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Sassù F, Vomáčková Kykalová B, Vieira CS, Volf P, Loza Telleria E. Stability and suitability of housekeeping genes in phlebotomine sand flies. Sci Rep 2024; 14:23353. [PMID: 39375431 PMCID: PMC11458623 DOI: 10.1038/s41598-024-74776-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2024] [Accepted: 09/30/2024] [Indexed: 10/09/2024] Open
Abstract
We investigated gene expression patterns in Lutzomyia and Phlebotomus sand fly vectors of leishmaniases. Using quantitative PCR, we assessed the expression stability of potential endogenous control genes commonly used in dipterans. We analyzed Lutzomyia longipalpis and Phlebotomus papatasi samples from L3 and L4 larval stages, adult sand flies of different sexes, diets, dsRNA injection, and Leishmania infection. Six genes were evaluated: actin, α-tubulin, GAPDH, 60 S ribosomal proteins L8 and L32 (RiboL8 and RiboL32), and elongation factor 1-α (EF1-α). EF1-α was among the most stably expressed along with RiboL8 in L. longipalpis larvae and RiboL32 in adults. In P. papatasi, EF1-α and RiboL32 were the top in larvae, while EF1-α and actin were the most stable in adults. RiboL8 and actin were the most stable genes in dissected tissues and infected guts. Additionally, five primer pairs designed for L. longipalpis or P. papatasi were effective in PCR with Lutzomyia migonei, Phlebotomus duboscqi, Phlebotomus perniciosus, and Sergentomyia schwetzi cDNA. Furthermore, L. longipalpis RiboL32 and P. papatasi α-tubulin primers were suitable for qPCR with cDNA from the other four species. Our research provides tools to enhance relative gene expression studies in sand flies, facilitating the selection of endogenous control for qPCR.
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Affiliation(s)
- Fabiana Sassù
- Department of Parasitology, Faculty of Science, Charles University, Viničná 7, Prague, 128 00, Czech Republic
| | - Barbora Vomáčková Kykalová
- Department of Parasitology, Faculty of Science, Charles University, Viničná 7, Prague, 128 00, Czech Republic
| | - Cecilia Stahl Vieira
- Department of Parasitology, Faculty of Science, Charles University, Viničná 7, Prague, 128 00, Czech Republic
| | - Petr Volf
- Department of Parasitology, Faculty of Science, Charles University, Viničná 7, Prague, 128 00, Czech Republic
| | - Erich Loza Telleria
- Department of Parasitology, Faculty of Science, Charles University, Viničná 7, Prague, 128 00, Czech Republic.
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2
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Meraj S, Salcedo-Porras N, Lowenberger C, Gries G. Activation of immune pathways in common bed bugs, Cimex lectularius, in response to bacterial immune challenges - a transcriptomics analysis. Front Immunol 2024; 15:1384193. [PMID: 38694504 PMCID: PMC11061471 DOI: 10.3389/fimmu.2024.1384193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Accepted: 04/02/2024] [Indexed: 05/04/2024] Open
Abstract
The common bed bug, Cimex lectularius, is an urban pest of global health significance, severely affecting the physical and mental health of humans. In contrast to most other blood-feeding arthropods, bed bugs are not major vectors of pathogens, but the underlying mechanisms for this phenomenon are largely unexplored. Here, we present the first transcriptomics study of bed bugs in response to immune challenges. To study transcriptional variations in bed bugs following ingestion of bacteria, we extracted and processed mRNA from body tissues of adult male bed bugs after ingestion of sterile blood or blood containing the Gram-positive (Gr+) bacterium Bacillus subtilis or the Gram-negative (Gr-) bacterium Escherichia coli. We analyzed mRNA from the bed bugs' midgut (the primary tissue involved in blood ingestion) and from the rest of their bodies (RoB; body minus head and midgut tissues). We show that the midgut exhibits a stronger immune response to ingestion of bacteria than the RoB, as indicated by the expression of genes encoding antimicrobial peptides (AMPs). Both the Toll and Imd signaling pathways, associated with immune responses, were highly activated by the ingestion of bacteria. Bacterial infection in bed bugs further provides evidence for metabolic reconfiguration and resource allocation in the bed bugs' midgut and RoB to promote production of AMPs. Our data suggest that infection with particular pathogens in bed bugs may be associated with altered metabolic pathways within the midgut and RoB that favors immune responses. We further show that multiple established cellular immune responses are preserved and are activated by the presence of specific pathogens. Our study provides a greater understanding of nuances in the immune responses of bed bugs towards pathogens that ultimately might contribute to novel bed bug control tactics.
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Affiliation(s)
- Sanam Meraj
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
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Tom A, Kumar NP, Kumar A, Saini P. Interactions between Leishmania parasite and sandfly: a review. Parasitol Res 2023; 123:6. [PMID: 38052752 DOI: 10.1007/s00436-023-08043-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Accepted: 11/06/2023] [Indexed: 12/07/2023]
Abstract
Leishmaniasis transmission cycles are maintained and sustained in nature by the complex crosstalk of the Leishmania parasite, sandfly vector, and the mammalian hosts (human, as well as zoonotic reservoirs). Regardless of the vast research on human host-parasite interaction, there persists a substantial knowledge gap on the parasite's development and modulation in the vector component. This review focuses on some of the intriguing aspects of the Leishmania-sandfly interface, beginning with the uptake of the intracellular amastigotes from an infected host to the development of the parasite within the sandfly's alimentary canal, followed by the transmission of infective metacyclic stages to another potential host. Upon ingestion of the parasite, the sandfly hosts an intricate repertoire of immune barriers, either to evade the parasite or to ensure its homeostatic coexistence with the vector gut microbiome. Sandfly salivary polypeptides and Leishmania exosomes are co-egested with the parasite inoculum during the infected vector bite. This has been attributed to the modulation of the parasite infection and subsequent clinical manifestation in the host. While human host-based studies strive to develop effective therapeutics, a greater understanding of the vector-parasite-microbiome and human host interactions could help us to identify the targets and to develop strategies for effectively preventing the transmission of leishmaniasis.
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Affiliation(s)
- Anns Tom
- ICMR-Vector Control Research Centre (Field Station), Kottayam, Kerala, India
| | - N Pradeep Kumar
- ICMR-Vector Control Research Centre (Field Station), Kottayam, Kerala, India
| | - Ashwani Kumar
- ICMR- Vector Control Research Centre, Puducherry, India
| | - Prasanta Saini
- ICMR-Vector Control Research Centre (Field Station), Kottayam, Kerala, India.
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4
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Telleria EL, Tinoco-Nunes B, Forrest DM, Di-Blasi T, Leštinová T, Chang KP, Volf P, Pitaluga AN, Traub-Csekö YM. Evidence of a conserved mammalian immunosuppression mechanism in Lutzomyia longipalpis upon infection with Leishmania. Front Immunol 2023; 14:1162596. [PMID: 38022562 PMCID: PMC10652419 DOI: 10.3389/fimmu.2023.1162596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Accepted: 10/13/2023] [Indexed: 12/01/2023] Open
Abstract
Introduction Sand flies (Diptera: Phlebotominae) belonging to the Lutzomyia genus transmit Leishmania infantum parasites. To understand the complex interaction between the vector and the parasite, we have been investigating the sand fly immune responses during the Leishmania infection. Our previous studies showed that genes involved in the IMD, Toll, and Jak-STAT immunity pathways are regulated upon Leishmania and bacterial challenges. Nevertheless, the parasite can thrive in the vectors' gut, indicating the existence of mechanisms capable of modulating the vector defenses, as was already seen in mammalian Leishmania infections. Methods results and discussion In this study, we investigated the expression of Lutzomyia longipalpis genes involved in regulating the Toll pathway under parasitic infection. Leishmania infantum infection upregulated the expression of two L. longipalpis genes coding for the putative repressors cactus and protein tyrosine phosphatase SHP. These findings suggest that the parasite can modulate the vectors' immune response. In mammalian infections, the Leishmania surface glycoprotein GP63 is one of the inducers of host immune depression, and one of the known effectors is SHP. In L. longipalpis we found a similar effect: a genetically modified strain of Leishmania amazonensis over-expressing the metalloprotease GP63 induced a higher expression of the sand fly SHP indicating that the L. longipalpis SHP and parasite GP63 increased expressions are connected. Immuno-stained microscopy of L. longipalpis LL5 embryonic cells cultured with Leishmania strains or parasite conditioned medium showed cells internalization of parasite GP63. A similar internalization of GP63 was observed in the sand fly gut tissue after feeding on parasites, parasite exosomes, or parasite conditioned medium, indicating that GP63 can travel through cells in vitro or in vivo. When the sand fly SHP gene was silenced by RNAi and females infected by L. infantum, parasite loads decreased in the early phase of infection as expected, although no significant differences were seen in late infections of the stomodeal valve. Conclusions Our findings show the possible role of a pathway repressor involved in regulating the L. longipalpis immune response during Leishmania infections inside the insect. In addition, they point out a conserved immunosuppressive effect of GP63 between mammals and sand flies in the early stage of parasite infection.
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Affiliation(s)
- Erich Loza Telleria
- Department of Parasitology, Faculty of Science, Charles University, Prague, Czechia
| | - Bruno Tinoco-Nunes
- Laboratório de Biologia Molecular de Parasitas e Vetores, Instituto Oswaldo Cruz - Fiocruz, Rio de Janeiro, RJ, Brazil
| | - David M. Forrest
- Laboratório de Biologia Molecular de Parasitas e Vetores, Instituto Oswaldo Cruz - Fiocruz, Rio de Janeiro, RJ, Brazil
| | - Tatiana Di-Blasi
- Laboratório de Biologia Molecular de Parasitas e Vetores, Instituto Oswaldo Cruz - Fiocruz, Rio de Janeiro, RJ, Brazil
| | - Tereza Leštinová
- Department of Parasitology, Faculty of Science, Charles University, Prague, Czechia
| | - Kwang Poo Chang
- Department of Microbiology and Immunology, Chicago Medical School, Rosalind Franklin University of Medicine and Science, North Chicago, IL, United States
| | - Petr Volf
- Department of Parasitology, Faculty of Science, Charles University, Prague, Czechia
| | - André Nóbrega Pitaluga
- Laboratório de Biologia Molecular de Parasitas e Vetores, Instituto Oswaldo Cruz - Fiocruz, Rio de Janeiro, RJ, Brazil
| | - Yara Maria Traub-Csekö
- Laboratório de Biologia Molecular de Parasitas e Vetores, Instituto Oswaldo Cruz - Fiocruz, Rio de Janeiro, RJ, Brazil
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Ducker C, French S, Pathak M, Taylor H, Sainter A, Askem W, Dreveny I, Santana AEG, Pickett JA, Oldham NJ. Characterisation of geranylgeranyl diphosphate synthase from the sandfly Lutzomyia longipalpis. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2023; 161:104001. [PMID: 37619821 DOI: 10.1016/j.ibmb.2023.104001] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 08/02/2023] [Accepted: 08/20/2023] [Indexed: 08/26/2023]
Abstract
Leishmaniasis is a debilitating and often fatal neglected tropical disease. Males from sub-populations of the Leishmania-harbouring sandfly, Lutzomyia longipalpis, produce the diterpene sex and aggregation pheromone, sobralene, for which geranylgeranyl diphosphate (GGPP) is the likely isoprenoid precursor. We have identified a GGPP synthase (lzGGPPS) from L. longipalpis, which was recombinantly expressed in bacteria and purified for functional and kinetic analysis. In vitro enzymatic assays using LC-MS showed that lzGGPPS is an active enzyme, capable of converting substrates dimethylallyl diphosphate (DMAPP), (E)-geranyl diphosphate (GPP), (E,E)-farnesyl diphosphate (FPP) with co-substrate isopentenyl diphosphate (IPP) into (E,E,E)-GGPP, while (Z,E)-FPP was also accepted with low efficacy. Comparison of metal cofactors for lzGGPPS highlighted Mg2+ as most efficient, giving increased GGPP output when compared against other divalent metal ions tested. In line with previously characterised GGPPS enzymes, GGPP acted as an inhibitor of lzGGPPS activity. The molecular weight in solution of lzGGPPS was determined to be ∼221 kDa by analytical SEC, suggesting a hexameric assembly, as seen in the human enzyme, and representing the first assessment of GGPPS quaternary structure in insects.
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Affiliation(s)
- Charles Ducker
- School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Stanley French
- School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Monika Pathak
- School of Pharmacy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Harry Taylor
- School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Adam Sainter
- School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - William Askem
- School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | - Ingrid Dreveny
- School of Pharmacy, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
| | | | - John A Pickett
- School of Chemistry, Cardiff University, Main Building, Park Pl, Cardiff, CF10 3AT, UK
| | - Neil J Oldham
- School of Chemistry, University of Nottingham, University Park, Nottingham, NG7 2RD, UK.
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Van Lommel J, Holtof M, Tilleman L, Cools D, Vansteenkiste S, Polgun D, Verdonck R, Van Nieuwerburgh F, Vanden Broeck J. Post-feeding transcriptomics reveals essential genes expressed in the midgut of the desert locust. Front Physiol 2023; 14:1232545. [PMID: 37692997 PMCID: PMC10484617 DOI: 10.3389/fphys.2023.1232545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 07/26/2023] [Indexed: 09/12/2023] Open
Abstract
The digestive tract constitutes an important interface between an animal's internal and external environment. In insects, available gut transcriptome studies are mostly exploratory or look at changes upon infection or upon exposure to xenobiotics, mainly performed in species belonging to holometabolan orders, such as Diptera, Lepidoptera or Coleoptera. By contrast, studies focusing on gene expression changes after food uptake and during digestion are underrepresented. We have therefore compared the gene expression profiles in the midgut of the desert locust, Schistocerca gregaria, between three different time points after feeding, i.e., 24 h (no active digestion), 10 min (the initial stage of feeding), and 2 h (active food digestion). The observed gene expression profiles were consistent with the polyphagous herbivorous lifestyle of this hemimetabolan (orthopteran) species. Our study reveals the upregulation of 576 genes 2 h post-feeding. These are mostly predicted to be associated with digestive physiology, such as genes encoding putative digestive enzymes or nutrient transporters, as well as genes putatively involved in immunity or in xenobiotic metabolism. The 10 min time point represented an intermediate condition, suggesting that the S. gregaria midgut can react rapidly at the transcriptional level to the presence of food. Additionally, our study demonstrated the critical importance of two transcripts that exhibited a significant upregulation 2 h post-feeding: the vacuolar-type H(+)-ATPase and the sterol transporter Niemann-Pick 1b protein, which upon RNAi-induced knockdown resulted in a marked increase in mortality. Their vital role and accessibility via the midgut lumen may make the encoded proteins promising insecticidal target candidates, considering that the desert locust is infamous for its huge migrating swarms that can devastate the agricultural production in large areas of Northern Africa, the Middle East, and South Asia. In conclusion, the transcriptome datasets presented here will provide a useful and promising resource for studying the midgut physiology of S. gregaria, a socio-economically important pest species.
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Affiliation(s)
- Joachim Van Lommel
- Molecular Developmental Physiology and Signal Transduction Lab, Department of Biology, University of Leuven, Leuven, Belgium
| | - Michiel Holtof
- Molecular Developmental Physiology and Signal Transduction Lab, Department of Biology, University of Leuven, Leuven, Belgium
| | | | - Dorien Cools
- Molecular Developmental Physiology and Signal Transduction Lab, Department of Biology, University of Leuven, Leuven, Belgium
| | - Seppe Vansteenkiste
- Molecular Developmental Physiology and Signal Transduction Lab, Department of Biology, University of Leuven, Leuven, Belgium
| | - Daria Polgun
- Molecular Developmental Physiology and Signal Transduction Lab, Department of Biology, University of Leuven, Leuven, Belgium
| | - Rik Verdonck
- Molecular Developmental Physiology and Signal Transduction Lab, Department of Biology, University of Leuven, Leuven, Belgium
- Environmental Biology, Centre for Environmental Sciences, Hasselt University, Hasselt, Belgium
| | | | - Jozef Vanden Broeck
- Molecular Developmental Physiology and Signal Transduction Lab, Department of Biology, University of Leuven, Leuven, Belgium
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Omondi ZN, Arserim SK, Töz S, Özbel Y. Host-Parasite Interactions: Regulation of Leishmania Infection in Sand Fly. Acta Parasitol 2022; 67:606-618. [PMID: 35107776 DOI: 10.1007/s11686-022-00519-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2021] [Accepted: 01/11/2022] [Indexed: 11/26/2022]
Abstract
PURPOSE Sand flies are the only proven vectors of leishmaniases, a tropical neglected disease endemic in at least 92 countries. Vector-parasite interactions play a significant role in vector-borne disease transmission. There are various bottlenecks to Leishmania colonization of the sand fly midgut. Such bottlenecks include the production of innate immune-related molecules, digestive proteases, parasite impermeable peritrophic membrane, and resident gut microbiota. These barriers determine the parasite load transmitted and, consequently, the disease outcome in mammalian host. Therefore, it is important to understand the molecular responses of both sand fly and Leishmania during infection. METHOD Here, we reviewed the published literature on sand fly-Leishmania interactions bringing together earlier and current findings to highlight new developments and research gaps in the field. CONCLUSION Recent research studies on sand fly-Leishmania interaction have revealed contrasting observations to past studies. However, how Leishmania parasites evade the sand fly immune response still needs further research. Sand fly response to Leishmania infection can be best understood by analyzing its tissue transcriptome. Better characterization of the role of midgut components could be a game changer in development of transmission-blocking strategies for leishmaniasis.
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Affiliation(s)
- Zeph Nelson Omondi
- Department of Biology, Faculty of Science, Ege University, Erzene Street, 35040, Bornova/Izmir, Turkey.
| | - Suha Kenan Arserim
- Vocational School of Health Sciences, Manisa Celal Bayar University, Manisa, Turkey
| | - Seray Töz
- Department of Parasitology, Faculty of Medicine, Ege University, Izmir, Turkey
| | - Yusuf Özbel
- Department of Parasitology, Faculty of Medicine, Ege University, Izmir, Turkey
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Metabolic interactions between disease-transmitting vectors and their microbiota. Trends Parasitol 2022; 38:697-708. [DOI: 10.1016/j.pt.2022.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 04/29/2022] [Accepted: 05/04/2022] [Indexed: 11/21/2022]
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Hendrickx S, Caljon G. The effect of the sugar metabolism on Leishmania infantum promastigotes inside the gut of Lutzomyia longipalpis: A sweet relationship? PLoS Negl Trop Dis 2022; 16:e0010293. [PMID: 35385472 PMCID: PMC8985994 DOI: 10.1371/journal.pntd.0010293] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Accepted: 03/02/2022] [Indexed: 11/26/2022] Open
Abstract
It is well-known that Leishmania parasites can alter the behavior of the sand fly vector in order to increase their transmission potential. However, little is known about the contribution of the infecting host’s blood composition on subsequent sand fly infection and survival. This study focused on the host’s glucose metabolism and the insulin/insulin-like growth factor 1 (IGF-1) pathway as both metabolic processes are known to impact vector-parasite interactions of other protozoa and insect species. The focus of this study was inspired by the observation that the glycemic levels in the blood of infected Syrian golden hamsters inversely correlated to splenic and hepatic parasite burdens. To evaluate the biological impact of these findings on further transmission, Lutzomyia longipalpis sand flies were infected with blood that was artificially supplemented with different physiological concentrations of several monosaccharides, insulin or IGF-1. Normoglycemic levels resulted in transiently higher parasite loads and faster appearance of metacyclics, whereas higher carbohydrate and insulin/IGF-1 levels favored sand fly survival. Although the recorded effects were modest or transient of nature, these observations support the concept that the host blood biochemistry may affect Leishmania transmission and sand fly longevity. Past research on the interaction between the Leishmania parasite and the sand fly vector has revealed that Leishmania is capable of changing vector behavior to favor transmission of parasites in the environment. Little is known about the impact of host blood composition on parasite development inside the vector and on vector survival. Here, we showed that parasite burdens in the spleen and the liver inversely correlated to the serum blood glucose levels of infected animals, which triggered us to further investigate the effect of blood monosaccharides, insulin and insulin-like growth factor 1 (IGF-1) on sand fly infection and survival. We demonstrated that normal serum glucose levels in the initial parasitized blood meal resulted in transiently higher parasite loads and a faster appearance of infectious parasites, whereas higher sugar and insulin/IGF-1 levels favored sand fly survival, which supports the concept that the host blood biochemistry may affect Leishmania transmission and sand fly longevity.
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Affiliation(s)
- Sarah Hendrickx
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Antwerp, Belgium
- * E-mail: (SH); (GC)
| | - Guy Caljon
- Laboratory of Microbiology, Parasitology and Hygiene (LMPH), University of Antwerp, Antwerp, Belgium
- * E-mail: (SH); (GC)
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Telleria EL, Azevedo-Brito DA, Kykalová B, Tinoco-Nunes B, Pitaluga AN, Volf P, Traub-Csekö YM. Leishmania infantum Infection Modulates the Jak-STAT Pathway in Lutzomyia longipalpis LL5 Embryonic Cells and Adult Females, and Affects Parasite Growth in the Sand Fly. FRONTIERS IN TROPICAL DISEASES 2021. [DOI: 10.3389/fitd.2021.747820] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Phlebotomine sand flies (Diptera, Psychodidae) belonging to the Lutzomyia genus transmit zoonoses in the New World. Lutzomyia longipalpis is the main vector of Leishmania infantum, which is the causative agent of visceral leishmaniasis in Brazil. To identify key molecular aspects involved in the interaction between vector and pathogens and contribute to developing disease transmission controls, we investigated the sand fly innate immunity mediated by the Janus kinase/signal transducer and activator of transcription (Jak-STAT) pathway in response to L. infantum infection. We used two study models: L. longipalpis LL5 embryonic cells co-cultured with L. infantum and sand fly females artificially infected with the parasite. We used qPCR to follow the L. longipalpis gene expression of molecules involved in the Jak-STAT pathway. Also, we modulated the Jak-STAT mediated immune response to understand its role in Leishmania parasite infection. For that, we used RNAi to silence the pathway regulators, protein inhibitor of activated STATs (PIAS) in LL5 cells, and STAT in adult females. In addition, the pathway suppression effect on parasite development within the vector was assessed by light microscopy in late-phase infection. The silencing of the repressor PIAS in LL5 cells led to a moderate increase in a protein tyrosine phosphatase 61F (PTP61F) expression. It suggests a compensatory regulation between these two repressors. L. infantum co-culture with LL5 cells upregulated repressors PIAS, suppressor of cytokine signaling (SOCS), and PTP61F. It also downmodulated virus-induced RNA-1 (VIR-1), a pathway effector, indicating that the parasite could repress the Jak-STAT pathway in LL5 cells. In Leishmania-infected L. longipalpis females, STAT and the antimicrobial peptide attacin were downregulated on the third day post-infection, suggesting a correlation that favors the parasite survival at the end of blood digestion in the sand fly. The antibiotic treatment of infected females showed that the reduction of gut bacteria had little effect on the Jak-STAT pathway regulation. STAT gene silencing mediated by RNAi reduced the expression of inducible nitric oxide synthase (iNOS) and favored Leishmania growth in sand flies on the first day post-infection. These results indicate that STAT participated in the iNOS regulation with subsequent effect on parasite survival.
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Salloum T, Tokajian S, Hirt RP. Advances in Understanding Leishmania Pathobiology: What Does RNA-Seq Tell Us? Front Cell Dev Biol 2021; 9:702240. [PMID: 34540827 PMCID: PMC8440825 DOI: 10.3389/fcell.2021.702240] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 07/30/2021] [Indexed: 11/23/2022] Open
Abstract
Leishmaniasis is a vector-borne disease caused by a protozoa parasite from over 20 Leishmania species. The clinical manifestations and the outcome of the disease vary greatly. Global RNA sequencing (RNA-Seq) analyses emerged as a powerful technique to profile the changes in the transcriptome that occur in the Leishmania parasites and their infected host cells as the parasites progresses through their life cycle. Following the bite of a sandfly vector, Leishmania are transmitted to a mammalian host where neutrophils and macrophages are key cells mediating the interactions with the parasites and result in either the elimination the infection or contributing to its proliferation. This review focuses on RNA-Seq based transcriptomics analyses and summarizes the main findings derived from this technology. In doing so, we will highlight caveats in our understanding of the parasite's pathobiology and suggest novel directions for research, including integrating more recent data highlighting the role of the bacterial members of the sandfly gut microbiota and the mammalian host skin microbiota in their potential role in influencing the quantitative and qualitative aspects of leishmaniasis pathology.
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Affiliation(s)
- Tamara Salloum
- Department of Natural Sciences, School of Arts and Sciences, Lebanese American University, Byblos, Lebanon
| | - Sima Tokajian
- Department of Natural Sciences, School of Arts and Sciences, Lebanese American University, Byblos, Lebanon
| | - Robert P. Hirt
- Faculty of Medical Sciences, Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
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12
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Leishmaniasis: the act of transmission. Trends Parasitol 2021; 37:976-987. [PMID: 34389215 DOI: 10.1016/j.pt.2021.07.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2021] [Revised: 07/07/2021] [Accepted: 07/08/2021] [Indexed: 02/06/2023]
Abstract
The contribution of vector transmission to pathogen establishment is largely underrated. For Leishmania, transmission by sand flies is critical to early survival involving an irreproducible myriad of parasite, vector, and host molecules acting in concert to promote infection at the bite site. Here, we review recent breakthroughs that provide consequential insights into how vector transmission of Leishmania unfolds. We focus on recent work pertaining to the effect of gut microbiota, sand fly immunity, and changes in metacyclogenesis upon multiple blood meals, on Leishmania development and transmission. We also explore how sand fly saliva, egested parasite molecules and vector gut microbiota, and bleeding have been implicated in modulating the early innate host response to Leishmania, affecting the phenotype of neutrophils and monocytes arriving at the bite site.
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13
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da Costa-Latgé SG, Bates P, Dillon R, Genta FA. Characterization of Glycoside Hydrolase Families 13 and 31 Reveals Expansion and Diversification of α-Amylase Genes in the Phlebotomine Lutzomyia longipalpis and Modulation of Sandfly Glycosidase Activities by Leishmania Infection. Front Physiol 2021; 12:635633. [PMID: 33897451 PMCID: PMC8063059 DOI: 10.3389/fphys.2021.635633] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 02/26/2021] [Indexed: 11/13/2022] Open
Abstract
Sugar-rich food sources are essential for sandflies to meet their energy demands, achieving more prolonged survival. The digestion of carbohydrates from food is mainly realized by glycoside hydrolases (GH). To identify genes coding for α-glycosidases and α-amylases belonging to Glycoside Hydrolase Family 13 (GH13) and Glycoside Hydrolase Family 31 (GH31) in Lutzomyia longipalpis, we performed an HMMER search against its genome using known sequences from other dipteran species. The sequences retrieved were classified based on BLASTP best hit, analysis of conserved regions by alignment with sequences of proteins with known structure, and phylogenetic analysis comparing with orthologous proteins from other dipteran species. Using RT-PCR analysis, we evaluated the expression of GH13 and GH31 genes, in the gut and rest of the body of females, in four different conditions: non-fed, sugar-fed, blood-fed, and Leishmania mexicana infected females. L. longipalpis has GH13/31 genes that code for enzymes involved in various aspects of sugar metabolism, as carbohydrate digestion, storage, and mobilization of glycogen reserves, proteins involved in transport, control of N-glycosylation quality, as well as others with a putative function in the regulation of myogenesis. These proteins are representatives of GH13 and GH31 families, and their roles seem to be conserved. Most of the enzymes seem to be active with conserved consense sequences, including the expected catalytic residues. α-amylases also demonstrated the presence of calcium and chloride binding sites. L. longipalpis genome shows an expansion in the α-amylase gene family, with two clusters. In contrast, a retraction in the number of α-glucosidases occurred. The expansion of α-amylases is probably related to the specialization of these proteins for different substrates or inhibitors, which might correlate with the higher diversity of plant foods available in the natural habitat of L. longipalpis. The expression of α-glucosidase genes is higher in blood-fed females, suggesting their role in blood digestion. Besides that, in blood-fed females infected with the parasite Leishmania mexicana, these genes were also modulated. Glycoside Hydrolases from families 13 and 31 are essential for the metabolism of L. longipalpis, and GH13 enzymes seem to be involved in the interaction between sandflies and Leishmania.
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Affiliation(s)
| | - Paul Bates
- Faculty of Health and Medicine, Division of Biomedical and Life Sciences, Lancaster University, Lancaster, United Kingdom
| | - Rod Dillon
- Faculty of Health and Medicine, Division of Biomedical and Life Sciences, Lancaster University, Lancaster, United Kingdom
- National Institute of Science and Technology for Molecular Entomology, Rio de Janeiro, Brazil
| | - Fernando Ariel Genta
- Laboratory of Insect Biochemistry and Physiology, Oswaldo Cruz Institute, Fundação Oswaldo Cruz, Rio de Janeiro, Brazil
- National Institute of Science and Technology for Molecular Entomology, Rio de Janeiro, Brazil
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14
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Talyuli OAC, Bottino-Rojas V, Polycarpo CR, Oliveira PL, Paiva-Silva GO. Non-immune Traits Triggered by Blood Intake Impact Vectorial Competence. Front Physiol 2021; 12:638033. [PMID: 33737885 PMCID: PMC7960658 DOI: 10.3389/fphys.2021.638033] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 02/08/2021] [Indexed: 11/13/2022] Open
Abstract
Blood-feeding arthropods are considered an enormous public health threat. They are vectors of a plethora of infectious agents that cause potentially fatal diseases like Malaria, Dengue fever, Leishmaniasis, and Lyme disease. These vectors shine due to their own physiological idiosyncrasies, but one biological aspect brings them all together: the requirement of blood intake for development and reproduction. It is through blood-feeding that they acquire pathogens and during blood digestion that they summon a collection of multisystemic events critical for vector competence. The literature is focused on how classical immune pathways (Toll, IMD, and JAK/Stat) are elicited throughout the course of vector infection. Still, they are not the sole determinants of host permissiveness. The dramatic changes that are the hallmark of the insect physiology after a blood meal intake are the landscape where a successful infection takes place. Dominant processes that occur in response to a blood meal are not canonical immunological traits yet are critical in establishing vector competence. These include hormonal circuitries and reproductive physiology, midgut permeability barriers, midgut homeostasis, energy metabolism, and proteolytic activity. On the other hand, the parasites themselves have a role in the outcome of these blood triggered physiological events, consistently using them in their favor. Here, to enlighten the knowledge on vector-pathogen interaction beyond the immune pathways, we will explore different aspects of the vector physiology, discussing how they give support to these long-dated host-parasite relationships.
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Affiliation(s)
- Octavio A C Talyuli
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Vanessa Bottino-Rojas
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Carla R Polycarpo
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, Brazil
| | - Pedro L Oliveira
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, Brazil
| | - Gabriela O Paiva-Silva
- Instituto de Bioquímica Médica Leopoldo de Meis, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.,Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, Brazil
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15
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Sloan MA, Sadlova J, Lestinova T, Sanders MJ, Cotton JA, Volf P, Ligoxygakis P. The Phlebotomus papatasi systemic transcriptional response to trypanosomatid-contaminated blood does not differ from the non-infected blood meal. Parasit Vectors 2021; 14:15. [PMID: 33407867 PMCID: PMC7789365 DOI: 10.1186/s13071-020-04498-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 11/23/2020] [Indexed: 02/13/2023] Open
Abstract
Background Leishmaniasis, caused by parasites of the genus Leishmania, is a disease that affects up to 8 million people worldwide. Parasites are transmitted to human and animal hosts through the bite of an infected sand fly. Novel strategies for disease control require a better understanding of the key step for transmission, namely the establishment of infection inside the fly. Methods The aim of this work was to identify sand fly systemic transcriptomic signatures associated with Leishmania infection. We used next generation sequencing to describe the transcriptome of whole Phlebotomus papatasi sand flies when fed with blood alone (control) or with blood containing one of three trypanosomatids: Leishmania major, L. donovani and Herpetomonas muscarum, the latter being a parasite not transmitted to humans. Results Of the trypanosomatids studied, only L. major was able to successfully establish an infection in the host P. papatasi. However, the transcriptional signatures observed after each parasite-contaminated blood meal were not specific to success or failure of a specific infection and they did not differ from each other. The transcriptional signatures were also indistinguishable after a non-contaminated blood meal. Conclusions The results imply that sand flies perceive Leishmania as just one feature of their microbiome landscape and that any strategy to tackle transmission should focus on the response towards the blood meal rather than parasite establishment. Alternatively, Leishmania could suppress host responses. These results will generate new thinking around the concept of stopping transmission by controlling the parasite inside the insect.![]()
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Affiliation(s)
- Megan A Sloan
- Department of Biochemistry, University of Oxford, South Parks Rd, Oxford, OX1 3QU, UK
| | - Jovana Sadlova
- Department of Parasitology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Tereza Lestinova
- Department of Parasitology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Mandy J Sanders
- The Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, CB10 1SA, Cambridgeshire, UK
| | - James A Cotton
- The Wellcome Sanger Institute, Wellcome Genome Campus, Hinxton, CB10 1SA, Cambridgeshire, UK
| | - Petr Volf
- Department of Parasitology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Petros Ligoxygakis
- Department of Biochemistry, University of Oxford, South Parks Rd, Oxford, OX1 3QU, UK.
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