scholarly journals Metabolic Cost of the Immune Response During Early Ontogeny of the Scallop Argopecten purpuratus

2021 ◽  
Vol 12 ◽  
Author(s):  
Isis Rojas ◽  
Georgina A. Rivera-Ingraham ◽  
Claudia B. Cárcamo ◽  
Katherine Jeno ◽  
Erwin de la Fuente-Ortega ◽  
...  
Keyword(s):  
Immune Response ◽  
Early Development ◽  
Bacterial Infections ◽  
Citrate Synthase ◽  
Early Ontogeny ◽  
Parental Origin ◽  
Mitochondrial Enzymes ◽  
Metabolic Demand ◽  
Argopecten Purpuratus ◽  
Veliger Larvae

The scallop Argopecten purpuratus is an important resource for Chilean and Peruvian aquaculture. Seed availability from commercial hatcheries is critical due to recurrent massive mortalities associated with bacterial infections, especially during the veliger larval stage. The immune response plays a crucial role in counteracting the effects of such infections, but being energetically costly, it potentially competes with the physiological and morphological changes that occur during early development, which are equally expensive. Consequently, in this study, energy metabolism parameters at the individual and cellular levels, under routine-basal status and after the exposure to the pathogenic strain bacteria (Vibrio splendidus VPAP18), were evaluated during early ontogeny (trochophore, D-veliger, veliger, pediveliger, and early juveniles) of A. purpuratus. The parameters measured were as follows: (1) metabolic demand, determined as oxygen consumption rate and (2) ATP supplying capacity measured by key mitochondrial enzymes activities [citrate synthase (CS), electron transport system (ETS), and ETS/CS ratio, indicative of ATP supplying efficiency], mitochondrial membrane potential (ΔΨm), and mitochondrial density (ρm) using an in vivo image analysis. Data revealed that metabolic demand/capacity varies significantly throughout early development, with trochophores being the most efficient in terms of energy supplying capacity under basal conditions. ATP supplying efficiency decreased linearly with larval development, attaining its lowest level at the pediveliger stage, and increasing markedly in early juveniles. Veliger larvae at basal conditions were inefficient in terms of energy production vs. energy demand (with low ρm, ΔΨm, enzyme activities, and ETS:CS). Post-challenged results suggest that both trochophore and D-veliger would have the necessary energy to support the immune response. However, due to an immature immune system, the immunity of these stages would rely mainly on molecules of parental origin, as suggested by previous studies. On the other hand, post-challenged veliger maintained their metabolic demand but decreased their ATP supplying capacity, whereas pediveliger increased CS activity. Overall, results suggest that veliger larvae exhibit the lowest metabolic capacity to overcome a bacterial challenge, coinciding with previous works, showing a reduced capacity to express immune-related genes. This would result in a higher susceptibility to pathogen infection, potentially explaining the higher mortality rates occurring during A. purpuratus farming.

A scanning electron microscopic study of the veliger larvae of the scallop argopecten purpuratus

1988 ◽  
Vol 46 ◽  
pp. 284-285
Author(s):  
G.C. Bellolio ◽  
K.S. Lohrmann ◽  
E.M. Dupré
Keyword(s):  
Morphological Description ◽  
Electron Microscopic ◽  
Larval Stages ◽  
Scanning Electron Microscopic Study ◽  
The Pacific ◽  
Argopecten Purpuratus ◽  
Veliger Larvae ◽  
20 Nm ◽  
Ethanol Series ◽  
Scanning Electron

Argopecten purpuratus is a scallop distributed in the Pacific coast of Chile and Peru. Although this species is mass cultured in both countries there is no morphological description available of the development of this bivalve except for few characterizations of some larval stages described for culture purposes. In this work veliger larvae (app. 140 pm length) were examined by the scanning electron microscope (SEM) in order to study some aspects of the organogenesis of this species.Veliger larvae were obtained from hatchery cultures, relaxed with a solution of MgCl2 and killed by slow addition of 21 glutaraldehyde (GA) in seawater (SW). They were fixed in 2% GA in calcium free artificial SW (pH 8.3), rinsed 3 times in calcium free SW, and dehydrated in a graded ethanol series. The larvae were critical point dried and mounted on double scotch tape (DST). To permit internal view, some valves were removed by slightly pressing and lifting the tip of a cactus spine wrapped with DST, The samples were coated with 20 nm gold and examined with a JEOL JSM T-300 operated at 15 KV.

Development of metabolic enzyme activity in locomotor and cardiac muscles of the migratory barnacle goose

1995 ◽  
Vol 269 (1) ◽  
pp. R64-R72 ◽  
Author(s):  
C. M. Bishop ◽  
P. J. Butler ◽  
S. Egginton ◽  
A. J. el Haj ◽  
G. W. Gabrielsen
Keyword(s):  
Plasma Glucose ◽  
Citrate Synthase ◽  
Specific Activity ◽  
Glycolytic Enzymes ◽  
Metabolic Enzyme ◽  
Mitochondrial Enzymes ◽  
Pectoralis Muscle ◽  
Barnacle Goose ◽  
Average Maximum ◽  
Cardiac Muscles

Preflight development of the goslings was typified by rapid increases in the mitochondrial enzymes of the semimembranosus and heart ventricular muscles resulting in near-adult values by 3 wk of age. In contrast, aerobic capacity of the pectoralis muscle initially developed slowly but showed a rapid increase between 5 and 7 wk of age, in preparation for becoming airborne. Activities of glycolytic enzymes in the pectoralis muscle showed similar patterns of development as those found for the aerobic enzymes, except for hexokinase, which was low at all ages, indicating an adaptation for catabolism of both intracellular glycogen and plasma fatty acids in preference to plasma glucose. Muscle mass specific activity of citrate synthase in the pectoralis increased by only 33% from goslings during the first few days of flight, compared with premigratory geese. Activities of anaerobic glycolytic enzymes in the ventricles were low, but values for hexokinase, which is involved in the phosphorylation of plasma glucose, developed rapidly. Values for lactate dehydrogenase were also high, reflecting the capacity of the heart to catabolize plasma lactate. Substrate flux supplied by carnitine palmitoyltransferase and oxoglutarate dehydrogenase (OGD), in the pectoralis muscles of the premigratory geese, appears to have the smallest excess capacities to meet the requirements of sustained aerobic flight. The average maximum oxygen uptake for premigratory geese during flight, as indicated by values for OGD, is calculated to be 484 ml O2/min (or 208 ml O2.min-1.kg-1).

Alteration of the phagocytosis and antimicrobial defense of Octodonta nipae (Coleoptera: Chrysomelidae) pupae to Escherichia coli following parasitism by Tetrastichus brontispae (Hymenoptera: Eulophidae)

2018 ◽  
Vol 109 (2) ◽  
pp. 248-256
Author(s):  
E. Meng ◽  
J. Li ◽  
B. Tang ◽  
Y. Hu ◽  
T. Qiao ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Immune Response ◽  
Immune Responses ◽  
Mrna Expression ◽  
Bactericidal Activity ◽  
Bacterial Infections ◽  
Expression Level ◽  
Primary Immune Response ◽  
Mrna Expression Level ◽  
E Coli

AbstractAlthough parasites and microbial pathogens are both detrimental to insects, little information is currently available on the mechanism involved in how parasitized hosts balance their immune responses to defend against microbial infections. We addressed this in the present study by comparing the immune response between unparasitized and parasitized pupae of the chrysomelid beetle, Octodonta nipae (Maulik), to Escherichia coli invasion. In an in vivo survival assay, a markedly reduced number of E. coli colony-forming units per microliter was detected in parasitized pupae at 12 and 24 h post-parasitism, together with decreased phagocytosis and enhanced bactericidal activity at 12 h post-parasitism. The effects that parasitism had on the mRNA expression level of selected antimicrobial peptides (AMPs) of O. nipae pupae showed that nearly all transcripts of AMPs examined were highly upregulated during the early and late parasitism stages except defensin 2B, whose mRNA expression level was downregulated at 24 h post-parasitism. Further elucidation on the main maternal fluids responsible for alteration of the primary immune response against E. coli showed that ovarian fluid increased phagocytosis at 48 h post-injection. These results indicated that the enhanced degradation of E. coli in parasitized pupae resulted mainly from the elevated bactericidal activity without observing the increased transcripts of target AMPs. This study contributes to a better understanding of the mechanisms involved in the immune responses of a parasitized host to bacterial infections.

scholarly journals Virus-Induced Changes of the Respiratory Tract Environment Promote Secondary Infections With Streptococcus pneumoniae

2021 ◽  
Vol 11 ◽  
Author(s):  
Vicky Sender ◽  
Karina Hentrich ◽  
Birgitta Henriques-Normark
Keyword(s):  
Immune Response ◽  
Streptococcus Pneumoniae ◽  
Bacterial Infections ◽  
Disease Burden ◽  
Influenza Infection ◽  
Pneumococcal Infection ◽  
Viral Pathogens ◽  
Complex Interactions ◽  
Secondary Infections ◽  
Induced Changes

Secondary bacterial infections enhance the disease burden of influenza infections substantially. Streptococcus pneumoniae (the pneumococcus) plays a major role in the synergism between bacterial and viral pathogens, which is based on complex interactions between the pathogen and the host immune response. Here, we discuss mechanisms that drive the pathogenesis of a secondary pneumococcal infection after an influenza infection with a focus on how pneumococci senses and adapts to the influenza-modified environment. We briefly summarize what is known regarding secondary bacterial infection in relation to COVID-19 and highlight the need to improve our current strategies to prevent and treat viral bacterial coinfections.

scholarly journals Importance of cellular immunity link for efficiency of replacement therapy in common variable immune deficiency

2020 ◽  
Vol 22 (4) ◽  
pp. 799-804
Author(s):  
L. P. Sizyakina ◽  
I. I. Andreeva ◽  
D. I. Danilova
Keyword(s):  
Immune Response ◽  
Replacement Therapy ◽  
Cellular Immunity ◽  
Bacterial Infections ◽  
Immune Cell ◽  
Respiratory Infections ◽  
Combined Treatment ◽  
Ivig Therapy ◽  
Continuous Treatment ◽  
Cellular Immune

Lifetime use of IgG replacement therapy  is the standard of CVID treatment. However, full control over stabilization of chronic infection loci is not always achieved, even if this therapy  is continuously applied. The purpose  of this study was to carry out comparative analysis of changes  in cellular  component of adaptive and  innate immune response, depending on effectiveness of replacement therapy  of patients with infectious CVID  phenotype. The  observation group  consisted of 15 patients with  CVID  who  were  diagnosed since early childhood in 100% of cases. They had prolonged respiratory infections followed by the development of complications requiring continuous treatment with antibiotics.After  reaching mean  age of 15 years  old,  the  intensity of infection-associated antibody deficiency was 6-8  times  per year. After verification of the  diagnosis, the  patients received  replacement therapy, first at the saturation dose,  and,  after stabilization of IgG  at the level of 7-8 g/l,  at the monthly maintenance dose. The clinical  course  of the disease was traced  during  a full year of replacement therapy, and the cellular  immunity indices  were evaluated. In all patients, after a year of therapy  corresponding to clinical  guidelines, there  was an improvement in quality  of life indices, decreased rates of recurrent bacterial infections. At the same time, 40% of them continued to suffer, on average, 5.4±1.1 times a year and required long-term courses of antibiotic therapy. Evaluation of immune status did not reveal statistically significant  differences in IgG plasma saturation between the groups of patients with different treatment efficiency: 8.7 (8-9) g/l and 9.1 (8.5-10.5) g/l, at p = 0.5. The  differences related  to immune cell factors  in cases of smaller  effect of IVIG  therapy  are manifested in higher  relative  numbers of T effectors  containing lytic Granzyme B granules  and CD14+CD284+  monocytes, accompanied by lower spontaneous active  oxygen forms produced by neutrophils, lesser contents of CD16+ natural killers in peripheral blood.The obtained data illustrate the value of monitoring, not only serum  IgG  level, but also the parameters of the  cellular  immune response. Such  analysis  may be essential  as a prognostic criterion for efficacy  of IVIG therapy. Reduced levels of some parameters of innate immunity cells serves a basis to formulate the concept of combined treatment and usage of tools that alter functions of immunocompetent cells.

scholarly journals Differential Requirements for Mediator Complex Subunits in Drosophila melanogaster Host Defense Against Fungal and Bacterial Pathogens

2021 ◽  
Vol 11 ◽  
Author(s):  
Chuqin Huang ◽  
Rui Xu ◽  
Samuel Liégeois ◽  
Di Chen ◽  
Zi Li ◽  
...  
Keyword(s):  
Immune Response ◽  
Host Defense ◽  
Bacterial Infections ◽  
Fungal Infections ◽  
Transcriptional Response ◽  
Erwinia Carotovora ◽  
Mediator Complex ◽  
Toll Pathway ◽  
Metarhizium Robertsii ◽  
Immune Factor

The humoral immune response to bacterial or fungal infections in Drosophila relies largely on a transcriptional response mediated by the Toll and Immune deficiency NF-κB pathways. Antimicrobial peptides are potent effectors of these pathways and allow the organism to attack invading pathogens. Dorsal-related Immune Factor (DIF), a transcription factor regulated by the Toll pathway, is required in the host defense against fungal and some Gram-positive bacterial infections. The Mediator complex is involved in the initiation of transcription of most RNA polymerase B (PolB)-dependent genes by forming a functional bridge between transcription factors bound to enhancer regions and the gene promoter region and then recruiting the PolB pre-initiation complex. Mediator is formed by several modules that each comprises several subunits. The Med17 subunit of the head module of Mediator has been shown to be required for the expression of Drosomycin, which encodes a potent antifungal peptide, by binding to DIF. Thus, Mediator is expected to mediate the host defense against pathogens controlled by the Toll pathway-dependent innate immune response. Here, we first focus on the Med31 subunit of the middle module of Mediator and find that it is required in host defense against Aspergillus fumigatus, Enterococcus faecalis, and injected but not topically-applied Metarhizium robertsii. Thus, host defense against M. robertsii requires Dif but not necessarily Med31 in the two distinct infection models. The induction of some Toll-pathway-dependent genes is decreased after a challenge of Med31 RNAi-silenced flies with either A. fumigatus or E. faecalis, while these flies exhibit normal phagocytosis and melanization. We have further tested most Mediator subunits using RNAi by monitoring their survival after challenges to several other microbial infections known to be fought off through DIF. We report that the host defense against specific pathogens involves a distinct set of Mediator subunits with only one subunit for C. glabrata or Erwinia carotovora carotovora, at least one for M. robertsii or a somewhat extended repertoire for A. fumigatus (at least eight subunits) and E. faecalis (eight subunits), with two subunits, Med6 and Med11 being required only against A. fumigatus. Med31 but not Med17 is required in fighting off injected M. robertsii conidia. Thus, the involvement of Mediator in Drosophila innate immunity is more complex than expected.

scholarly journals The Key Roles of Interferon Lambda in Human Molecular Defense against Respiratory Viral Infections

Pathogens ◽  
2020 ◽  
Vol 9 (12) ◽  
pp. 989
Author(s):  
Alexey A. Lozhkov ◽  
Sergey A. Klotchenko ◽  
Edward S. Ramsay ◽  
Herman D. Moshkoff ◽  
Dmitry A. Moshkoff ◽  
...  
Keyword(s):  
Immune Response ◽  
Bacterial Infections ◽  
Viral Infections ◽  
Public Health Problem ◽  
Negative Influence ◽  
Epithelial Tissue ◽  
Major Public Health Problem ◽  
Type Iii ◽  
Respiratory Viral Infections ◽  
Type Iii Ifn

Interferons (IFN) are crucial for the innate immune response. Slightly more than two decades ago, a new type of IFN was discovered: the lambda IFN (type III IFN). Like other IFN, the type III IFN display antiviral activity against a wide variety of infections, they induce expression of antiviral, interferon-stimulated genes (MX1, OAS, IFITM1), and they have immuno-modulatory activities that shape adaptive immune responses. Unlike other IFN, the type III IFN signal through distinct receptors is limited to a few cell types, primarily mucosal epithelial cells. As a consequence of their greater and more durable production in nasal and respiratory tissues, they can determine the outcome of respiratory infections. This review is focused on the role of IFN-λ in the pathogenesis of respiratory viral infections, with influenza as a prime example. The influenza virus is a major public health problem, causing up to half a million lethal infections annually. Moreover, the virus has been the cause of four pandemics over the last century. Although IFN-λ are increasingly being tested in antiviral therapy, they can have a negative influence on epithelial tissue recovery and increase the risk of secondary bacterial infections. Therefore, IFN-λ expression deserves increased scrutiny as a key factor in the host immune response to infection.

Daily training with high carbohydrate availability increases exogenous carbohydrate oxidation during endurance cycling

2010 ◽  
Vol 109 (1) ◽  
pp. 126-134 ◽  
Author(s):  
Gregory R. Cox ◽  
Sally A. Clark ◽  
Amanda J. Cox ◽  
Shona L. Halson ◽  
Mark Hargreaves ◽  
...  
Keyword(s):  
Citrate Synthase ◽  
Substrate Oxidation ◽  
Carbohydrate Intake ◽  
Whole Body ◽  
Test Block ◽  
Vastus Lateralis Muscle ◽  
Mitochondrial Enzymes ◽  
High Group ◽  
High Carbohydrate ◽  
Daily Training

We determined the effects of varying daily carbohydrate intake by providing or withholding carbohydrate during daily training on endurance performance, whole body rates of substrate oxidation, and selected mitochondrial enzymes. Sixteen endurance-trained cyclists or triathletes were pair matched and randomly allocated to either a high-carbohydrate group (High group; n = 8) or an energy-matched low-carbohydrate group (Low group; n = 8) for 28 days. Immediately before study commencement and during the final 5 days, subjects undertook a 5-day test block in which they completed an exercise trial consisting of a 100 min of steady-state cycling (100SS) followed by a 7-kJ/kg time trial on two occasions separated by 72 h. In a counterbalanced design, subjects consumed either water (water trial) or a 10% glucose solution (glucose trial) throughout the exercise trial. A muscle biopsy was taken from the vastus lateralis muscle on day 1 of the first test block, and rates of substrate oxidation were determined throughout 100SS. Training induced a marked increase in maximal citrate synthase activity after the intervention in the High group (27 vs. 34 μmol·g−1·min−1, P < 0.001). Tracer-derived estimates of exogenous glucose oxidation during 100SS in the glucose trial increased from 54.6 to 63.6 g ( P < 0.01) in the High group with no change in the Low group. Cycling performance improved by ∼6% after training. We conclude that altering total daily carbohydrate intake by providing or withholding carbohydrate during daily training in trained athletes results in differences in selected metabolic adaptations to exercise, including the oxidation of exogenous carbohydrate. However, these metabolic changes do not alter the training-induced magnitude of increase in exercise performance.

scholarly journals The activities of the citric acid-cycle enzymes in rat bone-marrow cells

1968 ◽  
Vol 108 (3) ◽  
pp. 413-415
Author(s):  
Eugene Goldwasser
Keyword(s):  
Bone Marrow ◽  
Citric Acid ◽  
Citric Acid Cycle ◽  
Citrate Synthase ◽  
Bone Marrow Cells ◽  
Mitochondrial Enzymes ◽  
Acid Cycle ◽  
Citric Acid Cycle Enzymes ◽  
Rat Bone ◽  
Marrow Cells

The activities of the eight citric acid-cycle enzymes of rat bone-marrow cells were determined along with several other mitochondrial and non-mitochondrial enzymes. Four of the citric acid-cycle enzymes (aconitase, succinyl-CoA thiokinase, α-oxoglutarate dehydrogenase and succinate dehydrogenase) have closely similar low activities; two [isocitrate dehydrogenase (NAD) and citrate synthase] have intermediate activities; the remaining two (malate dehydrogenase and fumarase) have high activities. The other enzymes surveyed also exhibited a spread of three orders of magnitude, the mitochondrial enzymes showing no less variation than the others.

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