Thermostability of Well-Ordered HIV Spikes Correlates with the Elicitation of Autologous Tier 2 Neutralizing Antibodies

PLoS Pathog. 2016 Aug 3;12(8):e1005767. doi: 10.1371/journal.ppat.1005767. eCollection 2016 Aug.


In the context of HIV vaccine design and development, HIV-1 spike mimetics displaying a range of stabilities were evaluated to determine whether more stable, well-ordered trimers would more efficiently elicit neutralizing antibodies. To begin, in vitro analysis of trimers derived from the cysteine-stabilized SOSIP platform or the uncleaved, covalently linked NFL platform were evaluated. These native-like trimers, derived from HIV subtypes A, B, and C, displayed a range of thermostabilities, and were "stress-tested" at varying temperatures as a prelude to in vivo immunogenicity. Analysis was performed both in the absence and in the presence of two different adjuvants. Since partial trimer degradation was detected at 37°C before or after formulation with adjuvant, we sought to remedy such an undesirable outcome. Cross-linking (fixing) of the well-ordered trimers with glutaraldehyde increased overall thermostability, maintenance of well-ordered trimer integrity without or with adjuvant, and increased resistance to solid phase-associated trimer unfolding. Immunization of unfixed and fixed well-ordered trimers into animals revealed that the elicited tier 2 autologous neutralizing activity correlated with overall trimer thermostability, or melting temperature (Tm). Glutaraldehyde fixation also led to higher tier 2 autologous neutralization titers. These results link retention of trimer quaternary packing with elicitation of tier 2 autologous neutralizing activity, providing important insights for HIV-1 vaccine design.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, Non-U.S. Gov't
  • Research Support, N.I.H., Extramural

MeSH terms

  • AIDS Vaccines / chemistry
  • AIDS Vaccines / immunology*
  • Animals
  • Antibodies, Neutralizing / immunology*
  • Glutaral / chemistry
  • Guinea Pigs
  • HIV Antibodies / immunology*
  • HIV-1 / chemistry
  • HIV-1 / immunology*
  • Humans
  • Immunogenicity, Vaccine / immunology
  • Protein Multimerization / immunology*
  • Protein Stability
  • env Gene Products, Human Immunodeficiency Virus / chemistry
  • env Gene Products, Human Immunodeficiency Virus / immunology*


  • AIDS Vaccines
  • Antibodies, Neutralizing
  • HIV Antibodies
  • env Gene Products, Human Immunodeficiency Virus
  • Glutaral