Humoral Reactivity of Renal Transplant-Waitlisted Patients to Cells from GGTA1/CMAH/B4GalNT2, and SLA Class i Knockout Pigs

Gregory R. Martens, Luz M. Reyes, James R. Butler, Joseph M. Ladowski, Jose L. Estrada, Richard A. Sidner, Devin E. Eckhoff, Matt Tector, A. Joseph Tector

Research output: Contribution to journalArticlepeer-review

91 Scopus citations

Abstract

Background Antipig antibodies are a barrier to clinical xenotransplantation. We evaluated antibody binding of waitlisted renal transplant patients to 3 glycan knockout (KO) pig cells and class I swine leukocyte antigens (SLA). Methods Peripheral blood mononuclear cells from SLA identical wild type (WT), α1, 3-galactosyltransferase (GGTA1) KO, GGTA1/ cytidine monophosphate-N-acetylneuraminic acid hydroxylase (CMAH) KO, and GGTA1/ CMAH /b1,4 N-acetylgalactosaminyl transferase (B4GalNT2) KO pigs were screened for human antibody binding using flow cytometric crossmatch (FCXM). Sera from 820 patients were screened on GGTA1/CMAH/B4GalNT2 KO cells and a subset with elevated binding was evaluated further. FCXM was performed on SLA intact cells and GGTA1/SLA class I KO cells after depletion with WT pig RBCs to remove cell surface reactive antibodies, but leave SLA antibodies. Lastly, human and pig reactive antibodies were eluted and tested for cross-species binding and reactivity to single-antigen HLA beads. Results Sequential glycan KO modifications significantly reduce antibody binding of waitlisted patients. Sera exhibiting elevated binding without reduction after depletion with WT RBCs demonstrate reduced binding to SLA class I KO cells. Human IgG, eluted from human and pig peripheral blood mononuclear cells, interacted across species and bound single-antigen HLA beads in common epitope-restricted patterns. Conclusions Many waitlisted patients have minimal xenoreactive antibody binding to the triple KO pig, but some HLA antibodies in sensitized patients cross-react with class I SLA. SLA class I is a target for genome editing in xenotransplantation.

Original languageEnglish (US)
Pages (from-to)e86-e92
JournalTransplantation
Volume101
Issue number4
DOIs
StatePublished - Apr 1 2017
Externally publishedYes

ASJC Scopus subject areas

  • Transplantation

Fingerprint

Dive into the research topics of 'Humoral Reactivity of Renal Transplant-Waitlisted Patients to Cells from GGTA1/CMAH/B4GalNT2, and SLA Class i Knockout Pigs'. Together they form a unique fingerprint.

Cite this