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1.
Sci Signal ; 12(580)2019 05 07.
Article in English | MEDLINE | ID: mdl-31064885

ABSTRACT

Bacterial adhesins mediate adhesion to substrates and biofilm formation. Adhesins of the LPXTG family are posttranslationally processed by the cell membrane-localized peptidase sortase A, which cleaves the LPXTG motif. This generates a short C-terminal peptide (C-pep) that remains in the cell membrane, whereas the mature adhesin is incorporated into the cell wall. Genes encoding adhesins of the oral bacterium Streptococcus gordonii were differentially expressed depending on whether the bacteria were isolated from saliva or dental plaque and appeared to be coordinately regulated. Deletion of sspA and sspB (sspAB), both of which encode LPXTG-containing adhesins, unexpectedly enhanced adhesion and biofilm formation. C-peps produced from a model LPXTG-containing adhesin localized to the cell membrane and bound to and inhibited the intramembrane sensor histidine kinase SGO_1180, thus preventing activation of the cognate response regulator SGO_1181. The absence of SspAB C-peps induced the expression of the scaCBA operon encoding the lipoprotein adhesin ScaA, which was sufficient to preserve and even enhance biofilm formation. This C-pep-driven regulatory circuit also exists in pathogenic streptococci and is likely conserved among Gram-positive bacteria. This quality control mechanism ensures that the bacteria can form biofilms under diverse environmental conditions and may play a role in optimizing adhesion and biofilm formation.


Subject(s)
Adhesins, Bacterial/metabolism , Aminoacyltransferases/metabolism , Bacterial Proteins/metabolism , Cysteine Endopeptidases/metabolism , Membrane Glycoproteins/metabolism , Streptococcus gordonii/metabolism , Adhesins, Bacterial/genetics , Amino Acid Motifs/genetics , Amino Acid Sequence , Aminoacyltransferases/genetics , Bacterial Proteins/genetics , Biofilms , Cysteine Endopeptidases/genetics , Dental Plaque/microbiology , Gene Expression Regulation, Bacterial , Mutation , Peptide Fragments/genetics , Peptide Fragments/metabolism , Saliva/microbiology , Sequence Homology, Amino Acid , Streptococcus gordonii/genetics , Streptococcus gordonii/physiology
2.
Microbes Infect ; 18(6): 387-398, 2016 Jun.
Article in English | MEDLINE | ID: mdl-27005450

ABSTRACT

Mucosal epithelial cells express an autonomous innate immune response that controls the overgrowth of invaded bacteria, mitigates the harmful effects of the bacteria carried within, and does not rely on other external arms of the immune response. Epithelial cell autonomous innate immunity "respects" the social biology of invading bacteria to achieve symbiosis, and is the primary protective mechanism against pathogens.


Subject(s)
Epithelial Cells/immunology , Epithelium/immunology , Immunity, Mucosal , Animals , Humans , Immunity, Innate
3.
Oncotarget ; 7(12): 14029-47, 2016 Mar 22.
Article in English | MEDLINE | ID: mdl-26883112

ABSTRACT

Calprotectin (S100A8/A9), a heterodimeric protein complex of calcium-binding proteins S100A8 and S100A9, plays key roles in cell cycle regulation and inflammation, with potential functions in squamous cell differentiation. While upregulated in many cancers, S100A8/A9 is downregulated in squamous cell carcinomas of the cervix, esophagus, and the head and neck (HNSCC). We previously reported that ectopic S100A8/A9 expression inhibits cell cycle progression in carcinoma cells. Here, we show that declining expression of S100A8/A9 in patients with HNSCC is associated with increased DNA methylation, less differentiated tumors, and reduced overall survival. Upon ectopic over-expression of S100A8/A9, the cancer phenotype of S100A8/A9-negative carcinoma cells was suppressed in vitro and tumor growth in vivo was significantly decreased. MMP1, INHBA, FST, LAMC2, CCL3, SULF1, and SLC16A1 were significantly upregulated in HNSCC but were downregulated by S100A8/A9 expression. Our findings strongly suggest that downregulation of S100A8/A9 through epigenetic mechanisms may contribute to increased proliferation, malignant transformation, and disease progression in HNSCC.


Subject(s)
Biomarkers, Tumor/metabolism , Calgranulin A/metabolism , Calgranulin B/metabolism , Carcinoma, Squamous Cell/metabolism , Head and Neck Neoplasms/metabolism , Animals , Apoptosis , Carcinoma, Squamous Cell/pathology , Cell Movement , Cell Proliferation , Head and Neck Neoplasms/pathology , Humans , Mice , Mice, Inbred BALB C , Mice, Nude , Neoplasm Staging , Prognosis , Tumor Cells, Cultured , Xenograft Model Antitumor Assays
5.
J Forensic Sci ; 60(3): 642-7, 2015 May.
Article in English | MEDLINE | ID: mdl-25682709

ABSTRACT

Although serial killings are relatively rare, they can be the cause of a great deal of anxiety while the killer remains at-large. Despite the fact that the motivations for serial killings are typically quite complex, the psychological analysis of a serial killer can provide valuable insight into how and why certain individuals become serial killers. Such knowledge may be instrumental in preventing future serial killings or in solving ongoing cases. In certain serial killings, the various incidents have a variety of similar features. Identification of similarities between separate homicidal incidents is necessary to recognize that a serial killer may be actively killing. In this report, the authors present a group of serial killings involving three prostitutes who were shot to death over a 3-month period. Scene and autopsy findings, including the unusual finding of postmortem enucleation of the eyes, led investigators to recognize the serial nature of the homicides.


Subject(s)
Eye Enucleation , Forensic Psychiatry , Homicide/psychology , Adult , Female , Humans , Male , Sex Work
6.
Int J Biochem Cell Biol ; 55: 279-87, 2014 Oct.
Article in English | MEDLINE | ID: mdl-25236491

ABSTRACT

Intracellular calprotectin (S100A8/A9) functions in the control of the cell cycle checkpoint at G2/M. Dysregulation of S100A8/A9 appears to cause loss of the checkpoint, which frequently characterizes head and neck squamous cell carcinoma (HNSCC). In the present study, we analyzed carcinoma cells for other S100A8/A9-directed changes in malignant phenotype. Using a S100A8/A9-negative human carcinoma cell line (KB), transfection to express S100A8 and S100A9 caused selective down-regulation of MMP-2 and inhibited in vitro invasion and migration. Conversely, silencing of endogenous S100A8 and S100A9 expression in TR146 cells, a well-differentiated HNSCC cell line, increased MMP-2 activity and in vitro invasion and migration. When MMP-2 expression was silenced, cells appeared to assume a less malignant phenotype. To more closely model the architecture of cell growth in vivo, cells were grown in a 3D collagen substrate, which was compared to 2D. Growth on 3D substrates caused greater MMP-2 expression. Whereas hypermethylation of CpG islands occurs frequently in HNSCC, S100A8/A9-dependent regulation of MMP-2 could not be explained by modification of the upstream promoters of MMP2 or TIMP2. Collectively, these results suggest that intracellular S100A8/A9 contributes to the cancer cell phenotype by modulating MMP-2 expression and activity to regulate cell migration and mobility.


Subject(s)
Calgranulin A/genetics , Calgranulin B/genetics , Cell Movement/genetics , Gene Expression Regulation, Neoplastic , Matrix Metalloproteinase 2/genetics , Blotting, Western , Calgranulin A/metabolism , Calgranulin B/metabolism , Carcinoma/genetics , Carcinoma/metabolism , Carcinoma/pathology , Cell Culture Techniques , Cell Line, Tumor , Collagen/metabolism , CpG Islands/genetics , DNA Methylation , Humans , MCF-7 Cells , Matrix Metalloproteinase 2/metabolism , Neoplasm Invasiveness , RNA Interference , Reverse Transcriptase Polymerase Chain Reaction
7.
Infect Immun ; 81(11): 3975-83, 2013 Nov.
Article in English | MEDLINE | ID: mdl-23940207

ABSTRACT

To protect against invading bacteria, oral epithelial cells appear to use two effector antimicrobial peptides (AMPs): calprotectin (S100A8-S100A9 heterodimer [S100A8/A9]) in the cytosol and cathelicidin antimicrobial protein (CAMP) in endosomes. We sought to learn whether innate immunity might be augmented benignly to increase resistance against invasive bacteria. Epithelial cells were transiently transfected with mRNA constructs containing either the CAMP, S100A8, and S100A9 open reading frames, A8-IRES-A9 (fusion sequence), or A8-nIRES-A9 (fusion with native internal ribosome entry site [IRES] sequence). CAMP, S100A8, and S100A9 protein levels generally peaked between 16 and 44 h after mRNA transfection, depending on the construct; CAMP was processed to LL-37 over time. Following transfection with the respective mRNAs, CAMP and S100A8/A9 each independently increased resistance of epithelial cells to invasion by Listeria and Salmonella for up to 48 h; tandem S100A8/A9 constructs were also effective. Cotransfection to express S100A8/A9 and CAMP together augmented resistance, but synergy was not seen. Independent of the new proteins produced, transfection reduced cell viability after 48 h by 20%, with only 2% attributable to apoptosis. Taken together, these results suggest that epithelial cell resistance to invasive pathogens can be augmented by transient transfection of antimicrobial mRNAs into epithelial cells.


Subject(s)
Antimicrobial Cationic Peptides/immunology , Epithelial Cells/immunology , Epithelial Cells/microbiology , Leukocyte L1 Antigen Complex/immunology , Listeria/immunology , RNA, Messenger/metabolism , Salmonella/immunology , Antimicrobial Cationic Peptides/genetics , Cell Line , Gene Expression , Humans , Leukocyte L1 Antigen Complex/genetics , RNA, Messenger/genetics , Transfection , Cathelicidins
8.
PLoS One ; 8(7): e69395, 2013.
Article in English | MEDLINE | ID: mdl-23874958

ABSTRACT

Malignant transformation results in abnormal cell cycle regulation and uncontrolled growth in head and neck squamous cell carcinoma (HNSCC) and other cancers. S100A8/A9 (calprotectin) is a calcium-binding heterodimeric protein complex implicated in cell cycle regulation, but the specific mechanism and role in cell cycle control and carcinoma growth are not well understood. In HNSCC, S100A8/A9 is downregulated at both mRNA and protein levels. We now report that downregulation of S100A8/A9 correlates strongly with a loss of cell cycle control and increased growth of carcinoma cells. To show its role in carcinogenesis in an in vitro model, S100A8/A9 was stably expressed in an S100A8/A9-negative human carcinoma cell line (KB cells, HeLa-like). S100A8/A9 expression increases PP2A phosphatase activity and p-Chk1 (Ser345) phosphorylation, which appears to signal inhibitory phosphorylation of mitotic p-Cdc25C (Ser216) and p-Cdc2 (Thr14/Tyr15) to inactivate the G2/M Cdc2/cyclin B1 complex. Cyclin B1 expression then downregulates and the cell cycle arrests at the G2/M checkpoint, reducing cell division. As expected, S100A8/A9-expressing cells show both decreased anchorage-dependent and -independent growth and mitotic progression. Using shRNA, silencing of S100A8/A9 expression in the TR146 human HNSCC cell line increases growth and survival and reduces Cdc2 inhibitory phosphorylation at Thr14/Tyr15. The level of S100A8/A9 endogenous expression correlates strongly with the reduced p-Cdc2 (Thr14/Tyr14) level in HNSCC cell lines, SCC-58, OSCC-3 and UMSCC-17B. S100A8/A9-mediated control of the G2/M cell cycle checkpoint is, therefore, a likely suppressive mechanism in human squamous cell carcinomas and may suggest new therapeutic approaches.


Subject(s)
Calgranulin A/genetics , Calgranulin B/genetics , Carcinoma, Squamous Cell/genetics , Cell Division/genetics , G2 Phase/genetics , Head and Neck Neoplasms/genetics , Calgranulin A/metabolism , Calgranulin B/metabolism , Carcinoma, Squamous Cell/metabolism , Cell Line, Tumor , Cell Proliferation , G2 Phase Cell Cycle Checkpoints , Gene Expression Regulation, Neoplastic , Head and Neck Neoplasms/metabolism , Humans , Models, Biological , Protein Binding , Protein Phosphatase 2/metabolism , Signal Transduction , Squamous Cell Carcinoma of Head and Neck
9.
Biochim Biophys Acta ; 1829(9): 954-62, 2013 Sep.
Article in English | MEDLINE | ID: mdl-23563247

ABSTRACT

S100A9 is a calcium-binding protein and subunit of antimicrobial calprotectin complex (S100A8/A9). Produced by neutrophils, monocytes/macrophages and keratinocytes, S100A9 expression increases in response to inflammation. For example, IL-1α produced by epithelial cells acts autonomously on the same cells to induce the expression of S100A8/A9 and cellular differentiation. Whereas it is well known that IL-1α and members of the IL-10 family of cytokines upregulate S100A8 and S100A9 in several cell lineages, the pathway and mechanism of IL-1α-dependent transcriptional control of S100A9 in epithelial cells are not established. Modeled using human epidermal keratinocytes (HaCaT cells), IL-1α stimulated the phosphorylation of p38 MAPK and induced S100A9 expression, which was blocked by IL-1 receptor antagonist, RNAi suppression of p38, or a p38 MAPK inhibitor. Transcription of S100A9 in HaCaT cells depended on nucleotides -94 to -53 in the upstream promoter region, based upon the use of deletion constructs and luciferase reporter activity. Within the responsive promoter region, IL-1α increased the binding activity of CCAAT/enhancer binding protein ß (C/EBPß). Mutated C/EBPß binding sequences or C/EBPß-specific siRNA inhibited the S100A9 transcriptional response. Hence, IL-1α is strongly suggested to increase S100A9 expression in a human epidermal keratinocyte cell line by signaling through the IL-1 receptor and p38 MAPK, increasing C/EBPß-dependent transcriptional activity.


Subject(s)
Calgranulin B/genetics , Epidermis/metabolism , Interleukin-1alpha/physiology , Keratinocytes/metabolism , Transcription, Genetic/physiology , Base Sequence , Cell Line , DNA Primers , Humans , Polymerase Chain Reaction , RNA Interference , p38 Mitogen-Activated Protein Kinases/metabolism
10.
AIDS Res Hum Retroviruses ; 28(12): 1574-8, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22077822

ABSTRACT

Saliva contains anti-HIV-1 factors, which show unclear efficacy in thwarting mucosal infection. When incubated in fresh, unfractionated whole saliva, infectious HIV-1 IIIb and BaL (X4- and R5-tropic, respectively) persisted from 4 to at least 30 min in a saliva concentration-dependent manner. In salivary supernatant for up to 6 h, both infectious HIV-1 strains "escaped" into immortalized oral epithelial cells; infectious BaL showed selectively enhanced escape in the presence of saliva. Fluorescently labeled HIV-1 virus-like particles entered oral epithelial cells within minutes of exposure. Using a previously unrecognized mechanism, therefore, strains of HIV-1 escape inactivation by saliva via rapid uptake into oral epithelial cells.


Subject(s)
Endocytosis , Epithelial Cells/virology , HIV-1/pathogenicity , Saliva/immunology , Adult , Humans , Microbial Viability
11.
Arch Oral Biol ; 56(8): 761-7, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21316034

ABSTRACT

In the oral cavity, mucosal keratinocytes resist bacterial infection, in part, by producing broad-spectrum antimicrobial peptides (AMPs) including defensin, adrenomedullin and calprotectin. Epidermal keratinocyte expression of many AMPs increases in response to interleukin-1α (IL-1α). IL-1α is produced by epidermal keratinocytes and regulates cell differentiation. To better understand innate immunity in the oral cavity, we sought to determine how IL-1α might regulate expression of AMPs by human gingival keratinocytes (HGKs) using DNA microarray and Western blot analyses. HGKs from three subjects expressed eleven AMPs, including S100A7, S100A8, S100A9, S100A12, secretory leucocyte protease inhibitor, lipocalin 2 (LCN2), cystatin C and ß-defensin 2. Of the expressed AMPs, S100A7, S100A12 and LCN2 were up-regulated by IL-1α (inducible AMPs); the other AMPs were considered to be constitutive. Human gingival keratinocytes, therefore, express constitutive and IL-1α-inducible AMPs to provide a rapid and robust innate response to microbial infection.


Subject(s)
Anti-Infective Agents/immunology , Antimicrobial Cationic Peptides/immunology , Gingiva/immunology , Interleukin-1alpha/immunology , Keratinocytes/immunology , Acute-Phase Proteins/analysis , Adolescent , Adult , Blotting, Western , Calgranulin A/analysis , Calgranulin B/analysis , Cell Culture Techniques , Cystatin C/analysis , Female , Gene Expression Regulation , Gingiva/cytology , Humans , Immunity, Innate/immunology , Lipocalin-2 , Lipocalins/analysis , Male , Oligonucleotide Array Sequence Analysis , Proline-Rich Protein Domains/immunology , Proto-Oncogene Proteins/analysis , S100 Calcium Binding Protein A7 , S100 Proteins/analysis , S100A12 Protein , Secretory Leukocyte Peptidase Inhibitor/analysis , Serine Proteinase Inhibitors/analysis , Up-Regulation , Young Adult , beta-Defensins/analysis , beta-Defensins/immunology
12.
Immunol Cell Biol ; 88(3): 328-33, 2010.
Article in English | MEDLINE | ID: mdl-20065999

ABSTRACT

Calprotectin is an antimicrobial complex composed of the S100A8 and S100A9 protein family subunits. Contributing to innate immunity, calprotectin expression is increased by interleukin-1alpha (IL-1alpha), which modulates keratinocyte differentiation. Keratinocyte growth factor (KGF) is produced by mesenchymal cells and has a mitogenic activity for epithelial cells. In this study, we investigated the effect of KGF on calprotectin expression in keratinocytes and modulation by IL-1alpha. Human keratinocytes were cultured with KGF in the presence or absence of a KGF receptor (KGFR) inhibitor or mitogen-activated protein kinase (MAPK) inhibitors. Calprotectin (S100A8/S100A9) expression was determined by northern blotting and enzyme-linked immunosorbent assay, respectively, whereas MAPK phosphorylation was analyzed by western blot analysis. KGF significantly decreased the expression of S100A8/S100A9-specific mRNAs and calprotectin protein. In the presence of KGF, KGFR inhibitor or extracellular-regulated kinase inhibitor restored KGF-downregulated expression of S100A8/S100A9. KGF increased IL-1alpha expression in keratinocytes, whereas IL-1alpha increased KGF expression in fibroblasts. Cocultured fibroblast and keratinocytes showed lower S100A8/S100A9 mRNA expression than keratinocytes alone in the presence or absence of IL-1alpha or KGF. These results suggest that fibroblast-derived KGF reduces or restricts calprotectin expression in keratinocytes, which supports our hypothesis that calprotectin expression in keratinocytes is modulated by factors associated with epithelial-mesenchymal interactions.


Subject(s)
Calgranulin A/biosynthesis , Calgranulin B/biosynthesis , Fibroblast Growth Factor 7/metabolism , Gene Expression Regulation/physiology , Interleukin-1alpha/metabolism , Keratinocytes/metabolism , Cell Line , Coculture Techniques , Fibroblast Growth Factor 7/pharmacology , Fibroblasts/metabolism , Gene Expression Regulation/drug effects , Humans , Interleukin-1alpha/pharmacology , Mitogen-Activated Protein Kinase Kinases/metabolism , Phosphorylation/drug effects , Phosphorylation/physiology
13.
Microbiology (Reading) ; 155(Pt 10): 3238-3246, 2009 Oct.
Article in English | MEDLINE | ID: mdl-19608609

ABSTRACT

Porphyromonas gingivalis activates protease-activated receptors (PARs) on oral keratinocytes, resulting in downstream signalling for an innate immune response. Activation depends on P. gingivalis gingipains, but could be confounded by lipopolysaccharide signalling through Toll-like receptors. We therefore hypothesized that P. gingivalis cleaves oral keratinocyte PARs in an Arg- (Rgp) or Lys- (Kgp) gingipain-specific manner to upregulate pro-inflammatory cytokines. Immortalized human oral keratinocytes (TERT-2) were incubated with wild-type P. gingivalis (ATCC 33277) or strains from a panel of isogenic gingipain deletion mutants: Kgp-deficient (KDP 129); Rgp-deficient (KDP 133); or Kgp- and Rgp-deficient (KDP 136). After incubation with P. gingivalis, keratinocytes were probed with specific antibodies against the N-terminus of PAR-1 and PAR-2. Using flow cytometry and immunofluorescence, receptor cleavage was marked by loss of specific antibody binding to the respective PARs. TERT-2 cells constitutively expressed high levels of PAR-1 and PAR-2, and lower levels of PAR-3. P. gingivalis ATCC 33277 cleaved PAR-1 and PAR-2 in a dose-dependent manner, while the receptors were unaffected by the protease-negative double mutant (KDP 136) at all m.o.i. tested. The single Kgp-negative mutant preferentially cleaved PAR-1, whereas the Rgp-negative mutant cleaved PAR-2. Wild-type or Kgp-negative mutant cleavage of PAR-1 upregulated expression of IL-1alpha, IL-1beta, IL-6 and TNF-alpha; the Rgp-negative mutant did not modulate these cytokines. Selective cleavage of PAR-1 on oral epithelial cells by P. gingivalis Rgp therefore upregulates expression of pro-inflammatory cytokines.


Subject(s)
Adhesins, Bacterial/metabolism , Cysteine Endopeptidases/metabolism , Epithelial Cells/drug effects , Epithelial Cells/immunology , Porphyromonas gingivalis/enzymology , Porphyromonas gingivalis/immunology , Receptor, PAR-1/metabolism , Receptor, PAR-2/metabolism , Adhesins, Bacterial/genetics , Antibodies/pharmacology , Cell Line , Cysteine Endopeptidases/genetics , Flow Cytometry , Gene Deletion , Gingipain Cysteine Endopeptidases , Humans , Indicators and Reagents/pharmacology , Staining and Labeling/methods
14.
J Biol Chem ; 284(11): 7078-90, 2009 Mar 13.
Article in English | MEDLINE | ID: mdl-19122197

ABSTRACT

Epithelial cells expressing calprotectin, a heterodimer of S100A8 and S100A9 proteins, are more resistant to bacterial invasion. To determine structural motifs that affect resistance to bacterial invasion, mutations were constructed in S100A9 targeting the calcium-binding loops I and II (E36Q, E78Q, E36Q,E78Q) and the C terminus (S100A9(1-99) and S100A9(1-112)), which contains putative antimicrobial zinc-binding and phosphorylation sites. The S100A8 and mutated S100A9 encoding plasmids were transfected into calprotectin-negative KB carcinoma cells. All transfected cells (except KB-sham) expressed 27E10-reactive heterodimers. In bacterial invasion assays with Listeria monocytogenes and Salmonella enterica serovar Typhimurium (Salmonella typhimurium), cell lines expressing S100A8 in complex with S100A9E36Q, S100A9E78Q, S100A9(1-99), or S100A9(1-112) mutants or the S100A9(1-114) (full-length) calprotectin resisted bacterial invasion better than KB-sham. When compared with KB-S100A8/A9(1-114), cells expressing truncated S100A9(1-99) or S100A9(1-112) with S100A8 also showed increased resistance to bacterial invasion. In contrast, glutamic acid residues 36 and 78 in calcium-binding loops I and II promote resistance in epithelial cells, because cells expressing S100A9E36Q,E78Q with S100A8 were unable to resist bacterial invasion. Mutations in S100A9 E36Q, E78Q were predicted to cause loss of the calcium-induced positive face in calprotectin, reducing interactions with microtubules and appearing to be crucial for keratinocyte resistance to bacterial invasion.


Subject(s)
Calcium/metabolism , Calgranulin A/metabolism , Calgranulin B/metabolism , Keratinocytes/metabolism , Listeria monocytogenes , Listeriosis/metabolism , Salmonella Infections/metabolism , Salmonella typhimurium , Amino Acid Motifs/genetics , Amino Acid Substitution , Binding Sites/genetics , Calgranulin A/genetics , Calgranulin B/genetics , Cell Line , Dimerization , Epithelial Cells/metabolism , Epithelial Cells/microbiology , Humans , Keratinocytes/microbiology , Listeriosis/genetics , Microtubules/genetics , Microtubules/metabolism , Mutation, Missense , Phosphorylation/genetics , Protein Structure, Secondary/genetics , Salmonella Infections/genetics , Zinc/metabolism
15.
Antiinflamm Antiallergy Agents Med Chem ; 8(4): 290-305, 2009 Dec 04.
Article in English | MEDLINE | ID: mdl-20523765

ABSTRACT

The calgranulins are a subgroup of proteins in the S100 family (calgranulin A, S100A8; calgranulin B, S100A9 and calgranulin C, S100A12) that provide protective anti-infective and anti-inflammatory functions for the mammalian host. In this review, we discuss the structure-function relationships whereby S100A8 and S100A9, and for comparison, S100A12, provide intra- and extracellular protection during the complex interplay between infection and inflammation and how the calgranulins are regulated to optimally protect the host. Ideally located to support epithelial barrier function, calprotectin, a complex of S100A8/S100A9, is expressed in squamous mucosal keratinocytes and innate immune cells present at mucosal surfaces. The calgranulins are also abundantly produced in neutrophils and monocytes, whereas expression is induced in epidermal keratinocytes, gastrointestinal epithelial cells and fibroblasts during inflammation. The calgranulins show species-specific expression and function. For example, S100A8 is chemotactic in rodents but not in humans. In humans, S100A12 appears to serve as a functional chemotactic homolog to murine S100A8. Transition metal-binding and oxidation sites within calgranulins are able to create structural changes that may orchestrate new protective functions or binding targets. The calgranulins thus appear to adopt a variety of roles to protect the host. In addition to serving as a leukocyte chemoattractant, protective functions include oxidant scavenging, antimicrobial activity, and chemokine-like activities. Each function may reflect the concentration of the calgranulin, post-transcriptional modifications, oligomeric forms, and the proximal intracellular or extracellular environments. Calprotectin and the calgranulins are remarkable as multifunctional proteins dedicated to protecting the intra- and extracellular environments during infection and inflammation.

16.
Retrovirology ; 5: 66, 2008 Jul 17.
Article in English | MEDLINE | ID: mdl-18637194

ABSTRACT

BACKGROUND: Oral keratinocytes on the mucosal surface are frequently exposed to HIV-1 through contact with infected sexual partners or nursing mothers. To determine the plausibility that oral keratinocytes are primary targets of HIV-1, we tested the hypothesis that HIV-1 infects oral keratinocytes in a restricted manner. RESULTS: To study the fate of HIV-1, immortalized oral keratinocytes (OKF6/TERT-2; TERT-2 cells) were characterized for the fate of HIV-specific RNA and DNA. At 6 h post inoculation with X4 or R5-tropic HIV-1, HIV-1gag RNA was detected maximally within TERT-2 cells. Reverse transcriptase activity in TERT-2 cells was confirmed by VSV-G-mediated infection with HIV-NL4-3Deltaenv-EGFP. AZT inhibited EGFP expression in a dose-dependent manner, suggesting that viral replication can be supported if receptors are bypassed. Within 3 h post inoculation, integrated HIV-1 DNA was detected in TERT-2 cell nuclei and persisted after subculture. Multiply spliced and unspliced HIV-1 mRNAs were not detectable up to 72 h post inoculation, suggesting that HIV replication may abort and that infection is non-productive. Within 48 h post inoculation, however, virus harbored by CD4 negative TERT-2 cells trans infected co-cultured peripheral blood mononuclear cells (PBMCs) or MOLT4 cells (CD4+ CCR5+) by direct cell-to-cell transfer or by releasing low levels of infectious virions. Primary tonsil epithelial cells also trans infected HIV-1 to permissive cells in a donor-specific manner. CONCLUSION: Oral keratinocytes appear, therefore, to support stable non-replicative integration, while harboring and transmitting infectious X4- or R5-tropic HIV-1 to permissive cells for up to 48 h.


Subject(s)
HIV-1 , Keratinocytes/virology , Mouth Mucosa/virology , Virus Integration , Virus Replication , Cell Line, Transformed , Cells, Cultured , Coculture Techniques , Epithelial Cells/cytology , Epithelial Cells/virology , HIV-1/pathogenicity , HIV-1/physiology , Humans , Keratinocytes/cytology , Leukocytes, Mononuclear/cytology , Leukocytes, Mononuclear/virology , Mouth Mucosa/cytology , Palatine Tonsil/cytology , Palatine Tonsil/virology , Telomerase
17.
Retrovirology ; 5: 29, 2008 Mar 27.
Article in English | MEDLINE | ID: mdl-18371227

ABSTRACT

BACKGROUND: Systemic infection with HIV occurs infrequently through the oral route. The frequency of occurrence may be increased by concomitant bacterial infection of the oral tissues, since co-infection and inflammation of some cell types increases HIV-1 replication. A putative periodontal pathogen, Porphyromonas gingivalis selectively up-regulates expression of the HIV-1 coreceptor CCR5 on oral keratinocytes. We, therefore, hypothesized that P. gingivalis modulates the outcome of HIV infection in oral epithelial cells. RESULTS: Oral and tonsil epithelial cells were pre-incubated with P. gingivalis, and inoculated with either an X4- or R5-type HIV-1. Between 6 and 48 hours post-inoculation, P. gingivalis selectively increased the infectivity of R5-tropic HIV-1 from oral and tonsil keratinocytes; infectivity of X4-tropic HIV-1 remained unchanged. Oral keratinocytes appeared to harbor infectious HIV-1, with no evidence of productive infection. HIV-1 was harbored at highest levels during the first 6 hours after HIV exposure and decreased to barely detectable levels at 48 hours. HIV did not appear to co-localize with P. gingivalis, which increased selective R5-tropic HIV-1 trans infection from keratinocytes to permissive cells. When CCR5 was selectively blocked, HIV-1 trans infection was reduced. CONCLUSION: P. gingivalis up-regulation of CCR5 increases trans infection of harbored R5-tropic HIV-1 from oral keratinocytes to permissive cells. Oral infections such as periodontitis may, therefore, increase risk for oral infection and dissemination of R5-tropic HIV-1.


Subject(s)
HIV Infections/virology , HIV-1/physiology , Keratinocytes/microbiology , Porphyromonas gingivalis/physiology , Receptors, CCR5/metabolism , Bacteroidaceae Infections/microbiology , Cell Line , Coculture Techniques , Epithelial Cells/immunology , Epithelial Cells/virology , Humans , Mouth Mucosa/cytology , Mouth Mucosa/microbiology , Risk Factors , Virus Replication
18.
J Immunol ; 179(4): 2542-50, 2007 Aug 15.
Article in English | MEDLINE | ID: mdl-17675516

ABSTRACT

Primary infection of oral epithelial cells by HIV-1, if it occurs, could promote systemic infection. Most primary systemic infections are associated with R5-type HIV-1 targeting the R5-specific coreceptor CCR5, which is not usually expressed on oral keratinocytes. Because coinfection with other microbes has been suggested to modulate cellular infection by HIV-1, we hypothesized that oral keratinocytes may up-regulate CCR5 in response to the oral endogenous pathogen Porphyromonas gingivalis by cysteine-protease (gingipains) activation of the protease-activated receptors (PARs) or LPS signaling through the TLRs. The OKF6/TERT-2-immortalized normal human oral keratinocyte line expressed CXCR4, whereas CCR5 was not detectable. When exposed to P. gingivalis ATCC 33277, TERT-2 cells induced greater time-dependent expression of CCR5-specific mRNA and surface coreceptors than CXCR4. By comparing arg- (Rgp) and lys-gingipain (Kgp) mutants, a mutant deficient in both proteases, and the action of trypsin, P. gingivalis Rgp was strongly suggested to cleave PAR-1 and PAR-2 to up-regulate CCR5. CCR5 was also slightly up-regulated by an isogenic gingipain-deficient mutant, suggesting the presence of a nongingipain-mediated mechanism. Purified P. gingivalis LPS also up-regulated CCR5. Blocking TLR2 and TLR4 receptors with Abs attenuated induction of CCR5, suggesting LPS signaling through TLRs. P. gingivalis, therefore, selectively up-regulated CCR5 by two independent signaling pathways, Rgp acting on PAR-1 and PAR-2, and LPS on TLR2 and TLR4. By inducing CCR5 expression, P. gingivalis coinfection could promote selective R5-type HIV-1 infection of oral keratinocytes.


Subject(s)
Bacteroidaceae Infections/immunology , HIV Infections/immunology , HIV-1/immunology , Keratinocytes/immunology , Mouth/immunology , Porphyromonas gingivalis/immunology , Receptors, CCR5/immunology , Up-Regulation/immunology , Adhesins, Bacterial/immunology , Adhesins, Bacterial/metabolism , Antibodies/immunology , Antibodies/pharmacology , Bacteroidaceae Infections/genetics , Bacteroidaceae Infections/pathology , Cell Line, Transformed , Cysteine Endopeptidases/deficiency , Cysteine Endopeptidases/immunology , Cysteine Endopeptidases/metabolism , Gingipain Cysteine Endopeptidases , HIV Infections/genetics , HIV Infections/metabolism , HIV Infections/pathology , HIV-1/metabolism , Humans , Keratinocytes/metabolism , Keratinocytes/pathology , Lipopolysaccharides/pharmacology , Mouth/metabolism , Mouth/pathology , Mutation/immunology , Porphyromonas gingivalis/genetics , Porphyromonas gingivalis/metabolism , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , RNA, Messenger/metabolism , Receptor, PAR-1/immunology , Receptor, PAR-1/metabolism , Receptor, PAR-2/immunology , Receptor, PAR-2/metabolism , Receptors, CCR5/biosynthesis , Receptors, CXCR4/biosynthesis , Receptors, CXCR4/genetics , Receptors, CXCR4/immunology , Signal Transduction/drug effects , Signal Transduction/genetics , Signal Transduction/immunology , Toll-Like Receptor 2/antagonists & inhibitors , Toll-Like Receptor 2/genetics , Toll-Like Receptor 2/immunology , Toll-Like Receptor 2/metabolism , Toll-Like Receptor 4/antagonists & inhibitors , Toll-Like Receptor 4/genetics , Toll-Like Receptor 4/immunology , Toll-Like Receptor 4/metabolism , Up-Regulation/drug effects
19.
Immunol Cell Biol ; 85(7): 532-7, 2007 Oct.
Article in English | MEDLINE | ID: mdl-17549071

ABSTRACT

Human epidermis and epithelium serve as physiologic barriers to protect against noxious and infectious agents. Contributing to the defense against infection, epithelial cells express antimicrobial peptides (AMPs). The expression of AMPs in keratinocytes is generally regulated directly by bacteria and indirectly by proinflammatory cytokines. Bacteria may also regulate AMP expression by inducing keratinocyte expression of the autonomous proinflammatory cytokine, interleukin-1alpha (IL-1alpha). To test the hypothesis that AMP expression may be regulated by cell autonomous cytokines, we investigated the effect of IL-1alpha on the expression of AMPs in human keratinocytes (HaCaT cells) by microarray, northern blot, reverse transcriptase (RT)-PCR and western blot analyses. IL-1alpha increased expression of mRNA in a dose- and time-dependent manner specific for lipocalin 2, S100A8, S100A9 and secretory leukocyte protease inhibitor (SLPI) more than twofold relative to nonstimulated cells (control), and slightly upregulated S100A7 and beta-defensin-2. Furthermore, the expression of lipocalin 2, S100A7, S100A8, S100A9 and SLPI proteins were upregulated by IL-1alpha. On the other hand, HaCaT cells expressed mRNA specific for other AMPs, including cystatin 3, adrenomedullin, RNase-7 and mucin 5, which were unaffected by IL-1alpha treatment. These results suggest that the autonomous keratinocyte cytokine, IL-1alpha, selectively upregulates the expression of AMPs which may modulate innate epithelial cell immunity in skin and mucosa.


Subject(s)
Antimicrobial Cationic Peptides/genetics , Gene Expression Regulation , Interleukin-1alpha/physiology , Keratinocytes/metabolism , Antimicrobial Cationic Peptides/metabolism , Cells, Cultured , Gene Expression Regulation/drug effects , Humans , Immunity, Innate/drug effects , Immunity, Innate/genetics , Interleukin-1alpha/pharmacology , Keratinocytes/drug effects , Mucous Membrane/immunology , Mucous Membrane/metabolism , Skin/immunology , Skin/metabolism
20.
Am J Forensic Med Pathol ; 26(3): 282-4, 2005 Sep.
Article in English | MEDLINE | ID: mdl-16121087

ABSTRACT

Cor triatriatum is a rare congenital cardiac anomaly in which the left atrium is divided into proximal (dorsal or upper) and distal (ventral or lower) chambers by a fibromuscular septum. The upper chamber receives the pulmonary veins and the lower chamber contains the atrial appendage and the mitral valve. The 2 chambers communicate through a defect in the membrane. Cor triatriatum is often associated with other congenital cardiac anomalies. Most frequently, the upper chamber communicates with the right atrium through a patent foramen ovale or atrial septal defect, and the clinical symptoms simulate anomalous pulmonary venous return. Less commonly, the foramen ovale communicates with the distal chamber and the clinical features mimic mitral stenosis. When cor triatriatum is the only abnormality, the clinical findings are also similar to mitral stenosis with development of pulmonary hypertension and subsequent right ventricular hypertrophy and atrial enlargement. The diagnosis is usually made in infancy or childhood, and the lack of treatment results in death in 75% of patients. We report the case of a woman who presented much later in life. The patient was a 57-year-old female with a clinical history of chronic atrial fibrillation who presented to the emergency department because of a "funny sensation" in her chest, though she denied chest pain, nausea, vomiting, or diaphoresis. EKG revealed atrial fibrillation with a rapid ventricular response and a tachycardic rate of 157. She had a therapeutic level of digoxin, and cardiac enzymes were normal. The patient was admitted and placed on Cardizem drip. Serial EKGs remained normal and heart rate control was achieved. On hospital day 2, the patient became dyspneic and cyanotic. She went into cardiac arrest and died.Autopsy revealed cardiomegaly (610 g) with 4-chamber dilatation. A septum divided the left atrium into 2 chambers. The defect in the dividing membrane measured 1 cm in diameter. No other congenital defects were noted. The large size of the defect in the membrane likely accounted for the late onset of symptoms that allowed this patient to survive into adulthood without previous diagnosis or surgical intervention (which is usually required in childhood).


Subject(s)
Atrial Fibrillation/etiology , Cor Triatriatum/complications , Cor Triatriatum/pathology , Cor Triatriatum/classification , Cor Triatriatum/diagnosis , Female , Forensic Pathology , Humans , Middle Aged
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