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Biochemical characterization and function of novel pattern molecules from Staphylococcus aureus
Abstracts / Molecular Immunology 44 (2007) 3909–3994
3979
spielmanii sp. nov. and demonstrates capture of human immune regulators to resist complement-mediated killing.
P104 Biochemical characterization and function of novel pattern molecules from Staphylococcus aureus
Acknowledgements
Ying Jie Ma a , Chan-Hee Kim a , Hyeon-Hwa Lee a , Bok-Luel Lee a , Peter Garred b
This work was funded by the Deutsche Forschungsgemeinschaft DFG, Project Kr3383/1-1 and Wa533/7-1. doi:10.1016/j.molimm.2007.06.181 P103 Reduced serum L-ficolin in paediatric patients with recurrent respiratory infection Nicholas J. Lynch, Silke Roscher, Wilhelm J. Schwaeble Department of Infection, Immunity and Inflammation, University of Leicester, Leicester LE1 9HN, UK The importance of MBL in anti-microbial host defence is well recognized; hereditary MBL deficiency results in defective opsonisation and is associated with recurrent bacterial infections, especially in children. However, at the Institute for Child Health and Great Ormond Street Hospital in London (a tertiary referral centre), only 25% of the patients presenting with unexplained recurrent infections are MBL deficient. In this study we measured serum L-ficolin, binding of Lficolin to lipoteichoic acid (LTA) and L-ficolin driven C4 activation in 99 paediatric patients with a history of recurrent respiratory infection, but with normal MBL levels. L-Ficolin concentration was significantly lower in the patients (median 0.9 g/ml, range undetectable—4.4 g/ml) than in 135 controls matched for age, gender and race (median 2.4 g/ml, range 0.4–4.9 g/ml, p < 0.01). L-Ficolin/LTA binding and C4 activation were correspondingly low in the patients. A separate cohort of 120 adult controls had significantly higher L-ficolin concentrations than either of the paediatric cohorts (median 6.2 g/ml, range 0.4–13.4 g/ml). A longitudinal study showed that Lficolin levels remain constant during the course of Gram-positive sepsis, suggesting that low L-ficolin levels are not a consequence of disease—they appear to be innate. We genotyped three FCN2 mutations previously reported to effect L-ficolin concentration and function; −602G > A, −4A > G and T236M. Although we were able to confirm that T236M significantly reduces L-ficolin/ligand binding and C4 activation, and that −602G > A has a minor effect upon L-ficolin serum concentration, we observed no difference in the frequency of any of the alleles among the three cohorts (patients, paediatric controls and adult controls). Re-sequencing of the patient DNA samples did not reveal any further polymorphisms, suggesting that the variation in FCN2 expression is controlled by trans acting elements, or at the post-transcriptional level, not by variation in FCN2 itself. doi:10.1016/j.molimm.2007.06.182
a
National Research Laboratory of Defense Proteins, College of Pharmacy, Pusan National University, Busan 609-735, South Korea b Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark Mast cells have been most widely studied in the context of allergic diseases, but little is known about critical role in host defense against bacterial infection. Recently, it has been reported that mast cells are involved in host defense against bacterial infections as the first-line defense cells through the release of various inflammatory cytokines, such as IL-6, TNF-␣, IL-. In this study, we explored how the mast cells respond to known immune stimulating molecules and attempted to find novel molecules stimulating the mast cell from Staphylococcus aureus, Grampositive bacteria, which infects human and often causes septic shock and multi-organ failure. Firstly, we tested whether mast cells respond directly by lipopolysaccharide (LPS), peptidoglycan (PGN), and lipoteichoic acid (LTA) by measuring the inflammatory cytokine expression level in mouse bone marrow-derived mast cell (mBMMC) and human mast cell line (HMC-1). Data showed that only LPS elicited mBMMC to produce the inflammatory cytokines. Surprisingly, we found that MBL and ficolin suppressed LPS-induced inflammatory cytokine production in mBMMC, which have been known as complement activating proteins through recognizing carbohydrates of bacterial surface. Subsequent experiments revealed that MBL and ficolin bound to LPS using their carbohydrates-recognition domains. These findings suggest that MBL and ficolin might regulate mast cellmediated inflammatory responses. Secondly, we have attempted to isolate novel mast cellstimulating molecules from S. aureus. We observed that a soluble fraction from S. aureus cell lysate strongly induced IL-6 in mBMMC and IL-8 in HMC-1, and we purified and identified adenosine from the fraction. Further experiment indicated that adenosine was excreted from macrophage via engulfment of S. aureus. In conclusion, the current study revealed that mast cells are activated by LPS, during which MBL and ficolin may desensitize the activation of mast cell by LPS, and adenosine which was newly identified from S. aureus stimulates mast cells. doi:10.1016/j.molimm.2007.06.183
3979
spielmanii sp. nov. and demonstrates capture of human immune regulators to resist complement-mediated killing.
P104 Biochemical characterization and function of novel pattern molecules from Staphylococcus aureus
Acknowledgements
Ying Jie Ma a , Chan-Hee Kim a , Hyeon-Hwa Lee a , Bok-Luel Lee a , Peter Garred b
This work was funded by the Deutsche Forschungsgemeinschaft DFG, Project Kr3383/1-1 and Wa533/7-1. doi:10.1016/j.molimm.2007.06.181 P103 Reduced serum L-ficolin in paediatric patients with recurrent respiratory infection Nicholas J. Lynch, Silke Roscher, Wilhelm J. Schwaeble Department of Infection, Immunity and Inflammation, University of Leicester, Leicester LE1 9HN, UK The importance of MBL in anti-microbial host defence is well recognized; hereditary MBL deficiency results in defective opsonisation and is associated with recurrent bacterial infections, especially in children. However, at the Institute for Child Health and Great Ormond Street Hospital in London (a tertiary referral centre), only 25% of the patients presenting with unexplained recurrent infections are MBL deficient. In this study we measured serum L-ficolin, binding of Lficolin to lipoteichoic acid (LTA) and L-ficolin driven C4 activation in 99 paediatric patients with a history of recurrent respiratory infection, but with normal MBL levels. L-Ficolin concentration was significantly lower in the patients (median 0.9 g/ml, range undetectable—4.4 g/ml) than in 135 controls matched for age, gender and race (median 2.4 g/ml, range 0.4–4.9 g/ml, p < 0.01). L-Ficolin/LTA binding and C4 activation were correspondingly low in the patients. A separate cohort of 120 adult controls had significantly higher L-ficolin concentrations than either of the paediatric cohorts (median 6.2 g/ml, range 0.4–13.4 g/ml). A longitudinal study showed that Lficolin levels remain constant during the course of Gram-positive sepsis, suggesting that low L-ficolin levels are not a consequence of disease—they appear to be innate. We genotyped three FCN2 mutations previously reported to effect L-ficolin concentration and function; −602G > A, −4A > G and T236M. Although we were able to confirm that T236M significantly reduces L-ficolin/ligand binding and C4 activation, and that −602G > A has a minor effect upon L-ficolin serum concentration, we observed no difference in the frequency of any of the alleles among the three cohorts (patients, paediatric controls and adult controls). Re-sequencing of the patient DNA samples did not reveal any further polymorphisms, suggesting that the variation in FCN2 expression is controlled by trans acting elements, or at the post-transcriptional level, not by variation in FCN2 itself. doi:10.1016/j.molimm.2007.06.182
a
National Research Laboratory of Defense Proteins, College of Pharmacy, Pusan National University, Busan 609-735, South Korea b Rigshospitalet, Copenhagen University Hospital, Copenhagen, Denmark Mast cells have been most widely studied in the context of allergic diseases, but little is known about critical role in host defense against bacterial infection. Recently, it has been reported that mast cells are involved in host defense against bacterial infections as the first-line defense cells through the release of various inflammatory cytokines, such as IL-6, TNF-␣, IL-. In this study, we explored how the mast cells respond to known immune stimulating molecules and attempted to find novel molecules stimulating the mast cell from Staphylococcus aureus, Grampositive bacteria, which infects human and often causes septic shock and multi-organ failure. Firstly, we tested whether mast cells respond directly by lipopolysaccharide (LPS), peptidoglycan (PGN), and lipoteichoic acid (LTA) by measuring the inflammatory cytokine expression level in mouse bone marrow-derived mast cell (mBMMC) and human mast cell line (HMC-1). Data showed that only LPS elicited mBMMC to produce the inflammatory cytokines. Surprisingly, we found that MBL and ficolin suppressed LPS-induced inflammatory cytokine production in mBMMC, which have been known as complement activating proteins through recognizing carbohydrates of bacterial surface. Subsequent experiments revealed that MBL and ficolin bound to LPS using their carbohydrates-recognition domains. These findings suggest that MBL and ficolin might regulate mast cellmediated inflammatory responses. Secondly, we have attempted to isolate novel mast cellstimulating molecules from S. aureus. We observed that a soluble fraction from S. aureus cell lysate strongly induced IL-6 in mBMMC and IL-8 in HMC-1, and we purified and identified adenosine from the fraction. Further experiment indicated that adenosine was excreted from macrophage via engulfment of S. aureus. In conclusion, the current study revealed that mast cells are activated by LPS, during which MBL and ficolin may desensitize the activation of mast cell by LPS, and adenosine which was newly identified from S. aureus stimulates mast cells. doi:10.1016/j.molimm.2007.06.183