Induction of Human Blood Group A Antigen Expression on Mouse Cells, Using Lentiviral Gene Transduction

Abstract

The ABO histo-blood group system is the most important antigen system in transplantation medicine, yet no small animal model of the ABO system exists. To determine the feasibility of developing a murine model, we previously subcloned the human a-1,2-fucosyltransferase (H-transferase, EC 2.4.1.69) cDNA and the human a-1,3-Nacetylgalactosaminyltransferase (A-transferase, EC 2.4.1.40) cDNA into lentiviral vectors to study their ability to induce human histo-blood group A antigen expression on mouse cells. Herein we investigated the optimal conditions for human A and H antigen expression in murine cells. We determined that transduction of a bicistronic lentiviral vector (LvEF1-AH-trs) resulted in the expression of A antigen in a mouse endothelial cell line. We also studied the in vivo utility of this vector to induce human A antigen expression in mouse liver. After intrahepatic injection of LvEF1-AH-trs, A antigen expression was observed on hepatocytes as detected by immunohistochemistry and real-time RT-PCR. In human group A erythrocyte-sensitized mice, A antigen expression in the liver was associated with tissue damage, and deposition of antibody and complement. These results suggest that this gene transfer strategy can be used to simulate the human ABO blood group system in a murine model. This model will facilitate progress in the development of interventions for ABO-incompatible transplantation and transfusion scenarios, which are difficult to develop in clinical or large animal settings.

ABO‐incompatible kidney transplantation can be successfully conducted by monitoring IgM isoagglutinin titers during desensitization

“…Although it is not yet clear which type of ABO antibody (IgM or IgG) is clinically more important in ABO‐i KT, our findings suggest that, unlike anti‐HLA antibodies, IgM anti‐ABO antibodies may have an important influence on AMR. This is in line with key studies that observed deposition of IgM and complement using immunohistochemical studies in hyperacutely rejected ABO‐i kidney grafts, as well as ABO‐specific IgM‐induced cytolysis in vitro and graft injury in vivo …”

“…This is in line with key studies that observed deposition of IgM and complement using immunohistochemical studies in hyperacutely rejected ABO-i kidney grafts, 2 as well as ABO-specific IgM-induced cytolysis in vitro 32 and graft injury in vivo. 33 The molecular characteristics of ABO antigens are different from those of HLA antigens, as they are carbohydratebased and protein-based antigens, respectively. The antibody response against nonprotein antigens, such as polysaccharides and lipids, primarily relies on IgM production.…”

Murine Noroviruses Bind Glycolipid and Glycoprotein Attachment Receptors in a Strain-Dependent Manner

“…Furthermore, it also raised the intriguing possibility that the choice of specific glycans contributes to species specificity. In support of this, no binding of MNV-1 to available synthetic HBGA has so far been observed (13) despite the ability of MNV RNA to replicate in human cells (60), and the human ABO HBGA system, which is pivotal for human norovirus infection, does not exist in mice or any other small animal model (16).…”

Accommodation in ABO‐incompatible organ transplants

“…Investigation of levels of antibodies against donor blood groups and B-cell responses has suggested that decreased production of donor-specific anti-blood group antibodies can be detected in graft recipients and the suggestion has been made that perhaps this decrease explains the well-being of ABO-incompatible kidney transplants. 55,56 However, the general experience has been that at least some recipients of ABO-incompatible kidney transplants produce substantial amounts of antibody against the donor antigen and the preponderance of ABO-incompatible transplants contain deposits of C4d, in the absence of impaired function and consistent with ongoing binding of anti-donor antibodies. [57][58][59] Even more to the point, the extent of antibody rebound after the first weeks appears to have little or no impact on the long-term outcome ( Figure 5).…”