Delivery of costimulatory blockade to lymph nodes promotes transplant acceptance in mice
Jing Zhao, … , Jonathan S. Bromberg, Reza Abdi
Jing Zhao, … , Jonathan S. Bromberg, Reza Abdi
Published December 15, 2022
Citation Information: J Clin Invest. 2022;132(24):e159672. https://doi.org/10.1172/JCI159672.
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Research Article

Delivery of costimulatory blockade to lymph nodes promotes transplant acceptance in mice

Abstract

The lymph node (LN) is the primary site of alloimmunity activation and regulation during transplantation. Here, we investigated how fibroblastic reticular cells (FRCs) facilitate the tolerance induced by anti-CD40L in a murine model of heart transplantation. We found that both the absence of LNs and FRC depletion abrogated the effect of anti-CD40L in prolonging murine heart allograft survival. Depletion of FRCs impaired homing of T cells across the high endothelial venules (HEVs) and promoted formation of alloreactive T cells in the LNs in heart-transplanted mice treated with anti-CD40L. Single-cell RNA sequencing of the LNs showed that anti-CD40L promotes a Madcam1+ FRC subset. FRCs also promoted the formation of regulatory T cells (Tregs) in vitro. Nanoparticles (NPs) containing anti-CD40L were selectively delivered to the LNs by coating them with MECA-79, which binds to peripheral node addressin (PNAd) glycoproteins expressed exclusively by HEVs. Treatment with these MECA-79–anti-CD40L-NPs markedly delayed the onset of heart allograft rejection and increased the presence of Tregs. Finally, combined MECA-79–anti-CD40L-NPs and rapamycin treatment resulted in markedly longer allograft survival than soluble anti-CD40L and rapamycin. These data demonstrate that FRCs are critical to facilitating costimulatory blockade. LN-targeted nanodelivery of anti-CD40L could effectively promote heart allograft acceptance.

Authors

Jing Zhao, Sungwook Jung, Xiaofei Li, Lushen Li, Vivek Kasinath, Hengcheng Zhang, Said N. Movahedi, Ahmad Mardini, Gianmarco Sabiu, Yoonha Hwang, Vikas Saxena, Yang Song, Bing Ma, Sophie E. Acton, Pilhan Kim, Joren C. Madsen, Peter T. Sage, Stefan G. Tullius, George C. Tsokos, Jonathan S. Bromberg, Reza Abdi

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Figure 5

MECA-79–anti-CD40L-NPs alone or in combination with rapamycin prolongs heart allograft survival in mice.

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MECA-79–anti-CD40L-NPs alone or in combination with rapamycin prolongs h...
(A) Comparison of heart allograft survival between WT recipients of BALB/c hearts that were given no treatment, free anti-CD40L, or MECA-79–anti-CD40L-NPs (n = 5 mice/group; MST = 7 days vs. 8 days vs. 17 days, respectively); comparison of heart allograft survival between C57BL/6 recipients of BALB/c hearts that were treated with rapamycin (RAPA) (n = 5 mice/group, MST = 9 days), a combination of free anti-CD40L and RAPA (n = 5 mice/group, MST = 24 days), or a combination of MECA-79–anti-CD40L-NPs and RAPA (n = 5 mice/group, MST = 80 days). Log-rank test for graft survival. (B) Comparison of percentage of area in cortical area of Foxp3+ Tregs in DLNs by immunofluorescence. (C) Comparison of cellular infiltration and vascular damage between heart allografts in WT recipients following treatment with a combination of free anti-CD40L and RAPA or a combination of MECA-79–anti-CD40L-NPs and RAPA (n = 4 mice/group). (D) Representative florescence micrographs of CD3+ T cells and Foxp3+ Tregs in heart allograft sections of WT recipients. Scale bars: 100 μm. (E) Quantification of Foxp3+/CD3+ ratio in heart allografts by immunofluorescence. (F) Representative fluorescence micrographs of fibronectin staining in heart allograft sections of WT recipients. Scale bars: 100 μm. (G) Comparison of the Treg/Teff ratio in DLNs by flow cytometry. Student’s t test for 2-group comparisons. Data presented as mean ± SEM. *P < 0.05; **P < 0.01.