Strategies Using Bio-Layer Interferometry Biosensor Technology for Vaccine Research and Development

Abstract

Bio-layer interferometry (BLI) real-time, label-free technology has greatly contributed to advances in vaccine research and development. BLI Octet platforms offer high-throughput, ease of use, reliability, and high precision analysis when compared with common labeling techniques. Many different strategies have been used to immobilize the pathogen or host molecules on BLI biosensors for real-time kinetics and affinity analysis, quantification, or high-throughput titer. These strategies can be used in multiple applications and shed light onto the structural and functional aspects molecules play during pathogen-host interactions. They also provide crucial information on how to achieve protection. This review summarizes some key BLI strategies used in human vaccine research and development.

Keywords: BLI; biosensor; label-free; real-time; vaccine.

Figure 1

Schematics of bio-layer interferometry (BLI) strategy using a nickel-charged tris-nitrilotriacetic (NTA) biosensor for the identification of viral L1 residues that are most active during vaccinia infection. Site-directed mutagenesis was used to alter L1 residues, and BLI was used to test their affinity to anti-L1 mAbs. Table shows binding constant results of M12B9-Fab versus wild-type, N27A, Q31A, and D35A. K_D is affinity constant, k_a is association constant, and k_d is dissociation constant. Table data was derived from published data [6] with author consent.

Figure 2

Schematics of BLI strategy using anti-human IgG Fc (AHC) biosensor for the characterization of Hepatitis C viral (HCV) epitope scaffolds (magenta) generated from antigenic sites of the HCV envelope glycoproteins E1 and E2. (A) Scaffold models and corresponding BLI sensorgrams showing fast on/fast off binding kinetics of E1 peptide and epitope scaffolds (2F60_K_ES and 1VQO_U_ES) to IGH526 antibodies; (B) Scaffold models and corresponding BLI sensorgrams showing fast on/slow off binding kinetics of E2 peptide and epitope scaffolds (3S7R_A_ES and 1T07_A_ES). All sensorgrams and epitope scaffolds reprinted from He et al. 2015 [10] with author permission.

Figure 3

Schematic drawing showing in-tandem epitope binning strategy using a biofilm formation protein from Klebsiella pneumoniae. Diagram depicts biotinylated MrkA antigen immobilized on a streptavidin (SA) biosensor and exposed to competing antibody clones, which interact with corresponding epitopes. Sensorgram, adapted from Wang et al. 2017 [14] with permission, shows binding curve of different clones; buffer and clone 4 (binding site not available) are controls.

Figure 4

Schematic drawing showing the high-throughput strategy used for screening and mapping antibodies in relation to corresponding Ebola viral GP antigen variants. In this case, an anti-human IgG Fc antibody that coats the AHQ biosensor was used to capture the antibodies from Ebola survivors [24].

Figure 5

Diagram showing how BLI can be used for characterization of bispecific antibodies. In this example, bi-specific antibodies were generated to harbor Fc regions of both VRC07 and PG9-16 neutralizing arms against HIV virus. The VRC07 arm was bound to the streptavidin (SA) biosensor containing its target CD4 antigen, then the second arm PG9-16 allowed to bind to its V₁V₂ antigen, in a classic sandwich approach. Sensorgram, reprinted with permission [29], shows VRC07 + PG9-16 bispecific antibody (red line) versus VRC07 (green line) and no antibody (Ab) (dark blue line) control binding profiles.

Figure 6

Schematic drawing showing a BLI strategy to capture virus-like particles (VLPs). mAbs were captured on the surface of the AR2G biosensor and the Chikungunya (CHIKV) VLPs allowed to bind to the mAbs. Sensorgram shows the binding of CHIKV VLP to the biosensor in comparison to the buffer control. Note that sensorgram was reprinted with author permission [30].

Figure 7

Pictorial representation of whole influenza virus binding to streptavidin (SA) biosensor by means of biotinylated sialic acid polymers.

Figure 8

Schematics of BLI approach using SA biosensor to bind to biotinylated 5′UTR RNA and allowed to bind to translational factor eEF1A, during HIV-host interaction. Sensorgrams shows the binding of 5′UTR to the eEF1A factor versus the controls, reprinted with author permission [33].