Plasma Cell Ontogeny Defined by Quantitative Changes in Blimp-1 Expression

Plasma cells comprise a population of terminally differentiated B cells that are dependent on the transcriptional regulator B lymphocyte–induced maturation protein 1 (Blimp-1) for their development. We have introduced a gfp reporter into the Blimp-1 locus and shown that heterozygous mice express the green fluorescent protein in all antibody-secreting cells (ASCs) in vivo and in vitro. In vitro, these cells display considerable heterogeneity in surface phenotype, immunoglobulin secretion rate, and Blimp-1 expression levels. Importantly, analysis of in vivo ASCs induced by immunization reveals a developmental pathway in which increasing levels of Blimp-1 expression define developmental stages of plasma cell differentiation that have many phenotypic and molecular correlates. Thus, maturation from transient plasmablast to long-lived ASCs in bone marrow is predicated on quantitative increases in Blimp-1 expression.

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Differential Expression of the Aspergillus fumigatus pksP Gene Detected In Vitro and In Vivo with Green Fluorescent Protein

Infection and Immunity ◽

10.1128/iai.69.10.6411-6418.2001 ◽

2001 ◽

Vol 69 (10) ◽

pp. 6411-6418 ◽

Cited By ~ 66

Author(s):

Kim Langfelder ◽

Bruno Philippe ◽

Bernhard Jahn ◽

Jean-Paul Latgé ◽

Axel A. Brakhage

Keyword(s):

Green Fluorescent Protein ◽

Aspergillus Fumigatus ◽

Polyketide Synthase ◽

Fluorescent Protein ◽

Developmental Stages ◽

Gene Encoding ◽

Immunocompromised Mice ◽

Green Fluorescent

ABSTRACT Aspergillus fumigatus is an important pathogen of immunocompromised hosts, causing pneumonia and invasive disseminated disease with high mortality. To be able to analyze the expression of putative virulence-associated genes of A. fumigatus, the use of the enhanced green fluorescent protein (EGFP) as a reporter was established. Two 5′ sequences, containing the putative promoters of thepyrG gene, encoding orotidine-5′-phosphate decarboxylase, and the pksP gene, encoding a polyketide synthase involved in both pigment biosynthesis and virulence ofA. fumigatus, were fused with the egfpgene. The PpksP-egfp construct was integrated via homologous recombination into the genomicpksP locus. EGFP production was analyzed by fluorescence spectrometry, Western blot analysis, and fluorescence microscopy. Differential gene expression in A. fumigatus was observed. Fluorescence derived from the PYRG-EGFP fusion protein was detected during all developmental stages of the fungus, i.e., during germination, during vegetative growth, in conidiophores, and weakly in conidia. In addition, it was also detected in germinating conidia when isolated from the lungs of immunocompromised mice. By contrast, PKSP-EGFP-derived fluorescence was not found in hyphae or stalks of conidiophores but was found in phialides and conidia in vitro when the fungus was grown under standard conditions, indicating a developmentally controlled expression of the gene. Interestingly,pksP-egfp expression was also detected in hyphae of germinating conidia isolated from the lungs of immunocompromised mice. This finding indicates that thepksP gene can also be expressed in hyphae under certain conditions and, furthermore, that the pksP gene might also contribute to invasive growth of the fungus.

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In Vivo Quantitative Assessment of Therapeutic Response to Bortezomib Therapy in Disseminated Animal Models of Multiple Myeloma With [18F]FDG and [64Cu]LLP2A PET

10.21203/rs.3.rs-647260/v1 ◽

2021 ◽

Author(s):

Anchal Ghai ◽

Nikki Fettig ◽

Francesca Fontana ◽

John DiPersio ◽

Mike Rettig ◽

...

Keyword(s):

Therapeutic Response ◽

Plasma Cells ◽

Fluorescent Protein ◽

Ex Vivo ◽

Molar Activity ◽

Quantitative Pet ◽

Late Antigen ◽

Green Fluorescent

Abstract BackgroundMultiple myeloma (MM) is a disease of cancerous plasma cells. Current treatments have improved the survival rate; however, most MM patients relapse. Imaging based timely determination of therapeutic response is critical for improving outcomes in MM patients. Very late antigen-4 (VLA4) is over expressed in MM cells. Here, we evaluated [18F]FDG and VLA4 targeted [64Cu]LLP2A for quantitative PET imaging in MM models of variable VLA4 expression, and following bortezomib therapy.MethodsIn vitro and ex vivo VLA4 expression was evaluated by flow cytometry. Human MM cells, MM.1S-CG and U266-CG (CG: luciferase and green fluorescent protein), were injected intravenously in NOD-SCID gamma mice. Tumor progression was monitored by bioluminescence imaging (BLI). Treatment group received bortezomib (1mg/kg, twice/week) intraperitoneally. All cohorts (treated, untreated and no-tumor) were longitudinally imaged with [64Cu]LLP2A (2-3 MBq; Molar Activity: 44.14±1.40 MBq/nmol) and [18F]FDG (7.4-8.0 MBq) PET respectively.ResultsFlow cytometry confirmed high expression of CD49d in U266 cells (>99%) and moderate expression in MM.1S cells (~52%). BLI showed decrease in total body flux in treated mice. In MM.1S-CG untreated versus treated mice, [64Cu]LLP2A localized with a significantly higher SUVmean in spine (0.58 versus 0.31) and femur (0.72 versus 0.39) at week 4 post tumor inoculation. In U266-CG treated versus untreated mice, there was a 4-time percent [64Cu]LLP2A increase in spine at week 3. Compared to [64Cu]LLP2A, [18F]FDG PET detected treatment related changes at later time points.Conclusion[64Cu]LLP2A is a promising tracer for in vivo assessment of therapeutic response in disseminated models of MM.

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Blimp-1 is required for maintenance of long-lived plasma cells in the bone marrow

Journal of Experimental Medicine ◽

10.1084/jem.20051611 ◽

2005 ◽

Vol 202 (11) ◽

pp. 1471-1476 ◽

Cited By ~ 159

Author(s):

Miriam Shapiro-Shelef ◽

Kuo-I Lin ◽

David Savitsky ◽

Jerry Liao ◽

Kathryn Calame

Keyword(s):

Bone Marrow ◽

B Lymphocyte ◽

Plasma Cells ◽

Brdu Incorporation ◽

Design Strategies ◽

Gene Encoding ◽

Maturation Protein

Long-lived plasma cells, residing primarily in the bone marrow, continuously secrete antibody and provide an important component of humoral memory. However, when such cells secrete autoantibodies or become transformed, they can be pathogenic. We have shown recently that the transcriptional repressor B lymphocyte–induced maturation protein 1 (Blimp-1) is required for the formation of plasma cells. To determine what role Blimp-1 might play in maintenance of plasma cells, we generated mice in which the gene encoding Blimp-1 could be deleted in an inducible manner. Deletion of Blimp-1 either in vitro or in vivo leads to loss of previously formed B220LOCD138HI plasma cells. Using BrdU incorporation, we confirmed that Blimp-1 is required for the maintenance of nondividing, long-lived plasma cells in the bone marrow. Blimp-1 is also required for long-term maintenance of antigen-specific immunoglobulin in serum. Thus Blimp-1 is required not only for the formation but also for the maintenance of long-lived plasma cells. This finding provides the possibility of new drug design strategies for autoimmunity and multiple myeloma focused on blocking Blimp-1 expression or activity.

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Development of a Fluorescent Tool for Studying Legionella bozemanae Intracellular Infection

Microorganisms ◽

10.3390/microorganisms9020379 ◽

2021 ◽

Vol 9 (2) ◽

pp. 379

Author(s):

Breanne M. Head ◽

Christopher I. Graham ◽

Teassa MacMartin ◽

Yoav Keynan ◽

Ann Karen C. Brassinga

Keyword(s):

Growth Kinetics ◽

Legionella Pneumophila ◽

Fluorescent Protein ◽

Disease Incidence ◽

Acanthamoeba Castellanii ◽

Infection Model ◽

Intracellular Infection ◽

Green Fluorescent

Legionnaires’ disease incidence is on the rise, with the majority of cases attributed to the intracellular pathogen, Legionella pneumophila. Nominally a parasite of protozoa, L. pneumophila can also infect alveolar macrophages when bacteria-laden aerosols enter the lungs of immunocompromised individuals. L. pneumophila pathogenesis has been well characterized; however, little is known about the >25 different Legionella spp. that can cause disease in humans. Here, we report for the first time a study demonstrating the intracellular infection of an L. bozemanae clinical isolate using approaches previously established for L. pneumophila investigations. Specifically, we report on the modification and use of a green fluorescent protein (GFP)-expressing plasmid as a tool to monitor the L. bozemanae presence in the Acanthamoeba castellanii protozoan infection model. As comparative controls, L. pneumophila strains were also transformed with the GFP-expressing plasmid. In vitro and in vivo growth kinetics of the Legionella parental and GFP-expressing strains were conducted followed by confocal microscopy. Results suggest that the metabolic burden imposed by GFP expression did not impact cell viability, as growth kinetics were similar between the GFP-expressing Legionella spp. and their parental strains. This study demonstrates that the use of a GFP-expressing plasmid can serve as a viable approach for investigating Legionella non-pneumophila spp. in real time.

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CRISPR/Cas9-based generation of a recombinant double-reporter pseudorabies virus and its characterization in vitro and in vivo

Veterinary Research ◽

10.1186/s13567-021-00964-4 ◽

2021 ◽

Vol 52 (1) ◽

Author(s):

Peng-Fei Fu ◽

Xuan Cheng ◽

Bing-Qian Su ◽

Li-Fang Duan ◽

Cong-Rong Wang ◽

...

Keyword(s):

Pseudorabies Virus ◽

Fluorescent Protein ◽

Antiviral Agents ◽

Firefly Luciferase ◽

Inhibitory Effect ◽

Economic Losses ◽

Green Fluorescent ◽

Swine Herds

AbstractPseudorabies, caused by pseudorabies virus (PRV) variants, has broken out among commercial PRV vaccine-immunized swine herds and resulted in major economic losses to the pig industry in China since late 2011. However, the mechanism of virulence enhancement of variant PRV is currently unclear. Here, a recombinant PRV (rPRV HN1201-EGFP-Luc) with stable expression of enhanced green fluorescent protein (EGFP) and firefly luciferase as a double reporter virus was constructed on the basis of the PRV variant HN1201 through CRISPR/Cas9 gene-editing technology coupled with two sgRNAs. The biological characteristics of the recombinant virus and its lethality to mice were similar to those of the parental strain and displayed a stable viral titre and luciferase activity through 20 passages. Moreover, bioluminescence signals were detected in mice at 12 h after rPRV HN1201-EGFP-Luc infection. Using the double reporter PRV, we also found that 25-hydroxycholesterol had a significant inhibitory effect on PRV both in vivo and in vitro. These results suggested that the double reporter PRV based on PRV variant HN1201 should be an excellent tool for basic virology studies and evaluating antiviral agents.

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Plasma cells shape the mesenchymal identity of ovarian cancers through transfer of exosome-derived microRNAs

Science Advances ◽

10.1126/sciadv.abb0737 ◽

2021 ◽

Vol 7 (9) ◽

pp. eabb0737

Author(s):

Zhengnan Yang ◽

Wei Wang ◽

Linjie Zhao ◽

Xin Wang ◽

Ryan C. Gimple ◽

...

Keyword(s):

Ovarian Cancer ◽

Cancer Cells ◽

Plasma Cell ◽

Plasma Cells ◽

Ovarian Cancer Cells ◽

Mesenchymal Phenotype ◽

Ovarian Cancers ◽

Novel Approach

Ovarian cancer represents a highly lethal disease that poses a substantial burden for females, with four main molecular subtypes carrying distinct clinical outcomes. Here, we demonstrated that plasma cells, a subset of antibody-producing B cells, were enriched in the mesenchymal subtype of high-grade serous ovarian cancers (HGSCs). Plasma cell abundance correlated with the density of mesenchymal cells in clinical specimens of HGSCs. Coculture of nonmesenchymal ovarian cancer cells and plasma cells induced a mesenchymal phenotype of tumor cells in vitro and in vivo. Phenotypic switch was mediated by the transfer of plasma cell–derived exosomes containing miR-330-3p into nonmesenchymal ovarian cancer cells. Exosome-derived miR-330-3p increased expression of junctional adhesion molecule B in a noncanonical fashion. Depletion of plasma cells by bortezomib reversed the mesenchymal characteristics of ovarian cancer and inhibited in vivo tumor growth. Collectively, our work suggests targeting plasma cells may be a novel approach for ovarian cancer therapy.

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The Great Capacity on Promoting Melanogenesis of Three Compatible Components in Vernonia anthelmintica (L.) Willd.

International Journal of Molecular Sciences ◽

10.3390/ijms22084073 ◽

2021 ◽

Vol 22 (8) ◽

pp. 4073

Author(s):

Yifan Lai ◽

Qingyuan Feng ◽

Rui Zhang ◽

Jing Shang ◽

Hui Zhong

Keyword(s):

Herbal Medicine ◽

Caffeic Acid ◽

Fluorescent Protein ◽

Traditional Chinese Herbal Medicine ◽

Expression Of Genes ◽

Proliferation And Differentiation ◽

Green Fluorescent ◽

Vernonia Anthelmintica

To investigate a possible methodology of exploiting herbal medicine and design polytherapy for the treatment of skin depigmentation disorder, we have made use of Vernonia anthelmintica (L.) Willd., a traditional Chinese herbal medicine that has been proven to be effective in treating vitiligo. Here, we report that the extract of Vernonia anthelmintica (L.) Willd. effectively enhances melanogenesis responses in B16F10. In its compound library, we found three ingredients (butin, caffeic acid and luteolin) also have the activity of promoting melanogenesis in vivo and in vitro. They can reduce the accumulation of ROS induced by hydrogen peroxide and inflammatory response induced by sublethal concentrations of copper sulfate in wild type and green fluorescent protein (GFP)-labeled leukocytes zebrafish larvae. The overall objective of the present study aims to identify which compatibility proportions of the medicines may be more effective in promoting pigmentation. We utilized the D-optimal response surface methodology to optimize the ratio among three molecules. Combining three indicators of promoting melanogenesis, anti-inflammatory and antioxidant capacities, we get the best effect of butin, caffeic acid and luteolin at the ratio (butin:caffeic acid:luteolin = 7.38:28.30:64.32) on zebrafish. Moreover, the effect of melanin content recovery in the best combination is stronger than that of the monomer, which suggests that the three compounds have a synergistic effect on inducing melanogenesis. After simply verifying the result, we performed in situ hybridization on whole-mount zebrafish embryos to further explore the effects of multi-drugs combination on the proliferation and differentiation of melanocytes and the expression of genes (tyr, mitfa, dct, kit) related to melanin synthesis. In conclusion, the above three compatible compounds can significantly enhance melanogenesis and improve depigmentation in vivo.

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Human Keratinocytes Adopt Neuronal Fates After In Utero Transplantation in the Developing Rat Brain

Cell Transplantation ◽

10.1177/0963689720978219 ◽

2021 ◽

Vol 30 ◽

pp. 096368972097821

Author(s):

Andrea Tenorio-Mina ◽

Daniel Cortés ◽

Joel Esquivel-Estudillo ◽

Adolfo López-Ornelas ◽

Alejandro Cabrera-Wrooman ◽

...

Keyword(s):

Green Fluorescent Protein ◽

Fluorescent Protein ◽

Ectopic Expression ◽

Neural Induction ◽

Human Keratinocytes ◽

Differentiation Potential ◽

Neuronal Proteins ◽

Green Fluorescent

Human skin contains keratinocytes in the epidermis. Such cells share their ectodermal origin with the central nervous system (CNS). Recent studies have demonstrated that terminally differentiated somatic cells can adopt a pluripotent state, or can directly convert its phenotype to neurons, after ectopic expression of transcription factors. In this article we tested the hypothesis that human keratinocytes can adopt neural fates after culturing them in suspension with a neural medium. Initially, keratinocytes expressed Keratins and Vimentin. After neural induction, transcriptional upregulation of NESTIN, SOX2, VIMENTIN, SOX1, and MUSASHI1 was observed, concomitant with significant increases in NESTIN detected by immunostaining. However, in vitro differentiation did not yield the expression of neuronal or astrocytic markers. We tested the differentiation potential of control and neural-induced keratinocytes by grafting them in the developing CNS of rats, through ultrasound-guided injection. For this purpose, keratinocytes were transduced with lentivirus that contained the coding sequence of green fluorescent protein. Cell sorting was employed to select cells with high fluorescence. Unexpectedly, 4 days after grafting these cells in the ventricles, both control and neural-induced cells expressed green fluorescent protein together with the neuronal proteins βIII-Tubulin and Microtubule-Associated Protein 2. These results support the notion that in vivo environment provides appropriate signals to evaluate the neuronal differentiation potential of keratinocytes or other non-neural cell populations.

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Atelocollagen Sponge as a Stem Cell Implantation Scaffold for the Treatment of Scarred Vocal Folds

Annals of Otology Rhinology & Laryngology ◽

10.1177/000348941011901110 ◽

2010 ◽

Vol 119 (11) ◽

pp. 805-810 ◽

Cited By ~ 1

Author(s):

Satoshi Ohno ◽

Shigeru Hirano ◽

Ichiro Tateya ◽

Shin-Ichi Kanemaru ◽

Hiroo Umeda ◽

...

Keyword(s):

Bone Marrow ◽

Stem Cell ◽

Stromal Cells ◽

Fluorescent Protein ◽

In Vitro Study ◽

Vocal Folds ◽

Green Fluorescent ◽

Cell Implantation

Objectives: Treatment of vocal fold scarring remains a therapeutic challenge. Our group previously reported the efficacy of treating injured vocal folds by implantation of bone marrow—derived stromal cells containing mesenchymal stem cells. Appropriate scaffolding is necessary for the stem cell implant to achieve optimal results. Terudermis is an atelocollagen sponge derived from calf dermis. It has large pores that permit cellular entry and is degraded in vivo. These characteristics suggest that this material may be a good candidate for use as scaffolding for implantation of cells. The present in vitro study investigated the feasibility of using Terudermis as such a scaffold. Methods: Bone marrow—derived stromal cells were obtained from GFP (green fluorescent protein) mouse femurs. The cells were seeded into Terudermis and incubated for 5 days. Their survival, proliferation, and expression of extracellular matrix were examined. Results: Bone marrow—derived stromal cells adhered to Terudermis and underwent significant proliferation. Immunohistochemical examination demonstrated that adherent cells were positive for expression of vimentin, desmin, fibronectin, and fsp1 and negative for beta III tubulin. These findings indicate that these cells were mesodermal cells and attached to the atelocollagen fibers biologically. Conclusions: The data suggest that Terudermis may have potential as stem cell implantation scaffolding for the treatment of scarred vocal folds.

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