Elucidation of the Interleukin 12 Production Mechanism during Intracellular Bacterial Infection in Amberjack, Seriola dumerili

ABSTRACT Intracellular bacterial infections affect all vertebrates. Cultured fish are particularly vulnerable because no effective protection measures have been established since such infections emerged approximately 50 years ago. As in other vertebrates, the induction of cell-mediated immunity (CMI) plays an important role in protecting fish against infection. However, details of the mechanism of CMI induction in fish have not been clarified. In the present study, we focused on the production of interleukin 12 (IL-12), an important factor in CMI induction in fish. Using several different approaches, we investigated IL-12 regulation in amberjack (Seriola dumerili), the species most vulnerable to intracellular bacterial disease. The results of promoter assays and transcription factor gene expression analyses showed that the expression of interferon regulatory factor-1 (IRF-1) and activator protein-1 (AP-1) is necessary for IL-12 production. Phagocytosis of living cells (LCs) of Nocardia seriolae bacteria induced IL-12 production in neutrophils, accompanied by IRF-1 and AP-1 gene expression. Bacteria in which the exported repetitive protein (Erp)-like gene was deleted (Δerp-L) could not establish intracellular parasitism or induce IRF-1 and AP-1 expression or IL-12 production, despite being phagocytosed by neutrophils. These data suggest that IL-12 production is regulated by (i) two transcription factors, IRF-1 and AP-1, (ii) phagocytosis of LCs by neutrophils, and (iii) one or more cell components of LCs. Our results enhance the understanding of the immune response to intracellular bacterial infections in vertebrates and could facilitate the discovery of new agents to prevent intracellular bacterial disease.

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Small-Molecule Antibiotics Inhibiting tRNA-Regulated Gene Expression Is a Viable Strategy for Targeting Gram-Positive Bacteria

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.01247-20 ◽

2020 ◽

Vol 65 (1) ◽

pp. e01247-20 ◽

Cited By ~ 1

Author(s):

Ville Y. P. Väre ◽

Ryan F. Schneider ◽

Haein Kim ◽

Erica Lasek-Nesselquist ◽

Kathleen A. McDonough ◽

...

Keyword(s):

Gene Expression ◽

Small Molecule ◽

Bacterial Infections ◽

Gram Positive ◽

Content Type ◽

T Box ◽

Gram Positive Bacteria ◽

Bactericidal Effects ◽

Low Levels ◽

Regulated Gene Expression

ABSTRACTBacterial infections and the rise of antibiotic resistance, especially multidrug resistance, have generated a clear need for discovery of novel therapeutics. We demonstrated that a small-molecule drug, PKZ18, targets the T-box mechanism and inhibits bacterial growth. The T-box is a structurally conserved riboswitch-like gene regulator in the 5′ untranslated region (UTR) of numerous essential genes of Gram-positive bacteria. T-boxes are stabilized by cognate, unacylated tRNA ligands, allowing the formation of an antiterminator hairpin in the mRNA that enables transcription of the gene. In the absence of an unacylated cognate tRNA, transcription is halted due to the formation of a thermodynamically more stable terminator hairpin. PKZ18 targets the site of the codon-anticodon interaction of the conserved stem I and reduces T-box-controlled gene expression. Here, we show that novel analogs of PKZ18 have improved MICs, bactericidal effects against methicillin-resistant Staphylococcus aureus (MRSA), and increased efficacy in nutrient-limiting conditions. The analogs have reduced cytotoxicity against eukaryotic cells compared to PKZ18. The PKZ18 analogs acted synergistically with aminoglycosides to significantly enhance the efficacy of the analogs and aminoglycosides, further increasing their therapeutic windows. RNA sequencing showed that the analog PKZ18-22 affects expression of 8 of 12 T-box controlled genes in a statistically significant manner, but not other 5′-UTR regulated genes in MRSA. Very low levels of resistance further support the existence of multiple T-box targets for PKZ18 analogs in the cell. Together, the multiple targets, low resistance, and synergy make PKZ18 analogs promising drugs for development and future clinical applications.

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Interleukin 34 Serves as a Novel Molecular Adjuvant against Nocardia Seriolae Infection in Largemouth Bass (Micropterus Salmoides)

Vaccines ◽

10.3390/vaccines8020151 ◽

2020 ◽

Vol 8 (2) ◽

pp. 151

Author(s):

Huy Hoa Hoang ◽

Pei-Chi Wang ◽

Shih-Chu Chen

Keyword(s):

Dna Vaccine ◽

Largemouth Bass ◽

Teleost Fish ◽

Bacterial Infections ◽

Micropterus Salmoides ◽

Cell Mediated Immunity ◽

Molecular Adjuvant ◽

Genes Encoding ◽

Immune Related Genes ◽

Nocardia Seriolae

DNA vaccines have been widely employed in controlling viral and bacterial infections in mammals and teleost fish. Co-injection of molecular adjuvants, including chemokines, cytokines, and immune co-stimulatory molecules, is one of the potential strategies used to improve DNA vaccine efficacy. In mammals and teleost fish, interleukin-34 (IL-34) had been described as a multifunctional cytokine and its immunological role had been confirmed; however, the adjuvant capacity of IL-34 remains to be elucidated. In this study, IL-34 was identified in largemouth bass. A recombinant plasmid of IL-34 (pcIL-34) was constructed and co-administered with a DNA vaccine encoding hypoxic response protein 1 (Hrp1; pcHrp1) to evaluate the adjuvant capacity of pcIL-34 against Nocardia seriolae infection. Our results indicated that pcIL-34 co-injected with pcHrp1 not only triggered innate immunity and a specific antibody response, but also enhanced the mRNA expression level of immune-related genes encoding for cytokines, chemokines, and humoral and cell-mediated immunity. Moreover, pcIL-34 enhanced the protection of pcHrp1 against N. seriolae challenge and conferred the relative percent survival of 82.14%. Collectively, IL-34 is a promising adjuvant in a DNA vaccine against nocardiosis in fish.

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Adapting Microarray Gene Expression Signatures for Early Melioidosis Diagnosis

Journal of Clinical Microbiology ◽

10.1128/jcm.01906-19 ◽

2020 ◽

Vol 58 (7) ◽

Author(s):

Ornuma Sangwichian ◽

Toni Whistler ◽

Arnone Nithichanon ◽

Chidchamai Kewcharoenwong ◽

Myint Myint Sein ◽

...

Keyword(s):

Gene Expression ◽

Bacterial Infections ◽

Sequence Similarity ◽

Clinical Signs ◽

Diagnostic Algorithm ◽

Microarray Gene Expression ◽

Predictive Values ◽

Content Type ◽

Tropical Regions ◽

Gene Expression Signatures

ABSTRACT Melioidosis is caused by Burkholderia pseudomallei and is predominantly seen in tropical regions. The clinical signs and symptoms of the disease are nonspecific and often result in misdiagnosis, failure of treatment, and poor clinical outcome. Septicemia with septic shock is the most common cause of death, with mortality rates above 40%. Bacterial culture is the gold standard for diagnosis, but it has low sensitivity and takes days to produce definitive results. Early laboratory diagnosis can help guide physicians to provide treatment specific to B. pseudomallei. In our study, we adapted host gene expression signatures obtained from microarray data of B. pseudomallei-infected cases to develop a real-time PCR diagnostic test using two differentially expressed genes, AIM2 (absent in melanoma 2) and FAM26F (family with sequence similarity 26, member F). We tested blood from 33 patients with B. pseudomallei infections and 29 patients with other bacterial infections to validate the test and determine cutoff values for use in a cascading diagnostic algorithm. Differentiation of septicemic melioidosis from other sepsis cases had a sensitivity of 82%, specificity of 93%, and negative and positive predictive values (NPV and PPV) of 82% and 93%, respectively. Separation of cases likely to be melioidosis from those unlikely to be melioidosis in nonbacteremic situations showed a sensitivity of 40%, specificity of 54%, and NPV and PPV of 44% and 50%, respectively. We suggest that our AIM2 and FAM26F expression combination algorithm could be beneficial for early melioidosis diagnosis, offering a result within 24 h of admission.

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Gene Expression Profile and Immunological Evaluation of Unique Hypothetical Unknown Proteins of Mycobacterium leprae by Using Quantitative Real-Time PCR

Clinical and Vaccine Immunology ◽

10.1128/cvi.00419-12 ◽

2012 ◽

Vol 20 (2) ◽

pp. 181-190 ◽

Cited By ~ 4

Author(s):

Hee Jin Kim ◽

Kalyani Prithiviraj ◽

Nathan Groathouse ◽

Patrick J. Brennan ◽

John S. Spencer

Keyword(s):

Gene Expression ◽

Real Time ◽

Real Time Pcr ◽

Specific Antigen ◽

Mycobacterium Leprae ◽

Bioinformatic Analysis ◽

Cell Mediated Immunity ◽

Quantitative Real Time Pcr ◽

Content Type

ABSTRACTThe cell-mediated immunity (CMI)-basedin vitrogamma interferon release assay (IGRA) ofMycobacterium leprae-specific antigens has potential as a promising diagnostic means to detect those individuals in the early stages ofM. lepraeinfection. Diagnosis of leprosy is a major obstacle toward ultimate disease control and has been compromised in the past by the lack of specific markers. Comparative bioinformatic analysis among mycobacterial genomes identified potentialM. leprae-specific proteins called “hypothetical unknowns.” Due to massive gene decay and the prevalence of pseudogenes, it is unclear whether any of these proteins are expressed or are immunologically relevant. In this study, we performed cDNA-based quantitative real-time PCR to investigate the expression status of 131 putative open reading frames (ORFs) encoding hypothetical unknowns. Twenty-six of theM. leprae-specific antigen candidates showed significant levels of gene expression compared to that of ESAT-6 (ML0049), which is an important T cell antigen of low abundance inM. leprae. Fifteen of 26 selected antigen candidates were expressed and purified inEscherichia coli. The seroreactivity to these proteins of pooled sera from lepromatous leprosy patients and cavitary tuberculosis patients revealed that 9 of 15 recombinant hypothetical unknowns elicitedM. leprae-specific immune responses. These nine proteins may be good diagnostic reagents to improve both the sensitivity and specificity of detection of individuals with asymptomatic leprosy.

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Differential Ability of Pandemic and Seasonal H1N1 Influenza A Viruses To Alter the Function of Human Neutrophils

mSphere ◽

10.1128/mspheredirect.00567-17 ◽

2018 ◽

Vol 3 (1) ◽

Cited By ~ 3

Author(s):

Natalia Malachowa ◽

Brett Freedman ◽

Daniel E. Sturdevant ◽

Scott D. Kobayashi ◽

Vinod Nair ◽

...

Keyword(s):

Gene Expression ◽

Bactericidal Activity ◽

Influenza A ◽

Bacterial Infections ◽

Viral Infections ◽

Fungal Infections ◽

Neutrophil Function ◽

Human Neutrophils ◽

Influenza A Viruses ◽

Content Type

ABSTRACTNeutrophils are essential cells of host innate immunity. Although the role of neutrophils in defense against bacterial and fungal infections is well characterized, there is a relative paucity of information about their role against viral infections. Influenza A virus (IAV) infection can be associated with secondary bacterial coinfection, and it has long been posited that the ability of IAV to alter normal neutrophil function predisposes individuals to secondary bacterial infections. To better understand this phenomenon, we evaluated the interaction of pandemic or seasonal H1N1 IAV with human neutrophils isolated from healthy persons. These viruses were ingested by human neutrophils and elicited changes in neutrophil gene expression that are consistent with an interferon-mediated immune response. The viability of neutrophils following coculture with either pandemic or seasonal H1N1 IAV was similar for up to 18 h of culture. Notably, neutrophil exposure to seasonal (but not pandemic) IAV primed these leukocytes for enhanced functions, including production of reactive oxygen species and bactericidal activity. Taken together, our results are at variance with the universal idea that IAV impairs neutrophil function directly to predispose individuals to secondary bacterial infections. Rather, we suggest that some strains of IAV prime neutrophils for enhanced bacterial clearance.IMPORTANCEA long-standing notion is that IAV inhibits normal neutrophil function and thereby predisposes individuals to secondary bacterial infections. Here we report that seasonal H1N1 IAV primes human neutrophils for enhanced killing ofStaphylococcus aureus. Moreover, we provide a comprehensive view of the changes in neutrophil gene expression during interaction with seasonal or pandemic IAV and report how these changes relate to functions such as bactericidal activity. This study expands our knowledge of IAV interactions with human neutrophils.

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Global Transcriptome Analysis of Staphylococcus aureus Biofilms in Response to Innate Immune Cells

Infection and Immunity ◽

10.1128/iai.00819-13 ◽

2013 ◽

Vol 81 (12) ◽

pp. 4363-4376 ◽

Cited By ~ 34

Author(s):

Tyler D. Scherr ◽

Christelle M. Roux ◽

Mark L. Hanke ◽

Amanda Angle ◽

Paul M. Dunman ◽

...

Keyword(s):

Gene Expression ◽

Staphylococcus Aureus ◽

Defense Mechanisms ◽

Bacterial Infections ◽

Expression Patterns ◽

Immune Defense ◽

Innate Immune ◽

Gene Expression Patterns ◽

Content Type ◽

Affymetrix Microarrays

ABSTRACTThe potent phagocytic and microbicidal activities of neutrophils and macrophages are among the first lines of defense against bacterial infections. YetStaphylococcus aureusis often resistant to innate immune defense mechanisms, especially when organized as a biofilm. To investigate howS. aureusbiofilms respond to macrophages and neutrophils, gene expression patterns were profiled using Affymetrix microarrays. The addition of macrophages toS. aureusstatic biofilms led to a global suppression of the biofilm transcriptome with a wide variety of genes downregulated. Notably, genes involved in metabolism, cell wall synthesis/structure, and transcription/translation/replication were among the most highly downregulated, which was most dramatic at 1 h compared to 24 h following macrophage addition to biofilms. Unexpectedly, few genes were enhanced in biofilms after macrophage challenge. Unlike coculture with macrophages, coculture ofS. aureusstatic biofilms with neutrophils did not greatly influence the biofilm transcriptome. Collectively, these experiments demonstrate thatS. aureusbiofilms differentially modify their gene expression patterns depending on the leukocyte subset encountered.

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Modulation of Chicken Intestinal Immune Gene Expression by Small Cationic Peptides as Feed Additives during the First Week Posthatch

Clinical and Vaccine Immunology ◽

10.1128/cvi.00322-13 ◽

2013 ◽

Vol 20 (9) ◽

pp. 1440-1448 ◽

Cited By ~ 17

Author(s):

Michael H. Kogut ◽

Kenneth J. Genovese ◽

Haiqi He ◽

Christina L. Swaggerty ◽

Yiwei Jiang

Keyword(s):

Gene Expression ◽

Proinflammatory Cytokines ◽

Proinflammatory Cytokine ◽

Feed Additives ◽

Feed Additive ◽

Cationic Peptides ◽

Type I ◽

Immune Gene ◽

Content Type ◽

Functional Efficiency

ABSTRACTWe have been investigating modulation strategies tailored around the selective stimulation of the host's immune system as an alternative to direct targeting of microbial pathogens by antibiotics. One such approach is the use of a group of small cationic peptides (BT) produced by a Gram-positive soil bacterium,Brevibacillus texasporus. These peptides have immune modulatory properties that enhance both leukocyte functional efficiency and leukocyte proinflammatory cytokine and chemokine mRNA transcription activitiesin vitro. In addition, when provided as a feed additive for just 4 days posthatch, BT peptides significantly induce a concentration-dependent protection against cecal and extraintestinal colonization bySalmonella entericaserovar Enteritidis. In the present studies, we assessed the effects of feeding BT peptides on transcriptional changes on proinflammatory cytokines, inflammatory chemokines, and Toll-like receptors (TLR) in the ceca of broiler chickens with and withoutS. Enteritidis infection. After feeding a BT peptide-supplemented diet for the first 4 days posthatch, chickens were then challenged withS. Enteritidis, and intestinal gene expression was measured at 1 or 7 days postinfection (p.i.) (5 or 11 days of age). Intestinal expression of innate immune mRNA transcripts was analyzed by quantitative real-time PCR (qRT-PCR). Analysis of relative mRNA expression showed that a BT peptide-supplemented diet did not directly induce the transcription of proinflammatory cytokine, inflammatory chemokine, type I/II interferon (IFN), or TLR mRNA in chicken cecum. However, feeding the BT peptide-supplemented diet primed cecal tissue for increased (P≤ 0.05) transcription of TLR4, TLR15, and TLR21 upon infection withS. Enteritidis on days 1 and 7 p.i. Likewise, feeding the BT peptides primed the cecal tissue for increased transcription of proinflammatory cytokines (interleukin 1β [IL-1β], IL-6, IL-18, type I and II IFNs) and inflammatory chemokine (CxCLi2) in response toS. Enteritidis infection 1 and 7 days p.i. compared to the chickens fed the basal diet. These small cationic peptides may prove useful as alternatives to antibiotics as local immune modulators in neonatal poultry by providing prophylactic protection againstSalmonellainfections.

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Methanobactin from Methylocystis sp. Strain SB2 Affects Gene Expression and Methane Monooxygenase Activity in Methylosinus trichosporium OB3b

Applied and Environmental Microbiology ◽

10.1128/aem.03981-14 ◽

2015 ◽

Vol 81 (7) ◽

pp. 2466-2473 ◽

Cited By ~ 11

Author(s):

Muhammad Farhan Ul-Haque ◽

Bhagyalakshmi Kalidass ◽

Alexey Vorobev ◽

Bipin S. Baral ◽

Alan A. DiSpirito ◽

...

Keyword(s):

Gene Expression ◽

Methane Monooxygenase ◽

Particulate Methane Monooxygenase ◽

Methylosinus Trichosporium Ob3b ◽

Methylosinus Trichosporium ◽

Monooxygenase Activity ◽

Content Type ◽

Soluble Methane Monooxygenase ◽

A Subunit ◽

Membrane Bound

ABSTRACTMethanotrophs can express a cytoplasmic (soluble) methane monooxygenase (sMMO) or membrane-bound (particulate) methane monooxygenase (pMMO). Expression of these MMOs is strongly regulated by the availability of copper. Many methanotrophs have been found to synthesize a novel compound, methanobactin (Mb), that is responsible for the uptake of copper, and methanobactin produced byMethylosinus trichosporiumOB3b plays a key role in controlling expression of MMO genes in this strain. As all known forms of methanobactin are structurally similar, it was hypothesized that methanobactin from one methanotroph may alter gene expression in another. WhenMethylosinus trichosporiumOB3b was grown in the presence of 1 μM CuCl2, expression ofmmoX, encoding a subunit of the hydroxylase component of sMMO, was very low.mmoXexpression increased, however, when methanobactin fromMethylocystissp. strain SB2 (SB2-Mb) was added, as did whole-cell sMMO activity, but there was no significant change in the amount of copper associated withM. trichosporiumOB3b. IfM. trichosporiumOB3b was grown in the absence of CuCl2, themmoXexpression level was high but decreased by several orders of magnitude if copper prebound to SB2-Mb (Cu-SB2-Mb) was added, and biomass-associated copper was increased. Exposure ofMethylosinus trichosporiumOB3b to SB2-Mb had no effect on expression ofmbnA, encoding the polypeptide precursor of methanobactin in either the presence or absence of CuCl2.mbnAexpression, however, was reduced when Cu-SB2-Mb was added in both the absence and presence of CuCl2. These data suggest that methanobactin acts as a general signaling molecule in methanotrophs and that methanobactin “piracy” may be commonplace.

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Modulation of the Tissue Expression Pattern of Zebrafish CRP-Like Molecules Suggests a Relevant Antiviral Role in Fish Skin

Biology ◽

10.3390/biology10020078 ◽

2021 ◽

Vol 10 (2) ◽

pp. 78

Author(s):

Melissa Bello-Perez ◽

Mikolaj Adamek ◽

Julio Coll ◽

Antonio Figueras ◽

Beatriz Novoa ◽

...

Keyword(s):

Gene Expression ◽

Bacterial Infections ◽

Quantitative Polymerase Chain Reaction ◽

Tissue Expression ◽

Interferon Response ◽

Fish Skin ◽

Tissue Expression Pattern ◽

Chain Reaction ◽

Polymerase Chain ◽

Antiviral Role

Recent studies suggest that short pentraxins in fish might serve as biomarkers for not only bacterial infections, as in higher vertebrates including humans, but also for viral ones. These fish orthologs of mammalian short pentraxins are currently attracting interest because of their newly discovered antiviral activity. In the present work, the modulation of the gene expression of all zebrafish short pentraxins (CRP-like proteins, CRP1-7) was extensively analyzed by quantitative polymerase chain reaction. Initially, the tissue distribution of crp1-7 transcripts and how the transcripts varied in response to a bath infection with the spring viremia of carp virus, were determined. The expression of crp1-7 was widely distributed and generally increased after infection (mostly at 5 days post infection), except for crp1 (downregulated). Interestingly, several crp transcription levels significantly increased in skin. Further assays in mutant zebrafish of recombinant activation gene 1 (rag1) showed that all crps (except for crp2, downregulated) were already constitutively highly expressed in skin from rag1 knockouts and only increased moderately after viral infection. Similar results were obtained for most mx isoforms (a reporter gene of the interferon response), suggesting a general overcompensation of the innate immunity in the absence of the adaptive one.

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A Polyphenol Enriched Variety of Apple Alters Circulating Immune Cell Gene Expression and Faecal Microbiota Composition in Healthy Adults: A Randomized Controlled Trial

Nutrients ◽

10.3390/nu13041092 ◽

2021 ◽

Vol 13 (4) ◽

pp. 1092

Author(s):

Matthew P. G. Barnett ◽

Wayne Young ◽

Kelly Armstrong ◽

Diane Brewster ◽

Janine M. Cooney ◽

...

Keyword(s):

Gene Expression ◽

Immune Cell ◽

Controlled Trial ◽

Composition Analysis ◽

Cell Mediated Immunity ◽

Anthocyanin Content ◽

Microbiota Composition ◽

Faecal Microbiota ◽

Apple Variety ◽

Relative Abundances

Polyphenols within fruits and vegetables may contribute to health benefits due to their consumption, with the anthocyanin sub-set also adding colour. The Lemonade™ apple variety has green skin and white flesh, with low anthocyanin content, while some apple varieties have high anthocyanin content in both the skin and flesh. Effects of red compared with white-fleshed apples were studied in healthy human subjects in a randomized, placebo-controlled, cross-over intervention trial. Twenty-five healthy subjects consumed dried daily portions of the red-fleshed or placebo (white-fleshed) apple for two weeks, followed by one-week washout and further two-week crossover period. During the study, volunteers provided faecal samples for microbiota composition analysis and blood samples for peripheral blood mononuclear cell (PBMC) gene expression analysis. Subtle differences were observed in the faecal microbiota of subjects that were fed the different apples, with significant (p < 0.05) reductions in relative abundances of Streptococcus, Ruminococcus, Blautia, and Roseburia, and increased relative abundances of Sutterella, Butyricicoccus, and Lactobacillus in subjects after consuming the red apple. Changes in PBMC gene expression showed 18 mRNA transcripts were differentially expressed between the two groups, of which 16 were immunoglobulin related genes. Pathway analysis showed that these genes had roles in pathways such as immunoglobulin production, B cell-mediated immunity, complement activation, and phagocytosis. In conclusion, this study shows that anthocyanin-rich apples may influence immune function compared to control apples, with changes potentially associated with differences in the faecal microbiota.

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