Multiple Low-dose Challenges in a Rhesus Macaque AIDS Vaccine Trial Result in an Evolving Host Response that affects Protective Outcome
Ontology highlight
ABSTRACT: Using whole-blood transcriptional profiling, we investigated differences in the host response to vaccination and challenge in a rhesus macaque AIDS vaccine trial. Samples were collected from animals prior to and after vaccination with live irradiated vaccine cells secreting the modified endoplasmic reticulum chaperone gp96-Ig loaded with SIV peptides, either alone or in combination with a SIV-gp120 protein boost. Additional samples were collected following multiple low-dose rectal challenge with SIVmac251. Animals in the boosted group had a 73% reduced risk of infection. Surprisingly, few changes in gene expression were observed during the vaccination phase. Focusing on post-challenge comparisons, in particular for protected animals, we identified a host response signature of protection comprised of strong interferon signaling after the first challenge, which then largely abated after further challenges. We also identified a host response signature, comprised of early macrophage-mediated inflammatory responses, in animals with undetectable viral load five days after the first challenge, but which had unusually high viral titers after subsequent challenges. Statistical analysis showed that prime-boost vaccination significantly lowered the probability of infection in a time-consistent manner throughout several challenges. Given that humoral responses in the prime-boost group were highly significant pre-challenge correlates of protection, the strong innate signaling after the first challenge suggests that interferon signaling enhances vaccine-induced antibody responses and is an important contributor to protection from infection during repeated low-dose exposure to SIV.
ORGANISM(S): Macaca mulatta
PROVIDER: GSE59068 | GEO | 2014/09/30
SECONDARY ACCESSION(S): PRJNA254325
REPOSITORIES: GEO
ACCESS DATA