Combined analysis of monocyte and lymphocyte messenger RNA expression with serum protein profiles in patients with scleroderma

Abstract

Objective. We attempted to elucidate possible pathogenetic mechanisms in scleroderma by analysis of gene expression patterns of purified monocytes and lymphocytes, as well as protein profiles of cytokines and growth factors.Methods. Expression analysis was performed on messenger RNA (mRNA) from cells that had been purified with magnetic beads. Plasma samples from the same patients were used for multiplex cytokine analysis. Potential sources of proteins were also examined by in situ hybridization of skin specimens.Results. A total of 1,800 genes from monocytes and 863 genes from CD4؉ T cells were differentially expressed in scleroderma patients. As observed by other investigators using unfractionated peripheral blood cells from patients with autoimmune connective tissue diseases, the cell type-specific analyses of our scleroderma samples showed expression of genes suggesting the presence of interferon-␣ (IFN␣), despite the apparent absence of this cytokine in plasma. IFN␣ RNA was, however, expressed at enhanced levels in vascular and perivascular cells in scleroderma skin samples. While levels of interleukin-1␣ (IL-1␣) and IL-16 were among 10 proteins found to be significantly elevated in scleroderma patients, none of the large panel of plasma cytokines we analyzed correlated with the expression levels of putative IFN response genes.Conclusion. The pattern of up-regulation of mRNA in both the monocytes and CD4 lymphocytes of scleroderma patients, together with the detection of IFN␣ RNA in the microvasculature, suggests that leukocytes respond to this cytokine locally in the vessels. Detection of high levels of IL-1␣ and IL-16 in plasma and the independence of these protein levels from the IFN signature, implicates an independent contribution of other cytokines to immune activation and/or inflammation in scleroderma.

Antigen-Presenting Cells and their Fcγ and Toll-Like Receptors: Leading Suspects in Autoimmunity

“…In line with findings in SLE, data on an IFN type I signature are growing [134][135][136] and a recent report from Kim et al [137] showed interferogenic activity by antitopo I ICs. Although a role for type I IFNs in SSc is counterintuitive knowing that these IFN are potent inhibitors of collagen production in fibroblasts [138], a report describing the rapid onset of SSc symptoms in patients treated with intense IFN therapy suggests a clear pathologic contribution of IFNs to the development of SSc [139].…”

“…[10] Increased transcription of certain type I IFN regulated genes in peripheral blood cells. [135] Endogenous TLR4ligands in serum. [39] Myeloid APCs in diseased skin.…”

Molecular subtypes of systemic sclerosis in association with anti-centromere antibodies and digital ulcers

“…[6][7][8] Using gene sets from public data 9 (Supplementary Table 2), here we provide evidence that type I rather than type II IFNs are responsible for the increased expression of IFN-induced genes. This was validated with specific type I and II IFN gene sets from Baechler et al 10 (Supplementary Table 3).…”

“…The most significant upregulated process that distinguished SSc patients from controls was 'interferon (IFN)-mediated immunity,' which is a subgroup of the ontology group 'immunity and defense' (Figure 1, cluster B, indicated with b1). [6][7][8] Other biological processes that were upregulated in patients compared with healthy individuals within this cluster were: 'protein metabolism and modification,' 'nucleoside, nucleotide and nucleic acid metabolism' and 'apoptosis.' Genes in cluster C genes were related to 'cell cycle,' and those in cluster D to 'signal transduction' and 'immunity and defense.'…”

Treatment Failure of a TLR-7 Agonist Occurs Due to Self-Regulation of Acute Inflammation and Can Be Overcome by IL-10 Blockade

“…The quality of RNA was assessed for each sample using an Agilent 2100 Bioanalyzer (Agilent Technologies, Palo Alto, CA). cRNA preparation, probe labeling, and chip hybridization was performed as previously described (17). Labeled cRNA was hybridized to the Sentrix MouseRef-8 Expression BeadChip v1.0a (Illumina, San Diego, CA).…”