Infectious Diseases and the Lymphoid Extracellular Matrix Remodeling: A Focus on Conduit System.

The conduit system was described in lymphoid organs as a tubular and reticular set of structures compounded by collagen, laminin, perlecan, and heparin sulfate proteoglycan wrapped by reticular fibroblasts. This tubular system is capable of rapidly transport small molecules such as viruses, antigens, chemokines, cytokines, and immunoglobulins through lymphoid organs. This structure plays an important role in guiding the cells to their particular niches, therefore participating in cell cooperation, antigen presentation, and cellular activation. The remodeling of conduits has been described in chronic inflammation and infectious diseases to improve the transport of antigens to specific T and B cells in lymphoid tissue. However, malnutrition and infectious agents may induce extracellular matrix remodeling directly or indirectly, leading to the microarchitecture disorganization of secondary lymphoid organs and their conduit system. In this process, the fibers and cells that compound the conduit system may also be altered, which affects the development of a specific immune response. This review aims to discuss the extracellular matrix remodeling during infectious diseases with an emphasis on the alterations of molecules from the conduit system, which damages the cellular and molecular transit in secondary lymphoid organs compromising the immune response.

In Silico Selection and In Vitro Evaluation of New Molecules That Inhibit the Adhesion of Streptococcus mutants through Antigen I/II.

Streptococcus mutans is the main early colonizing cariogenic bacteria because it recognizes salivary pellicle receptors. The Antigen I/II (Ag I/II) of S. mutans is among the most important adhesins in this process, and is involved in the adhesion to the tooth surface and the bacterial co-aggregation in the early stage of biofilm formation. However, this protein has not been used as a target in a virtual strategy search for inhibitors. Based on the predicted binding affinities, drug-like properties and toxicity, molecules were selected and evaluated for their ability to reduce S. mutans adhesion. A virtual screening of 883,551 molecules was conducted; cytotoxicity analysis on fibroblast cells, S. mutans adhesion studies, scanning electron microscopy analysis for bacterial integrity and molecular dynamics simulation were also performed. We found three molecules ZINC19835187 (ZI-187), ZINC19924939 (ZI-939) and ZINC19924906 (ZI-906) without cytotoxic activity, which inhibited about 90% the adhesion of S. mutans to polystyrene microplates. Molecular dynamic simulation by 300 nanoseconds showed stability of the interaction between ZI-187 and Ag I/II (PDB: 3IPK). This work provides new molecules that targets Ag I/II and have the capacity to inhibit in vitro the S. mutans adhesion on polystyrene microplates.

Cytotoxic and Immunomodulatory Potential Activity of Physalis peruviana Fruit Extracts on Cervical Cancer (HeLa) and Fibroblast (L929) Cells.

It was purposed to evaluate the biological potential of ethanol and isopropanol crude extracts of ripe Physalis peruviana fruits. Cytotoxic and immunomodulatory effects of the expression of interleukin-6, interleukin-8, and monocyte chemoattractant protein-1 (MCP-1) were evaluated on human cervical cancer (HeLa) and murine fibroblast (L929) cells. The composition was evaluated by high-performance liquid chromatography diode-array detection and high-performance liquid chromatography ultraviolet/visible detection. The presence of ursolic acid and rosmarinic acid was found in both solvents. However, gallic acid, quercetin, and epicatechin were higher in isopropanol extracts ( P < .05). The results indicated a relationship among the total polyphenol content, antioxidant activity, and cytotoxic activity that was dependent on the solvent used. Isopropanol extracts presented a half-maximal inhibition concentration value (IC50) of 60.48 ± 3.8 µg/mL for HeLa cells and 66.62 ± 2.67 µg/mL for L929 fibroblasts. The extracts reduced the release of interleukin-6, interleukin-8, and MCP-1 in a dose-dependent manner. Extracts showed anticancer and immunomodulatory potential for new complementary pharmaceutical products development.

GibbsCluster: unsupervised clustering and alignment of peptide sequences.

Receptor interactions with short linear peptide fragments (ligands) are at the base of many biological signaling processes. Conserved and information-rich amino acid patterns, commonly called sequence motifs, shape and regulate these interactions. Because of the properties of a receptor-ligand system or of the assay used to interrogate it, experimental data often contain multiple sequence motifs. GibbsCluster is a powerful tool for unsupervised motif discovery because it can simultaneously cluster and align peptide data. The GibbsCluster 2.0 presented here is an improved version incorporating insertion and deletions accounting for variations in motif length in the peptide input. In basic terms, the program takes as input a set of peptide sequences and clusters them into meaningful groups. It returns the optimal number of clusters it identified, together with the sequence alignment and sequence motif characterizing each cluster. Several parameters are available to customize cluster analysis, including adjustable penalties for small clusters and overlapping groups and a trash cluster to remove outliers. As an example application, we used the server to deconvolute multiple specificities in large-scale peptidome data generated by mass spectrometry. The server is available at http://www.cbs.dtu.dk/services/GibbsCluster-2.0.

Development of Recombinant Canarypox Viruses Expressing Immunogens.

Canarypox viruses (CNPV) are excellent candidates to develop recombinant vector vaccines due to both their capability to induce protective immune responses and their incompetence to replicate in mammalian cells (safety profile). In addition, CNPV and the derived recombinants can be manipulated under biosafety level 1 conditions. There is no commercially available system to obtain recombinant CNPV; however, the methodology and tools required to develop recombinant vaccinia virus (VV), prototype of the Poxviridae family, can be easily adapted. This chapter provides protocols for the generation, plaque isolation, molecular characterization, amplification and purification of recombinant CNPV.

Expression and function of toll-like receptor 4 and inflammasomes in cardiac fibroblasts and myofibroblasts: IL-1ß synthesis, secretion, and degradation.

UNLABELLED: Cardiac inflammation can be produced by pathogen-associated molecular patterns (PAMPs), from parasitic, bacterial or viral origin; or by danger-associated molecular patterns (DAMPs), released from dead cells after cardiac tissue damage, for example by cardiac infarction. Both, PAMPS and DAMPS activate TLR4 on resident immune cells and heart tissue cells, triggering an inflammatory process necessary to begin the wound healing process. Cardiac fibroblasts (CF) are the most abundant cells in the heart and are critical to wound healing, along with cardiac myofibroblasts (CMF), which are differentiated from CF through a TGF-ß1-mediated process. While TLR4 and the inflammasome complex are known to play important roles in CF function, the effects of TGF-ß1 on TLR4 and inflammasome expression and activity remain unknown. To elucidate this important point, we evaluated the effect of TGF-ß1 on TLR4, and the inflammasome protein expression and activity through activation by LPS, mimicking a myocarditis condition by bacterial origin. We found that TGF-ß1 increased TLR4 expression in CF and that the process was mediated by the TGFßRI and p38 signaling pathways. In both CF and CMF, LPS triggered ERK1/2, PI3K-Akt, and p65-NF-κB phosphorylation. All of these effects were blocked by TAK-242, a TLR4 signaling pathway inhibitor. LPS increased pro-IL-1ß levels, which were dependent on the ERK1/2, PI3K-Akt, and NF-κB signaling pathways, and levels were higher in CF than CMF. NLRP3 and ASC levels were similar in CF and CMF, while pro-caspase-1 levels and caspase-1 activity were higher in CMF. LPS+ATP treatment induced inflammasome complex assembly and activation, triggering the release of IL-1ß in both CMF and CF. Finally, the unsecreted pro-IL-1ß in the CF was degraded by autophagy. CONCLUSION: TGF-ß1 increases TLR4 expression in CF. Despite different pro-IL-1ß and caspase-1 activity levels in CF versus CMF, the two cell types secreted similar levels of IL-1ß after LPS+ATP treatment. These findings suggest that both cell types are active participants in inflammation.

Brazilin Limits Inflammatory Responses through Induction of Prosurvival Autophagy in Rheumatoid Fibroblast-Like Synoviocytes.

Brazilin is an active compound of Caesalpinia sappan L. (Leguminosae), which possesses pro-apoptotic and anti-inflammation potentials depending on the specific cell type. However, it is largely unknown whether autophagy is implicated in the mechanism underlying its chemotherapeutic and anti-inflammatory effects in rheumatoid arthritis (RA). Here, we show that treatment of RA fibroblast-like synoviocytes (FLS) with brazilin results in enhanced level of autophagic flux, evidenced by accumulation of autophagosome and increased level of lipidated LC3 (LC3-II), which is mainly mediated by enhanced production of reactive oxygen species (ROS). Interestingly, long-term exposure of brazilin was able to restore cell survival against the cytotoxity, exclusively in RA FLS, but not in normal fibroblast. Importantly, such a restoration from brazilin-induced cytotoxity in RA FLS was completely abrogated after co-treatment with autophagy inhibitors including NH4Cl or chloroquine. Furthermore, we found that the pretreatment of RA FLS with brazilin reduced LPS- or TNF-induced NF-κB activation and the secretion of inflammatory cytokines in parallel with the enhanced autophagic flux. Such anti-NF-κB potentials of brazilin were drastically masked in RA FLS when autophagy was suppressed. These results suggest that brazilin is capable of activating autophagy exclusively in RA FLS, and such inducible autophagy promotes cell survival and limits inflammatory response.

Oropouche virus infection and pathogenesis are restricted by MAVS, IRF-3, IRF-7, and type I interferon signaling pathways in nonmyeloid cells.

UNLABELLED: Oropouche virus (OROV) is a member of the Orthobunyavirus genus in the Bunyaviridae family and a prominent cause of insect-transmitted viral disease in Central and South America. Despite its clinical relevance, little is known about OROV pathogenesis. To define the host defense pathways that control OROV infection and disease, we evaluated OROV pathogenesis and immune responses in primary cells and mice that were deficient in the RIG-I-like receptor signaling pathway (MDA5, RIG-I, or MAVS), downstream regulatory transcription factors (IRF-3 or IRF-7), beta interferon (IFN-ß), or the receptor for type I IFN signaling (IFNAR). OROV replicated to higher levels in primary fibroblasts and dendritic cells lacking MAVS signaling, the transcription factors IRF-3 and IRF-7, or IFNAR than in wild-type (WT) cells. In mice, deletion of IFNAR, MAVS, or IRF-3 and IRF-7 resulted in uncontrolled OROV replication, hypercytokinemia, extensive liver damage, and death, whereas WT congenic animals failed to develop disease. Unexpectedly, mice with a selective deletion of IFNAR on myeloid cells (CD11c Cre(+) Ifnar(f/f) or LysM Cre(+) Ifnar(f/f)) did not sustain enhanced disease with OROV or a selective (flox/flox) deletion La Crosse virus, a closely related encephalitic orthobunyavirus. In bone marrow chimera studies, recipient irradiated Ifnar(-/-) mice reconstituted with WT hematopoietic cells sustained high levels of OROV replication and liver damage, whereas WT mice reconstituted with Ifnar(-/-) bone marrow were resistant to disease. Collectively, these results establish a dominant protective role for MAVS, IRF-3 and IRF-7, and IFNAR in restricting OROV infection and tissue injury and suggest that IFN signaling in nonmyeloid cells contributes to the host defense against orthobunyaviruses. IMPORTANCE: Oropouche virus (OROV) is an emerging arthropod-transmitted orthobunyavirus that causes episodic outbreaks of a debilitating febrile illness in humans in countries of South and Central America. The continued expansion of the range and number of its arthropod vectors increases the likelihood that OROV will spread into new regions. At present, the pathogenesis of OROV in humans or other vertebrate animals remains poorly understood. To define cellular mechanisms of control of OROV infection, we performed infection studies in a series of primary cells and mice that were deficient in key innate immune genes involved in pathogen recognition and control. Our results establish that a MAVS-dependent type I IFN signaling pathway has a dominant role in restricting OROV infection and pathogenesis in vivo.

Immunoexpression of transforming growth factor beta and interferon gamma in radicular and dentigerous cysts.

INTRODUCTION: The aim of this study was to evaluate and compare the immunohistochemical expression of transforming growing factor beta (TGF-ß) and interferon gamma (IFN-γ) between radicular cysts (RCs) and dentigerous cysts (DCs). METHODS: Twenty RCs and DCs were selected for analysis of the immunoexpression of TGF-ß and IFN-γ in the epithelium and capsule. RESULTS: The cell reactivity of TGF-ß and IFN-γ in the lining epithelium and capsule of RCs showed no significant differences when compared with DCs (P > .05). There was a tendency of a higher expression of TGF-ß in the capsule of DCs. CONCLUSIONS: Our results showed the presence of TGF-ß and IFN-γ in RCs and DCs, supporting the hypothesis that both participate in the development of these lesions, where IFN-γ usually plays a role in bone resorption, which is counterbalanced by the osteoprotective activity performed by TGF-ß.

Multifunctional roles of reticular fibroblastic cells: more than meets the eye?

Fibroblastic reticular cells (FRCs) are stromal cells found in secondary lymphoid organ. Despite its structural function in the lymph nodes being well established, recent studies indicate that the FRCs also play a key role in immunological processes, associated with cell transit, immune response, and cells activation quality, and contribute to peripheral tolerance. To this end, we focus this review on lymph nodes FRC characterization and discuss functional aspects such as production of cytokines and chemokines and their involvement in the immune response, seeking to establish whether certain subsets have a more functional specialization.

Myeloid-specific Rictor deletion induces M1 macrophage polarization and potentiates in vivo pro-inflammatory response to lipopolysaccharide.

The phosphoinositide-3-kinase (PI3K)/protein kinase B (Akt) axis plays a central role in attenuating inflammation upon macrophage stimulation with toll-like receptor (TLR) ligands. The mechanistic target of rapamycin complex 2 (mTORC2) relays signal from PI3K to Akt but its role in modulating inflammation in vivo has never been investigated. To evaluate the role of mTORC2 in the regulation of inflammation in vivo, we have generated a mouse model lacking Rictor, an essential mTORC2 component, in myeloid cells. Primary macrophages isolated from myeloid-specific Rictor null mice exhibited an exaggerated response to TLRs ligands, and expressed high levels of M1 genes and lower levels of M2 markers. To determine whether the loss of Rictor similarly affected inflammation in vivo, mice were either fed a high fat diet, a situation promoting chronic but low-grade inflammation, or were injected with lipopolysaccharide (LPS), which mimics an acute, severe septic inflammatory condition. Although high fat feeding contributed to promote obesity, inflammation, macrophage infiltration in adipose tissue and systemic insulin resistance, we did not observe a significant impact of Rictor loss on these parameters. However, mice lacking Rictor exhibited a higher sensitivity to septic shock when injected with LPS. Altogether, these results indicate that mTORC2 is a key negative regulator of macrophages TLR signalling and that its role in modulating inflammation is particularly important in the context of severe inflammatory challenges. These observations suggest that approaches aimed at modulating mTORC2 activity may represent a possible therapeutic approach for diseases linked to excessive inflammation.

Critical role of 5-lipoxygenase and heme oxygenase-1 in wound healing.

Lipid mediators derived from 5-lipoxygenase (5-LO) metabolism can activate both pro- and anti-inflammatory pathways, but their role in wound healing remains largely unexplored. In this study we show that 5-LO knockout (5-LO(-/-)) mice exhibited faster wound healing than wild-type (WT) animals, and exhibited upregulation of heme oxygenase-1 (HO-1). Furthermore, HO-1 inhibition in 5-LO(-/-) mice abolished the beneficial effect observed. Despite the fact that 5-LO(-/-) mice exhibited faster healing, in in vitro assays both migration and proliferation of human dermal fibroblasts (HDFs) were inhibited by the 5-LO pharmacologic inhibitor AA861. No changes were observed in the expression of fibronectin, transforming growth factor (I and III), and α-smooth muscle actin (α-SMA). Interestingly, AA861 treatment significantly decreased ROS formation by stimulated fibroblasts. Similar to 5-LO(-/-) mice, induction of HO-1, but not superoxide dismutase-2 (SOD-2), was also observed in response to 5-LO (AA861) or 5-LO activating protein (MK886) inhibitors. HO-1 induction was independent of nuclear factor (erythroid derived-2) like2 (Nrf-2), cyclooxygenase 2 (COX-2) products, or lipoxin action. Taken together, our results show that 5-LO disruption improves wound healing and alters fibroblast function by an antioxidant mechanism based on HO-1 induction. Overexpression of HO-1 in wounds may facilitate early wound resolution.

Myricetin suppresses lipoteichoic acid-induced interleukin-1ß and cyclooxygenase-2 expression in human gingival fibroblasts.

Periodontitis is an inflammatory disease affecting the connective tissue and supporting bone surrounding the teeth. In periodontitis, human gingival fibroblasts (HGFs) synthesize IL-1ß, causing a progressive inflammatory response. Flavones demonstrate a variety of biological activity: among others, they possess anti-inflammatory properties. Myricetin is a flavone with a strong anti-inflammatory activity. The objective of this study was to evaluate the effect of the flavonoid myricetin on HGFs under inflammatory conditions induced by lipoteichoic acid (LTA). the effect of myricetin on HGFs was assessed by measuring cell viability, signaling pathways and IL-1ß expression and synthesis. It was found that, over time, myricetin did not affect cell viability. However, it inhibited activation of p38 and extracellular-signal-regulated kinase-1/2 in LTA-treated HGFs and also blocked IκB degradation and cyclooxygenase-2 and prostaglandin E2 synthesis and expression. These findings suggest that myricetin has therapeutic effects in the form of controlling LTA-induced inflammatory responses.

MyD88 or TRAM knockdown regulates interleukin (IL)-6, IL-8, and CXCL12 mRNA expression in human gingival and periodontal ligament fibroblasts.

BACKGROUND: In a previous report, it was shown that Toll-like receptor (TLR) 2 knockdown modulates interleukin (IL)-6 and IL-8 but not the chemokine CXCL12, an important mediator with inflammatory and proangiogenic effects, in human gingival fibroblasts (HGF) and human periodontal ligament fibroblasts (HPDLF). This study investigates whether knocking down two important TLR adaptor molecules, such as myeloid differentiation protein 88 (MyD88) and TRIF-related adaptor molecule (TRAM), could affect mRNA expression of IL-6, IL-8, and CXCL12 in HGF and HPDLF. METHODS: After small interfering (si) RNA-mediated silencing of MyD88 or TRAM, HGF and HPDLF were stimulated with Porphyromonas gingivalis (Pg) lipopolysaccharide (LPS) or two synthetic ligands of TLR2 (Pam2CSK4 and Pam3CSK4) for 6 hours. IL-6, IL-8, and CXCL12 mRNAs were evaluated by quantitative polymerase chain reaction. RESULTS: Knockdown of MyD88 or TRAM partially impaired the IL-8 mRNA upregulation in both fibroblast subpopulations. Similarly, IL-6 upregulation was partially prevented by siMyD88 or siTRAM in HGF stimulated with Pg LPS, as well as in both fibroblast subtypes challenged with Pam2CSK4. Conversely, constitutive CXCL12 mRNA levels were upregulated by MyD88 or TRAM knockdown in non-stimulated cells. CONCLUSIONS: These results suggest that TLR adaptor molecules knockdown, such as MyD88 or TRAM, can decrease IL-6 and IL-8 mRNA and increase CXCL12 mRNA expression in HGF and HPDLF. This can be an important step for better understanding the mechanisms that control the inflammatory cytokine and chemokine expression, which in turn contributes to periodontal pathogenesis.

Reconhecimento de Candida albicans por fibroblastos murinos: envolvimento de receptores de reconhecimento de patógenos (TLR2 e CD14) e a proteína adaptadora MyD88 / The recognition of Candida albicans by fibroblasts: Toll like receptors pathogens (TLR2 and CD14) abt the MyD88 protein evaluation

Os tecidos pulpar e periodontal são frequentemente agredidos por fatores ambientais como calor, trauma mecânico e micro-organismos, sendo estes considerados o fator etiológico principal das periodontopatias e periapicopatias. Dentre as células residentes desses tecidos, especial atenção tem sido dada ao papel dos fibroblastos no desenvolvimento da resposta imune. Fibroblastos são células que respondem à estímulos microbianos e existem evidências do papel de receptores do tipo Toll (TLR) no reconhecimento desses estímulos. Dessa forma, o presente trabalho teve como objetivo principal avaliar o reconhecimento de Candida albicans por fibroblastos gengivais e pulpares. Para tal, fibroblastos isolados a partir de tecido gengival e pulpar de camundongos do grupo controle e deficientes de TLR2, CD14 e MyD88 foram avaliados quanto à expressão de TLRs e moléculas de superfície, resposta proliferativa e produção de citocinas (TGF-β, IL-1β, TNF-α, IL-13 e IL-6), após a estimulação com agonistas de TLR2, TLR4 e C. albicans. Fibroblastos gengivais e pulpares, apesar de provenientes de tecidos diferentes, apresentaram características morfológicas semelhantes. Contudo, a cinética de crescimento dos fibroblastos gengivais deficientes de MyD88 foi mais lenta, e fibroblastos pulpares demoraram mais tempo para surgir a partir dos fragmentos de tecido. A ausência de TLR2 e da molécula adaptadora MyD88 não afetaram a produção de colágeno Tipo I pelos fibroblastos gengivais. Entretanto, fibroblastos deficientes de CD14 apresentaram baixa produção de colágeno. Ademais, os fibroblastos gengivais expressaram TLR2, TLR3, TLR4, assim como as moléculas de adesão ICAM-1 e CD44. A ausência de TLR2 e CD14 interferiu na resposta proliferativa de fibroblastos gengivais e pulpares, respectivamente. O reconhecimento de C. albicans por fibroblastos gengivais e pulpares modulou a produção das citocinas. A produção de TNF-α foi...

Pulpal and periapical tissue are frequently injured by heat, mechanical trauma and microorganisms, which are considered the main etiological factor of periodontal and endodontic diseases. Among these tissue resident cells, special attention has been given to fibroblasts in the immune response. Fibroblasts are cells that recognize pathogens through Toll like receptors (TLR). The aim of this study was to evaluate the recognition of Candida albicans by pulpal and gingival fibroblasts from TLR2, CD14, MyD88 knockout mice and control group mice. The results were analyzed concerning the expression of TLR(s) and surface molecules, proliferative response and citokynes production (TGF-β, IL-1β, TNF-α, IL-13 e IL-6) after the cells stimulation with TLR2, TLR4 and C.albicans agonists. Gingival and Pulpal fibroblasts, even isolated from different tissue, showed morphological similarities; however, gingival fibroblast deficient of MyD88 show lower proliferative response and pulpa l fibroblasts needed more time to detach from tissue fragments. The production of Type I collagen was affected in gingival cells deficient of CD14. Gingival fibroblasts expressed TLR2, TLR3, TLR4, and the adhesion molecules (ICAM-1 and CD44). The absence of TLR2 and CD14 interfered with the proliferative response of pulpal and gingival fibroblasts, respectively. The recognition of C. albicans by gingival and pulpal fibroblasts modulated the citokynes production. TNF-α production after the recognition of C. albicans was dependent from MyD88, CD14 and TLR2 molecules, whereas the production of IL-1β and IL-13 was dependent of TLR2.

Immunohistochemical evaluation of CD25+ cell expression in the progression of periodontal disease.

It was assessed the immunohistochemical profile of CD25+ cells in cases of chronic gingivitis (CG) and chronic periodontitis (CP). Immunohistochemistry was carried out using streptoavidin-biotin complex and anti-CD25 antibody in 17 cases of CG and 25 cases of CP. Sixteen cases (94.1%) of CG were immunopositive. CD25 was focally expressed in 50% of the sample and diffusely expressed in 25%. The stained cells were localized not only beneath the epithelium, but also far from it. In relation to the cellular density quantification of CD25+ cells, score ++ was the most common. Concerning CP, all cases were immunopositive. CD25+ cells were expressed in focal or diffuse pattern either close or far from the epithelium. Diffuse distribution of positive cells throughout the connective tissue was seen in 60% of the cases and 32% showed focal or diffuse cellular pattern. Sixteen cases (64%) received score +++. It was identified that CD25+ cells are present in either a focal or a diffuse pattern in connective tissue. Significant differences in the density of cellular immunostaining between CG and CP were found. The greatest density was observed in CP cases, which suggests that the infiltrate of lymphocytes show a higher degree of cellular activation in periodontitis compared with gingivitis.

Toll-like receptor 3 activation promotes desensitization of histamine response in human gingival fibroblasts: Poly (I:C) induces histamine receptor desensitization in human gingival fibroblasts.

Viruses are associated with the development of periodontal disease, particularly during periods of suppressed cellular immunity. For this reason, we evaluated the hypothesis that viral components regulate the actions of histamine, an important mediator of immune responses. We assessed the effect of Poly (I:C) on histamine-mediated intracellular calcium mobilization in human gingival fibroblasts. Our results show that histamine induces an increase in intracellular calcium concentrations in a dose-dependent manner. This response was blocked when cells were incubated in the presence of Poly (I:C). In addition, phorbol esters, a diacylglycerol analog, mimics the inhibitory actions of Poly (I:C) in response to histamine. The effect of Poly (I:C) was reversed by Stuarosporine (1 µM), GÖ6983 (7 µM), Bisindolylmaleimide (1 µM) [a protein inhibitor (PKC)], and SB 203580 (3 µM) (a p38-MAPK inhibitor). These findings suggest that Poly (I:C) regulates histamine-induced calcium mobilization through activation of PKC and p38.

Role of anti-ß1 adrenergic antibodies from patients with periodontitis in cardiac dysfunction.

BACKGROUND: The presence of serum autoantibodies against ß(1) adrenoreceptors (ß(1)-ARs) in human gingival fibroblast from patients with periodontitis inhibits primary cell-specific growth and induces over-expression of pro-inflammatory mediators. Serum ß(1)-AR autoantibodies from patients with periodontitis react with myocardium and modify cardiac contractility. The relationship between the presence of serum ß(1)-AR autoantibodies and alterations in heart rate variability (HRV) was also studied. METHODS: An enzyme-linked immunosorbent assay (ELISA) using cardiac and gingival fibroblast membranes or synthetic peptides corresponding to the second extracellular loop of human ß(1)-AR was used to detect serum autoantibodies. The HRV was assessed from RR interval files generated from 22:00 to 08:00 hours. The autoantibody effects on contractility were measured on spontaneous rat isolated atria. RESULTS: Circulating autoantibodies from 36 patients with periodontitis and 20 healthy individuals (controls) interacted with fibroblasts, the cardiac surface, and ß(1)-AR synthetic peptides. The distributions of serum antibodies against gingival and myocardium membranes and ß(1)-AR synthetic peptide were 88.8%, 77.7%, and 92.8%, respectively. Moreover, 88.5% of patients with periodontitis whose sera were positive against ß(1)-AR synthetic peptide had decreased HRV. The corresponding affinity-purified anti-ß(1)-AR peptide IgG displayed partial agonist-like activity modifying the isolated atria contractility. CONCLUSION: This manuscript describes that patients with periodontitis showed increased levels of serum IgG with reactive activity against ß(1)-AR. Those patients demonstrated decrease in heart rate, and IgG derived from their sera induced aberrant contractility of heart atrium. We propose that periodontitis increases the risk of cardiovascular diseases, although it increases anti-ß(1)-AR autoantibody that alters myocardial contractility.

Immunohistochemical evaluation of CD25+ cell expression in the progression of periodontal disease

It was assessed the immunohistochemical profile of CD25+ cells in cases of chronic gingivitis (CG) and chronic periodontitis (CP). Immunohistochemistry was carried out using streptoavidin-biotin complex and anti-CD25 antibody in 17 cases of CG and 25 cases of CP. Sixteen cases (94.1%) of CG were immunopositive. CD25 was focally expressed in 50% of the sample and diffusely expressed in 25%. The stained cells were localized not only beneath the epithelium, but also far from it. In relation to the cellular density quantification of CD25+ cells, score ++ was the most common. Concerning CP, all cases were immunopositive. CD25+ cells were expressed in focal or diffuse pattern either close or far from the epithelium. Diffuse distribution of positive cells throughout the connective tissue was seen in 60% of the cases and 32% showed focal or diffuse cellular pattern. Sixteen cases (64%) received score +++. It was identified that CD25+ cells are present in either a focal or a diffuse pattern in connective tissue. Significant differences in the density of cellular immunostaining between CG and CP were found. The greatest density was observed in CP cases, which suggests that the infiltrate of lymphocytes show a higher degree of cellular activation in periodontitis compared with gingivitis.

Foi avaliado o perfil imunohistoquímico das células CD25+ em casos de gengivite (CG) e periodontite crônica (CP). A imunohistoquímica foi realizada utilizando o complexo de streptoavidina-biotina e o anticorpo anti-CD25 em 17 casos de CG e 25 casos de CP. 16 casos (94.1%) de CG foram imunopositivos. O CD25 foi expresso focalmente em 50% da amostra e difusamente em 25% dos casos. As células imunomarcadas estavam localizadas não apenas no epitélio, mas também por todo o tecido conjuntivo. Em relação à quantificação da densidade celular de células CD25+, o escore ++ foi o mais comum. Em relação a CP, todos os casos foram imunopositivos. As células CD25+ foram expressas em padrão ora focal ora difuso, tanto no epitélio como no conjuntivo. A distribuição difusa das células positivas apenas no tecido conjuntivo foi observada em 60% dos casos, e 32% dos casos exibiram padrão celular ora focal ora difuso. 16 casos (64%) foram considerados como escore +++. Identificamos que as células CD25+ estão presentes em padrão ora focal ora difuso no tecido conjuntivo. Diferenças significantes na densidade da imunomarcação celular entre CG and CP foram encontradas. A maior densidade celular foi observada na periodontite, sugerindo que o infiltrado de linfócitos mostrou um maior grau de ativação celular na periodontite comparada à gengivite.