A Bivalent, Chimeric Rabies Virus Expressing Simian Immunodeficiency Virus Envelope Induces Multifunctional Antibody Responses

AIDS Res Hum Retroviruses. 2015 Nov;31(11):1126-38. doi: 10.1089/AID.2014.0319. Epub 2015 May 5.

Abstract

We previously showed that a matrix (M) gene-deleted rabies virus (RABV)-based vaccine (RABV-ΔM) is highly immunogenic and induces potent B cell responses in the context of RABV infection. We speculated that RABV-ΔM expressing HIV proteins would also induce potent B cell responses against HIV antigens. As a prerequisite to future studies in nonhuman primates, we completed immunogenicity studies in mice to confirm the ability of RABV-ΔM to induce polyfunctional B cell responses in the context of HIV. To that end, the envelope protein from the mac239 strain of SIV (SIVmac239Env) was cloned into RABV-ΔM, resulting in RABV-ΔM-Env. Infectious virus was recovered following standard methods and propagated on baby hamster kidney cells stably expressing RABV M [>10(7) focus forming units (ffu)/ml]. Western blot analysis of cell lysates or of purified virions confirmed Env expression on the surface of infected cells and within virus particles, respectively. Positive neutralization activity against a neutralization-sensitive SIV strain and to a lesser extent against a neutralization-resistant SIV strain was detected in mice after a single intramuscular inoculation with RABV-ΔM-Env. The quality, but not quantity, of the antibody response was enhanced via boosting with recombinant gp130 or RABV-ΔM-Env as measured by an increase in antibody avidity and a skewing toward a Th1-type antibody response. We also show that an intradermal inoculation induces higher antibodies than an intramuscular or intranasal inoculation. An intradermal inoculation of RABV-ΔM-Env followed by a boost inoculation with recombinant gp130 produced anti-SIV antibodies with neutralizing and nonneutralizing antibody (nNAb) effector functions. Together, RABV-ΔM-Env induces B cells to secrete antibodies against SIV with the potential to clear both "free" and cell-associated virus. Strategies capable of eliciting both NAbs as well as nNAbs might help to improve the efficacy of HIV-1 vaccines.

Publication types

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

MeSH terms

  • Animals
  • Antibodies, Viral / blood*
  • Antibody Formation*
  • B-Lymphocytes / immunology
  • Female
  • Injections, Intradermal
  • Injections, Intramuscular
  • Mice, Inbred C57BL
  • Rabies Vaccines / administration & dosage
  • Rabies Vaccines / genetics
  • Rabies Vaccines / immunology*
  • Rabies virus / genetics
  • Rabies virus / immunology*
  • SAIDS Vaccines / administration & dosage
  • SAIDS Vaccines / genetics
  • SAIDS Vaccines / immunology*
  • Simian Immunodeficiency Virus / genetics
  • Simian Immunodeficiency Virus / immunology*

Substances

  • Antibodies, Viral
  • Rabies Vaccines
  • SAIDS Vaccines