International Journal of Nanomedicine (Jan 2025)

Viral Mimetic Bacterial Outer Membrane Vesicles for Targeting Angiotensin-Converting Enzyme 2

  • Ahn G,
  • Yoon HW,
  • Jeong JH,
  • Kim YH,
  • Shin WR,
  • Song MS,
  • Ahn JY

Journal volume & issue
Vol. Volume 20
pp. 669 – 684

Abstract

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Gna Ahn,1,2,* Hyo-Won Yoon,1,* Ju Hwan Jeong,3,4,* Yang-Hoon Kim,1,* Woo-Ri Shin,1,5,6 Min-Suk Song,3 Ji-Young Ahn1 1Department of Microbiology, Chungbuk National University, Cheongju, Republic of Korea; 2Center for Ecology and Environmental Toxicology, Chungbuk National University, Cheongju, Republic of Korea; 3Department of Microbiology, College of Medicine and Medical Research Institute, Chungbuk National University, Cheongju, Republic of Korea; 4Functional Biomaterial Research Center, Korea Research Institute of Bioscience and Biotechnology, Jeongeup, Republic of Korea; 5Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA; 6Department of Animal Bioscience & Integrated Biotechnology, Gyeongsang National University, Jinju, Republic of Korea*These authors contributed equally to this workCorrespondence: Ji-Young Ahn; Min-Suk Song, Tel +82-43-261-2301 ; +82-43-261-3778, Email [email protected]; [email protected]: Outer membrane vesicles (OMVs) derived from Gram-negative bacteria naturally serve as a heterologous nano-engineering platform, functioning as effective multi-use nanovesicles for diagnostics, vaccines, and treatments against pathogens. To apply refined OMVs for human theranostic applications, we developed naturally exposed receptor-binding domain (RBD) OMVs grafted with antigen 43 as a minimal modular system targeting angiotensin-converting enzyme 2 (ACE2).Methods: We constructed E. coli-derived OMVs using the antigen 43 autotransporter system to display RBD referred to as viral mimetic Ag43β 700_RBD OMVs. Based on this, Ag43β 700_RBD protein were expressed onto Escherichia coli (E. coli) membrane. Artificial viral mimetic Ag43β 700_RBD OMVs were fabricated by self-assembly through membrane disruption of the Ag43β 700_RBD E. coli using a chemical detergent mainly containing lysozyme. Through serial centrifugation to purify fabricated OMVs, spherical Ag43β 700_RBD OMVs with an average diameter of 218 nm were obtained. The confirmation of the RBD expressed on OMVs was performed using trypsin treatment.Results: Our viral mimetic Ag43β 700_RBD OMVs had an impact on the theranostic studies: (i) angiotensin-converting enzyme 2 blockade assay, (ii) enzyme-linked immunosorbent assay for the OMVs, and (iii) intracellular uptake and neutralization assay. As serodiagnostic surrogates, Ag43β 700_RBD OMVs were applied to ACE2 blockade and OMVs-ELISA assay to quantify neutralization antibodies (nAbs). They reduced the robust immune response in vitro, especially IL-6 and IL-1β. Experiments in mice, Ag43β 700_RBD OMVs was successfully proven to be safe and effective; they produced a detectable level of nAbs with 39– 58% neutralisation and reduced viral titres in the lungs and brain without weight loss.Conclusion: The developed viral mimetic Ag43β 700_RBD OMVs may therefore be applied as a nanovesicle-theranostic platform for further emerging infectious disease-related diagnosis, vaccination, and treatment. Keywords: outer membrane vesicle, antigen 43 autotransporters, targeted delivery vehicle, theranostics, angiotensin-converting enzyme 2

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