The human cytomegalovirus-specific and UL40-mediated imprint in the natural killer cell repertoire is associated with antibody-mediated rejection in lung transplant recipients

J Heart Lung Transplant. 2023 Mar;42(3):305-314. doi: 10.1016/j.healun.2022.10.014. Epub 2022 Oct 21.

Abstract

Background: CD16+ natural killer (NK-) cells play, together with donor-specific antibodies (DSA) and via antibody-dependent cellular cytotoxicity (ADCC), an important role in the pathogenesis of antibody-mediated rejection (ABMR) in lung-transplant recipients (LTRs). Cytotoxic CD16+NKG2C+ NK cells proliferate in response to human Cytomegalovirus (HCMV) infections via the presentation of HCMV-encoded and highly polymorphic UL40 peptides. In our study, we aimed to clarify whether infections with HCMV-strains carrying different UL40 peptide variants are associated with the shift of the NK cell repertoire and the development of ABMR in LTRs.

Methods: We included 30 DSA+ABMR+, 30 DSA+ABMR- and 90 DSA-ABMR- LTRs. In all patients, 1 episode of high-level HCMV-replication occurred. In all DSA+ABMR+ LTRs, HCMV-replication occurred prior to ABMR diagnosis. The association of HCMV UL40 variants with the expansion of CD16+ NK cell subsets and ABMR was assessed in NK cell proliferation and ADCC assays.

Results: Our study revealed that the VMAPRTLIL and VMTPRTLVL UL40 variants were significantly overrepresented in DSA+ABMR+ LTRs. Both peptides were associated with a pronounced proliferation of cytotoxic and proinflammatory CD16+NKG2C+ NK cells. The stimulation with both peptides led to a shift of the NK cell repertoire towards CD16+NKG2C+ NK cells, which was associated with strong ADCC responses after stimulation with endothelial cells and plasma from DSA+ABMR+ LTRs.

Conclusions: Distinct UL40 peptide variants of the infecting HCMV-strain are associated with the development of ABMR after lung transplantation, due to a shift towards a highly cytotoxic CD16+NKG2C+ NK cell population. These peptides are thus potential prognostic markers for ABMR.

Keywords: ADCC, antibody-dependent cellular cytotoxicity; HCMV, humancy tomegalovirus; NK cells; NKG2C; antibody-mediated rejection, ABMR; humoral rejection; natural killer cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies
  • Cytomegalovirus Infections*
  • Cytomegalovirus*
  • Endothelial Cells
  • Humans
  • Killer Cells, Natural
  • Lung
  • Transplant Recipients

Substances

  • Antibodies