scholarly journals Molecular Diversity and Evolution of Antimicrobial Peptides in Musca domestica

Diversity ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 107
Author(s):  
Sudong Qi ◽  
Bin Gao ◽  
Shunyi Zhu

As a worldwide sanitary insect pest, the housefly Musca domestica can carry and transmit more than 100 human pathogens without suffering any illness itself, indicative of the high efficiency of its innate immune system. Antimicrobial peptides (AMPs) are the effectors of the innate immune system of multicellular organisms and establish the first line of defense to protect hosts from microbial infection. To explore the molecular diversity of the M. domestica AMPs and related evolutionary basis, we conducted a systematic survey of its full AMP components based on a combination of computational approaches. These components include the cysteine-containing peptides (MdDefensins, MdEppins, MdMuslins, MdSVWCs and MdCrustins), the linear α-helical peptides (MdCecropins) and the specific amino acid-rich peptides (MdDomesticins, MdDiptericins, MdEdins and MdAttacins). On this basis, we identified multiple genetic mechanisms that could have shaped the molecular and structural diversity of the M. domestica AMPs, including: (1) Gene duplication; (2) Exon duplication via shuffling; (3) Protein terminal variations; (4) Evolution of disulfide bridges via compensation. Our results not only enlarge the insect AMP family members, but also offer a basic platform for further studying the roles of such molecular diversity in contributing to the high efficiency of the housefly antimicrobial immune system.

2019 ◽  
Vol 12 (6) ◽  
pp. dmm037721 ◽  
Author(s):  
Mayo Araki ◽  
Massanori Kurihara ◽  
Suzuko Kinoshita ◽  
Rie Awane ◽  
Tetsuya Sato ◽  
...  

2011 ◽  
Vol 32 (2) ◽  
pp. 143-171 ◽  
Author(s):  
Mukesh Pasupuleti ◽  
Artur Schmidtchen ◽  
Martin Malmsten

2016 ◽  
Vol 397 (9) ◽  
pp. 939-945 ◽  
Author(s):  
Mohammad Reza Bolouri Moghaddam ◽  
Miray Tonk ◽  
Christine Schreiber ◽  
Denise Salzig ◽  
Peter Czermak ◽  
...  

Abstract Antimicrobial peptides (AMPs) are ubiquitous components of the insect innate immune system. The model insect Galleria mellonella has at least 18 AMPs, some of which are still uncharacterized in terms of antimicrobial activity. To determine why G. mellonella secretes a repertoire of distinct AMPs following an immune challenge, we selected three different AMPs: cecropin A (CecA), gallerimycin and cobatoxin. We found that cobatoxin was active against Micrococcus luteus at a minimum inhibitory concentration (MIC) of 120 μm, but at 60 μm when co-presented with 4 μm CecA. In contrast, the MIC of gallerimycin presented alone was 60 μm and the co-presentation of CecA did not affect this value. Cobatoxin and gallerimycin were both inactive against Escherichia coli at physiological concentrations, however gallerimycin could potentiate the sublethal dose of CecA (0.25 μm) at a concentration of 30 μm resulting in 100% lethality. The ability of gallerimycin to potentiate the CecA was investigated by flow cytometry, revealing that 30 μm gallerimycin sensitized E. coli cells by inducing membrane depolarization, which intensified the otherwise negligible effects of 0.25 μm CecA. We therefore conclude that G. mellonella maximizes the potential of its innate immune response by the co-presentation of different AMPs that become more effective at lower concentrations when presented simultaneously.


Author(s):  
S. Neelima ◽  
K. Archana ◽  
P. P. Athira ◽  
M. V. Anju ◽  
V. V. Anooja ◽  
...  

Abstract Background The concern regarding a post-antibiotic era with increasing drug resistance by pathogens imposes the need to discover alternatives for existing antibiotics. Antimicrobial peptides (AMPs) with their versatile therapeutic properties are a group of promising molecules with curative potentials. These evolutionarily conserved molecules play important roles in the innate immune system of several organisms. The β-defensins are a group of cysteine rich cationic antimicrobial peptides that play an important role in the innate immune system by their antimicrobial activity against the invading pathogens. The present study deals with a novel β-defensin isoform from the red-toothed trigger fish, Odonus niger. Total RNA was isolated from the gills, cDNA was synthesized and the β-defensin isoform obtained by polymerase chain reaction was cloned and subjected to structural and functional characterization in silico. Results A β-defensin isoform could be detected from the gill mRNA of red-toothed trigger fish, Odonus niger. The cDNA encoded a 63 amino acid peptide, β-defensin, with a 20 amino acid signal sequence followed by 43 amino acid cationic mature peptide (On-Def) having a molecular weight of 5.214 kDa and theoretical pI of 8.89. On-Def possessed six highly conserved cysteine residues forming disulfide bonds between C1–C5, C2–C4, and C3–C6, typical of β-defensins. An anionic pro-region was observed prior to the β-defensin domain within the mature peptide. Clustal alignment and phylogenetic analyses revealed On-Def as a group 2 β-defensin. Furthermore, it shared some structural similarities and functional motifs with β-defensins from other organisms. On-Def was predicted to be non-hemolytic with anti-bacterial, anti-viral, anti-fungal, anti-cancer, and immunomodulatory potential. Conclusion On-Def is the first report of a β-defensin from the red-toothed trigger fish, Odonus niger. The antimicrobial profile showed the potential for further studies as a suitable candidate for antimicrobial peptide therapeutics.


2011 ◽  
Vol 57 (5) ◽  
pp. 63-71 ◽  
Author(s):  
V Ia Shvarts

This review considers the role of adenovirus 36, Chlamydia pneumoniae, Helicobacter pylori, and Trypanosoma cruzi in pathogenesis of obesity. Infection with either of the three microorganisms leads to the development of obesity in animals. The infected people usually have antibodies to these bacteria. One of the causes of obesity is believed to be activation of the receptors of the innate immune system (TLR2 and TLR4) by certain factors of the microorganisms; these receptors are known to localize in the adipose tissue. Saturated fatty acids as well as lipoploysaccharides (components of the microbial cells) are the ligands of TLR2 and TLR4. Activation of TLR2 and TLR4 promotes the development of both inflammation in the adipose tissue and insulin resistance and thereby leads to obesity. The mechanism of action of activated TLR2 and TLR4 during microbial infection consists of the suppression of sensitivity of adipose, hepatic, and muscular cells to insulin in conjunction with the enhancement of the blood glucose and fatty acid levels to produce the energy-rich substrates necessary to maintain the immune processes. The fact that saturated fatty acids and components of microbial cells can function as ligands for the receptors of the innate immune system and induce identical reactions gives evidence of the possible cumulative action of both excessively consumed dietary items and certain species of microorganisms.


2020 ◽  
Vol 117 (44) ◽  
pp. 27620-27626 ◽  
Author(s):  
Renee M. Fleeman ◽  
Luis A. Macias ◽  
Jennifer S. Brodbelt ◽  
Bryan W. Davies

The extracellular polysaccharide capsule ofKlebsiella pneumoniaeresists penetration by antimicrobials and protects the bacteria from the innate immune system. Host antimicrobial peptides are inactivated by the capsule as it impedes their penetration to the bacterial membrane. While the capsule sequesters most peptides, a few antimicrobial peptides have been identified that retain activity against encapsulatedK. pneumoniae,suggesting that this bacterial defense can be overcome. However, it is unclear what factors allow peptides to avoid capsule inhibition. To address this, we created a peptide analog with strong antimicrobial activity toward severalK. pneumoniaestrains from a previously inactive peptide. We characterized the effects of these two peptides onK. pneumoniae, along with their physical interactions withK. pneumoniaecapsule. Both peptides disrupted bacterial cell membranes, but only the active peptide displayed this activity against capsulatedK. pneumoniae. Unexpectedly, the active peptide showed no decrease in capsule binding, but did lose secondary structure in a capsule-dependent fashion compared with the inactive parent peptide. We found that these characteristics are associated with capsule-peptide aggregation, leading to disruption of theK. pneumoniaecapsule. Our findings reveal a potential mechanism for disrupting the protective barrier thatK. pneumoniaeuses to avoid the immune system and last-resort antibiotics.


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