Antigenic characterisation of a novel Streptococcus anginosus antigen that induces nitric oxide synthesis by murine peritoneal exudate cells

Abstract

A novel antigen that induces nitric oxide (NO) synthesis by murine peritoneal exudate cells (PEC) was prepared from a culture supernate of Streptococcus anginosus NCTC 10713 in dialysed medium by column chromatography with DEAE-Sephacel followed by size-exclusion high performance liquid chromatography (HPLC). A chemical analysis of the S. anginosus antigen (SAA) revealed that it mainly consisted of carbohydrates (rhamnose, N-acetylglucosamine, glucose and galactose), smaller quantities of protein and a trace amount of phosphorus. The SAA stimulated PEC from C57BL/6N mice to produce NO and accumulate induced NO synthetase (iNOS) mRNA in a dose-dependent manner, reaching a plateau with 10±30 ìg=ml. Furthermore, a reverse transcription-PCR assay revealed that SAA 10 ìg=ml could induce mRNA accumulation of tumour necrosis factor-á, interleukin (IL)-1â and IL-6 as well as iNOS. In contrast, RantzRandall antigen (RRA), a carbohydrate antigen prepared from the organisms, could not induce NO synthesis or cause the accumulation of iNOS mRNA, although cytokine production was observed after stimulation. The SAA-induced NO synthesis, but not the cytokine production, was sensitive to heat. Furthermore, an immunoblot analysis of SAA indicated that the 43-kDa protein band reacted with anti-SAA but not anti-RRA antibodies. In immunodiffusion, SAA reacted with both anti-SAA and anti-RRA antibodies, and the precipitin bands formed crossing lines, suggesting that SAA could possess two different antigenic components ± one that reacts speci®cially with anti-SAA antibodies and another that has an identity similar to that of RRA. Taken together, SAA, a novel antigen of S. anginosus, was found to induce NO synthesis as well as produce in¯ammatory cytokines in murine PEC. It is suggested that the protein molecule of SAA may exclusively induce NO synthesis, and its carbohydrate component(s) could have a relationship to cytokine production.

Streptococcus anginosus infection in oral cancer and its infection route

“…We previously reported that SAA, a novel bioactive antigen of S. anginosus , induces NO synthesis and COX‐2 mRNA expression by murine PEC (Sasaki et al , 1995b; Sasaki et al , 2001). Therefore, it is possible that, in some cases of oral squamous cell carcinoma, S. anginosus in dental plaque could infect to oral mucosa and the infection may lead to increased rates of DNA damage by the over‐synthesis of NO and/or COX‐2, resulting in carcinogenesis of the infected tissues.…”

“…We previously reported a novel bioactive antigen (SAA) that induces NO synthesis by murine peritoneal exudate cells (PEC) from a culture supernatant of S. anginosus (Sasaki et al , 2001). Furthermore, SAA induced cyclooxygenase‐2 (COX‐2) mRNA expression by PEC (Sasaki et al , 1995b), the overexpression of which has also been observed in cancer tissues (Zang et al , 1998; Doi et al , 1999; Marrogi et al , 2000).…”

Detection of Streptococcus anginosus from saliva by real-time polymerase chain reaction

“…Streptococcus anginosus, one of the oral streptococci, is considered a common commensal organism found in the human oral cavity. However, this organism has become known as an important pathogen in respiratory infections and subacute bacterial endocarditis (Shinzato and Saito 1995;Sasaki et al 2001;Allen et al 2002). It is also known that the presence of Strep.…”

Organ Microbiota in Cancer Development: The Holy Grail of Biological Carcinogenesis

“…According to the data of Yumoto et al ( 2001 ) , Eikenella corrodens is able to stimulate human oral epithelial cells in producing various mediators including IL-6, IL-8, and PGE2, possibly, via the secretion of soluble proteins. S. anginosus and S. mitis were observed to induce the production of in fl ammatory cytokines in human esophageal epithelial cell lines (Sasaki et al 2001 ;Narikiyo et al 2004 ) . Sugano et al ( 2003 ) detected the signi fi cant elevation in carcinogenic 8-hydroxy-deoxyguanosine (8-OHdG, resulting from the continuous generation of reactive oxygen species associated with chronic in fl ammation) in patients who tested positive for S. anginosus compared to individuals who tested negative for the bacterium.…”