siRNA against CD40 delivered via a fungal recognition receptor ameliorates murine acute graft-versus-host disease

Beate Heissig; Yousef Salama; Masatoshi Tateno; Satoshi Takahashi; Koichi Hattori

doi:10.1002/jha2.439

siRNA against CD40 delivered via a fungal recognition receptor ameliorates murine acute graft-versus-host disease

EJHaem. 2022 May 6;3(3):849-861. doi: 10.1002/jha2.439. eCollection 2022 Aug.

Authors

Beate Heissig¹, Yousef Salama², Masatoshi Tateno³, Satoshi Takahashi⁴, Koichi Hattori⁵

Affiliations

¹ Department of Research Support Utilizing Bioresource Bank Graduate School of Medicine Juntendo University School of Medicine Tokyo Japan.
² An-Najah Center for Cancer and Stem Cell Research Faculty of Medicine and Health Sciences An-Najah National University Nablus Palestine.
³ Department of Pathology Kushiro Red Cross Hospital Kushiro Hokkaido Japan.
⁴ Division of Clinical Precision Research Platform Institute of Medical Science University of Tokyo Tokyo Japan.
⁵ Center for Genomic & Regenerative Medicine Juntendo University School of Medicine Tokyo Japan.

Abstract

Acute graft-versus-host disease (aGvHD) remains a major threat to a successful outcome after allogeneic hematopoietic stem cell transplantation (HSCT). Although antibody-based targeting of the CD40/CD40 ligand costimulatory pathway can prevent aGvHD, side effects hampered their clinical application, prompting a need for other ways to interfere with this important dendritic T-cell costimulatory pathway. Here, we used small interfering RNA (siRNA) complexed with β-glucan allowing the binding and uptake of the siRNA/β-glucan complex (siCD40/schizophyllan [SPG]; chemical modifications called NJA-312, NJA-302, and NJA-515) into Dectin1+ cells, which recognize this pathogen-associated molecular pattern receptor. aGvHD was induced by the transplantation of splenocytes and bone marrow cells from C57BL/6J into CBF1 mice. Splenic dendritic cells retained Dectin1 expression after HSCT but showed lower expression after irradiation. The administration of siCD40/SPG, NJA-312, and NJA-302 ameliorated aGvHD-mediated lethality and tissue damage of spleen and liver, but not skin. Multiple NJA-312high injections prevented aGvHD but resulted in early weight loss in allogeneic HSCT mice. In addition, NJA-312 treatment caused delayed initial donor T and B-cell recovery but resulted in stable chimerism in surviving mice. Mechanistically, NJA-312 reduced organ damage by suppressing CCR2+, F4/80+, and IL17A-expressing cell accumulation in spleen, liver, and thymus but not the skin of mice with aGvHD. Our work demonstrates that siRNA targeting of CD40 delivered via the PAMP-recognizing lectin Dectin1 changes the immunological niche, suppresses organ-specific murine aGvHD, and induces immune tolerance after organ transplantation. Our work charts future directions for therapeutic interventions to modulate tissue-specific immune reactions using Pathogen-associated molecular pattern (PAMP) molecules like 1,3-β-glucan for cell delivery of siRNA.

Keywords: CCR2; CD40; Dectin1; IL17A; PAMP; acute GvHD; bone marrow transplantation; cytokine; siRNA.