We have shown that nanoparticles (NPs) can be used as ligand-multimerization platforms to activate specific cellular receptors in vivo. Nanoparticles coated with autoimmune disease-relevant peptide-major histocompatibility complexes (pMHC) blunted autoimmune responses by triggering the differentiation and expansion of antigen-specific regulatory T cells in vivo. Here, we define the engineering principles impacting biological activity, detail a synthesis process yielding safe and stable compounds, and visualize how these nanomedicines interact with cognate T cells. We find that the triggering properties of pMHC–NPs are a function of pMHC intermolecular distance and involve the sustained assembly of large antigen receptor microclusters on murine and human cognate T cells. These compounds show no off-target toxicity in zebrafish embryos, do not cause haematological, biochemical or histological abnormalities, and are rapidly captured by phagocytes or processed by the hepatobiliary system. This work lays the groundwork for the design of ligand-based NP formulations to re-program in vivo cellular responses using nanotechnology.

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We thank S. Thiessen, J. Erickson and J. Luces for technical assistance, and L. Kennedy for flow cytometry. We acknowledge T. DiLorenzo for providing JurMA cells, H. Benediktsson for structural analyses of kidney TEM, R. Interior for amino acid analysis, W. White and D. Cramb for assistance with GD-mass spectrometry, FTIR and DLS, T. Furstenhaupt and W. Dong for SEBD and TEM, J.M. Rebled, A. Garcia, R. Rivera and A. Martínez from the TEM–SEM unit from the University of Barcelona (CCiT-UB) for TEM analyses of human T-cell clone:pMHC–NP conjugates, and the CMHD Unit at the Lunenfeld–Tanenbaum Institute for haematology and biochemistry. This work was funded by the Collaborative Health Research Program of the Canadian Institutes of Health Research (CIHR) and the Natural Sciences and Engineering Research Council of Canada, the Instituto de Investigaciones Sanitarias Carlos III, the Ministerio de Economia y Competitividad of Spain (MINECO), and the Sardà Farriol Research Programme. X.C.C. was supported by studentships from the AXA Research Fund and the endMS network. K.S. is funded by Eyes’ High/Alberta Innovates-Technology Futures, Alberta Innovates–Health Solutions (AI-HS) and Banting-CIHR fellowships. C.S.U. is supported by AI-HS and Banting-CIHR fellowhips. R.H.N. is supported by studentships from AI-HS and CIHR. S.W.L. was partially supported by a studentship from Fonds de Recherche du Quebec - Nature et Technologies. J.B. was supported by a Rio Hortega fellowship from the Ministry of Economy and Competitiveness of Spain and by a fellowship from the European Association for the Study of Diabetes (EASD). P.Serra is a Ramon y Cajal investigator supported by a Juvenile Diabetes Research Foundation Career Development Award. P.Santamaria is Scientist of the Alberta Innovates-Health Solutions and a scholar of the IISCIII. The JMDRC is supported by the Canadian Diabetes Association (CDA).

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Author notes

    • Santiswarup Singha
    •  & Kun Shao

    These authors contributed equally to this work.


  1. Julia McFarlane Diabetes Research Centre (JMDRC) and Department of Microbiology, Immunology and Infectious Diseases, Snyder Institute for Chronic Diseases and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada

    • Santiswarup Singha
    • , Kun Shao
    • , Yang Yang
    • , Xavier Clemente-Casares
    • , Jun Yamanouchi
    • , Channakeshava Sokke Umeshappa
    • , Roopa Hebbandi Nanjundappa
    •  & Pere Santamaria
  2. Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada

    • Yang Yang
  3. Institut D'Investigacions Biomèdiques August Pi i Sunyer, Barcelona 08036, Spain

    • Patricia Solé
    • , Antonio Clemente
    • , Jesús Blanco
    • , César Fandos
    • , Pau Serra
    •  & Pere Santamaria
  4. Institute of Biomaterials and Biomedical Engineering, Departments of Chemistry, Chemical Engineering, and Materials Sciences and Engineering, Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 164 College Street, Toronto, Ontario M5S 3G9, Canada

    • Qin Dai
    • , Fayi Song
    •  & Warren C. W. Chan
  5. Department of Physiology, McGill University, McIntyre Medical Building, Montreal, Quebec H3G 1Y6, Canada

    • Shang Wan Liu
    •  & Anmar Khadra
  6. Departments of Cell Biology and Anatomy, and Pathology & Laboratory Medicine, Faculty of Medicine, University of Calgary, Calgary, Alberta T2N 4N1, Canada

    • Pascal Detampel
    •  & Matthias Amrein
  7. Environmental & Molecular Toxicology Sinnhuber Aquatic Research Laboratory, Oregon State University, Corvalis, Oregon 97333, USA

    • Robert Tanguay
  8. Center for Modeling Human Disease, Toronto Centre for Phenogenomics, Lunenfeld Research Institute, 25 Orde Street, Toronto, Ontario M5T 3H7, Canada

    • Susan Newbigging


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S.S. and Y.Y. developed and produced all the pMHC–NPs, and data for Figs 1, 2a–j, 4a–c, 4e–g and Supplementary Figs 1, 4d–f,g, 5a and 7b, in collaboration with K.S.; K.S. produced data for Figs 2l, 4d, and Supplementary Figs 4a–c and 8. X.C. produced data for Figs 3e–h and 4i and Supplementary Figs 3 and 7a, in collaboration with J.Y.; P. Solé produced the JurMA TCR/mCDA transfectants and produced the data for Fig. 2k. J.Y. produced the data for Supplementary Fig. 4c. C.S.U. and R.H.N. produced murine pMHCs for this study. C.F. purified human pMHCs. J.B., A.C. and P. Serra produced data for Fig. 5. Q.D., F.S. and W.C.W.C. produced data for Fig. 6 and Supplementary Fig. 5. S.W.L. and A.K. generated all the mathematical models and produced Fig. 3a–d and Supplementary Figs 9 and 10. P.D. and M.A. contributed expertise in confocal microscopy and SEM. R.T. generated the zebrafish embryo toxicology data for Supplementary Fig. 6. S.N. carried out the multi-organ histopathology. P. Santamaria designed and supervised the study and wrote the manuscript with the assistance of S.S.

Competing interests

P. Santamaria is scientific founder of Parvus Therapeutics Inc. and has a financial interest in the company.

Corresponding authors

Correspondence to Yang Yang or Pere Santamaria.

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