Synergistic oligodeoxynucleotide strongly promotes CpG-induced interleukin-6 production

Abstract

BackgroundBacterial genomes span a significant portion of diversity, reflecting their adaptation strategies; these strategies include nucleotide usage biases that affect chromosome configuration. Here, we explore an immuno-synergistic oligodeoxynucleotide (iSN-ODN, named iSN34), derived from Lactobacillus rhamnosus GG (LGG) genomic sequences, that exhibits a synergistic effect on immune response to CpG-induced immune activation.MethodsThe sequence of iSN34 was designed based on the genomic sequences of LGG. Pathogen-free mice were purchased from Japan SLC and maintained under temperature- and light-controlled conditions. We tested the effects of iSN34 exposure in vitro and in vivo by assessing effects on mRNA expression, protein levels, and cell type in murine splenocytes.ResultsWe demonstrate that iSN34 has a significant stimulatory effect when administered in combination with CpG ODN, yielding enhanced interleukin (IL)-6 expression and production. IL-6 is a pleotropic cytokine that has been shown to prevent epithelial apoptosis during prolonged inflammation.ConclusionsOur results are the first report of a bacterial-DNA-derived ODN that exhibits immune synergistic activity. The potent over-expression of IL-6 in response to treatment with the combination of CpG ODN and iSN34 suggests a new approach to immune therapy. This finding may lead to novel clinical strategies for the prevention or treatment of dysfunctions of the innate and adaptive immune systems.Electronic supplementary materialThe online version of this article (10.1186/s12865-017-0227-7) contains supplementary material, which is available to authorized users.

Immune synergistic oligodeoxynucleotide from Lactobacillus rhamnosus GG enhances the immune response upon co‐stimulation by bacterial and fungal cell wall components

“…Each PS‐ODN was reconstituted in endotoxin‐free water and passed through a 0.22‐μm pore microfilter (Nihon Millipore K.K., Tokyo, Japan) prior to use. Mouse splenocytes were treated with iSN34, an ODN with the sequence 5′‐TTCCTAAGCTTGAGGCCT‐3′ that is derived from Lactobacillus rhamnosus GG (Nigar et al., ). Phosphate‐buffered saline (PBS; pH 7.4) was used as a control.…”

“…The host Toll‐like receptor 9 (TLR9) recognizes bacterial DNA or single‐stranded synthetic oligodeoxynucleotides (ODNs) that harbor unmethylated CpG motifs that are characteristic of bacterial DNA (Alexopoulou, Holt, Medzhitov, & Flavell, ; Heil et al., ; Kawai & Akira, ; Takeshita et al., ); this recognition leads to abrogation of immunostimulatory activity. In our previous study, we described an immune‐synergistic oligodeoxynucleotide (iSN34), derived from Lactobacillus rhamnosus (LGG) genomic sequences, that exhibited a synergistic effect on the immune response to CpG‐induced immune activation (Nigar et al., ). CpG‐ODNs are among the nucleic acids that are responsible for the immune stimulatory effect of bacterial DNA (Krieg, ).…”

Cooperation of Oligodeoxynucleotides and Synthetic Molecules as Enhanced Immune Modulators

“…Initially, research was conducted on the immunomodulatory (43), immunosuppressive (44, 45), and immunostimulatory (46) effects of ODNs. In 2017, Nigar et al explored a novel ODN (named “iSN34”) incorporated into Lactobacillus rhamnosus , GGATCC53108, that has synergistic effects on the immune response in CpG-induced immune activation (47). The iSN34 sequence is TTCCTAAGCTTGAGGCCT (48).…”

“…As a synergistic ODN, iSN34 could be incorporated with CpG to trigger the production of IL-6 and IL-6-secreting CD19 + B cells. Thus, iSN34 may be an extraordinarily impressive adjuvant-mediated vaccine via Th1 that defends against intracellular pathogens, or iSN34 may provide antibody-mediated immunity compared to extracellular pathogens (47). We also conducted further investigations into the synergistic induction of IL-6 by the consolidation of iSN34 with the cell wall components of bacteria (TLR1/TLR2, TLR4) and fungi (TLR2/TLR6) (48).…”

“…Thus, the synergistic effects of CpG ODNs enhance both Th1 and Th2 responses and advances maturation of APCs. This review demonstrated the widespread immune response involving CpG and different synthetic molecules such as granulocyte-macrophage colony-stimulating factor (112), IL-15 (113), the STING ligand (114), Gardiquimod (115), IL-10 siRNA (116), poly (I:C) (57, 117, 118), encapsulated poly(γ-PGA-Phe) (119), imiquimod (120, 121), TLR2-neutralizing antibody (95), and iSN34 (47, 48) (Table 1). Furthermore, the application of CpG ODNs and synthetic molecules as adjuvant treatment was demonstrated to improve immunity even in cases with weakened immune systems.…”