scholarly journals A pigment-deficient mosquito line with fluorescent salivary glands enables in vivo imaging of individual Plasmodium sporozoites

2021 ◽  
Author(s):  
Dennis Klug ◽  
Katharina Arnold ◽  
Eric Marois ◽  
Stéphanie A. Blandin
Keyword(s):  
Salivary Gland ◽  
Salivary Glands ◽  
Specific Activity ◽  
Middle Lobe ◽  
Sub Saharan Africa ◽  
Functional Domain ◽  
Anopheles Coluzzii ◽  
Fluorescent Reporters ◽  
Sub Saharan

AbstractPlasmodium parasites are the causative agent of malaria, a major health burden in sub- Saharan Africa. A key step in the transmission process of Plasmodium is the colonization of the salivary glands of the female Anopheles mosquito by the parasite sporozoite stage. How sporozoites recognize and invade the salivary glands is still poorly understood. Here we generated salivary gland reporter lines in the African malaria mosquito Anopheles coluzzii using salivary gland-specific promoters of the genes encoding anopheline antiplatelet protein (AAPP), the triple functional domain protein (TRIO) and saglin (SAG). The observed expression pattern of the DsRed and roGFP2 fluorescent reporters revealed lobe-specific activity of these promoters within the salivary glands, restricted either to the distal lobes or the middle lobe. We characterized four mosquito lines (AAPP-DsRed, AAPP-roGFP2, TRIO- DsRed and SAG-EGFP) in terms of localization, expression strength and onset of expression, as well as potential influences of the expressed fluorescent reporters on the infection with Plasmodium berghei and salivary gland morphology. Furthermore, using crosses with a pigmentation deficient yellow(-) mosquito line, we demonstrate that our salivary gland reporter lines represent a valuable tool to study the process of salivary gland colonization by Plasmodium parasites in live mosquitoes.

scholarly journals Schistosoma mansoni eggs induce Wnt/β-catenin signaling and activate the protooncogene c-Jun in human and hamster colon

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Jakob Weglage ◽  
Friederike Wolters ◽  
Laura Hehr ◽  
Jakob Lichtenberger ◽  
Celina Wulz ◽  
...  
Keyword(s):  
Signaling Pathways ◽  
Colorectal Carcinogenesis ◽  
Sub Saharan Africa ◽  
Interleukin 4 ◽  
Health Burden ◽  
Sub Saharan ◽  
Considerable Morbidity ◽  
First Time

AbstractSchistosomiasis (bilharzia) is a neglected tropical disease caused by parasitic flatworms of the genus Schistosoma, with considerable morbidity in parts of the Middle East, South America, Southeast Asia, in sub-Saharan Africa, and particularly also in Europe. The WHO describes an increasing global health burden with more than 290 million people threatened by the disease and a potential to spread into regions with temperate climates like Corsica, France. The aim of our study was to investigate the influence of S. mansoni infection on colorectal carcinogenic signaling pathways in vivo and in vitro. S. mansoni infection, soluble egg antigens (SEA) and the Interleukin-4-inducing principle from S. mansoni eggs induce Wnt/β-catenin signaling and the protooncogene c-Jun as well as downstream factor Cyclin D1 and markers for DNA-damage, such as Parp1 and γH2a.x in enterocytes. The presence of these characteristic hallmarks of colorectal carcinogenesis was confirmed in colon biopsies from S. mansoni-infected patients demonstrating the clinical relevance of our findings. For the first time it was shown that S. mansoni SEA may be involved in the induction of colorectal carcinoma-associated signaling pathways.

scholarly journals Functional analysis of the biochemical activity of mammalian phosphatidylinositol 5 phosphate 4-kinase enzymes

2019 ◽  
Vol 39 (2) ◽  
Author(s):  
Swarna Mathre ◽  
K. Balasankara Reddy ◽  
Visvanathan Ramya ◽  
Harini Krishnan ◽  
Avishek Ghosh ◽  
...  
Keyword(s):  
Salivary Gland ◽  
Cell Size ◽  
Kinase Activity ◽  
Gland Cell ◽  
Specific Activity ◽  
Salivary Gland Cell ◽  
Drosophila Genome ◽  
Biochemical Activity

Abstract Phosphatidylinositol 5 phosphate 4-kinase (PIP4K) are enzymes that catalyse the phosphorylation of phosphatidylinositol 5-phosphate (PI5P) to generate PI(4,5)P2. Mammalian genomes contain three genes, PIP4K2Α, 2B and 2C and murine knockouts for these suggested important physiological roles in vivo. The proteins encoded by PIP4K2A, 2B and 2C show widely varying specific activities in vitro; PIP4K2A is highly active and PIP4K2C 2000-times less active, and the relationship between this biochemical activity and in vivo function is unknown. By contrast, the Drosophila genome encodes a single PIP4K (dPIP4K) that shows high specific activity in vitro and loss of this enzyme results in reduced salivary gland cell size in vivo. We find that the kinase activity of dPIP4K is essential for normal salivary gland cell size in vivo. Despite their highly divergent specific activity, we find that all three mammalian PIP4K isoforms are able to enhance salivary gland cell size in the Drosophila PIP4K null mutant implying a lack of correlation between in vitro activity measurements and in vivo function. Further, the kinase activity of PIP4K2C, reported to be almost inactive in vitro, is required for in vivo function. Our findings suggest the existence of unidentified factors that regulate PIP4K enzyme activity in vivo.

scholarly journals Physiological Differences in Cryptococcus neoformans Strains In Vitro versus In Vivo and Their Effects on Antifungal Susceptibility

2016 ◽  
Vol 61 (3) ◽  
Author(s):  
Nina T. Grossman ◽  
Arturo Casadevall
Keyword(s):  
Cryptococcus Neoformans ◽  
Cryptococcal Meningitis ◽  
Antifungal Susceptibility ◽  
Sub Saharan Africa ◽  
Content Type ◽  
Laboratory Conditions ◽  
Physiological Differences ◽  
Sub Saharan

ABSTRACT Cryptococcus neoformans is an environmentally ubiquitous fungal pathogen that primarily causes disease in people with compromised immune systems, particularly those with advanced AIDS. There are estimated to be almost 1 million cases per year of cryptococcal meningitis in patients infected with human immunodeficiency virus, leading to over 600,000 annual deaths, with a particular burden in sub-Saharan Africa. Amphotericin B (AMB) and fluconazole (FLC) are key components of cryptococcal meningitis treatment: AMB is used for induction, and FLC is for consolidation, maintenance and, for occasional individuals, prophylaxis. However, the results of standard antifungal susceptibility testing (AFST) for AMB and FLC do not correlate well with therapeutic outcomes and, consequently, no clinical breakpoints have been established. While a number of explanations for this absence of correlation have been proffered, one potential reason that has not been adequately explored is the possibility that the physiological differences between the in vivo infection environment and the in vitro AFST environment lead to disparate drug susceptibilities. These susceptibility-influencing factors include melanization, which does not occur during AFST, the size of the polysaccharide capsule, which is larger in infecting cells than in those grown under normal laboratory conditions, and the presence of large polyploid “titan cells,” which rarely occur under laboratory conditions. Understanding whether and how C. neoformans differentially expresses mechanisms of resistance to AMB and FLC in the AFST environment compared to the in vivo environment could enhance our ability to interpret AFST results and possibly lead to the development of more applicable testing methods.

scholarly journals Effects of Local and Systemic Immune Challenges on the Expression of Selected Salivary Genes in the Malaria Mosquito Anopheles coluzzii

Pathogens ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 1300
Author(s):  
Giulia Bevivino ◽  
Bruno Arcà ◽  
Fabrizio Lombardo
Keyword(s):  
Salivary Gland ◽  
Salivary Glands ◽  
Antimicrobial Properties ◽  
Transcript Abundance ◽  
Structural Features ◽  
Anopheles Coluzzii ◽  
Transcriptional Modulation ◽  
Immune Challenges

Salivary glands play a crucial tripartite role in mosquito physiology. First, they secrete factors that greatly facilitate both sugar and blood meal acquisition. Second, the transmission of pathogens (parasites, bacteria and viruses) to the vertebrate host requires both the recognition and invasion of the salivary glands. Third, they produce immune factors that both protect the organ from invading pathogens and are also able to exert their activity in the crop and the midgut when saliva is re-ingested during feeding. Studies on mosquito sialomes have revealed the presence of several female and/or male salivary gland-specific or enriched genes whose function is completely unknown so far. We focused our attention on these orphan genes, and we selected, according to sequence and structural features, a shortlist of 11 candidates with potential antimicrobial properties. Afterwards, using qPCR, we investigated their expression profile at 5 and 24 h after an infectious sugar meal (local challenge) or thoracic microinjection (systemic challenge) of Gram-negative (Escherichia coli, EC) or Gram-positive (Staphylococcus aureus, SA) bacteria. We observed a general increase in the transcript abundance of our salivary candidates between 5 and 24 h after local challenge. Moreover, transcriptional modulation was determined by the nature of the stimulus, with salivary gland-enriched genes (especially hyp15 upon SA stimulus) upregulated shortly after the local challenge and later after the systemic challenge. Overall, this work provides one of the first contributions to the understanding of the immune role of mosquito salivary glands. Further characterization of salivary candidates whose expression is modulated by immune challenge may help in the identification of possible novel antimicrobial peptides.

scholarly journals Solution structure, glycan specificity and of phenol oxidase inhibitory activity of Anopheles C-type lectins CTL4 and CTLMA2

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Ritika Bishnoi ◽  
Gregory L. Sousa ◽  
Alicia Contet ◽  
Christopher J. Day ◽  
Chun-Feng David Hou ◽  
...  
Keyword(s):  
Malaria Vector ◽  
Solution Structure ◽  
Biochemical Characterization ◽  
Phenol Oxidase ◽  
Sub Saharan Africa ◽  
Scattering Data ◽  
Molecular Features ◽  
Sub Saharan

Abstract Malaria, the world’s most devastating parasitic disease, is transmitted between humans by mosquitoes of the Anopheles genus. An. gambiae is the principal malaria vector in Sub-Saharan Africa. The C-type lectins CTL4 and CTLMA2 cooperatively influence Plasmodium infection in the malaria vector Anopheles. Here we report the purification and biochemical characterization of CTL4 and CTLMA2 from An. gambiae and An. albimanus. CTL4 and CTLMA2 are known to form a disulfide-bridged heterodimer via an N-terminal tri-cysteine CXCXC motif. We demonstrate in vitro that CTL4 and CTLMA2 intermolecular disulfide formation is promiscuous within this motif. Furthermore, CTL4 and CTLMA2 form higher oligomeric states at physiological pH. Both lectins bind specific sugars, including glycosaminoglycan motifs with β1-3/β1-4 linkages between glucose, galactose and their respective hexosamines. Small-angle x-ray scattering data supports a compact heterodimer between the CTL domains. Recombinant CTL4/CTLMA2 is found to function in vivo, reversing the enhancement of phenol oxidase activity in dsCTL4-treated mosquitoes. We propose these molecular features underline a common function for CTL4/CTLMA2 in mosquitoes, with species and strain-specific variation in degrees of activity in response to Plasmodium infection.

Direct in vivo adenovirus-mediated gene transfer to salivary glands

1994 ◽  
Vol 266 (6) ◽  
pp. G1146-G1155 ◽  
Author(s):  
A. Mastrangeli ◽  
B. O'Connell ◽  
W. Aladib ◽  
P. C. Fox ◽  
B. J. Baum ◽  
...  
Keyword(s):  
Salivary Gland ◽  
Gene Transfer ◽  
Salivary Glands ◽  
De Novo ◽  
Recombinant Adenovirus ◽  
Salivary Gland Cell ◽  
Immunodeficient Mice ◽  
Ductal Cells ◽  
Adenovirus Vectors

Gene transfer to the salivary glands holds the potential for the therapy of salivary gland disorders and for delivery of therapeutic proteins to the mouth and upper gastrointestinal tract. Administration of the recombinant adenovirus vectors Ad.RSV beta gal [coding for the intracellular protein beta-galactosidase (beta-Gal)] and Ad alpha 1AT [coding for human alpha 1-antitrypsin (alpha 1-AT), a secreted protein] to salivary gland cell lines in vitro demonstrated exogenous gene expression. Retrograde ductal injection of the Ad.RSV beta gal vector to rat salivary glands in vivo resulted in beta-Gal expression in acinar and ductal cells. Exposure of submandibular glands in vivo to Ad alpha 1AT resulted in expression of alpha 1-AT mRNA transcripts, de novo synthesis of alpha 1-AT, and secretion in the saliva. To evaluate the feasibility of adenovirus-mediated gene transfer to human glands, human minor salivary glands were infected ex vivo with Ad.RSV beta gal, and implanted into severe combined immunodeficient mice. Evaluation of the human tissue demonstrated beta-Gal activity. These observations demonstrate that adenovirus vectors are capable of direct delivery of genes to the salivary glands, suggesting a variety of possible gene therapy applications.

scholarly journals In Vitro, Ex Vivo, and In Vivo Activities of Diamidines against Trypanosoma congolense and Trypanosoma vivax

2017 ◽  
Vol 61 (5) ◽  
Author(s):  
Kirsten Gillingwater ◽  
Christina Kunz ◽  
Christiane Braghiroli ◽  
David W. Boykin ◽  
Richard R. Tidwell ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Trypanosoma Congolense ◽  
Tsetse Fly ◽  
Sub Saharan Africa ◽  
Content Type ◽  
Lead Compounds ◽  
Single Bolus Dose ◽  
Sub Saharan

ABSTRACT African animal trypanosomosis (AAT) is caused by the tsetse fly-transmitted protozoans Trypanosoma congolense and T. vivax and leads to huge agricultural losses throughout sub-Saharan Africa. Three drugs are available to treat nagana in cattle (diminazene diaceturate, homidium chloride, and isometamidium chloride). With increasing reports of drug-resistant populations, new molecules should be investigated as potential candidates to combat nagana. Dicationic compounds have been demonstrated to have excellent efficacy against different kinetoplastid parasites. This study therefore evaluated the activities of 37 diamidines, using in vitro and ex vivo drug sensitivity assays. The 50% inhibitory concentrations obtained ranged from 0.007 to 0.562 μg/ml for T. congolense and from 0.019 to 0.607 μg/ml for T. vivax. On the basis of these promising results, 33 of these diamidines were further examined using in vivo mouse models of infection. Minimal curative doses of 1.25 mg/kg of body weight for both T. congolense- and T. vivax-infected mice were seen when the diamidines were administered intraperitoneally (i.p.) over 4 consecutive days. From these observations, 15 of these 33 diamidines were then further tested in vivo, using a single bolus dose for administration. The total cure of mice infected with T. congolense and T. vivax was seen with single i.p. doses of 5 and 2.5 mg/kg, respectively. This study identified a selection of diamidines which could be considered lead compounds for the treatment of nagana.

scholarly journals Transcriptomic analysis of resistance and short-term induction response to pyrethroids, in Anopheles coluzzii legs

2021 ◽  
Author(s):  
Mary Kefi ◽  
Jason Charamis ◽  
Vasileia Balabanidou ◽  
Panagiotis Ioannidis ◽  
Hilary Ranson ◽  
...  
Keyword(s):  
Salivary Gland ◽  
Resistant Strain ◽  
Indoor Residual Spraying ◽  
Control Measures ◽  
Sub Saharan Africa ◽  
Detoxification Enzymes ◽  
Bed Nets ◽  
Anopheles Coluzzii ◽  
Short Term ◽  
Susceptible Population

Abstract BackgroundInsecticide-treated bed nets and indoor residual spraying comprise the major control measures against Anopheles gambiae sl, the dominant vector in sub-Saharan Africa. The primary site of contact with insecticide is through the mosquitoes’ legs, which represents the first barrier insecticides have to bypass to reach their neuronal targets. Proteomic changes and leg cuticle modifications have been associated with insecticide resistance that may reduce the rate of penetration of insecticides. Here, we performed a multiple transcriptomic analyses focusing on An. coluzzii legs. ResultsFirstly, leg-specific enrichment analysis identified 359 genes including the pyrethroid-binder SAP2 and 2 other chemosensory proteins, along with 4 ABCG transporters previously shown to be leg enriched. Enrichment gene families included those involved in detecting chemical stimuli including gustatory and ionotropic receptors and genes implicated in hydrocarbon-synthesis. Subsequently, we compared transcript expression in the legs of a highly resistant strain (VK7-HR) to both a strain with very similar genetic background which has reverted to susceptibility after several generations without insecticide pressure (VK7-LR) and a lab susceptible population. 232 differentially expressed genes (73 up-regulated and 159 down-regulated) were identified in the resistant strain when compared to the two susceptible counterparts, indicating an over-expression of phase I detoxification enzymes and cuticular proteins, with decrease in hormone-related metabolic processes in legs from the insecticide resistant population. Finally, we analysed the short-term effect of pyrethroid exposure on An. coluzzii legs, comparing 1hour-deltamethrin-exposed (VK7-IN) to unexposed (VK7-HR) leg transcriptomes and identified 348 up-regulated genes including those encoding for GPCRs, ABC transporters, odorant-binding proteins and members of the divergent salivary gland protein family. ConclusionsThe data on An. coluzzii leg-specific transcriptome provides valuable insights into the first line of defense in pyrethroid resistant and short-term deltamethrin-exposed mosquitoes. Our results suggest that xenobiotic detoxification is likely occurring in legs, while the enrichment of sensory proteins, ABCG transporters and cuticular genes is also evident. Constitutive resistance is primarily associated with elevated levels of detoxification and cuticular genes, while short-term insecticide-induced tolerance is linked with overexpression of transporters, GPCRs and GPCR-related genes, sensory/binding and salivary gland proteins.

scholarly journals Comparative diagnostic sensitivity of the substantia nigra transcranial sonography and salivary gland biopsy in patients with Parkinson’s disease

2021 ◽  
Vol 40 (4) ◽  
pp. 101-106
Author(s):  
Kristina K. Khacheva ◽  
Sergey N. Illarioshkin ◽  
Alexey V. Karabanov ◽  
Andrey O. Chechetkin
Keyword(s):  
Salivary Gland ◽  
Substantia Nigra ◽  
Salivary Glands ◽  
Transcranial Sonography ◽  
Nerve Fibers ◽  
Parkinsons Disease ◽  
Salivary Gland Biopsy ◽  
Disease Stages ◽  
Clinical Diagnostic Criteria

Parkinsons disease is a chronic neurodegenerative disease, the diagnosis of which remains challenging at the early stages, although clinical diagnostic criteria are developed. The diagnostic accuracy is only 58% for patients at early Parkinsons disease stages. The sensitivity and specificity of transcranial sonography of the substantia nigra used for Parkinsons disease verification is about 85% and 71%, respectively. It has been shown that the aggregates of -synuclein in the nerve fibers in major salivary glands may be seen in Parkinsons disease patients. The availability of the salivary glands for morphological study made it possible to investigate the approaches of the in vivo histological diagnosis of Parkinsons disease based on the detection of -synuclein aggregates in the nerve fibers innervating the glands. Aim: To evaluate and compare the sensitivity of transcranial sonography of the substantia nigra and sublingual salivary gland biopsy. Materials and methods: Six patients with clinically verified Parkinsons disease were enrolled. Evaluation of the neurological state using special scales, transcranial sonography of the substantia nigra and sublingual salivary gland biopsy was performed. Results: Mean age of patients was 59 [58; 60.7] years, mean disease duration period was 5 [3; 7.75] years and the mean HoehnYahr stage was 2.25 [2; 2.5]. Hyperechogenicity of the substantia nigra was found in 3 of 6 patients and the substantia nigra sensitivity was shown to be 50%. Sublingual salivary gland biopsy was positive for -synuclein in 6 of 6 patients and the sensitivity of method was shown to be 100%. No adverse events after biopsy were registered. Conclusion: The sensitivity of sublingual salivary gland biopsy was higher than those of transcranial sonography of the substantia nigra, which indicates the prospect of using the biopsy method as a more sensitive diagnostic tool in Parkinsons disease (1 table, bibliography: 19 refs)

scholarly journals Microsporidia MB is found predominantly associated with Anopheles gambiae s.s and Anopheles coluzzii in Ghana

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jewelna Akorli ◽  
Esinam Abla Akorli ◽  
Seraphim Naa Afoley Tetteh ◽  
Godwin Kwame Amlalo ◽  
Millicent Opoku ◽  
...  
Keyword(s):  
West Africa ◽  
Malaria Vector ◽  
Sibling Species ◽  
Horizontal Transfer ◽  
Anopheles Arabiensis ◽  
Sub Saharan Africa ◽  
Anopheles Coluzzii ◽  
Vector Species ◽  
Anopheles Gambiae S.S ◽  
Sub Saharan

AbstractA vertically transmitted microsporidian, Microsporidia MB, with the ability to disrupt Plasmodium development was reported in Anopheles arabiensis from Kenya, East Africa. To demonstrate its range of incidence, archived DNA samples from 7575 Anopheles mosquitoes collected from Ghana were screened. MB prevalence was observed at 1.8%. An. gambiae s.s constituted 87% of positive mosquitoes while the remaining were from An. coluzzii. Both sibling species had similar positivity rates (24% and 19%; p = 0.42) despite the significantly higher number of An. gambiae s.s analysed (An. gambiae s.s = 487; An. coluzzii = 94; p = 0.0005). The microsporidian was also more prevalent in emerged adults from field-collected larvae than field-caught adults (p < 0.0001) suggestive of an efficient vertical transmission and/or horizontal transfer among larvae. This is the first report of Microsporidia MB in Anopheles mosquitoes in West Africa. It indicates possible widespread among malaria vector species and warrants investigations into the symbiont’s diversity across sub-Saharan Africa.

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