Physiological responses of Oxyrrhis marina to a diet of virally infected Emiliania huxleyi

10.7287/peerj.preprints.26851v1 ◽

2018 ◽

Author(s):

Andrew G Goode ◽

David M Fields ◽

Stephen D Archer ◽

Joaquín Martínez Martínez

Keyword(s):

Growth Rates ◽

Viral Infections ◽

Emiliania Huxleyi ◽

Ingestion Rates ◽

Predator Prey ◽

Marine Food Webs ◽

Oxyrrhis Marina ◽

Prey Interaction ◽

Infected Cells ◽

Important Food Source

The coccolithophore Emiliania huxleyi forms some of the largest phytoplankton blooms in the ocean. The rapid demise of these blooms has been linked to viral infections. E. huxleyi abundance, distribution, and nutritional status make them an important food source for the heterotrophic protists which are classified as microzooplankton in marine food webs. In this study we investigated the fate of E. huxleyi (CCMP 374) infected with virus strain EhV-86 in a simple predator-prey interaction. The ingestion rates of Oxyrrhis marina were significantly lower (between 26.9 and 50.4%) when fed virus-infected E. huxleyi cells compared to non-infected cells. Despite the lower ingestion rates, O. marina showed significantly higher growth rates (between 30 and 91.3%) when fed infected E. huxleyi cells, suggesting higher nutritional value and/or greater assimilation of infected E. huxleyi cells. No significant differences were found in O. marina cell volumes or fatty acids profiles. These results show that virally infected E. huxleyi support higher growth rates of single celled heterotrophs and in addition to the “viral shunt” hypothesis, viral infections may also divert more carbon to mesozooplankton grazers.

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Physiological responses ofOxyrrhis marinato a diet of virally infectedEmiliania huxleyi

PeerJ ◽

10.7717/peerj.6722 ◽

2019 ◽

Vol 7 ◽

pp. e6722 ◽

Cited By ~ 1

Author(s):

Andrew G. Goode ◽

David M. Fields ◽

Stephen D. Archer ◽

Joaquín Martínez Martínez

Keyword(s):

Growth Rates ◽

Viral Infections ◽

Ingestion Rates ◽

Predator Prey ◽

Marine Food Webs ◽

Oxyrrhis Marina ◽

Prey Interaction ◽

Infected Cells ◽

Important Food Source ◽

Marine Food

The coccolithophoreEmiliania huxleyiforms some of the largest phytoplankton blooms in the ocean. The rapid demise of these blooms has been linked to viral infections.E. huxleyiabundance, distribution, and nutritional status make them an important food source for the heterotrophic protists which are classified as microzooplankton in marine food webs. In this study we investigated the fate ofE. huxleyi(CCMP 374) infected with virus strain EhV-86 in a simple predator-prey interaction. The ingestion rates ofOxyrrhis marinawere significantly lower (between 26.9 and 50.4%) when fed virus-infectedE. huxleyicells compared to non-infected cells. Despite the lower ingestion rates,O. marinashowed significantly higher growth rates (between 30 and 91.3%) when fed infectedE. huxleyicells, suggesting higher nutritional value and/or greater assimilation of infectedE. huxleyicells. No significant differences were found inO. marinacell volumes or fatty acids profiles. These results show that virally infectedE. huxleyisupport higher growth rates of single celled heterotrophs and in addition to the “viral shunt” hypothesis, viral infections may also divert more carbon to mesozooplankton grazers.

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Interactions Between the Kleptoplastidic Dinoflagellate Shimiella gracilenta and Several Common Heterotrophic Protists

Frontiers in Marine Science ◽

10.3389/fmars.2021.738547 ◽

2021 ◽

Vol 8 ◽

Author(s):

Sang Ah Park ◽

Hae Jin Jeong ◽

Jin Hee Ok ◽

Hee Chang Kang ◽

Ji Hyun You ◽

...

Keyword(s):

Growth Rates ◽

Ingestion Rate ◽

Maximum Growth ◽

Maximum Growth Rate ◽

Prey Concentration ◽

Ingestion Rates ◽

Oxyrrhis Marina ◽

Planktonic Food ◽

Moderate Growth ◽

Algal Prey

The newly described dinoflagellate, Shimiella gracilenta, is known to survive for approximately 1 month on the plastids of ingested prey cells during starvation, indicating kleptoplastidy. To understand the population dynamics of this dinoflagellate in marine planktonic food webs, its growth and mortality rate due to predation should be assessed. Thus, we investigated the feeding occurrence of eight common heterotrophic protists on S. gracilenta. We also determined the growth and ingestion rates of Oxyrrhis marina and the naked ciliate, Rimostrombidium sp. on S. gracilenta as a function of the prey concentration. The common heterotrophic dinoflagellates (HTDs) Gyrodinium dominans, O. marina, and Pfiesteria piscicida and a naked ciliate Rimostrombidium sp. were able to feed on S. gracilenta; whereas the HTDs Aduncodinium glandula, Gyrodinium jinhaense, Oblea rotunda, and Polykrikos kofoidii were not. Shimiella gracilenta supported positive growth of O. marina and Rimostrombidium sp. but did not support that of G. dominans and P. piscicida. With increasing prey concentrations, the growth and ingestion rates of O. marina and Rimostrombidium sp. on S. gracilenta increased and became saturated. The maximum growth rates of O. marina and Rimostrombidium sp. on S. gracilenta were 0.645 and 0.903 day−1, respectively. Furthermore, the maximum ingestion rates of O. marina and Rimostrombidium sp. on S. gracilenta were 0.11 ng C predator day−1 (1.6 cells predator−1 day−1) and 35 ng C predator day−1 (500 cells predator−1 day−1), respectively. The maximum ingestion rate of O. marina on S. gracilenta was lower than that on any other algal prey reported to date, although its maximum growth rate was moderate. In conclusion, S. gracilenta had only a few common heterotrophic protist predators but could support moderate growth rates of the predators. Thus, S. gracilenta may not be a common prey species for diverse heterotrophic protists but may be a suitable prey for a few heterotrophic protists.

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Infective prey leads to a partial role reversal in a predator-prey interaction

PLoS ONE ◽

10.1371/journal.pone.0249156 ◽

2021 ◽

Vol 16 (9) ◽

pp. e0249156

Author(s):

Veijo Kaitala ◽

Mikko Koivu-Jolma ◽

Jouni Laakso

Keyword(s):

Sea Cucumber ◽

Apostichopus Japonicus ◽

Grazing Rate ◽

Role Reversal ◽

Relative Population ◽

Predator Prey ◽

Population Dynamics Model ◽

Prey Interaction ◽

Population Sizes ◽

Important Food Source

An infective prey has the potential to infect, kill and consume its predator. Such a prey-predator relationship fundamentally differs from the predator-prey interaction because the prey can directly profit from the predator as a growth resource. Here we present a population dynamics model of partial role reversal in the predator-prey interaction of two species, the bottom dwelling marine deposit feeder sea cucumber Apostichopus japonicus and an important food source for the sea cucumber but potentially infective bacterium Vibrio splendidus. We analyse the effects of different parameters, e.g. infectivity and grazing rate, on the population sizes. We show that relative population sizes of the sea cucumber and V. Splendidus may switch with increasing infectivity. We also show that in the partial role reversal interaction the infective prey may benefit from the presence of the predator such that the population size may exceed the value of the carrying capacity of the prey in the absence of the predator. We also analysed the conditions for species extinction. The extinction of the prey, V. splendidus, may occur when its growth rate is low, or in the absence of infectivity. The extinction of the predator, A. japonicus, may follow if either the infectivity of the prey is high or a moderately infective prey is abundant. We conclude that partial role reversal is an undervalued subject in predator-prey studies.

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Immunosurveillance of Cancer and Viral Infections with Regard to Alterations of Human NK Cells Originating from Lifestyle and Aging

Biomedicines ◽

10.3390/biomedicines9050557 ◽

2021 ◽

Vol 9 (5) ◽

pp. 557

Author(s):

Xuewen Deng ◽

Hiroshi Terunuma ◽

Mie Nieda

Keyword(s):

Nk Cells ◽

Viral Infections ◽

Nk Cell ◽

Healthy Lifestyle ◽

Cell Activity ◽

Nk Cell Activity ◽

Effector Cells ◽

Cell Dysfunction ◽

Forest Bathing ◽

Infected Cells

Natural killer (NK) cells are cytotoxic immune cells with an innate capacity for eliminating cancer cells and virus- infected cells. NK cells are critical effector cells in the immunosurveillance of cancer and viral infections. Patients with low NK cell activity or NK cell deficiencies are predisposed to increased risks of cancer and severe viral infections. However, functional alterations of human NK cells are associated with lifestyles and aging. Personal lifestyles, such as cigarette smoking, alcohol consumption, stress, obesity, and aging are correlated with NK cell dysfunction, whereas adequate sleep, moderate exercise, forest bathing, and listening to music are associated with functional healthy NK cells. Therefore, adherence to a healthy lifestyle is essential and will be favorable for immunosurveillance of cancer and viral infections with healthy NK cells.

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Poxviral Strategies to Overcome Host Cell Apoptosis

Pathogens ◽

10.3390/pathogens10010006 ◽

2020 ◽

Vol 10 (1) ◽

pp. 6

Author(s):

Chathura D. Suraweera ◽

Mark G. Hinds ◽

Marc Kvansakul

Keyword(s):

Viral Infections ◽

B Cell Lymphoma ◽

Intrinsic Apoptosis ◽

Host Cell Apoptosis ◽

Successful Infection ◽

Infected Cells ◽

Host Virus Interactions ◽

Almost All ◽

Virus Interactions ◽

Multicellular Organisms

Apoptosis is a form of cellular suicide initiated either via extracellular (extrinsic apoptosis) or intracellular (intrinsic apoptosis) cues. This form of programmed cell death plays a crucial role in development and tissue homeostasis in multicellular organisms and its dysregulation is an underlying cause for many diseases. Intrinsic apoptosis is regulated by members of the evolutionarily conserved B-cell lymphoma-2 (Bcl-2) family, a family that consists of pro- and anti-apoptotic members. Bcl-2 genes have also been assimilated by numerous viruses including pox viruses, in particular the sub-family of chordopoxviridae, a group of viruses known to infect almost all vertebrates. The viral Bcl-2 proteins are virulence factors and aid the evasion of host immune defenses by mimicking the activity of their cellular counterparts. Viral Bcl-2 genes have proved essential for the survival of virus infected cells and structural studies have shown that though they often share very little sequence identity with their cellular counterparts, they have near-identical 3D structures. However, their mechanisms of action are varied. In this review, we examine the structural biology, molecular interactions, and detailed mechanism of action of poxvirus encoded apoptosis inhibitors and how they impact on host–virus interactions to ultimately enable successful infection and propagation of viral infections.

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Mass Spectrometry versus Conventional Techniques of Protein Detection: Zika Virus NS3 Protease Activity towards Cellular Proteins

Molecules ◽

10.3390/molecules26123732 ◽

2021 ◽

Vol 26 (12) ◽

pp. 3732

Author(s):

Agnieszka Dabrowska ◽

Aleksandra Milewska ◽

Joanna Ner-Kluza ◽

Piotr Suder ◽

Krzysztof Pyrc

Keyword(s):

Mass Spectrometry ◽

Zika Virus ◽

Viral Infections ◽

Protein Detection ◽

Extensive Discussion ◽

Protein Targets ◽

Highly Sensitive ◽

Infected Cells ◽

Ns3 Protease ◽

To Receive

Mass spectrometry (MS) used in proteomic approaches is able to detect hundreds of proteins in a single assay. Although undeniable high analytical power of MS, data acquired sometimes lead to confusing results, especially during a search of very selective, unique interactions in complex biological matrices. Here, we would like to show an example of such confusing data, providing an extensive discussion on the observed phenomenon. Our investigations focus on the interaction between the Zika virus NS3 protease, which is essential for virus replication. This enzyme is known for helping to remodel the microenvironment of the infected cells. Several reports show that this protease can process cellular substrates and thereby modify cellular pathways that are important for the virus. Herein, we explored some of the targets of NS3, clearly shown by proteomic techniques, as processed during infection. Unfortunately, we could not confirm the biological relevance of protein targets for viral infections detected by MS. Thus, although mass spectrometry is highly sensitive and useful in many instances, also being able to show directions where cell/virus interaction occurs, we believe that deep recognition of their biological role is essential to receive complete insight into the investigated process.

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