Abstract
Purpose :
We have previously demonstrated that adoptively transferred donor-derived plasmacytoid dendritic cells (pDCs) promoted allograft survival in a mouse model of corneal transplantation. Herein, we aimed to determine whether third-party pDCs, the logical and most relevant origin in a clinical setting, have the potential to improve corneal allograft survival, and whether adoptively transferred pDCs home to the sites for allo-sensitization of T cells, which mediate immune rejection, the main cause of graft failure.
Methods :
We performed corneal transplantation using BALB/c mice (H2d) recipients and C57BL/6 (H2b) donors. At d1 post-surgery, we sorted splenic pDCs from C3H/HeJ mice (H2k) via flow cytometry, followed by labeling pDCs with CellTrace (CMTMR) and transferring labeled pDCs (2×104) or saline (sham control) to the cornea using fibrin sealant. We performed immunostaining to assess presence of pDCs in the cornea and conjunctiva, and flow cytometry to examine pDCs in ipsilateral draining lymph node (dLNs), spleen, and thymus. Corneas were assessed for 42 days via slit-lamp for neovascularization (NV, 0-8 scale), graft opacity (0-5 scale) and rejection (graft opacity ≥ score 3). We evaluated graft survival by Kaplan-Meier survival curves followed by log-rank test. We performed comparisons using unpaired t-test.
Results :
On day 7 after transplantation, only a few CMTMR+pDCs remained in the cornea and to a lesser degree in the conjunctiva. The majority of transferred CMTMR+pDCs (2,000±714.7) were found in dLNs, accounting for 10.0±3.57% of total transferred pDCs. CMTMR+pDCs were also found in the thymus (512.8±61.64 and 2.6±0.31% respectively) and spleen (362.5±70.32 and 1.8±0.35% respectively). Transferred pDCs suppressed corneal NV between d10 to d42 (score 3.1±0.38/mean±SEM to 4.4±0.31, for pDC-treated group vs. 4.0±0.23 to 6.4±0.22, for sham group; p<0.05 for all timepoints), alleviated graft opacity from d14 to d42 (score 1.6±0.22 to 2.0±0.25 vs 1.1±0.21 to 3.8±0.45; all p<0.05), and improved grafts survival (90% vs 37.5%; p=0.010) through the end of 42 days. The effect of third-Party pDCs on allograft survival was comparable to that of donor-specific pDCs (83.3%, p>0.05) previously in this model.
Conclusions :
Adoptive transfer of third party allo-pDCs are effective in promoting allograft survival in a murine model of corneal transplantation
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.