Dynamics of circulating dendritic cells and cytokines after kidney transplantation-No effect of remote ischaemic conditioning

Abstract

Inflammation resulting from ischaemia/reperfusion injury can cause kidney graft dysfunction, increase the risk of delayed graft function and possibly reduce long-term graft survival. Remote ischaemic conditioning may protect against ischaemia/reperfusion injury and mitigate the immunological response to the graft. We investigated the immunological effects of remote ischaemic conditioning on kidney transplantation from deceased donors in the randomized CONTEXT study. Three circulating dendritic cell (DC) subtypes identified in peripheral blood from kidney transplant recipients [myeloid DCs, plasmacytoid DCs and immunoglobulin-like transcript (ILT)3+ DCs] were measured at baseline, days 1, 3 and 5 and 1 and 3 months after transplantation. We also quantified 21 cytokines at baseline, days 1 and 5 and 3 months after transplantation. Neither DC counts nor cytokine levels differed between patients receiving remote ischaemic conditioning and controls; however, several parameters exhibited dynamic and parallel alterations in the two groups over time, reflecting the immunological response to the kidney transplantation and immunosuppression.

Trial registration: ClinicalTrials.gov NCT01395719.

Keywords: cytokines; dendritic cells; immunology; kidney transplantation; remote ischaemic conditioning.

Conflict of interest statement

The authors declare that they have no conflicts of interest.

© 2021 British Society for Immunology.

Figures

FIGURE 1

Gating strategy to measure total circulating dendritic cells (DCs) and DC subpopulations. (a) Scatter gating to discriminate cells and TruCount beads, (b) live gating of human leucocyte antigen (HLA)‐DR+ cells, (c) gating for lineage marker (CD3, CD19, CD56, CD14)‐negative cells, (d) gating for CD11c+ and CD123+ cells, (e) identification of CD123+CD11c‐ pDCs CD123‐CD11c+ mDCs and immunoglobulin‐like transcript (ILT)3+ DCs and (f) backgating of the mDCs (green), plasmacytoid (pDCs) (blue) and ILT3+ DCs (orange) to the CD11c versus CD123 plot

FIGURE 2

(a) Total circulating myeloid dendritic cells (mDCs), plasmacytoid DCs (pDCs) and immunoglobulin‐like transcript (ILT)3+ DCs measured at baseline. (b) CD86 levels [mean fluorescence, intensity (MFI)] in the three identified DC subpopulations at baseline (c) human leucocyte antigen (HLA)‐DR levels (MFI) in the three identified DC subpopulations measured at baseline. Graphs represent individual values with mean values and 95% confidence interval

FIGURE 3

Levels of circulating dendritic cells (DCs) and DC subtypes after kidney transplantation in patients who received remote ischaemic conditioning (RIC) or non‐RIC. (a) Levels of total DCs. (b) Levels of mDCs and fraction of mDCs over total DCs. (c) Levels of plasmacytoid (pDCs) and fraction of pDCs over total DCs. (d) Levels of immunoglobulin‐like transcript (ILT)3+ DCs and fraction of ILT3+ DCs over total DCs. Levels per ml whole blood are presented as median and 95% confidence interval. Fraction of DC subtypes over total DC are presented as mean values and 95% confidence interval

FIGURE 4

CD86 density in myeloid dendritic cells (mDCs) (a), plasmacytoid (pDCs) (b) and immunoglobulin‐like transcript (ILT)3+ DCs (c) after kidney transplantation in patients receiving remote ischaemic conditioning (RIC) or non‐RIC. human leucocyte antigen (HLA)‐DR density in mDCs (d), pDCs (e) and ILT3+ DCs (f) after kidney transplantation in patients receiving RIC or non‐RIC. Graphs represent mean values and 95% confidence interval

FIGURE 5

Iterative cluster analysis based on total dendritic cell (DC) count and ratios of immunoglobulin‐like transcript (ILT)3+ DC to plasmacytoid (pDCs) and myeloid DCs (mDCs), respectively. Principal components of the cluster analysis are plotted to illustrate the segregation of the three clusters (a), estimated Glomerular Filtration Rate (eGFR) in the three clusters at 3 (b) and 12 (c) months, respectively

FIGURE 6

Plasma levels of 11 cytokines (of 21 measured) in non‐remote ischaemic conditioning (non‐RIC) and RIC‐treated patients who showed significant changes in time after transplantation. Graph represents mean values with 95% confidence interval