Augmented humoral responses to HIV Env trimers delivered as transmembrane immunogens by self-replicating RNA

Parisa Yousefpour; Amrit Raj Ghosh; Himanshi Chawla; Rachel Yeung; Justin Gregory; Kristen Si; Tanaka K Remba; Kristen A Rodrigues; Mariane B Melo; Jonathan Dye; Jon M Steichen; Yuebao Zhang; Yizhou Dong; Max Crispin; William R Schief; Facundo D Batista; Darrell J Irvine

doi:10.1016/j.ymthe.2025.07.036

Augmented humoral responses to HIV Env trimers delivered as transmembrane immunogens by self-replicating RNA

Mol Ther. 2025 Oct 1;33(10):4858-4873. doi: 10.1016/j.ymthe.2025.07.036. Epub 2025 Jul 29.

Authors

Parisa Yousefpour¹, Amrit Raj Ghosh², Himanshi Chawla³, Rachel Yeung⁴, Justin Gregory⁴, Kristen Si⁵, Tanaka K Remba⁴, Kristen A Rodrigues⁶, Mariane B Melo⁷, Jonathan Dye⁴, Jon M Steichen⁸, Yuebao Zhang⁹, Yizhou Dong¹⁰, Max Crispin³, William R Schief¹¹, Facundo D Batista¹², Darrell J Irvine¹³

Affiliations

¹ Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA; Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA, USA; Consortium for HIV/AIDS Vaccine Development, The Scripps Research Institute, La Jolla, CA 92037, USA.
² Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA, USA.
³ School of Biological Sciences, University of Southampton, SO17 1BJ Southampton, UK.
⁴ Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA.
⁵ Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA.
⁶ Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA; Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA, USA; Consortium for HIV/AIDS Vaccine Development, The Scripps Research Institute, La Jolla, CA 92037, USA; Harvard-MIT Health Sciences and Technology Program, Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
⁷ Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA; Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA, USA; Consortium for HIV/AIDS Vaccine Development, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA.
⁸ Consortium for HIV/AIDS Vaccine Development, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA; IAVI Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA.
⁹ Division of Pharmaceutics & Pharmacology, College of Pharmacy, The Ohio State University, Columbus, OH 43210, USA.
¹⁰ Icahn Genomics Institute, Precision Immunology Institute, Department of Immunology and Immunotherapy, Department of Oncological Sciences, Tisch Cancer Institute, Friedman Brain Institute, Biomedical Engineering and Imaging Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
¹¹ Consortium for HIV/AIDS Vaccine Development, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA; IAVI Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037, USA; Moderna, Cambridge, MA 02139, USA.
¹² Ragon Institute of Massachusetts General Hospital, Massachusetts Institute of Technology and Harvard University, Cambridge, MA, USA; Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
¹³ Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA; Consortium for HIV/AIDS Vaccine Development, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Immunology and Microbiology, The Scripps Research Institute, La Jolla, CA 92037, USA; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA; Howard Hughes Medical Institute, Chevy Chase, MD, USA. Electronic address: djirvine@scripps.edu.

Abstract

mRNA vaccines have emerged as an important platform for vaccine development. Unlike protein subunit vaccines, mRNA-expressed antigens can be expressed in either secreted or transmembrane (TM) forms mimicking a viral envelope (Env) protein. Here, we investigated the impact of antigen expression format on the antigenicity profile, glycosylation, and immunogenicity of stabilized HIV Env trimer immunogens expressed from self-replicating RNA (replicon) vaccines. Replicon-encoded trimers in both forms exhibited proper folding, and replicon-expressed secreted trimers exhibited glycosylation patterns largely consistent with recombinant trimer protein, although with enrichment of complex glycans over high mannose at some sites. Both formats were highly immunogenic in mice, eliciting comparable serum antibody and T cell responses. Interestingly, the TM format initiated smaller germinal center (GC) responses, but these GCs were enriched for trimer-binding B cells compared to secreted trimer vaccines. In a B cell receptor knockin adoptive transfer model for assessing germline targeting, the replicon-encoded TM trimer elicited a greater frequency of epitope-targeting antibodies and recruited broadly neutralizing antibody precursor B cells to the GC response more efficiently compared to the replicon-encoded secreted trimer or protein trimer combined with adjuvant. These results indicate that the form of immunogen expression can impact key elements of immune responses to RNA vaccines.

Keywords: BG18; HIV bnAbs; HIV trimer; RNA vaccines; expression form; replicon RNA.

MeSH terms

AIDS Vaccines* / genetics
AIDS Vaccines* / immunology
Animals
Antibodies, Neutralizing / immunology
B-Lymphocytes / immunology
Epitopes / immunology
Female
Germinal Center / immunology
Glycosylation
HIV Antibodies / immunology
HIV Infections* / immunology
HIV Infections* / prevention & control
HIV Infections* / virology
HIV-1* / immunology
Humans
Immunity, Humoral*
Mice
Protein Multimerization
env Gene Products, Human Immunodeficiency Virus* / chemistry
env Gene Products, Human Immunodeficiency Virus* / genetics
env Gene Products, Human Immunodeficiency Virus* / immunology
mRNA Vaccines / immunology

Substances

env Gene Products, Human Immunodeficiency Virus
AIDS Vaccines
Antibodies, Neutralizing
HIV Antibodies
Epitopes
mRNA Vaccines

Abstract

MeSH terms

Substances

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