Single-Cell RNA sequencing reveals immune cell dynamics and local intercellular communication in acute murine cardiac allograft rejection

Abstract

Rationale: Transplant rejection is a major impediment to long-term allograft survival, in which the actions of immune cells are of fundamental importance. However, the immune cell dynamics and local intercellular communication of acute cardiac allograft rejection are not completely clear. Methods: Here we performed single-cell RNA sequencing on CD45 + immune cells isolated from cardiac grafts and spleens in a model of murine heterotopic heart transplantation. Moreover, we applied unsupervised clustering, functional enrichment analysis, cell trajectory construction and intercellular communication analysis to explore the immune cell dynamics and local intercellular communication of acute cardiac allograft rejection at single-cell level. The effect of CXCR3 antagonist and neutralizing antibody against its ligand on allograft rejection and T cell function was evaluated in murine heart transplantation model. Results: We presented the immune cell landscape of acute murine cardiac allograft rejection at single-cell resolution, and uncovered the functional characteristics and differentiation trajectory of several alloreactive cell subpopulations, including Mki67 hi CTLs, Ccl5 hi CTLs, activated Tregs and alloreactive B cells. We demonstrated local intercellular communication and revealed the upregulation of CXCR3 and its ligands in cardiac allografts. Finally, CXCR3 blockade significantly suppressed acute cardiac allograft rejection and inhibited the alloreactive T cell function. Conclusions: These results provide a new insight into the immune cell dynamics and local intercellular communication of acute cardiac allograft rejection, and suggest CXCR3 pathway may serve as a potential therapeutic target for transplant rejection.

CD74+fibroblasts proliferate upon mechanical stretching to promote angiogenesis in keloid

“…The occurrence of MMT in keloid has not been documented. However, in a murine skin wound healing model (50), a unilateral ureteral obstruction (UUO)-induced murine renal fibrosis model (51), and a myocardial ischemia=reperfusion (MIR)-induced murine heart fibrosis model (52) where MMT activities were discovered, fibroblasts derived from MMT were characterized by Lyz2 , Cd206/Mrc1 , and S100A9 expression, respectively. In CD74 + fibroblasts, specific expression of these three MMT marker genes, as well as a variety of lineage-specific markers of macrophages, was well preserved (Supplementary figure 2B), reemphasizing the possibility that CD74 + fibroblasts in keloid are originated from myeloid cells through MMT.…”

“…Through analysis of single-cell data, we noted the possibility that macrophage to myofibroblast transition (MMT) may contribute to CD74 + fibroblasts in keloid. Since its discovery in renal fibrosis (51), evidence of MMT has been proposed in pulmonary fibrosis, cardiac fibrosis, and wound healing process (50)(51)(52)61). However, the occurrence of MMT in keloid has not been documented.…”

Biomarkers from subcutaneous engineered tissues predict acute rejection of organ allografts

“…Git1 has been shown to regulate macrophage inflammatory responses ( 74 ). H2-Eb1 has been associated with antigen-presenting macrophages in murine cardiac allografts ( 75 ). Also, Zbp1 regulates innate immune-mediated inflammatory cell death, particularly through macrophages ( 76 ).…”

MEK1/2-PKM2 Pathway Modulates the Immunometabolic Reprogramming of Proinflammatory Allograft-Infiltrating Macrophages During Heart Transplant Rejection

“…Murine heterotopic heart transplantation was performed as previously described. 21 The mice were anesthetized with 2% isoflurane and maintained on a nose cone. The group details are provided in the Supplemental Material ( SDC , http://links.lww.com/TP/C952 ).…”