Estimating Vaccine Potency Using Antibody-Based Competition Assays

2021 ◽  
pp. 693-705
Author(s):  
Jennifer Doering ◽  
Greta Van Slyke ◽  
Oreola Donini ◽  
Nicholas J. Mantis
Keyword(s):  
Vaccine Potency ◽  
Competition Assays

scholarly journals Sperm Competition in the Absence of Fertilization in Caenorhabditis elegans

Genetics ◽  
1999 ◽  
Vol 152 (1) ◽  
pp. 201-208 ◽  
Author(s):  
Andrew Singson ◽  
Katherine L Hill ◽  
Steven W L’Hernault
Keyword(s):  
Caenorhabditis Elegans ◽  
Sperm Competition ◽  
Sperm Function ◽  
Sperm Precedence ◽  
Wild Type ◽  
Nematode Caenorhabditis Elegans ◽  
C Elegans ◽  
Normal Sperm ◽  
Self Fertilization ◽  
Competition Assays

Abstract Hermaphrodite self-fertilization is the primary mode of reproduction in the nematode Caenorhabditis elegans. However, when a hermaphrodite is crossed with a male, nearly all of the oocytes are fertilized by male-derived sperm. This sperm precedence during reproduction is due to the competitive superiority of male-derived sperm and results in a functional suppression of hermaphrodite self-fertility. In this study, mutant males that inseminate fertilization-defective sperm were used to reveal that sperm competition within a hermaphrodite does not require successful fertilization. However, sperm competition does require normal sperm motility. Additionally, sperm competition is not an absolute process because oocytes not fertilized by male-derived sperm can sometimes be fertilized by hermaphrodite-derived sperm. These results indicate that outcrossed progeny result from a wild-type cross because male-derived sperm are competitively superior and hermaphrodite-derived sperm become unavailable to oocytes. The sperm competition assays described in this study will be useful in further classifying the large number of currently identified mutations that alter sperm function and development in C. elegans.

scholarly journals Frequency-dependent interactions determine outcome of competition between two breast cancer cell lines

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Audrey R. Freischel ◽  
Mehdi Damaghi ◽  
Jessica J. Cunningham ◽  
Arig Ibrahim-Hashim ◽  
Robert J. Gillies ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cell ◽  
Critical Density ◽  
Low Ph ◽  
Breast Cancer Cell Lines ◽  
Frequency Dependent ◽  
Density Dependent ◽  
Low Glucose ◽  
Competition Assays ◽  
Mcf 7

AbstractTumors are highly dynamic ecosystems in which diverse cancer cell subpopulations compete for space and resources. These complex, often non-linear interactions govern continuous spatial and temporal changes in the size and phenotypic properties of these subpopulations. Because intra-tumoral blood flow is often chaotic, competition for resources may be a critical selection factor in progression and prognosis. Here, we quantify resource competition using 3D spheroid cultures with MDA-MB-231 and MCF-7 breast cancer cells. We hypothesized that MCF-7 cells, which primarily rely on efficient aerobic glucose metabolism, would dominate the population under normal pH and low glucose conditions; and MDA-MB-231 cells, which exhibit high levels of glycolytic metabolism, would dominate under low pH and high glucose conditions. In spheroids with single populations, MCF-7 cells exhibited equal or superior intrinsic growth rates (density-independent measure of success) and carrying capacities (density-dependent measure of success) when compared to MDA-MB-231 cells under all pH and nutrient conditions. Despite these advantages, when grown together, MCF-7 cells do not always outcompete MDA-MB-231 cells. MDA-MB-231 cells outcompete MCF-7 cells in low glucose conditions and coexistence is achieved in low pH conditions. Under all conditions, MDA-MB-231 has a stronger competitive effect (frequency-dependent interaction) on MCF-7 cells than vice-versa. This, and the inability of growth rate or carrying capacity when grown individually to predict the outcome of competition, suggests a reliance on frequency-dependent interactions and the need for competition assays. We frame these results in a game-theoretic (frequency-dependent) model of cancer cell interactions and conclude that competition assays can demonstrate critical density-independent, density-dependent and frequency-dependent interactions that likely contribute to in vivo outcomes.

scholarly journals Enhancement of Sindbis Virus Self-Replicating RNA Vaccine Potency by Linkage ofMycobacterium tuberculosisHeat Shock Protein 70 Gene to an Antigen Gene

2001 ◽  
Vol 166 (10) ◽  
pp. 6218-6226 ◽  
Author(s):  
Wen-Fang Cheng ◽  
Chien-Fu Hung ◽  
Chee-Yin Chai ◽  
Keng-Fu Hsu ◽  
Liangmai He ◽  
...  
Keyword(s):  
Sindbis Virus ◽  
Antigen Gene ◽  
Vaccine Potency ◽  
Rna Vaccine

scholarly journals Fitness of Erysiphe necator with G143A-Based Resistance to Quinone Outside Inhibitors

Plant Disease ◽  
2014 ◽  
Vol 98 (11) ◽  
pp. 1494-1502 ◽  
Author(s):  
Lynn Esther E. Rallos ◽  
Nels G. Johnson ◽  
David G. Schmale ◽  
Aaron J. Prussin ◽  
Anton B. Baudoin
Keyword(s):  
Powdery Mildew ◽  
Quantitative Polymerase Chain Reaction ◽  
Field Trials ◽  
Resistance Development ◽  
Erysiphe Necator ◽  
Potted Plants ◽  
Sterol Demethylation Inhibitors ◽  
Quinone Outside Inhibitors ◽  
Competition Assays ◽  
Qoi Resistance

Management of grape powdery mildew (Erysiphe necator) using quinone outside inhibitors (QoIs) has eroded in an increasing number of regions due to resistance development. To determine persistence of resistance when QoIs are withdrawn, competition assays were conducted on unsprayed grape plants (Vitis vinifera ‘Chardonnay’) by cycling mixtures of resistant and sensitive isolates characterized as genetically diverse based on microsatellite analyses. Under laboratory conditions, %G143A, quantified by quantitative polymerase chain reaction (qPCR), increased significantly, indicating competitiveness of the resistant fraction. To confirm competitiveness in the field, trials using potted plants were conducted. Percent G143A tended to decrease in one growing season, probably due to spore migration and mixing of populations with natural background inoculum. In a second season, QoI resistance persisted at high frequency for 4 weeks. Resistant populations were also found to persist in one vineyard without QoI application for four consecutive years. The frequency was still about 25% in the fourth year, with higher frequency (36%) in a hotspot section. QoI-resistant populations with >5% G143A also harbored Y136F in the cyp51 gene that confers some resistance to sterol demethylation inhibitors, another fungicide class for powdery mildew control. Double resistance could have been partly responsible for persistence of QoI resistance at this location.

Combining competition assays with genetic complementation strategies to dissect mouse embryonic stem cell self-renewal and pluripotency

2012 ◽  
Vol 7 (4) ◽  
pp. 729-748 ◽  
Author(s):  
Dung-Fang Lee ◽  
Jie Su ◽  
Ana Sevilla ◽  
Julian Gingold ◽  
Christoph Schaniel ◽  
...  
Keyword(s):  
Stem Cell ◽  
Embryonic Stem Cell ◽  
Embryonic Stem ◽  
Mouse Embryonic Stem Cell ◽  
Genetic Complementation ◽  
Self Renewal ◽  
Competition Assays

Rabies Vaccine Potency and Stability Testing

1988 ◽  
pp. 187-193
Author(s):  
Morag Ferguson ◽  
Valerie Seagroatt ◽  
G. C. Schild
Keyword(s):  
Rabies Vaccine ◽  
Stability Testing ◽  
Vaccine Potency

A GacS deficiency does not affectPseudomonas chlororaphisPA23 fitness when growing on canola, in aged batch culture or as a biofilm

2006 ◽  
Vol 52 (12) ◽  
pp. 1177-1188 ◽  
Author(s):  
N Poritsanos ◽  
C Selin ◽  
W G.D Fernando ◽  
S Nakkeeran ◽  
T.R. de Kievit
Keyword(s):  
Antifungal Activity ◽  
Batch Culture ◽  
Hydrogen Cyanide ◽  
Fungal Pathogen ◽  
Biocontrol Agent ◽  
Antifungal Compounds ◽  
Pseudomonas Chlororaphis ◽  
Wild Type ◽  
Biocontrol Activity ◽  
Competition Assays

Pseudomonas chlororaphis PA23 is a biocontrol agent that protects against the fungal pathogen Sclerotinia sclerotiorum. Employing transposon mutagenesis, we isolated a gacS mutant that no longer exhibited antifungal activity. Pseudomonas chlororaphis PA23 was previously reported to produce the nonvolatile antibiotics phenazine 1-carboxylic acid and 2-hydroxyphenazine. We report here that PA23 produces additional compounds, including protease, lipase, hydrogen cyanide, and siderophores, that may contribute to its biocontrol ability. In the gacS mutant background, generation of these products was markedly reduced or delayed with the exception of siderophores, which were elevated. Not surprisingly, this mutant was unable to protect canola from disease incited by S. sclerotiorum. The gacS mutant was able to sustain itself in the canola phyllosphere, therefore, the loss of biocontrol activity can be attributed to a reduced production of antifungal compounds and not a declining population size. Competition assays between the mutant and wild type revealed equivalent fitness in aged batch culture; consequently, the gacS mutation did not impart a growth advantage in the stationary phase phenotype. Under minimal nutrient conditions, the gacS-deficient strain produced a tenfold less biofilm than the wild type. However, no difference was observed in the ability of the mutant biofilm to protect cells from lethal antibiotic challenge.Key words: Pseudomonas, biocontrol, gacS, fitness, biofilms.

scholarly journals VACCRaksha Calc: A computer program for the calculation of vaccine potency

2015 ◽  
Vol 6 (2) ◽  
pp. 116
Author(s):  
SaiMaheshReddy Avula ◽  
Venkata SubbaReddy Avula
Keyword(s):  
Computer Program ◽  
Vaccine Potency

scholarly journals Engineering of highly immunogenic long-lived DC vaccines by antiapoptotic protein gene transfer to enhance cancer vaccine potency

Gene Therapy ◽  
2008 ◽  
Vol 15 (19) ◽  
pp. 1321-1329 ◽  
Author(s):  
T Yoshikawa ◽  
T Niwa ◽  
H Mizuguchi ◽  
N Okada ◽  
S Nakagawa
Keyword(s):  
Gene Transfer ◽  
Cancer Vaccine ◽  
Protein Gene ◽  
Antiapoptotic Protein ◽  
Vaccine Potency ◽  
Dc Vaccines
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