A Lambda-evo (λ) phage platform for Zika virus E protein display.

One of the most significant bacteriophage technologies is phage display, in which heterologous peptides are exhibited on the virion surface. This work describes the display of λ decorative protein D linked to the E protein domain III of Zika virus (D-ZE), to the GFP protein (D-GFP), or to different domain III epitopes of the E protein (D-TD), exhibited on the surface of an in vitro evolved lambda phage (λ). This phage harbors a gene D deletion and was subjected to directed evolution using Escherichia coli W3110/pD-ZE as background. After 20 days (20 cycles of dilution), the λ phage developed a ~ 22% genome deletion affecting the non-essential λ b region, rendering a more stable phage that exhibited fusion proteins D-ZE or D-GFP but not D-TD. Despite the λ system was able to decorate itself with the D-ZE protein, the production of viral particles was ~ 1000-fold lower than the λ wild-type, due to the unexpected D-ZE protein aggregation into bacterial inclusion bodies. Decorated phages (10 PFU (plaque forming units)/100 µl) were inoculated into BALB/c mice, and subsequent dot blot and Western blot immunoassays proved the production of murine antibodies against ZIKV (Zika virus). This multipurpose λ phage display platform may be used interchangeably with other more soluble peptides, providing better yields. KEY POINTS: • λ platform for displaying recombinant peptides. • Directed evolution to generate λ with more efficient decoration. • Antigenic reaction in BALB/c mice by inoculating λ with recombinant peptides.