Frontiers in Immunology (Apr 2022)

Dichotomy in Neutralizing Antibody Induction to Peptide-Conjugated Vaccine in Squalene Emulsion Contrast With Aluminum Hydroxide Formulation

  • Olivia Bonduelle,
  • Chloé Chaudesaigues,
  • Monica Tolazzi,
  • Ehsan Suleiman,
  • Simon de Bernard,
  • Karine Alves,
  • Julien Nourikyan,
  • Mylene Bohec,
  • Laura G. Baudrin,
  • Dietmar Katinger,
  • Patrice Debré,
  • Gabriella Scarlatti,
  • Vincent Vieillard,
  • Behazine Combadière

DOI
https://doi.org/10.3389/fimmu.2022.848571
Journal volume & issue
Vol. 13

Abstract

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W614A-3S peptide is a modified 3S motif of the HIV-gp41 (mutation W614A). We previously detected the presence of natural neutralizing antibodies directed against W614A-3S peptide (NAbs) in long-term non-progressor HIV+ patients. Here, we compared the efficacy of W614A-3S peptide formulated in either squalene emulsion (SQE) or in aluminum hydroxide (Alum) in inducing broadly-NAbs (bNAbs). Rabbit and mouse models were used to screen the induction of bNAbs following 4 immunizations. SQE was more efficient than Alum formulation in inducing W614A-3S-specific bNAbs with up to 67%–93% of HIV strains neutralized. We then analyzed the quality of peptide-specific murine B cells by single-cell gene expression by quantitative reverse transcription-PCR and single-cell V(D)J sequencing. We found more frequent germinal center B cells in SQE than in Alum, albeit with a different gene expression profile. The V(D)J sequencing of W614A-3S-specific BCR showed significant differences in BCR sequences and validates the dichotomy between adjuvant formulations. All sixteen BCR sequences which were cloned were specific of peptide. Adjuvant formulations of W614A-3S-peptide-conjugated immunogen impact the quantity and quality of B cell immune responses at both the gene expression level and BCR sequence.

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