Biology subjects

Dvorina, N.

Publications and source records attributed to Dvorina, N..

3 recordsLinked to original sources

bioRxiv2026

NK Cells Effectively Mediating Antibody-Mediated Kidney Allograft Rejection Requires a Specific Activation Receptor and Graft Expression of the Ligand

Acute antibody-mediated rejection (aABMR) is an important cause of clinical kidney graft injury and failure. Transcripts associated with NK cell activation in graft biopsies are diagnostic of aABMR, but mechanisms underlying NK cell activation during ABMR remain poorly understood. In contrast to the long-term (> 60 days) survival of complete MHC-mismatched kidney allografts in wild type C57BL/6 mice, B6.CCR5-/- recipients develop high titers of donor-specific antibody (DSA) with allograft rejection between days 18 to 28 post-transplant. This has allowed investigation of mechanisms underlying NK cell activation within kidney allografts during aABMR. DSA titers first became detectable in B6.CCR5-/- (H-2b) recipients of A/J (H-2a) kidney allografts at day 8 and peaked on day 15 post-transplant and was accompanied by a parallel increase in mRNA levels of Rae-1e, a ligand for the NK cell activation receptor NKG2D. A/J kidneys in B6.CCR5-/-NKG2D-/- recipients and A/J.Rae-1e-/- kidneys in B6.CCR5-/- recipients survived >60 days, despite high serum DSA levels. Flow cytometric analysis of allograft infiltrating cells in B6.CCR5-/- recipients on day 15 post-transplant revealed inflammatory monocyte and NK cell infiltration and NK cell activation to proliferate and express CD107a, a marker of cytotoxic function. These features of aABMR were absent or markedly reduced by recipient NKG2D- or donor graft Rae-1e-deficiency. These findings suggest that interference with expression of allograft Rae-1e or recipient NK cell NKG2D abrogates aABMR despite persistently high DSA levels and that aABMR requires coordination between infiltrating NK cell and inflammatory monocyte activation within the kidney allograft.

immunology↗

bioRxiv2025

Inhibition of De Novo Autoantibody Production Attenuates Chronic Antibody-Mediated Rejection of Kidney Allografts Despite Maintenance of High Donor-Specific Antibody Titers

Acute and chronic antibody mediated rejection (ABMR) continues to decrease clinical kidney graft function and survival. Dysregulated donor-specific antibody (DSA) responses are induced in B6.CCR5-/- recipients of complete MHC-mismatched A/J kidney allografts with NK cells playing a critical role in the acute ABMR. We tested the role of neutrophils in ABMR by transplanting A/J kidneys to CCR5-/- mice with a deletion in the neutrophil serine protease cathepsin G. Whereas B6.CCR5-/- recipients rejected all kidney allografts between days 18-25, 70% of allografts survived beyond day 60 in B6.CCR5-/-cG-/- recipients. At days 15-17 post-transplant DSA titers in B6.CCR5-/-cG-/- recipients were 24.3-fold higher than those in wild-type C57BL/6 allograft recipients. Allografts from B6.CCR5-/-cG-/- recipients on days 45 and 60 had typical characteristics of chronic graft injury including interstitial collagen deposition and peri-glomerular fibrosis that was accompanied by a fibrogenic transcript signature and late post-transplant production of autoantibodies to many targets, including structural proteins including collagen IV and fibronectin. Depletion of B cells at the time DSA peak titers were achieved on day 14 post-transplant decreased serum autoantibodies levels, the kidney allograft fibrogenic transcript signature, and the chronic kidney allograft injury, despite maintenance of the high DSA titers. These results indicate a critical role for neutrophil cathepsin G during acute ABMR of kidney allografts and in its absence, DSA induced late appearance of autoantibodies mediating development of chronic kidney allograft injury.

immunology↗

bioRxiv2022

Recipient LAG3 deficiency results in antibody-mediated rejection of mouse renal allografts

Lymphocyte activation gene-3 (LAG3) is a coinhibitory receptor expressed by a range of immune cells. While immunomodulatory potential of LAG3 is being actively explored in cancer and autoimmunity fields, there is no information on how this pathway affects alloreactive immune responses following organ transplantation. The goal of this study was to investigate the functions of recipient LAG3 in a mouse model of renal allograft rejection. We found that mice deficient in LAG3 expression have elevated heterologous immunity against a panel of alloantigens prior to transplantation. Recipient LAG3 deficiency results in rapid rejection of MHC-mismatched renal allografts that are spontaneously accepted by WT recipients, with graft histology characteristic of antibody mediated rejection (ABMR). Depletion of recipient B cells but not CD8+ T cells significantly extended kidney allograft survival in LAG3-/- recipients further supporting ABMR as the main mechanism of graft loss. Treatment of WT recipients with an antagonistic LAG3 antibody enhanced anti-donor immune responses and induced kidney damage associated with chronic rejection. The experiments using conditional LAG3 knockout recipients demonstrated that LAG3 expression on either T or B cells is sufficient to regulate anti-donor humoral immunity. These results are the first to identify LAG3 as a regulator of both T and B cell responses to kidney allografts and a potential therapeutic target for ABMR prevention and treatment.

immunology↗