Incorporating B cell activating factor (BAFF) into the membrane of rabies virus (RABV) particles improves the speed and magnitude of vaccine-induced antibody responses

PLoS Negl Trop Dis. 2019 Nov 14;13(11):e0007800. doi: 10.1371/journal.pntd.0007800. eCollection 2019 Nov.

Abstract

B cell activating factor (BAFF) is a member of the tumor necrosis factor (TNF) superfamily of cytokines that links innate with adaptive immunity. BAFF signals through receptors on B cells, making it an attractive molecule to potentiate vaccine-induced B cell responses. We hypothesized that a rabies virus (RABV)-based vaccine displaying both antigen and BAFF on the surface of the same virus particle would target antigen-specific B cells for activation and improve RABV-specific antibody responses. To test this hypothesis, we constructed a recombinant RABV-based vector expressing virus membrane-anchored murine BAFF (RABV-ED51-mBAFF). BAFF was incorporated into the RABV particle and determined to be biologically functional, as demonstrated by increased B cell survival of primary murine B cells treated ex-vivo with RABV-ED51-mBAFF. B cell survival was inhibited by pre-treating RABV-ED51-mBAFF with an antibody that blocks BAFF functions. RABV-ED51-mBAFF also activated primary murine B cells ex-vivo more effectively than RABV as shown by significant upregulation of CD69, CD40, and MHCII on the surface of infected B cells. In-vivo, RABV-ED51-mBAFF induced significantly faster and higher virus neutralizing antibody (VNA) titers than RABV while not adversely affecting the longevity of the vaccine-induced antibody response. Since BAFF was incorporated into the virus particle and genome replication was not required for BAFF expression in-vivo, we hypothesized that RABV-ED51-mBAFF would be effective as an inactivated vaccine. Mice immunized with 250 ng/mouse of β-propriolactone-inactivated RABV-ED51-mBAFF showed faster and higher anti-RABV VNA titers compared to mice immunized with inactivated RABV. Together, this model stands as a potential foundation for exploring other virus membrane-anchored molecular adjuvants to make safer, more effective inactivated RABV-based vaccines.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adjuvants, Immunologic
  • Animals
  • Antibodies, Viral / blood
  • Antibody Formation / immunology*
  • B-Cell Activating Factor / immunology*
  • B-Lymphocytes / immunology*
  • Cytokines / metabolism
  • Female
  • Immunization
  • Kinetics
  • Mice
  • Mice, Inbred C57BL
  • Rabies / immunology*
  • Rabies / prevention & control*
  • Rabies Vaccines / adverse effects
  • Rabies Vaccines / immunology*
  • Rabies virus / genetics
  • Rabies virus / growth & development
  • Rabies virus / immunology
  • Vaccination
  • Vaccines, Attenuated / immunology
  • Vaccines, Inactivated / adverse effects
  • Vaccines, Inactivated / immunology
  • Vaccines, Synthetic
  • Virion / immunology*

Substances

  • Adjuvants, Immunologic
  • Antibodies, Viral
  • B-Cell Activating Factor
  • Cytokines
  • Rabies Vaccines
  • Vaccines, Attenuated
  • Vaccines, Inactivated
  • Vaccines, Synthetic