Molecular immune signatures of HIV-1 vaccines in human PBMCs

Abstract

The global transcriptional profile of peripheral blood mononuclear cells (PBMCs) stimulated with HIV candidate vaccine (virus-like particles, VLPs) has been evaluated in HIV-infected patients with low/high viral load compared to healthy volunteers. Baseline activation of chemokine production was observed in PBMC from HIV-infected patients and innate immune stimulation with HIV-VLPs was not blunted. The immune profile among HIV-infected patients was found to be qualitatively similar but quantitatively extremely variable. This diversity was independent of viral load and it might be dependent on individual immunogenetic traits or concurrent immunological status. This ex vivo screening strategy represents an efficient tool for guiding modifications/optimizations of vaccination strategies and understanding failures in individuals enrolled in clinical trials.

Fig. 1

Self-organizing heat map based on genes with immune annotation according to Gene Ontology, most differentially expressed in unstimulated PBMCs from normal volunteers compared to PBMCs stimulated with VLPs or LPS in the same cohort.

Fig. 2

(A) Self-organizing heat map representing 1097 genes differentially expressed in PBMC. The red and yellow arrows points to subjects #12 and #5, respectively, who were found anergic to VLP-stimulation among the high and low-viremia patients. (B) Immune genes selected, among those identified according to the criteria in panel A, according the list in Fig. 1.

Fig. 3

Unsupervised hierarchical clustering of PBMC samples stimulated with LPS (A) or VLPs (B). High stringent filter was applied resulting in the inclusion of 4,529 cDNA clones. Venn Diagram comparing the overlap of genes differentially expressed in PBMCs upon stimulation with LPS (B) or VLPs (D).

Fig. 4

(A) Self-organizing heat map based on 156 genes with immune annotations according to gene ontology modulated at high degree of significance by stimulation with either VLPs or LPS. The orange dashed line emphasizes the ISGs cluster (a); the blue dashed line emphasizes the lymphokine pattern (b). (B) The yellow and red arrows point to patient 05 and 12, respectively.

Fig. 5

(A–E) Relative Cy5/Cy3 values of IL-6, IL-8, CCL3, CCL22 and IRF-7 in different patient cohorts and type of stimulation. Data represent cumulative Cy5/Cy3 values for each experimental category. Red, yellow and green boxes indicate high–low-viral load and healthy normal controls, respectively. (*, **, *** = P-value <0.05, <01 and <0.001, respectively) [15].