:1318, 1997 3. Artrip JH, Kwiatkowski P, Michler RE, et al: J Biol Chem 16:10717, 1999 4. Sandrin MS, Vaughan HA, Dabkowski PL, et al: Proc Natl Acad Sci USA 90:11391, 1993
6. Snapper CM, Mond JJ: J Immunol 157:2229, 1996
From Transplantation Immunology, Department of Surgery, Columbia University, New York, New York. Address reprint requests to Silviu Itescu, MD, ColumbiaPresbyterian Medical Center, 630 W 168th St, PH 14-1485, New York, NY 10032.
© 2000 by Elsevier Science Inc. 655 Avenue of the Americas, New York, NY 10010 Transplantation Proceedings, 32, 928 (2000)