Rapid Myeloid Cell Transcriptional and Proteomic Responses to Periodontopathogenic Porphyromonas gingivalis

Abstract

Long-lived monocytes, macrophages, and dendritic cells (DCs) are Toll-like receptor-expressing, antigenpresenting cells derived from a common myeloid lineage that play key roles in innate and adaptive immune responses. Based on immunohistochemical and molecular analyses of inflamed tissues from patients with chronic destructive periodontal disease, these cells, found in the inflammatory infiltrate, may drive the progressive periodontal pathogenesis. To investigate early transcriptional signatures and subsequent proteomic responses to the periodontal pathogen, Porphyromonas gingivalis, donor-matched human blood monocytes, differentiated DCs, and macrophages were exposed to P. gingivalis lipopolysaccharide (LPS) and gene expression levels were measured by oligonucleotide microarrays. In addition to striking differences in constitutive transcriptional profiles between these myeloid populations, we identify a P. gingivalis LPS-inducible convergent, transcriptional core response of more than 400 annotated genes/ESTs among these populations, reflected by a shared, but quantitatively distinct, proteomic response. Nonetheless, clear differences emerged between the monocytes, DCs, and macrophages. The finding that long-lived myeloid inflammatory cells, particularly DCs, rapidly and aggressively respond to P. gingivalis LPS by generating chemokines, proteases, and cytokines capable of driving T-helper cell lineage polarization without evidence of corresponding immunosuppressive pathways highlights their prominent role in host defense and progressive tissue pathogenesis. The shared, unique, and/or complementary transcriptional and proteomic profiles may frame the context of the host response to P. gingivalis, contributing to the destructive nature of periodontal inflammation.

Interleukin-27 inhibition of HIV-1 involves an intermediate induction of type I interferon

“…Based on this analysis, IFN-␣-induced genes above the red line and implicated in defense against HIV are listed in Table 2. Although LPS did not substantially up-regulate antiviral genes such as OAS or MX1, it did stimulate IFN-␤1 greater than 100-fold and other molecules, which may directly or indirectly influence viral infection 27 (see supplemental Table 1). Both IFN-␣ and LPS dramatically up-regulated chemokines, including CCL5, which may influence HIV entry by competing for coreceptor binding, but in this study, we did not focus on the plethora of shared genes found within the lines of identity or unique to LPS.…”

“…Moreover, cytokine and cytokine-related genes were also early macrophage IFN-␣ targets: pentraxin-related gene (PTX3), TNF (ligand) superfamily member 10 (TRAIL), IL-7R, TNF superfamily member 2 (TNF-␣), TNFAIP2, TNFAIP3 interacting protein 3, TNF receptor-associated factor 1 (TRAF1), and IL-6 (IFN-␤2), Epstein-Barr virus-induced 3 (EBI3), IL-12B(p40), IL-1B, and IL-15 (Ͼ 10-fold), along with other proinflammatory and/or potentially toxic molecules, including indoleamine(2,3)-dioxygenase (IDO) and GTP cyclohydrolase I (GCHI), are involved in neopterin production. 29 Only a limited number of probe sets 27 were down-regulated in macrophages upon exposure to IFN-␣ (see supplemental Table 1). …”

“…Macrophages exposed to a TLR4 stimulus (LPS) up-regulated a multitude of genes commonly The 35 gene symbols were selected based on putative antiviral activities that are differentially regulated by IFN-␣ through IFNAR and LPS through toll-like receptors as fold change (FC; see "Methods"). 27 but not genes classically associated with antiviral activity seen in the high stringency IFN-␣-induced transcriptional profile, represented by myxovirus (influenza virus) resistance 1 (MX1; Ͼ10-fold) and 2Ј-5Ј-oligoadenylate synthetase-like (OAS; Ͼ30-fold). This discrimination between LPS and IFN-␣ in inducing OAS and MX1 provided a basis for differentiating macrophage activation from IFN-␣ induction of potential antiviral genes.…”

“…The 40 most affected gene symbols are represented in Table 1. Table 1) and with LPSstimulated cultures (100 ng/mL) 27 and RNA extracted and processed for microarray analysis using the Affymetrix system. Macrophage gene expression after treatment with IFN-␣ as ratio to control (IFN-␣/c) compared with LPS/Control ratio, in common logartithmic scale.…”

“…14,27 Preparation of biotin-labeled cRNA, hybridization, and scanning were performed per protocol (Affymetrix). Briefly, 10 g total RNA was used to generate double-stranded cDNA using One-Cycle cDNA Synthesis Kit and oligo (dT) 24 primer containing a 3Ј T7 RNA polymerase promoter site.…”