Deletion of naïve T cells recognizing the minor histocompatibility antigen HY with toxin-coupled peptide-MHC class I tetramers inhibits cognate CTL responses and alters immunodominance

Abstract

Alloreactive T-cell responses directed against minor histocompatibility (H) antigens, which arise from diverse genetic disparities between donor and recipient outside the MHC, are an important cause of rejection of MHC-matched grafts. Because clinically significant responses appear to be directed at only a few antigens, the selective deletion of naïve T cells recognizing donor-specific, immunodominant minor H antigens in recipients before transplantation may be a useful tolerogenic strategy. We have previously demonstrated that peptide-MHC class I tetramers coupled to a toxin can efficiently eliminate specific TCR-transgenic T cells in vivo. Here, using the minor histocompatibility antigen HY as a model, we investigated whether toxic tetramers could inhibit the subsequent priming of the two H2-Db-restricted, immunodominant T-cell responses by deleting precursor CTL. Immunization of female mice with male bone marrow elicited robust CTL activity against the Uty and Smcy epitopes, with Uty constituting the major response. As hypothesized, toxic tetramer administration prior to immunization increased survival of cognate peptide-pulsed cells in an in vivo CTL assay, and reduced the frequency of corresponding T cells. However, tetramer-mediated decreases in either T-cell population magnified CTL responses against the non-targeted epitope, suggesting that Db-Uty+ and Db-Smcy+ T cells compete for a limited common resource during priming. Toxic tetramers conceivably could be used in combination to dissect or manipulate CD8+ T-cell immunodominance hierarchies, and to prevent the induction of donor-specific, minor H antigen CTL responses in allotransplantation.

HLA-B*14:02-Restricted Env-Specific CD8+T-Cell Activity Has Highly Potent Antiviral Efficacy Associated with Immune Control of HIV Infection

“…Cytotoxic saporin-conjugated tetramers were produced by the same method using streptavidin-SAP (Advanced Targeting Systems) to tetramerize peptide-MHC monomers according to the published approach ( 93 ). Briefly, these modified tetramers are coupled to a toxin, the ribosome-inactivating protein saporin (SAP), which can selectively kill antigen-specific cells of interest and thereby evaluate the contribution of a particular CD8 + T-cell specificity to viral inhibition ( 93 – 97 ). The efficiency of tetramerization was confirmed by staining with anti-mouse Ig κ beads (BD Biosciences) with an anti-HLA antibody, followed by tetramer staining.…”

Saporin-conjugated tetramers identify efficacious anti-HIV CD8+ T-cell specificities

“…Cytotoxic saporin-conjugated tetramers were produced by the same method using streptavidin-saporin (Advanced Targeting Systems) to tetramerise peptide-MHC monomers according to the published approach [ 4 ]. Briefly, these modified tetramers are coupled to a toxin, ribosome-inactivating protein saporin (SAP), that can selectively kill antigen-specific cells of interest and thereby evaluate the contribution of a particular CD8+ T-cell specificity to viral inhibition [ 4 – 7 , 13 ]. Biotinylated peptide-MHC class I monomers generated as per standard published approach [ 11 ] were tetramerised by stepwise addition (1/10 th volume every 10 minutes) of streptavidin-SAP (Advanced Targeting Systems) at a 1:1 molar ratio of biotinylated MHC to biotin binding sites [ 22 ].…”

“…An elegant proof-of-concept study in the mouse-LCMV model exploited the idea of SAP-conjugated tetramers and demonstrated tetramer-mediated selective depletion of certain CD8+ T-cells in vitro and in vivo [ 4 ]. These cytotoxic tetramers were later used in vivo in further murine studies to delete diabetogenic T-cells [ 6 ], encephalopathogenic T-cells [ 5 ], minor histocompatibility HY-specific T-cells to prevent organ rejection [ 7 ], or to study ‘memory inflation’ [ 13 ].…”

RNA Interference as a Tool to Reduce the Risk of Rejection in Cell-Based Therapies

“…Improved use of post-transplant immunosuppression to prevent acute and chronic rejection allowed allogeneic transplantation as a widespread, successful therapy. [10][11][12][13] However, graft rejection remains a major concern in the field of transplantation. The registry of the International Society for Heart and Lung Transplantation (ISHLT) reported that within the first year after lung transplantation, up to 55% patients need to be treated for acute rejection and only 50% are alive after five years.…”