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B lymphocytes have a unique role as antibody-producing cells. Antibodies are key mediators of humoral immunity against infections, and are thought to account for the protection afforded by successful vaccines. B cells can also secrete cytokines and subsequently regulate immune responses mediated by T and innate cells. Remarkably, recent studies identified plasma blasts/plasma cells as the main types of activated B cells producing the cytokines interleukin (IL)-10, IL-35, tumor necrosis factor (TNF)-α, IL-17, and GM-CSF in various contexts in mice. Here, we discuss these observations, which suggest the existence of various subsets of plasma blast/plasma cells distinguishable through their cytokine expression pattern., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Bisphosphonate drugs are well known to inhibit osteoclastic activity and have been proposed for the management of bone diseases, including periodontitis which is associated with alveolar bone destruction. In this study, we evaluated the effects of four arylsulfonamide bisphosphonates on growth of the periodontopathogenic bacterium Porphyromonas gingivalis as well as their capacity to reduce cytokine secretion by lipopolysaccharide (LPS)-stimulated oral epithelial cells. The growth of P. gingivalis was inhibited by (4'-Chloro-biphenyl-4-sulfonylamino)methyl-1,1- bisphosphonic acid while the three other arylsulfonamide bisphosphonates ((4-Methoxy-phenylsulfonylamino)methyl-1,1- bisphosphonic acid, (4-Nitro-phenylsulfonylamino)methyl-1,1-bisphosphonic acid, and (Biphenyl-4-sulfonylamino) methyl-1,1-bisphosphonic acid) had no effect. Growth inhibition was more pronounced under an iron-restricted condition. All four arylsulfonamide bisphosphonates decreased the production of the pro-inflammatory cytokines IL-6 and IL-8 by Aggregatibacter actinomycetemcomitans LPS-stimulated oral epithelial cells. In conclusion, we uncovered additional properties of bisphosphonates that may be beneficial for the treatment of periodontal diseases. In particular, (4'-Chlorobiphenyl- 4-sulfonylamino)methyl-1,1-bisphosphonic acid combines the already disclosed antiresoptive activity with antiinflammatory and antibacterial properties.

Background: Inflammatory cytokines and matrix metalloproteinases (MMPs) produced by resident and inflammatory cells in response to periodontopathogens play a major role in the tissue destruction observed in periodontitis, which is a disease that affects tooth-supporting structures. In the present study, we investigate the effects of licorice-derived licoricidin (LC) and licorisoflavan A (LIA) on the secretion of various cytokines and MMPs by human monocyte-derived macrophages stimulated with Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans) lipopolysaccharide (LPS)., Methods: Macrophages were treated with non-toxic concentrations of LC or LIA before being stimulated with A. actinomycetemcomitans LPS. The secretion of cytokines and MMPs and the activation of nuclear factor-kappa B (NF-κB) p65 and activator protein (AP)-1 were assessed by enzyme-linked immunosorbent assays., Results: LC and LIA inhibited the secretion of interleukin (IL)-6 and chemokine (C-C motif) ligand 5 in a concentration-dependent manner but did not affect the secretion of IL-8 by LPS-stimulated macrophages. LC and LIA also inhibited the secretion of MMP-7, -8, and -9 by macrophages. The suppression of cytokine and MMP secretion by LC and LIA was associated with the reduced activation of NF-κB p65 but not that of AP-1., Conclusion: The present study suggests that LC and LIA have potential for the development of novel host-modulating strategies for the treatment of cytokine and/or MMP-mediated disorders such as periodontitis.

Background: Periodontal diseases are a group of inflammatory disorders initiated by specific Gram-negative periodontopathogenic bacteria that lead to the destruction of tooth-supporting tissues. In this study, we tested whether a carbon dioxide-supercritical extract of Glycyrrhiza uralensis (licorice) can reduce the periodontopathogen-induced inflammatory response., Methods: Monocyte-derived macrophages were treated with various concentrations of the licorice extract prior to being stimulated with Aggregatibacter actinomycetemcomitans (previously Actinobacillus actinomycetemcomitans) and Porphyromonas gingivalis lipopolysaccharide (LPS). The capacity of the licorice extract to mediate the inflammatory response was also tested in an ex vivo whole blood model stimulated with P. gingivalis LPS. The secretion of interleukin (IL)-1beta, -6, and -8 and tumor necrosis factor-alpha (TNF-alpha) in both models was assessed by enzyme-linked immunosorbent assays. Changes in the phosphorylation state of macrophage intracellular kinases induced by A. actinomycetemcomitans LPS and the licorice extract in the macrophage model were characterized by immunoblotting., Results: The licorice extract exhibited potent anti-inflammatory properties, inhibiting the periodontopathogen LPS-induced IL-1beta, -6, and -8 and TNF-alpha responses of macrophages. The licorice extract inhibited the phosphorylation of important macrophage intracellular signaling proteins, including nuclear factor-kappa B p65 nuclear transcription factor and Jun proto-oncogene-encoded activator protein (AP) 1 transcription factor, which are involved in inflammatory signaling pathways. The licorice extract was also a potent inhibitor of the proinflammatory cytokine response in the ex vivo human whole blood model., Conclusion: This CO(2)-supercritical licorice extract is a potential candidate for the development of a new therapy to prevent and/or treat periodontitis-associated tissue destruction.