scholarly journals Phlebotomus papatasi Antimicrobial Peptides in Larvae and Females and a Gut-Specific Defensin Upregulated by Leishmania major Infection

2021 ◽  
Vol 9 (11) ◽  
pp. 2307
Author(s):  
Barbora Kykalová ◽  
Lucie Tichá ◽  
Petr Volf ◽  
Erich Loza Telleria

Phlebotomus papatasi is the vector of Leishmania major, causing cutaneous leishmaniasis in the Old World. We investigated whether P. papatasi immunity genes were expressed toward L. major, commensal gut microbes, or a combination of both. We focused on sand fly transcription factors dorsal and relish and antimicrobial peptides (AMPs) attacin and defensin and assessed their relative gene expression by qPCR. Sand fly larvae were fed food with different bacterial loads. Relish and AMPs gene expressions were higher in L3 and early L4 larval instars, while bacteria 16S rRNA increased in late L4 larval instar, all fed rich-microbe food compared to the control group fed autoclaved food. Sand fly females were treated with an antibiotic cocktail to deplete gut bacteria and were experimentally infected by Leishmania. Compared to non-infected females, dorsal and defensin were upregulated at early and late infection stages, respectively. An earlier increase of defensin was observed in infected females when bacteria recolonized the gut after the removal of antibiotics. Interestingly, this defensin gene expression occurred specifically in midguts but not in other tissues of females and larvae. A gut-specific defensin gene upregulated by L. major infection, in combination with gut-bacteria, is a promising molecular target for parasite control strategies.

Parasitology ◽  
1997 ◽  
Vol 115 (4) ◽  
pp. 359-369 ◽  
Author(s):  
P. F. P. PIMENTA ◽  
G. B. MODI ◽  
S. T. PEREIRA ◽  
M. SHAHABUDDIN ◽  
D. L. SACKS

The role of the peritrophic matrix (PM) in the development of Leishmania major infections in a natural vector, Phlebotomus papatasi, was investigated by addition of exogenous chitinase to the bloodmeal, which completely blocked PM formation. Surprisingly, the absence of the PM was associated with the loss of midgut infections. The chitinase was not directly toxic to the parasite, nor were midgut infections lost due to premature expulsion of the bloodmeal. Most parasites were killed in chitinase-treated flies within the first 4 h after feeding. Substantial early killing was also observed in control flies, suggesting that the lack of PM exacerbates lethal conditions which normally exist in the blood-fed midgut. Early parasite mortality was reversed by soybean trypsin inhibitor. Allosamadin, a specific inhibitor of chitinase, led to a thickening of the PM, and also prevented the early parasite mortality seen in infected flies. Susceptibility to gut proteases was extremely high in transitional-stage parasites, while amastigotes and fully transformed promastigotes were relatively resistant. A novel role for the PM in promoting parasite survival is suggested, in which the PM creates a barrier to the rapid diffusion of digestive enzymes, and limits the exposure of parasites to these enzymes during the time when they are especially vulnerable to proteolytic damage.


Vaccine ◽  
2017 ◽  
Vol 35 (48) ◽  
pp. 6611-6619 ◽  
Author(s):  
William H. Wheat ◽  
Erik N. Arthun ◽  
John S. Spencer ◽  
Daniel P. Regan ◽  
Richard G. Titus ◽  
...  

2021 ◽  
Vol 90 (4 - Ahead of print) ◽  
pp. 175-193
Author(s):  
Maha Moustafa Ahmed ◽  
Heba Yehia Mady ◽  
Amira Hassan El Namaky

The sand fly, Phlebotomus papatasi (Scopoli, 1786) (Diptera: Psychodidae), is the main vector of Leishmania major Yakimoff and Schokhor, 1914, the causative agent of zoonotic cutaneous leishmaniasis North Africa, the Middle East, and North Sinai. The purpose of this study was to determine the effect of fungi on P. papatasi larvae, pupae, and adults using light microscopic analysis, scanning electron microscope (SEM), and histopathological studies. Specifically, larvae, pupae, and adult P. papatasi were infected with the entomopathogenic fungi Beauveria bassiana and Metarhizium anisopliae. Scanning electron microscope and histopathological methods were used to investigate the destructive impact of the fungi on the external and internal structures of P. papatasi. The results revealed propagation of the conidia on the cuticles of all P. papatasi life stages, including on the compound eyes, leg setae, thorax, wings, and abdomen of the adults. Histological sections of the control and treated larvae, pupae, and adults showed many alterations and malformations in the body and tissues of all life stages after 72 h. These results demonstrated that B. bassiana was more effective than M. anisopliae as a biological control of phlebotomine sand flies. Further studies to determine the best methods for delivery and application in the diverse ecological settings of the various leishmaniasis vectors are recommended.


Author(s):  
Zohreh LASJERDI ◽  
Hossein GHANBARIAN ◽  
Samira MOHAMMADI YEGANEH ◽  
Seyyed Javad SEYYED TABAEI ◽  
Mehdi MOHEBALI ◽  
...  

Background: Cutaneous Leishmaniasis (CL) is an emerging uncontrollable and neglected infectious disease worldwide including Iran. The aim of this study was to investigate the expression profile of apoptosis- related miRNA and its target gene in macrophages. Methods: This study was carried out in the Department of Medical Parasitology and Mycology, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran from January 2016 to November 2018. Applying literature reviews, bioinformatics software, and microarray expression analysis, we selected miRNA-24-3p interfering in apoptosis pathway. The expression profile of this miRNA and target gene were investigated in Leishmania major (MRHO/IR/75/ER)-infected primary and RAW 264.7 macrophages (IBRC-C10072) compared with non-infected macrophages (control group) using quantitative Real-time PCR. Results: Results of bioinformatics analysis showed that miR-24-3p as anti-apoptotic miRNA inhibits pro-apoptotic genes (Caspases 3 and 7). Microarray expression data presented in Gene Expression Omnibus (GEO) revealed a significant difference in the expression level of selected miRNA and its target gene between two groups. QRT-PCR results showed that the expression of miR-24-3p was upregulated in L. major infectioned macrophages that approved the results of bioinformatics and microarray analysis. Conclusion: Parasite can alter miRNAs expression pattern in the host cells to establish infection and its survival. Alteration in miRNAs levels likely plays an important role in regulating macrophage functions following L. major infection. These results could highlight current understanding and new insights concerning the gene expression in macrophages during leishmaniasis and will help to development of novel strategies for control and treatment of CL.


2021 ◽  
Vol 70 (6) ◽  
Author(s):  
Fatemeh Sharifi ◽  
Fariba Sharififar ◽  
Mostafa Pournamdari ◽  
Mehdi Ansari ◽  
Razieh Tavakoli Oliaee ◽  
...  

Introduction. Leishmaniasis is a neglected tropical and subtropical disease caused by over 20 protozoan species. Hypothesis. Treatment of this complex disease with traditional synthetic drugs is a major challenge worldwide. Natural constituents are unique candidates for future therapeutic development. Aim. This study aimed to assess the in vivo anti-leishmanial effect of the Gossypium hirsutum extract, and its fractions compared to the standard drug (Glucantime, MA) in a murine model and explore the mechanism of action. Methodology. Footpads of BALB/c mice were infected with stationary phase promastigotes and treated topically and intraperitoneally with G. hirsutum extract, its fractions, or Glucantime, 4 weeks post-infection. The extract and fractions were prepared using the Soxhlet apparatus with chloroform followed by the column procedure. Results. The crude extract significantly decreased the footpad parasite load and lesion size compared to the untreated control group (P<0.05), as revealed by dilution assay, quantitative real-time PCR, and histopathological analyses. The primary mode of action involved an immunomodulatory role towards the Th1 response in the up-regulation of IFN-γ and IL-12 and the suppression of IL-10 gene expression profiling against cutaneous leishmaniasis caused by Leishmania major. Conclusion. This finding suggests that the extract possesses multiple combinatory effects of diverse bioactive phytochemical compositions that exert its mechanisms of action through agonistic-synergistic interactions. The topical extract formulation could be a suitable and unique candidate for future investigation and pharmacological development. Further studies are crucial to evaluate the therapeutic potentials of the extract alone and in combination with conventional drugs using clinical settings.


mBio ◽  
2019 ◽  
Vol 10 (4) ◽  
Author(s):  
Isabelle Louradour ◽  
Kashinath Ghosh ◽  
Ehud Inbar ◽  
David L. Sacks

ABSTRACT Sand flies are the natural vectors for the Leishmania species that produce a spectrum of diseases in their mammalian hosts, including humans. Studies of sand fly/Leishmania interactions have been limited by the absence of genome editing techniques applicable to these insects. In this report, we adapted CRISPR (clustered regularly interspaced palindromic repeat)/Cas9 (CRISPR-associated protein 9) technology to the Phlebotomus papatasi sand fly, a natural vector for Leishmania major, targeting the sand fly immune deficiency (IMD) pathway in order to decipher its contribution to vector competence. We established a protocol for transformation in P. papatasi and were able to generate transmissible null mutant alleles for Relish (Rel), the only transcription factor of the IMD pathway. While the maintenance of a homozygous mutant stock was severely compromised, we were able to establish in an early generation their greater susceptibility to infection with L. major. Flies carrying different heterozygous mutant alleles variably displayed a more permissive phenotype, presenting higher loads of parasites or greater numbers of infective-stage promastigotes. Together, our data show (i) the successful adaptation of the CRISPR/Cas9 technology to sand flies and (ii) the impact of the sand fly immune response on vector competence for Leishmania parasites. IMPORTANCE Sand flies are the natural vectors of Leishmania parasites. Studies of sand fly/Leishmania interactions have been limited by the lack of successful genomic manipulation of these insects. This paper shows the first example of successful targeted mutagenesis in sand flies via adaptation of the CRISPR/Cas9 editing technique. We generated transmissible null mutant alleles of relish, a gene known to be essential for the control of immune response in other insects. In addition to the expected higher level of susceptibility to bacteria, the mutant flies presented higher loads of parasites when infected with L. major, showing that the sand fly immune response impacts its vector competence for this pathogen.


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