Antigen-Specific Gene Expression Profiles of Peripheral Blood Mononuclear Cells Do Not Reflect Those of T-Lymphocyte Subsets

Abstract

Advances in microarray technology have allowed for the monitoring of thousands of genes simultaneously. This technology is of particular interest to immunologists studying infectious diseases, because it provides tremendous potential for investigating host-pathogen interactions at the level of immune gene expression. To date, many studies have focused either on cell lines, where the physiological relevance is questionable, or on mixed cell populations, where the contributions of individual subpopulations are unknown. In the present study, we perform an intrasubject comparison of antigen-stimulated immune gene expression profiles between a mixed population of peripheral blood mononuclear cells (PBMC) and the two predominant cell types found in PBMC, CD4+ and CD8+ T lymphocytes. We show that the microarray profiles of CD4+ and CD8+ T lymphocytes differ from each other as well as from that of the mixed cell population. The independence of the gene expression profiles of different cell types is demonstrated with a ubiquitous antigen (Candida albicans) as well as with a disease-specific antigen (human immunodeficiency virus p24). This study has important implications for microarray studies of host immunity and underscores the importance of profiling the expression of specific cell types.

Distinct gene-expression profiles associated with the susceptibility of pathogen-specific CD4 T cells to HIV-1 infection

“…Unlike previous microarray studies that were conducted with either whole PBMCs 41,42 or a specific cell type (CD4 or CD8 ϩ T cells), [43][44][45][46] microarray analysis in our study was performed with FACS-sorted, antigen-specific CD4 populations. Microarray analysis revealed that CMV-specific CD4 T cells activated a broad array of innate antiviral genes or pathways that have known anti-HIV or SIV activities.…”

Gene Array Studies in HIV-1 Infection

“…The use of PBMCs may limit interpretations because of dilution and may not reflect the gene profile from individual subpopulations [29]. It has been suggested that researchers limit studies using PBMCs in favor of those within subpopulations [30]. …”

Identification of Novel Th2-Associated Genes in T Memory Responses to Allergens

“…Of particular interest was the potential contribution of CD4 ϩ vs CD8 ϩ T cells, as these subsets within PBMC are known to have distinct gene expression profiles (59).…”

“…Data expressed on the log 2 scale. Table II The data of primary interest in Table II are those derived from CD4 ϩ and CD8 ϩ populations in which enrichment for responder cells may be expected to reduce the background noise relative to unfractionated PBMC (59,61). Our principal focus was upon 12/24 h time points which encompass the peak of the early Th2-associated cluster, and where specified genes which did not validate at these time points were followed up further in 48-h samples.…”