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Synthetic Oligodeoxynucleotides (synthetic + oligodeoxynucleotide)
Selected AbstractsStructure,Activity Relationship Studies on the Immune Stimulatory Effects of Base-Modified CpG Toll-Like Receptor 9 AgonistsCHEMMEDCHEM, Issue 9 2006Marion Jurk Dr. Abstract Synthetic oligodeoxynucleotides containing unmethylated deoxycytidylyl-deoxyguanosine dinucleotide (CpG) motifs are able to stimulate potent immune responses through a signaling pathway involving Toll-like receptor 9 (TLR9). We have investigated the structure,activity relationship (SAR) of base-modified CpG oligonucleotides with TLR9 by measuring TLR9 activation by 20-mer oligonucleotides having just a single human recognition motif (5,-GTCGTT-3,) in functional cell-based TLR9 assays. Substitution of guanine by hypoxanthine and 6-thioguanine resulted in activity similar to the unmodified parent molecule, whereas purine, 2-aminopurine, 2,6-diaminopurine, and 8-oxo-7,8-dihydroguanine substitution resulted in approximately 40,60,% reduction in activity, and 7-deazaguanine substitution led to the strongest (80,%) reduction in TLR9 stimulation. Furthermore, none of the investigated modifications at C5 and N4 of cytosine were well tolerated with respect to human TLR9 stimulation. Our results are compatible with a SAR model in which guanine is recognized by the Hoogsteen site, and C5 is most critical for recognition of cytosine. In addition, we found significant species-specific differences between human and murine TLR9 recognition, which demonstrates the importance of choosing appropriate assay systems for SAR studies. [source] CpG-containing ODN has a limited role in the protection against Toxoplasma gondiiPARASITE IMMUNOLOGY, Issue 2 2004R. Saavedra SUMMARY Bacterial DNA containing immunostimulatory motifs (CpG) induces the development of a TH1 immune response. Since protection against Toxoplasma gondii is correlated with this type of response, the aim of this work was to determine if a synthetic oligodeoxynucleotide (ODN) containing CpG sequences could be useful as adjuvant for the induction of a long-lasting protective immune response against T. gondii. BALB/c mice immunized with a total soluble antigen of T. gondii (TSA2) mixed with ODN-containing CpG sequences developed a typical TH1 response, as determined by antibody isotypes and interferon-, (IFN-,) and interleukin-4 (IL-4) production by spleen cells. However, they did not resist a challenge with the virulent RH strain of the parasite. Absence of protection paralleled with lower levels of IFN-,, when compared with mice vaccinated with the live tachyzoites of the attenuated ts.4 strain of the parasite, which resisted this challenge. Intraperitoneal injection of ODN alone to mice induced a high degree of resistance to a lethal challenge inoculated by the same route. Nevertheless, this nonspecific protection was transient. Thus, the use of ODN containing CpG motifs as adjuvant is of limited value for the induction of a protective immune response against T. gondii. [source] Interferon-, priming is involved in the activation of arginase by oligodeoxinucleotides containing CpG motifs in murine macrophagesIMMUNOLOGY, Issue 1pt2 2009Miriam V. Liscovsky Summary Recognition of microbial products by macrophages (M,) stimulates an inflammatory response and plays a critical role in directing the host immune response against infection. In the present work, we showed for the first time that synthetic oligodeoxynucleotides containing unmethylated cytosine guanine motifs (CpG) are able to stimulate, in the presence of interferon-, (IFN-,), both arginase and inducible nitric oxide synthase (iNOS) in murine M,. Unexpectedly, IFN-,, a cytokine believed to be an inhibitor of arginase activity, intervened in the activation of this enzyme. A significant increase in arginase activity was observed upon a short pre-incubation (1 hr) with IFN-, and subsequent CpG stimulation. Therefore, a very interesting observation of this study was that the CpG-mediated arginase activity is dependent on IFN-, priming. The increase in arginase activity as a result of stimulation with CpG plus IFN-,was correlated with augmented expression of the arginase II isoform. The use of pharmacological specific inhibitors revealed that arginase activity was dependent on p38 mitogen-activated protein kinase (MAPK) and extracellular signal-regulated protein kinase (ERK), but independent of c-Jun N-terminal kinase (JNK) activation. This report reveals a singular effect of the combination of CpG and IFN-,, one of the mayor cytokines produced in response to CpG administration in vivo. [source] Oral immunization with Porphyromonas gingivalis outer membrane protein and CpG oligodeoxynucleotides elicits T helper 1 and 2 cytokines for enhanced protective immunityMOLECULAR ORAL MICROBIOLOGY, Issue 3 2010C. Liu Summary The aim of this study was to evaluate the efficacy of an oral vaccine containing the 40-kDa outer membrane protein of Porphyromonas gingivalis (40K-OMP) and synthetic oligodeoxynucleotides containing unmethylated CpG dinucleotides (CpG ODN) to control oral infection by P. gingivalis. Oral immunization with 40K-OMP plus CpG ODN induced significant 40K-OMP-specific serum immunoglobulin G (IgG), IgA, and saliva IgA antibody responses. The 40K-OMP-specific CD4+ T cells induced by oral 40K-OMP plus CpG ODN produced both T helper type 1 (Th1; interferon-,) and Th2 (interleukin-4) cytokines. Furthermore, increased frequencies of CD11c+ B220+ dendritic cells (DCs) and CD11c+ CD11b+ DCs with upregulated expression of CD80, CD86, CD40, and major histocompatibility complex class II molecules were noted in spleen, Peyer's patches, and cervical lymph nodes. Immunized mice were then infected orally with P. gingivalis to determine whether the immune responses induced by oral 40K-OMP plus CpG ODN were capable of suppressing the bone resorption caused by P. gingivalis infection. Mice given 40K-OMP plus CpG ODN showed significantly reduced bone loss associated with oral infection by P. gingivalis. Oral administration of 40K-OMP together with CpG ODN induces Th1-type and Th2-type cells, which provide help for protective immunity against P. gingivalis infection. This may be an important tool for the prevention of chronic periodontitis. [source] Anti-HBV effects of CpG oligodeoxynucleotide-activated peripheral blood mononuclear cells from patients with chronic hepatitis B,APMIS, Issue 10 2005NING LI Unmethylated CpG dinucleotides in bacterial DNA or synthetic oligodeoxynucleotides containing immunostimulatory CpG motifs (CpG ODN) are known as a potent Th1-like immune enhancer in vertebrates. Chronic hepatitis B is the immunocompromising condition. We therefore investigated the effects of CpG ODN on cultured cells from chronic hepatitis B patients and healthy controls. The inhibitory effects of CpG ODN on hepatitis B virus (HBV) were also studied. The secretion of IFN-, by CpG ODN-activated peripheral blood mononuclear cells (PBMCs) from chronic hepatitis B patients and healthy controls was significantly increased when compared with PBMCs alone or GpC ODN-stimulated PBMCs. After activation with CpG ODN, the IFN-, secretion by chronically HBV-infected patient PBMCs is less than that by healthy control PBMCs. Treatment of HepG2 2.2.15 cells with culture supernatants of PBMCs activated by CpG ODN can significantly suppress the secretion of HBsAg, HBeAg and HBV DNA as compared with that of PBMCs without CpG ODN activation under the same conditions. No inhibitory effect on the replication of HBV was found for CpG ODN treatment alone. Our results indicated that CpG ODN could efficiently enhance the immune response of chronic hepatitis B patients. Moreover, the CpG ODN-activated PBMCs from chronic hepatitis B patients were able to significantly inhibit HBV replication in vitro, suggesting that CpG ODN may be a potential immunoregulator against HBV infection in the future. [source] On the use of ESI-QqTOF-MS/MS for the comparative sequencing of nucleic acidsBIOPOLYMERS, Issue 6 2009Herbert Oberacher Abstract The usability of a quadrupole,quadrupole,time-of-flight (QqTOF) instrument for the tandem mass spectrometric sequencing of oligodeoxynuleotides was investigated. The sample set consisted of 21 synthetic oligodeoxynucleotides ranging in length from 5 to 42 nucleotides. The sequences were randomly selected. For the majority of tested oligonucleotides, two or three different charge states were selected as precursor ions. Each precursor ion was fragmented applying several different collision voltages. Overall 282 fragment ion mass spectra were acquired. Computer-aided interpretation of fragment ion mass spectra was accomplished with a recently introduced comparative sequencing algorithm (COMPAS). The applied version of COMPAS was specifically optimized for the interpretation of information-rich spectra obtained on the QqTOF. Sequences of oligodeoxynucleotides as large as 26-mers were correctly verified in >94% of cases (182 of 192 spectra acquired). Fragment ion mass spectra of larger oligonucleotides were not specific enough for sequencing. Because of the occurrence of extensive internal fragmentation causing low sequence coverage paired with a high probability of assigning fragment ions to wrong sequences, tandem mass spectra obtained from oligonucleotides consisting of 30 and more nucleotides could not be used for sequence verification neither manually nor with COMPAS. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 401,409, 2009. This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com [source] | |||||||||||||