Abstract
Lung transplantation (LTx) elicits an alloimmune response of innate and adaptive immune system. Our goal was to map the diversity and emergence of immune cells post-LTx.
Murine orthotopic left LTx was performed in isografts (B6 to B6) and allografts (Balbc to B6), receiving daily immunosuppression. After in vivo µCT, mice were sacrificed at post-operative day (POD) 1, 7 and 35 (n=6/timepoint/group). Single cell suspensions of LTx lungs were made and absolute cell numbers were quantified by flow cytometry. One allograft and isograft were scanned with high resolution (HR) ex vivo μCT at POD 70.
Endothelial cell (EC) numbers were decreased in allografts vs isografts (p=0.001), HR μCT confirmed vascular injury, showing narrowed vessel lumens in the allograft. Granulocytes demonstrated similar patterns in both groups. In allografts, dendritic cells (DCs) (p=0.005), interstitial macrophages (p<0.0001), CD4+ (p=0.0009) and CD8+ (p=0.004) T cells were increased vs isografts at POD 7. All cell numbers returned to baseline isograft values at POD 35, except for DCs (p=0.004) and CD4+ T cells (p=0.04). At POD 35, histology confirmed the presence of perivascular lymphocytic infiltrates and in vivo µCT showed increased lung density of LTx lungs in allografts vs isografts (p=0.036).
Destruction of ECs may represent the onset of the alloimmune response post-LTx, followed by innate immune activation and subsequent lymphoid follicle formation around arteries.
Footnotes
Cite this article as Eur Respir J 2022; 60: Suppl. 66, LSC-0034.
This article was presented at the 2022 ERS International Congress, in session “-”.
This is an ERS International Congress abstract. No full-text version is available. Further material to accompany this abstract may be available at www.ers-education.org (ERS member access only).
- Copyright ©the authors 2022
