bluuebunny/crossref_metadata_2025_split huggingface dataset:
Functional and Molecular Characterization of a Newly Discovered Bacteriocin‐like Substance
Authors: Brock Susan R. , Knadler Judith , Triplet Meredith , Baker Jason C. 
Published: June 2021

Bacteriocins are antimicrobial peptides produced by bacteria while antibiotics are non‐proteinacous small organic antimicrobial molecules. They also differ from antibiotics in modes of action. Their wide range of molecular and functional characteristics include: molecular weight, structure, temperature/pH stability, and killing spectrums of susceptible species. Bacteriocins present potential for diverse applications as treatment/prevention of infectious diseases, food preservers, ect. In the spring of 2006, a bacteriocin‐like substance, currently referred to as Bacteriocin X (Bac. X), was discovered from a putative strain of Bacillus amyloliquefaciens. The objective of this study was to discern the functional and molecular characteristics of Bac. X. It demonstrated a wide spectrum of activity against an array of bacterial organisms (both Gram(+) and Gram(−)), including a variety of potential pathogens. It displayed stability under extreme temperature and pH conditions. It was not notably susceptible to Proteinase K or Trypsin; but its activity was destroyed by Pronase E. Bac. X was also able to destroy mammalian cells. This study is still pursuing the purification of Bac. X from cell filtrate or perhaps a plasmid isolation of its gene to facilitate sequencing and homology comparisons, looking for the identification of the bacteriocin or documentation of a new one.MWSU Summer Research Institute
CD8 T cells prime CD8a dendritic cells for IL‐12p70 production via CD40 CD40L interactions
Authors: Wong Kok Loon 
Published: June 2021

Dendritic cells prime CD8 T cells to proliferate and acquire effector function. However, how CD8 T cells could modulate DC function during this priming is less understood. Here, we show that activated CD8 T cells can prime DCs for IL‐12p70 in the presence of LPS. This ability was not seen with freshly isolated CD8 T cells or when LPS was absent. Direct contact involving MHC class I peptide and CD40‐CD40L interactions was essential for IL‐12p70 production, whereas soluble factors, including IFN‐g, TNF‐a, IL‐4 and GM‐CSF was little or no role to play in this process. CD8 T cells primed the CD8a+ but not the CD8a− DC subset for IL‐12p70 production. Hence apart from their role as killer cells, activated CD8 T cells may provide help to DCs via CD40L to pathogenically challenged CD8a+ DCs for IL‐12p70 and Th1 induction.This work is funded by the Biomedical Research Council (Grant no. 04/1/21/19/373). Wong KL is supported by an A*STAR graduate scholarship.
Targeting DNA to Dendritic Cells Using Major Compatibility Complex (MHC) Class II Ligands
Authors: Kovacs Jeffrey R , Zheng Ying , Jia Liang , Gawalt Ellen S , Shen Hongmei , Meng Wilson S 
Published: June 2021

Objectives:This study was aimed at developing DNA delivery systems by exploiting MHC‐binding motifs. We tested the hypothesis that particles guided by MHC class II ligands can enhance uptake of oligodeoxynucleotides (ODN) into dendritic cells (DCs).Methods:Particles fabricated from PLGA or polystyrene (PS) were coated with the peptide VHA (amino acid sequence VHASHAVHAAHAVHA) which fulfills the binding motif of the murine class II MHC molecule I‐Ad. FITC‐labeled NF‐κB decoy ODN were condensed on the surface of the particles via the cationic peptide O10H6. DCs derived from BALB/c (I‐Ad) and C57BL/6 (I‐Ab) mice were used as the surrogate target and control, respectively.Results:VHA‐anchored particles carrying the decoy were found to be in the nano‐sized range (120–400nm). VHA‐mediated ODN uptake was demonstrated using flow cytometry (2‐fold higher MFI in I‐Ad vs. I‐Ab DCs). The uptake in BALB/c DCs was blocked by an anti‐I‐Ad antibody. Lysotracker staining showed lysosomal escape of DNA in cells. BALB/c DCs treated with VHA‐directed ODN show decreased sensitivity to LPS as measured by CD86 expression (2‐fold, n=3 p<0.05). Differential IFN‐γ production (34%±5%, n=4, p<0.05) upon stimulation was observed in VHA‐guided ODN exposed I‐Ad DCs compared to I‐Ab DCs.Conclusion:The results support the concept that MHC class II ligands can be used to facilitate delivery of DNA into DCs.
Expression and release of angiopoietin‐1 from neutrophils: intracellular mechanisms
Authors: Sirois Martin G. , Neagoe Paul‐Eduard , Brkovic Alexandre 
Published: June 2021

We recently detected the expression of Tie2 receptor on neutrophils which can be activated by both angiopoietins (Ang1 and Ang2), and promoting β2‐integrin activation, platelet‐activating factor synthesis (PAF) and migration. Recruitment of neutrophils to inflammatory sites contributes to pathological angiogenesis by their capacity to produce proangiogenic cytokines, including vascular endothelial growth factor (VEGF).Herein, we assessed if human neutrophils can produce both angiopoietins, and if so, determined their mechanisms of release.We observed by RT‐PCR, FACScan analysis, ELISA and confocal microscopy that neutrophils express Ang1 but not Ang2. For each condition, VEGF detection was performed as positive control. Using nitrogen cavitation, we observed that Ang1 is localized in the cytosolic fraction whereas VEGF is found in the specific granules (β‐granules). By ELISA we quantified the concentration of Ang1 (2727 ± 22 pg/ml) and VEGF (609 ± 7 pg/ml) from 2.5 × 108 neutrophils. Using selective agonists (PMA, Il‐8, fMLP, TNF‐α, calcium ionophore A23187) capable to promote VEGF release by the neutrophils, we assessed their capacity to support Ang1 release. Only a treatment with PMA (50 ng/ml), and A23187 (10 μM) induced Ang1 release by up to 5.9‐ and 4‐fold respectively as compared to PBS‐treated neutrophils, and these effects were maximal within 15 minutes. Supported by the CIHR and HSFQ.
IL‐12 and IFNα/β regulate non‐redundant functions in human CD8+ T cells
Authors: Ramos Hilario J , Farrar J. David 
Published: June 2021

During viral infection, dendritic cells secrete the innate cytokines IL‐12 and IFNα/β to facilitate viral clearance. These cytokines have been linked to CD8+ T cell and are widely thought to act in a redundant manner to facilitate cytokine secretion and cytolytic activity. We examined the ability of IL‐12 and IFNα/β to drive these responses in human CD8+CD45RA+ T cells. We found that IL‐12 was sufficient for the generation of CD8+ effector cell activity, marked by IFNγ and TNFα secretion and strong cytolytic activity. In contrast, IFNα/β alone did not promote IFNγ or TNFα. Although, IFNα/β markedly induced perforin and granzyme B expression as a whole, these cells displayed functionally defective lytic activity in the absence of IL‐12 signaling. Thus, IL‐12 but not IFNα/β regulates primary effector functions in human CD8+ T cells. Interestingly, IFNα/β enhanced the expression of lymph node homing receptor CCR7 on a subset of T cells. This subpopulation displayed various characteristics of a memory phenotype, such as low CXCR3 and perforin expression while retaining granzyme B expression. Further, development of this CCR7 hi sub population was regulated solely by IFNα/β and was independent of the effects of IL‐12. These results demonstrate that IL‐12 and IFNα/β are not functionally redundant and in fact, impart unique phenotypes on human CD8+ T cells.This study is supported by a grant from the National Institutes of Health/National Institute of Allergy and Infectious Disease (AI56222) and by a predoctoral fellowship from the National Instititue of Health/Nation Institute of Allergy and Infectious Disease (AI68622).
Impaired Dendritic Cell Migration and T cell Stimulation in Aging Lead to Defective Dendritic Cell‐Mediated Antitumor Immunity
Authors: Grolleau‐Julius Annabelle , Harning Erin , Yung Raymong 
Published: June 2021

We recently reported that bone marrow‐derived dendritic cells (DCs) from old C57BL/6 mice are less effective than their young counterpart in inducing the regression of B16‐OVA melanomas. To examine the underlying mechanisms, we investigated the effect of aging on DC tumor antigen presentation and migration. Although aging does not affect the ability of DCs to present OVA peptide (257–264), DCs from aged (18–20 months) mice are less efficient than those from young (3–6 months) mice in stimulating MHC class I OVA‐specific T cells in vitro (p<0.0025). Phenotypic analysis revealed a selective decrease in DC‐specific/intracellular adhesion molecule type 3‐grabbing, nonintegrin (DC‐SIGN) level in aged DCs. Importantly, vaccination of young mice using old OVA‐peptide(257–264) pulsed DCs resulted in impaired activation of OVA‐specific CD8+ splenic T cells in vivo (p<0.025). These splenic T cells from aged animals were able to differentiateinto IFN‐γ‐producing and cytotoxic effectors, but to a significantly less extent than those vaccinated with young OVA PP‐DCs. A decrease influx of CD8+ T cells within the tumor was also observed seven days after old DC injection. Finally, adoptive transfer experiments showed defective in vivo DC trafficking in aging, with half as many aged DCs migrated to the regional lymph nodes (p<0.025). This correlates with reduced CCR7 gene expression, impaired in vitro migration of aged DCs in response to CCL21, and defective CCR7 signaling in aged DCs. Taken together, our findings suggest that defective DC migration and T cell stimulation contribute to the observed impaired DC tumor immunotherapeutic response in aging.This work id supported by the NIH (1RO1AG020628‐01A2; 3RO1 AR42525) (RY), the Ann Arbor VA Health System (VA Merit Review) (RY), and by the NIH‐NIA (AG024824, University of Michigan OAIC Pepper Center) (AG).
Upregulation of PD‐1 expression on tumor antigen‐specific CD8+ T cells in patients with advanced melanoma is associated with reversible immune dysfunction
Authors: Fourcade Julien , Kudela Pavol , Sun Zhaojun , Shen Hongmei , Land Stephanie , Sander Cindy , Kirkwood John M. , Zarour Hassane M. 
Published: June 2021

The inhibitory receptor programmed death 1 (PD‐1) is a negative regulator of activated T cells and is upregulated on the surface of exhausted virus‐specific CD8+ T cells in chronically infected mice and humans. Blockade of this pathway using antibodies against PD ligand 1 (PD‐L1) reversed CD8+ T cell dysfunction. Here, we have investigated the role of the PD‐1/PD‐L1 pathway in impairing human tumor‐induced CD8+ T cells directed against multiple tumor antigens. In sharp contrast to the Epstein Barr virus (EBV) and influenza matrix (flu), we observed that ex vivo detectable CD8+ T cells recognizing well‐defined MHC class I‐restricted tumor epitopes in patients with advanced melanoma, upregulated PD‐1. After blockade of the PD1/PD‐L1 pathway, these tumor antigen‐specific CD8+ T cells exhibited increased proliferation and production of cytokines in response to the cognate antigen. Our findings contribute to a better understanding of the intriguing coexistence of strong tumor antigen‐specific CD8+ T cell responses with clinical progression in patients with advanced melanoma. They further provide a strong rationale for the use of PD 1/PDL‐1 blockade alone or in the context of cancer vaccines to reverse CD8+ T cell dysfunction and increase the likelihood of tumor regression.This work was supported by NIH/NCI Grants CA90360 and CA112198 (to HMZ)
Mechanism of IL‐12's suppression of VEGFR3 upregulation on tumor vessels
Authors: Sorensen Elizabeth Welty , Gerber Scott , Frelinger John , Lord Edith 
Published: June 2021

IL‐12 is a powerful anticancer agent in many tumor models, but how IL‐12 exerts its anti‐tumoral effect in vivo is still largely unknown. We are exploring this using B16, a C57BL/6‐derived melanoma line transfected to express IL‐12 (B16/IL‐12), a system that provides constant, IL‐12 production within the tumor microenvironment.We have shown that the presence of intratumoral IL‐12 delays tumor growth, and causes phenotypic changes in the blood vasculature. The vessels within B16/IL‐12 tumors have a more normal morphology and fail to upregulate expression of the angiogenic vessel marker, vascular endothelial growth factor receptor 3 (VEGFR3). Studies performed in transgenic mice have shown that the failure to upregulate VEGFR3 is mediated by IFN‐γ and that T cells are required for this effect. We hypothesize that IFN‐γ is acting directly on the endothelial cells to prevent upregulation of VEGFR3. This is being tested with IFN‐γ receptor knock out mice in a bone marrow chimera system. IL‐12 also stimulates the immune system resulting in a marked increase in the number of tumor infiltrating lymphocytes (TILs) and more of these are producing IFN‐γ. These studies suggest that the vascular effects of immunotherapy may be as important to the beneficial effects of immunotherapy on tumor growth as the effects on the immune cells themselves.Supported by NIH R01‐CA28332
Myeloid‐derived suppressor cells (MDSCs) and tumor‐associated macrophages (TAMs) produce CCL22 which selectively recruits regulatory T‐cells (Tregs) to the tumor microenvironment
Authors: Mailloux Adam William , Young M Rita I 
Published: June 2021

Tumor‐induced immune suppression involves the accumulation of immune suppressive infiltrates in the microenvironment. We demonstrated an increased number of Tregs in Lewis Lung Carcinoma (LLC). High levels of CCR4 on Tregs lead us to hypothesize that CCR4‐chemokines are secreted by LLC and selectively recruit Tregs. ELISA shows a large increase in CCL22 secretion by LLC bearing tissue. Lack of CCL22 in primary cultures suggests that CCL22 is NOT produced by the tumor, but rather by some other component of the microenvironment. Migration assays showed that normal, and to a greater extent, LLC‐bearing tissue selectively recruits Tregs. Neutralization of CCL22 significantly reduced the selective Treg migration. Fractionated normal and LLC bearing tissue shows that while NK, CD31+, and CD11c+ cells all produce CCL22, only the CD11b+ population secretes higher levels in LLC bearing tissue. This is magnified by the increased number of CD11b+ cells found in LLC bearing tissue. Of the CD11b+ cells, two populations emerge. One population is absent in normal lung tissue and expresses F4/80, suggesting that these are TAMs. The other population expresses Gr‐1, which is consistent with MDSCs. Together, our data suggests that other immune suppressive phenotypes such as TAMS and MDSCs play an active role in Treg recruitment to the microenvironment through the production of CCL22.Supported by the Dept. of Veteran's Affairs & NIH
Anthocyanin‐rich extract mitigates skin photoaging in ultraviolet‐B irradiation‐induced human dermal fibroblasts
Authors: Bae Ji‐Young , Kang Young‐Hee 
Published: June 2021

Bog blueberries are rich in anthocyanins, phytochemicals that belong to the flavonoid family and provide pigmentation to fruits and vegetables. Anthocyanins have received attention as agents that may have potential in preventing chronic diseases such as cardiovascular diseases and certain cancers. The present study investigated the capacity of an anthocyanin(ATH)‐rich extract from bog blueberry to inhibit degradation of collagen, secretion of collagenolytic MMP enzymes and production of inflammatory cytokines in ultraviolet (UV)‐B irradiated human dermal fibroblasts. The ATH‐rich extract attenuated the UV‐B‐induced cytotoxicity accompanying a blockade of ROS production. In addition, the ATH‐rich extract markedly suppressed collagen degradation in UV‐B‐exposed dermal fibroblasts by blunting production of these MMP enzymes. We next attempted to explore whether the ATH‐rich extract down‐regulated MMP production via interfering with the MAPK‐dependent and/or NF‐κB‐responsive pathways. This extract mitigated activation of MAPK, which resulted in a consequent decrease in MMP‐1 secretion. Additionally, the ATH‐rich extract reduced release of multiple inflammatory cytokines such as IL‐1β, IL‐6, IL‐8 and TNF‐α. These results demonstrate that the ATH‐rich extract dampens UV‐B‐triggered collagen destruction and inflammatory responses through modulating MAPK‐ and NF‐κB‐dependent pathways. Therefore, the ATH‐rich extract from bog blueberries may be a protective agent against UV‐induced skin photoaging.Grant Funding Source: Korea Research Foundation (KRF‐2006‐521‐F00072) and Brain Korea 21
NF‐κB ORCHESTRATES GENE EXPRESSION ASSOCIATED WITH MYOCARDIAL INFARCTION AND PROTECTION
Authors: Wilhide Michael E. , Tranter Michael , Ren Xiaoping , Jones W. Keith 
Published: June 2021

NF‐κB has been shown to contribute to myocardial infarction (MI) after ischemia/reperfusion (I/R) and to cardioprotection after permanent coronary occlusion (PO). The aim is to discover the mechanism by which NF‐κB regulates these opposing effects after MI. The hypothesis is that, after different ischemic stimuli, NF‐κB mediates different sets of genes that are responsible for opposite effects. We employed transgenic mice that block NF‐κB in a cardiac‐specific manner. These mice were subjected either to I/R or PO and microarrays were used to delineate the genes regulated acutely by NF‐κB. Interestingly, after I/R NF‐κB activation leads to at least a two‐fold increase in the expression levels of several heat shock proteins. After PO, NF‐κB leads to a three‐fold higher level of Hsp70 compared to I/R. Cox2 was also found to be differentially expressed. Different heat shock proteins are known to be either anti‐apoptotic or pro‐apoptotic, and HSPs may affect processing and activity of Cox2 via endoplasmic reticulum (ER) stress response/processing pathways. Thus, HSP and Cox2 regulation by NF‐κB may underlie, at least in part, the differential effects of NF‐κB. Understanding the role of NF‐κB in the regulation of these sets of genes will aid in the discovery of novel therapeutic targets for the treatment of heart disease.This work was supported by NIH grant R01 HL63034 (WKJ) and 5F31 HL081923 (MW).
Effect of Sildenafil on mdx Skeletal Muscle
Authors: Parchen Candace M , Gray Heidi , Percival Justin , Froehner Stanley C , Beavo Joseph A 
Published: June 2021

Duchenne muscular dystrophy (DMD) affects 1 in 3,500 boys and is a severe X‐linked disease caused by a complete loss of dystrophin. DMD patients are born healthy but by age five, develop progressive skeletal muscle necrosis, fibrosis and abnormal hypertrophy. Sildenafil Citrate (Viagra®) is a phosphodiesterase 5 (PDE5) inhibitor that induces vasodilation and is currently approved for use in treatment of erectile dysfunction and pulmonary hypertension.Previous studies have shown Sildenafil activates PKG‐1, resulting in anti‐hypertrophic and anti‐fibrotic effects on pressure‐induced cardiac hypertrophy (Takimoto et al (2005) Nature 11(2):214–222). Recently, another PDE5 inhibitor, tadalafil, has been reported to be effective in ameliorating some of the dystrophic symptoms in the mdx mouse, a dystrophin knockout model of DMD (Asai et al (2007) PLoS ONE 2(8): e806). We have been exploring the use of non‐invasive techniques such as echocardiography and MRI, to track the progression of Sildenafil treatment throughout the life of the mdx mouse. After one year of chronic Sildenafil treatment, we see a decrease in the MRI T2 relaxation time of the hind‐leg muscle, indicating a decrease in dystrophic tissue. Earlier times also show a trend toward beneficial effect. With eight weeks of treatment, there is a decrease in Tibialis Anterior muscle atrophy and centrinucleation, thus less overall damage and a decrease in the need for muscle regeneration. This data provides preliminary evidence that PDE5 regulation can reduce muscle damage in skeletal dystrophic muscle indicating Sildenafil could be a possible treatment for DMD patients. Supported by Charley's Fund and NIH grant DK21623.
Diammonium Glycyrrhizinate protects against trinitrobenzene sulfonic acid‐induced colitis in rats
Authors: Ding Hong , Liu Ying , Mao Yao , Qi Zheng , Wang Ying , Xiang Jin , Zhou Huiping 
Published: June 2021

Glycyrrhizinate is the major active component of licorice root extract, an ancient medicinal plant with various pharmacological activates. Diammonium Glycyrrhizinate (DG) has long been used to treat hepatitis in China. Recently, it has been reported that DG could reduce acetic acid‐induced inflammatory injury in a rat ulcerative colitis (UC). However, whether DG has anti‐inflammatory effect in other UC models remains unknown. The aim of the present study is to examine the protective effects of DG on trinitrobenzene sulfonic acid (TNBS)‐induced UC in rats.Methods: Sprague‐Dawley rats were randomly assigned into five groups: 1) normal control; 2) TNBS; 3) TNBS+DG (2 mg/kg); 4) TNBS+DG (10 mg/kg); 5) TNBS+DG (50 mg/kg); 5) TNBS+ sulfasalazine (SASP, 225mg/kg). After induction of UC with TNBS, DG or SASP was rectally administrated daily for 8 days, the normal control and TNBS groups were administrated with the same volume of saline. Colonic inflammation was evaluated by disease activity index, histological changes, and myeloperoxidase (MPO) activity. Radioimmunoassay was used to measure TNF‐a and IL‐1b levels in the serum.Results: DG not only significantly inhibited TNBS‐induced increase of MPO, TNF‐α and IL‐1β, but also prevented TNBS‐induced colonic injury.Conclusions: TNBS‐induced colitis was reliable rat UC model. Rectal administration of DG could effectively prevent TNBS‐induced inflammatory injury.
Antineuroinflammatory polyketide plakortide N from the Brazilian marine sponge Plakortis angulospiculatus
Authors: Mayer Alejandro M , Kossuga Miriam H , Veloso Katyuscya , Ferreira Antonio G , Hajdu Eduardo , Berlinck Roberto G 
Published: June 2021

Involvement of brain microglia (BMΦ) in neuroinflammation has been hypothesized (Mayer AMS, MEDICINA 58:377, 1998; Mayer AMS et al., SHOCK 11: 180, 1999). We have reported marine chemicals as a potential source of antineuroinflammatory compounds (Mayer et al. BioMedCentral Pharmacology 5:6, 2005) using Escherichia coli lipopolysaccharide (LPS)‐activated BMΦ as our in vitro model (Mayer AMS et al., SHOCK 11:180, 1999). The purpose of this investigation was to study the effect of several polyketides isolated from the marine sponge Plakortis angulospiculatus on phorbol ester (PMA)‐stimulated thromboxane B2 (TXB2) and superoxide anion (O2−) generation from E. coli LPS‐activated rat BMΦ O2− was determined by superoxide dismutase‐inhibitable reduction of ferricytochrome C and TXB2 using commercially available immunoassays. Only plakortide N potently inhibited TXB2 (IC50=0.93μM) but not O2− (IC50 >10μM), with low lactic dehydrogenase release (LDH50>10μM). Because LDH release was low, our current data suggests that the significant inhibitory effect of plakortide N on BMΦ TXB2 release was pharmacologic rather than toxic in nature, although the molecular mechanism of inhibition remains undetermined at this time. (Supported by American Society of Pharmacognosy 1998 Research Starter Grant, NIH grant CA 67786 and FAPESP grants 01/03095‐0 and 05/60175‐2 to RGB and Midwestern University to AMM).TOTAL