Genomic analysis reveals pre- and postchallenge differences in a rhesus macaque AIDS vaccine trial: insights into mechanisms of vaccine efficacy.
We have employed global transcriptional profiling of whole blood to identify biologically relevant changes in cellular gene expression in response to alternative AIDS vaccine strategies with subsequent viral challenge in a rhesus macaque vaccine model. Samples were taken at day 0 (prechallenge), day 14 (peak viremia), and week 12 (set point) from animals immunized with replicating adenovirus type 5 host range (Ad5hr) recombinant viruses expressing human immunodeficiency virus HIV(env)(89.6P), simian immunodeficiency virus SIV(gag)(239), or SIV(nef)(239) alone or in combination with two intramuscular boosts with HIV(89.6P)gp140ΔCFI protein (L. J. Patterson et al., Virology 374:322-337, 2008), and each treatment resulted in significant control of viremia following simian-human immunodeficiency virus SHIV(89.6P) challenge (six animals per group plus six controls). At day 0, 8 weeks after the last treatment, the microarray profiles revealed significant prechallenge differences between treatment groups; data from the best-protected animals led to identification of a network of genes related to B cell development and lymphocyte survival. At peak viremia, expression profiles of the immunized groups were extremely similar, and comparisons to control animals reflected immunological differences other than effector T cell functions. Suggested protective mechanisms for vaccinated animals included upregulation of interleukin-27, a cytokine known to inhibit lentivirus replication, and increased expression of complement components, which may synergize with vaccine-induced antibodies. Divergent expression profiles at set point for the immunized groups implied distinct immunological responses despite phenotypic similarities in viral load and CD4(+) T cell levels. Data for the gp140-boosted group provided evidence for antibody-dependent, cell-mediated viral control, whereas animals immunized with only the replicating Ad5hr recombinants exhibited a different evolution of the B cell compartment even at 3 months postchallenge. This study demonstrates the sensitivity and discrimination of gene expression profiling of whole blood as an analytical tool in AIDS vaccine trials, providing unique insights into in vivo mechanisms and potential correlates of protection.
Department of Microbiology, University of Washington, Box 358070, Seattle, WA 98195-8070, USA. palermor@u.washington.edu
Robert E
RE
Palermo
L Jean
LJ
Patterson
Lauri D
LD
Aicher
Marcus J
MJ
Korth
Marjorie
M
Robert-Guroff
Michael G
MG
Katze
D016915:AIDS Vaccines / Q000235:genetics / Q000276:immunology*; D000256:Adenoviridae / Q000235:genetics; D000818:Animals; D004195:Disease Models, Animal; D020869:Gene Expression Profiling; D005822:Genetic Vectors; D006678:HIV / Q000235:genetics / Q000276:immunology*; D007117:Immunization, Secondary / Q000379:methods; D007273:Injections, Intramuscular; D008253:Macaca mulatta; D008297:Male; D046228:Microarray Analysis; D011995:Recombination, Genetic; D018449:SAIDS Vaccines / Q000235:genetics / Q000276:immunology*; D016097:Simian Acquired Immunodeficiency Syndrome / Q000276:immunology* / Q000517:prevention & control / Q000821:virology; D015302:Simian Immunodeficiency Virus / Q000235:genetics / Q000276:immunology*; D014611:Vaccination / Q000379:methods; D019562:Viral Load; D014766:Viremia
D016915:AIDS Vaccines; D018449:SAIDS Vaccines