High-resolution phenotyping of early acute rejection reveals a conserved alloimmune signature

Abstract

Alloimmune responses in acute rejection are complex, involving multiple interacting cell types and pathways. Deep profiling of these cell types has been limited by technology that lacks the capacity to resolve this high dimensionality. Single-cell mass cytometry is used to characterize the alloimmune response in early acute rejection, measuring 37 parameters simultaneously, across multiple time points in two models: a murine cardiac and vascularized composite allotransplant (VCA). Semi-supervised hierarchical clustering is used to group related cell types defined by combinatorial expression of surface and intracellular proteins, along with markers of effector function and activation. This expression profile is mapped to visualize changes in antigen composition across cell types, revealing phenotypic signatures in alloimmune T cells, natural killer (NK) cells, and myeloid subsets that are conserved and that firmly distinguish rejecting from non-rejecting grafts. These data provide a comprehensive, high-dimensional profile of cellular rejection after allograft transplantation.

The Value of Single-cell Technologies in Solid Organ Transplantation Studies

“…41,42 These studies provide a reference for comparing gene expression patterns of cell populations in a diseased state, for example, certain immune cells during allograft rejection following SOT. Indeed, single-cell studies are used in the SOT setting with increasing frequency, both in mice [43][44][45][46][47] and humans. [48][49][50] Previous mouse studies have investigated the role of different cell types involved in acute rejection, 43,46,47 the role of myeloid cell subsets in allograft rejection and tolerance, 44 and the transition from acute to chronic rejection.…”

“…Indeed, single-cell studies are used in the SOT setting with increasing frequency, both in mice [43][44][45][46][47] and humans. [48][49][50] Previous mouse studies have investigated the role of different cell types involved in acute rejection, 43,46,47 the role of myeloid cell subsets in allograft rejection and tolerance, 44 and the transition from acute to chronic rejection. 45 Although these studies are generally hard to extrapolate to the human setting, animal studies such as these can still be of great value.…”

Classic and Current Opinions in Human Organ and Tissue Transplantation

“…It is common in renal grafts. Acute cellular rejection detection involves biopsy, B-lymphocyte antigen CD20 staining in cases not responding to treatment, negative kidney C4d staining, positive activating lymphocyte markers test, and proteomic study [62]. The first rejection instance is treated with pulse intravenous steroids and may be repeated in cases of recurring or refractory rejections.…”

“…The second line of treatment (Thymoglobulin and a murine monoclonal antibody, OKT3) may be used for deteriorating grafts. The prognosis depends on the number of rejection episodes, potent drugs, time of rejection from transplantation, and response to treatment [62].…”

Single-Cell Immunoprofiling Technologies in and Beyond Solid Organ Transplantation

“…www.transplantjournal.com ISSN: 0041-1337/21/10511-2332 DOI: 10.1097/TP.0000000000003909Single-Cell Immunoprofiling Technologies in and Beyond Solid Organ TransplantationAndrea Peloso, MD, PhD1,2 …”