Exposure to wild-type AAV drives distinct capsid immunity profiles in humans
Klaudia Kuranda, Priscilla Jean-Alphonse, Christian Leborgne, Romain Hardet, Fanny Collaud, Solenne Marmier, Helena Costa Verdera, Giuseppe Ronzitti, Philippe Veron, Federico Mingozzi
Klaudia Kuranda, Priscilla Jean-Alphonse, Christian Leborgne, Romain Hardet, Fanny Collaud, Solenne Marmier, Helena Costa Verdera, Giuseppe Ronzitti, Philippe Veron, Federico Mingozzi
View: Text | PDF
Research Article Immunology

Exposure to wild-type AAV drives distinct capsid immunity profiles in humans

Abstract

Recombinant adeno-associated virus (AAV) vectors have been broadly adopted as a gene delivery tool in clinical trials, owing to their high efficiency of transduction of several host tissues and their low immunogenicity. However, a considerable proportion of the population is naturally exposed to the WT virus from which AAV vectors are derived, which leads to the acquisition of immunological memory that can directly determine the outcome of gene transfer. Here, we show that prior exposure to AAV drives distinct capsid immunity profiles in healthy subjects. In peripheral blood mononuclear cells (PBMCs) isolated from AAV-seropositive donors, recombinant AAV triggered TNF-α secretion in memory CD8+ T cells, B cell differentiation into antibody-secreting cells, and anti-capsid antibody production. Conversely, PBMCs isolated from AAV-seronegative individuals appeared to carry a population of NK cells reactive to AAV. Further, we demonstrated that the AAV capsid activates IL-1β and IL-6 cytokine secretion in monocyte-related dendritic cells (moDCs). IL-1β and IL-6 blockade inhibited the anti-capsid humoral response in vitro and in vivo. These results provide insights into immune responses to AAV in humans, define a possible role for moDCs and NK cells in capsid immunity, and open new avenues for the modulation of vector immunogenicity.

Authors

Klaudia Kuranda, Priscilla Jean-Alphonse, Christian Leborgne, Romain Hardet, Fanny Collaud, Solenne Marmier, Helena Costa Verdera, Giuseppe Ronzitti, Philippe Veron, Federico Mingozzi

×

Figure 6

AAV capsid triggers Il-1β–dependent B cell differentiation in vitro and in vivo.

Options: View larger image (or click on image) Download as PowerPoint
AAV capsid triggers Il-1β–dependent B cell differentiation in vitro and ...
(A) Percentage of ASCs defined as CD3–CD19+IgD–CD24–CD27+CD38++ relative to control PBMC cultures (n = 8). (B) Percentage of AAV2-specific ASCs in PBMCs from seropositive versus seronegative donors. (C) Percentage of AAV2-specific TNF-α+CD8+ T cells in PBMCs comprising or not capsid-specific ASCs. (D) Percentage of AAV2-specific IFN-γ+ NK cells in PBMCs comprising or not capsid-specific ASCs. (E) Concentration of anti–AAV2 IgM secreted in PBMC cultures obtained from AAV2-seropositive donors. (F) Percentage of B cell differentiation in PBMCs obtained from AAV2-seropositive donors, stimulated with an antigen pool of peptides and supplemented with cytokine-neutralizing antibodies or an isotype control (± SD). The numbers of ASCs in cultures with the isotype control were considered to be 100% of the antigen-specific B cell differentiation (n = 4). α–IL-1β, anti–IL-1β; α–IL-6, anti–IL-6. (G) Concentration of anti–AAV2 IgM secreted in PBMC cultures, stimulated with the AAV2 capsid particles and supplemented with cytokine-neutralizing antibodies or an isotype control. PBMCs were obtained from AAV2-seropositive donors (n = 3). (H) Experimental design for the data shown in I and J. On days –2, –1, 0, 1, 2, and 7, mice were injected i.p. with 1 mg/kg anti–IL-1β– or anti–IL-6–neutralizing antibodies or the corresponding isotype control (Ab). All mice received AAV8-hF.IX by i.v. injection (109 vg) on day 0. Blood was collected on day 21. (I) Effect of anti–IL-1β– and anti–IL-6–neutralizing antibodies on the anti-AAV8 antibody titers in mouse blood (n = 5/group). (J) VGCN per cell, measured by qPCR in mouse liver 3 months after vector injection. The box plots in B, C, D, I, and J show the median ± SD. *P < 0.05 and ***P < 0.001, by nonparametric Mann-Whitney U test (A–D), 2-tailed Student’s t test (E), and nonparametric Kruskal-Wallis 1-way ANOVA with Dunn’s multiple comparisons test (F, G, I, and J).