Pattern of Proinflammatory Cytokine Induction in RAW264.7 Mouse Macrophages Is Identical for Virulent and AttenuatedBorrelia burgdorferi

Abstract

Lyme disease pathogenesis results from a complex interaction between Borrelia burgdorferi and the host immune system. The intensity and nature of the inflammatory response of host immune cells to B. burgdorferi may be a determining factor in disease progression. Gene array analysis was used to examine the expression of genes encoding cytokines, chemokines, and related factors in the joint tissue of infected C3H/HeJ mice and in a murine macrophage-like cell line in response to a disseminating or attenuated clinical isolate of B. burgdorferi. Both isolates elicited a robust proinflammatory response in RAW264.7 cells characterized by an increase in transcript levels of genes encoding CC and CXC chemokines, proinflammatory cytokines, and TNF superfamily members. Transcription of genes encoding IL-1β, IL-6, MCP-1, MIP-1α, CXCR4, and TLR2 induced in RAW264.7 cells by either live or heat-killed spirochetes did not differ significantly at any time point over a 24-h period, nor was there a difference in the protein levels of IL-10, TNF-α, IL-6, and IL-12p70 in culture supernatants. Thus, induction of host macrophage expression of proinflammatory mediators by host macrophages does not contribute to the differential pathogenicity of different B. burgdorferi strains.

Interleukin-10 Alters Effector Functions of Multiple Genes Induced by Borrelia burgdorferi in Macrophages To Regulate Lyme Disease Inflammation

“…This cytokine is produced in response to stimulation by B. burgdorferi in different cells and tissue types, as reported in mice (17,24,27,53,61), rhesus macaques (40), and human patients (50,94). Moreover, IL-10 has been shown to control Lyme disease inflammation in vitro (17,35,53,54,96) and in vivo (16,17). In this paper, we focused on understanding the mechanism(s) by which IL-10 controls B. burgdorferi-induced inflammatory responses in macrophages.…”

“…We (35) along with others (17,53,54,96) have reported results of experiments conducted in vitro showing that in response to B. burgdorferi or its lipoproteins, IL-10 dampens proinflammatory cytokines such as IL-1␤, tumor necrosis factor (TNF), IL-6, IL-12, IL-18, and gamma interferon (IFN-␥) of cells that are involved in innate and adaptive immunity in the murine model. Using human monocytic THP-1 cells, we demonstrated that IL-10 down-modulated the production of IL-1␤, TNF, IL-12, and IL-6, as elicited by spirochetal lipoproteins (66).…”

Hemocyanins Stimulate Innate Immunity by Inducing Different Temporal Patterns of Proinflammatory Cytokine Expression in Macrophages

“…The oligonucleotide primers for wellcharacterized markers of inflammation, including IL-1b, IL-6, IL-12p40, and TNF-a, as well as those of the housekeeping genes, b-actin and GAPDH, were prepared by Eurofins MWG Operon (Huntsville, AL) and are provided in Supplemental Table I ( [39][40][41]. The resulting PCR products were electrophoresed on a 2% agarose gel, stained with GelRed (Biotium, Hayward, CA), and photographed.…”

The Lyme Disease SpirocheteBorrelia burgdorferiUtilizes Multiple Ligands, Including RNA, for Interferon Regulatory Factor 3-Dependent Induction of Type I Interferon-Responsive Genes

“…Previous reports from both our laboratory and those of colleagues have demonstrated that B. burgdorferi stimulation results in IFN-responsive gene induction in joint tissue of infected mice, in skin and blood from Lyme disease patients, and in cultured macrophages/monocytes derived from humans and mice (30,38,39,49,50). We recently reported that induction of IFN-responsive genes in Borrelia burgdorferi-stimulated murine bone marrow-derived macrophages (BMDMs) was mediated by type I IFN, as transcription of IFN-responsive genes was abolished in type I IFN receptor-deficient (IFNAR1 Ϫ/Ϫ ) BMDMs.…”