E2 multimeric scaffold for vaccine formulation: immune response by intranasal delivery and transcriptome profile of E2-pulsed dendritic cells

Abstract

BackgroundThe E2 multimeric scaffold represents a powerful delivery system able to elicit robust humoral and cellular immune responses upon systemic administrations. Here recombinant E2 scaffold displaying the third variable loop of HIV-1 Envelope gp120 glycoprotein was administered via mucosa, and the mucosal and systemic immune responses were analysed. To gain further insights into the molecular mechanisms that orchestrate the immune response upon E2 vaccination, we analysed the transcriptome profile of dendritic cells (DCs) exposed to the E2 scaffold with the aim to define a specific gene expression signature for E2-primed immune responses.ResultsThe in vivo immunogenicity and the potential of E2 scaffold as a mucosal vaccine candidate were investigated in BALB/c mice vaccinated via the intranasal route. Fecal and systemic antigen-specific IgA antibodies, cytokine-producing CD4+ and CD8+ cells were induced assessing the immunogenicity of E2 particles via intranasal administration. The cytokine analysis identified a mixed T-helper cell response, while the systemic antibody response showed a prevalence of IgG1 isotype indicative of a polarized Th2-type immune response. RNA-Sequencing analysis revealed that E2 scaffold up-regulates in DCs transcriptional regulators of the Th2-polarizing cell response, defining a type 2 DC transcriptomic signature.ConclusionsThe current study provides experimental evidence to the possible application of E2 scaffold as antigen delivery system for mucosal immunization and taking advantages of genome-wide approach dissects the type of response induced by E2 particles.

Distinct Antigen Delivery Systems Induce Dendritic Cells’ Divergent Transcriptional Response: New Insights from a Comparative and Reproducible Computational Analysis

“…Collectively, the model that we propose based on our previous reports [5,10,14,25] and on data emerging from this comparative analysis is: the fd bacteriophage targeted to the dendritic cells via the DEC-205 receptor exactly recapitulates what happens after a viral infection, activating the cytosolic DNA sensors and in turn the inflammosome and the Il-1b production.…”

“…Isolation of RNA from BMDCs, library preparation, and sequencing have been described previously [10,14]. Briefly, RNA was isolated from cells collected in Tri Reagent (Sigma-Aldrich) according to the manufacturer’s instructions.…”

“…We have already demonstrated that the E2 system is able to induce, upon systemic administrations, a strong humoral response in a mouse model, also inducing the formation of neutralizing antibodies against a clade of Human Immunodeficiency Virus (HIV) viruses, when used to display the third variable (V3) loop of the gp120 HIV protein [5,9]. Using a mouse model of mucosal vaccination, we also proved the potential application of the E2 scaffold as an antigen delivery system for mucosal immunization [10]. The second antigen delivery system described here is based on a modification of the phage display technology.…”

Analysis of the Consolidation Phase of Immunological Memory within the IgG Response to a B Cell Epitope Displayed on a Filamentous Bacteriophage

“…Monthly immunizations with fdAD(2-6) afford a significant reduction of Aβ plaque pathology in a mouse model of Alzheimer's Disease [11]. Phage vaccine fdAD(2-6) differs from the (1-11)E2 vaccine that was initially used to identify the memory consolidation phase in the nature of the vaccine carrier (filamentous phage versus multimeric protein), in the polarization of the T cell response (TH1 versus TH2), and in the length of the B cell epitope (5 aminoacid Aβ peptide AEFRH versus 11 aminoacid Aβ peptide DAEFRHDSGYE) [9][10][11][12][13][14].…”

Vaccination with (1–11)E2 in alum efficiently induces an antibody response to β-amyloid without affecting brain β-amyloid load and microglia activation in 3xTg mice

“…(1-11)E2 is able to induce an antibody response to β-amyloid, immunological memory, and IL-4 production, with no concomitant anti-Aβ T cell response and induces antibodies that recognize β-amyloid oligomers, protofibrils, and fibrils [5][6][7][8]. In this study, we show that a three-dose vaccination with (1-11)E2 in alum did not reduce β-amyloid load in 3xTg mice, despite efficiently inducing anti-β-amyloid antibodies.…”