scholarly journals Insect antimicrobial peptides act synergistically to inhibit a trypanosome parasite

2016 ◽  
Vol 371 (1695) ◽  
pp. 20150302 ◽  
Author(s):  
Monika Marxer ◽  
Vera Vollenweider ◽  
Paul Schmid-Hempel
Keyword(s):  
Antimicrobial Peptides ◽  
Evolutionary Ecology ◽  
Bombus Terrestris ◽  
Parasite Strain ◽  
Strain Specificity ◽  
Variable Expression ◽  
Combination Treatments ◽  
Crithidia Bombi ◽  
Spectrum Activity ◽  
Different Strains

The innate immune system provides protection from infection by producing essential effector molecules, such as antimicrobial peptides (AMPs) that possess broad-spectrum activity. This is also the case for bumblebees, Bombus terrestris , when infected by the trypanosome, Crithidia bombi . Furthermore, the expressed mixture of AMPs varies with host genetic background and infecting parasite strain (genotype). Here, we used the fact that clones of C. bombi can be cultivated and kept as strains in medium to test the effect of various combinations of AMPs on the growth rate of the parasite. In particular, we used pairwise combinations and a range of physiological concentrations of three AMPs, namely Abaecin , Defensin and Hymenoptaecin , synthetized from the respective genomic sequences. We found that these AMPs indeed suppress the growth of eight different strains of C. bombi , and that combinations of AMPs were typically more effective than the use of a single AMP alone. Furthermore, the most effective combinations were rarely those consisting of maximum concentrations. In addition, the AMP combination treatments revealed parasite strain specificity, such that strains varied in their sensitivity towards the same mixtures. Hence, variable expression of AMPs could be an alternative strategy to combat highly variable infections. This article is part of the themed issue ‘Evolutionary ecology of arthropod antimicrobial peptides’.

Antimicrobial Peptides: A Promising Avenue for Human Healthcare

2020 ◽  
Vol 21 (2) ◽  
pp. 90-96 ◽  
Author(s):  
Girish M. Bhopale
Keyword(s):  
Antimicrobial Peptides ◽  
Antimicrobial Peptide ◽  
Antimicrobial Agents ◽  
Current Status ◽  
Antimicrobial Drugs ◽  
Spectrum Activity ◽  
Low Levels ◽  
Human Healthcare ◽  
Broad Spectrum Activity ◽  
Promising Avenue

Antimicrobial drugs resistant microbes have been observed worldwide and therefore alternative development of antimicrobial peptides has gained interest in human healthcare. Enormous progress has been made in the development of antimicrobial peptide during the last decade due to major advantages of AMPs such as broad-spectrum activity and low levels of induced resistance over the current antimicrobial agents. This review briefly provides various categories of AMP, their physicochemical properties and mechanism of action which governs their penetration into microbial cell. Further, the recent information on current status of antimicrobial peptide development, their applications and perspective in human healthcare are also described.

scholarly journals Antimicrobial peptides play a functional role in bumblebee anti-trypanosome defense

2014 ◽  
Author(s):  
Soni Deshwal ◽  
Eamonn Mallon
Keyword(s):  
Gene Expression ◽  
Gut Microbiota ◽  
Antimicrobial Peptides ◽  
Functional Role ◽  
Immune Gene ◽  
Ecological Immunology ◽  
Previous Evidence ◽  
Immune Gene Expression ◽  
Crithidia Bombi ◽  
First Time

Bumblebees, amongst the most important of pollinators, are under enormous population pressures. One of these is disease. The bumblebee and its gut trypanosome Crithidia bombi are one of the fundamental models of ecological immunology. Although there is previous evidence of increased immune gene expression upon Crithidia infection, recent work has focussed on the bumblebee's gut microbiota. Here, by knocking down gene expression using RNAi, we show for the first time that antimicrobial peptides (AMPs) have a functional role in anti-Crithidia defense.

scholarly journals Bacterial strategies of resistance to antimicrobial peptides

2016 ◽  
Vol 371 (1695) ◽  
pp. 20150292 ◽  
Author(s):  
Hwang-Soo Joo ◽  
Chih-Iung Fu ◽  
Michael Otto
Keyword(s):  
Antimicrobial Peptides ◽  
Innate Immune System ◽  
Evolutionary Ecology ◽  
Resistance Mechanisms ◽  
Innate Immune ◽  
Surface Structures ◽  
Antimicrobial Drugs ◽  
Bacterial Surface ◽  
Membrane Charge ◽  
Virulence Potential

Antimicrobial peptides (AMPs) are a key component of the host's innate immune system, targeting invasive and colonizing bacteria. For successful survival and colonization of the host, bacteria have a series of mechanisms to interfere with AMP activity, and AMP resistance is intimately connected with the virulence potential of bacterial pathogens. In particular, because AMPs are considered as potential novel antimicrobial drugs, it is vital to understand bacterial AMP resistance mechanisms. This review gives a comparative overview of Gram-positive and Gram-negative bacterial strategies of resistance to various AMPs, such as repulsion or sequestration by bacterial surface structures, alteration of membrane charge or fluidity, degradation and removal by efflux pumps. This article is part of the themed issue ‘Evolutionary ecology of arthropod antimicrobial peptides’.

scholarly journals Friend, foe or food? Recognition and the role of antimicrobial peptides in gut immunity and Drosophila –microbe interactions

2016 ◽  
Vol 371 (1695) ◽  
pp. 20150295 ◽  
Author(s):  
Nichole A. Broderick
Keyword(s):  
Antimicrobial Peptides ◽  
Plant Material ◽  
Host Response ◽  
Evolutionary Ecology ◽  
Close Association ◽  
Food Recognition ◽  
Gut Immunity ◽  
Microbe Interactions ◽  
By Products

Drosophila melanogaster lives, breeds and feeds on fermenting fruit, an environment that supports a high density, and often a diversity, of microorganisms. This association with such dense microbe-rich environments has been proposed as a reason that D. melanogaster evolved a diverse and potent antimicrobial peptide (AMP) response to microorganisms, especially to combat potential pathogens that might occupy this niche. Yet, like most animals, D. melanogaster also lives in close association with the beneficial microbes that comprise its microbiota, or microbiome, and recent studies have shown that antimicrobial peptides (AMPs) of the epithelial immune response play an important role in dictating these interactions and controlling the host response to gut microbiota. Moreover, D. melanogaster also eats microbes for food, consuming fermentative microbes of decaying plant material and their by-products as both larvae and adults. The processes of nutrient acquisition and host defence are remarkably similar and use shared functions for microbe detection and response, an observation that has led to the proposal that the digestive and immune systems have a common evolutionary origin. In this manner, D. melanogaster provides a powerful model to understand how, and whether, hosts differentiate between the microbes they encounter across this spectrum of associations. This article is part of the themed issue ‘Evolutionary ecology of arthropod antimicrobial peptides’.

Infection with the trypanosome Crithidia bombi and expression of immune-related genes in the bumblebee Bombus terrestris

2010 ◽  
Vol 34 (7) ◽  
pp. 705-709 ◽  
Author(s):  
Helge Schlüns ◽  
Ben M. Sadd ◽  
Paul Schmid-Hempel ◽  
Ross H. Crozier
Keyword(s):  
Bombus Terrestris ◽  
Crithidia Bombi ◽  
Immune Related Genes

scholarly journals Fasciola hepatica isolates induce different immune responses in unmaturated bovine macrophages

2019 ◽  
Vol 63 (1) ◽  
pp. 63-70 ◽  
Author(s):  
Piotr Bąska ◽  
Anna Zawistowska-Deniziak ◽  
Luke James Norbury ◽  
Marcin Wiśniewski ◽  
Kamil Januszkiewicz
Keyword(s):  
Liver Fluke ◽  
Fasciola Hepatica ◽  
Interleukin 10 ◽  
Parasite Strain ◽  
A Cell ◽  
Immunomodulatory Properties ◽  
Secretory Products ◽  
Different Strains ◽  
Factor Α ◽  
Necrosis Factor

AbstractIntroduction:Fasciola hepatica(liver fluke) is a parasite of great socioeconomic importance. A number of fluke isolates have been identified; however, to date the differences between the immunomodulatory properties of different parasite isolates have not been sufficiently investigated. The aim of this study was to explore differences between the immunomodulatory properties of twoF. hepaticaisolates using unmaturated bovine macrophages.Material and Methods:A cell line of bovine macrophages was stimulated with excretory/secretory products released by adult flukes from either a laboratory (Fh-WeyES) or wild (Fh-WildES) strain and subsequently subjected to microarray and ELISA analyses.Results:BothFh-WeyES andFh-WildES dampened the release of interleukin-10 by bovine macrophages, but onlyFh-WildES dampened the release of proinflammatory tumour necrosis factor-α. Microarray analysis revealed thatFh-WildES down- and upregulated 90 and 18 genes, respectively, when compared toFh-WeyES.Conclusion:The results indicated different impacts of the isolates on macrophages. A number of researchers use flukes obtained from local slaughterhouses for experiments. Our findings may explain some discrepancies between published results arising from parasite strain choice. The findings indicate that consideration should be given to the use of different strains, and open new and currently unexplored avenues in parasitology for controlling the parasite.

scholarly journals Mating precedes selective immune priming which is maintained throughout bumblebee queen diapause

2019 ◽  
Author(s):  
Thomas J Colgan ◽  
Sive Finlay ◽  
Mark JF Brown ◽  
James C Carolan
Keyword(s):  
Antimicrobial Peptides ◽  
Evolutionary Biology ◽  
Molecular Mechanisms ◽  
Bombus Terrestris ◽  
Molecular Evidence ◽  
Biological Processes ◽  
Arrested Development ◽  
Immune Priming ◽  
Female Behaviour

Abstract Background: Understanding the mechanisms by which organisms adapt to unfavourable conditions is a fundamental question in ecology and evolutionary biology. One such mechanism is diapause, a period of dormancy typically found in nematodes, fish, crustaceans and insects. This state is a key life-history event characterised by arrested development, suppressed metabolism and increased stress tolerance and allows an organism to avoid prolonged periods of harsh and inhospitable environmental conditions. For some species, diapause is preceded by mating which can have a profound effect on female behaviour, physiology and key biological processes, including immunity. However, our understanding of how mating impacts long-term immunity and whether these effects persist throughout diapause is currently limited. To address this, we explored molecular changes in the haemolymph of the ecologically important pollinator, the buff-tailed bumblebee Bombus terrestris . B. terrestris queens mate prior to entering diapause, a non-feeding period of arrested development that can last 6-9 months. Using mass-spectrometry-based proteomics, we quantified changes in the pre-diapause queen haemolymph after mating, as well as the subsequent protein expression of mated queens during and post-diapause. Results: Our analysis identified distinct proteome profiles associated with diapause preparation, maintenance and termination. More specifically, mating pre-diapause was followed by an increase in the abundance of antimicrobial peptides, key effectors of the immune system. Furthermore, we identified the elevated abundance of these proteins to be maintained throughout diapause. This finding was in contrast to a general reduction in immune proteins during diapause suggestive of selective immune priming and expression during diapause. Diapause also affected the expression of proteins involved in cuticular maintenance, olfaction, as well as proteins of unknown function, which may have roles in diapause regulation. Conclusions: Our results provide clear molecular evidence for the consequences and benefits of mating at the immune level as it precedes the selective increased abundance of antimicrobial peptides that are sustained throughout diapause. In addition, our results provide novel insights into the molecular mechanisms by which bumblebees prepare for, survive, and recover from diapause, insights that may have implications for our general understanding of these processes in other insect groups.

Immunocompetence in workers of a social insect, Bombus terrestris L., in relation to foraging activity and parasitic infection

2000 ◽  
Vol 78 (6) ◽  
pp. 1060-1066 ◽  
Author(s):  
Claudie Doums ◽  
Paul Schmid-Hempel
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Intestinal Parasite ◽  
Bombus Terrestris ◽  
Parasitic Infection ◽  
General Mechanism ◽  
Immune Defence ◽  
Foraging Activity ◽  
Natural Conditions ◽  
Crithidia Bombi

The immune system is a general mechanism that reduces the fitness cost of parasitism. In this study, we examined variation in immune responses under natural conditions in the bumblebee Bombus terrestris. Using 14 colonies reared in the field, we compared the immune response to an artificial implant between workers that could or could not forage (86 control and 91 nonforaging workers). Foraging activity was prevented by cutting a large part of the wings. As expected, control workers had lower immune responses than nonforaging workers in 10 of 14 colonies. Overall, the treatment effect was significant even though weak, suggestive of a trade-off between immune defence and foraging activity. We also examined the environmental factors that might covary with the immune response in workers. The immune response significantly decreased in workers that were naturally infected by the intestinal parasite Crithidia bombi and increased with a measure of colony success, the maximum number of workers. These correlations suggest that the strength of immune responses reflects individual, and hence colony condition.

Single-clone and mixed-clone infections versus host environment in Crithidia bombi infecting bumblebees

Parasitology ◽  
1998 ◽  
Vol 117 (4) ◽  
pp. 331-336 ◽  
Author(s):  
B. IMHOOF ◽  
P. SCHMID-HEMPEL
Keyword(s):  
Bombus Terrestris ◽  
Infection Intensity ◽  
Parasite Prevalence ◽  
Mixed Genotype ◽  
Host Environment ◽  
Crithidia Bombi ◽  
The Family ◽  
Single Clone ◽  
Parasite Evolution ◽  
Host Heterogeneity

Current theories assume that adaptive parasite evolution explains variation in the level of virulence and parasite success. In particular, mixed-genotype infections by parasites should generally be more virulent, and faster multiplying strains more successful, either because fixed strategies have evolved or because parasites facultatively alter virulence in response to co-infecting competitors. We compared several measures of parasite success and virulence between single-clone and mixed-clone infections of 2 strains of the trypanosome Crithidia bombi in its bumblebee host, Bombus terrestris. Contrary to expectation, we could not find differences between single-clone and mixed-clone infections in parasite prevalence, infection success, duration and clearance rate. However, a clearly significant effect of colony on infection intensity was present, and the colony effect emerged in virtually all other measures. We thus conclude that host environment as defined by the family (colony) genotype and thus host heterogeneity are more important in determining parasite virulence than the parasite characteristics. This does not invalidate modern theories of parasite evolution but suggests that variation in both hosts and parasites must be taken into account in more detail.

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