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1.
Dis Aquat Organ ; 146: 23-28, 2021 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-34498607

RESUMO

The cockle Cerastoderma edule, a socioeconomically important bivalve of the northeast Atlantic, is host to several trematodes, including Himasthla elongata. In the life cycle of this trematode, cercariae (free-living stages) emerge from the first intermediate host, a snail, to infect cockles as second intermediate hosts. During their lifespan (less than 2 d), cercariae must ensure successful host-to-host transmission via the surrounding water and therefore are exposed to and impacted by different environmental conditions, including abiotic factors. Given that the light:dark cycle is one of the major drivers of behaviour in aquatic habitats, we aimed to determine the influence of light on cercariae and host behaviour based on 3 hypotheses. First, by having a benthic second intermediate host, these cercariae will display a photonegative orientation; second, and conversely, host behaviour will not be influenced by light; and third, cercariae infection success will be light-dependent. Results showed that cercariae display a photopositive orientation (first hypothesis rejected), displaying movements towards light. Host activity (evaluated by oxygen consumption) was similar among conditions, i.e. dark vs. light (second hypothesis accepted), but hosts acquired more parasites when experimentally infected in the dark (third hypothesis accepted). This light-dependent infection of the host is explained by a change of cercarial behaviour when exposed to light, decreasing their infection success. This study highlights that trematode responses to external conditions may be linked to successful life cycle completion rather than being altered by the host habitat. Light influence on cercarial behaviour resulted in increased infection success that may affect trematode population dynamics and their distributional range.


Assuntos
Bivalves , Cardiidae , Trematódeos , Infecções por Trematódeos , Animais , Cercárias , Interações Hospedeiro-Parasita , Caramujos , Infecções por Trematódeos/veterinária
2.
J Insect Sci ; 21(5)2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34477875

RESUMO

Parasites sometimes manipulate their host's behavior to increase their own fitness by enhancing the likelihood that their offspring will reach their hosts. Bees are often parasitized by immobile adult female strepsipterans which seem to modify bees' behavior to facilitate the release of mobile first-instar larvae onto flowers. To better understand how the parasite may modify the host's behavior, we compared the foraging behavior of the sweat bee Lasioglossum apristum (Vachal, 1903) (Hymenoptera: Halictidae) between bees parasitized and unparasitized by the strepsipteran Halictoxenos borealis Kifune, 1982 (Strepsiptera: Stylopidae). Both parasitized and unparasitized bees frequently visited Hydrangea serrata (Thunb.) (Cornales: Hydrangeaceae) inflorescences, which are polleniferous but nectarless. On H. serrata inflorescences, unparasitized bees collected pollen from the anthers, but parasitized bees did not collect or eat pollen. Instead, they displayed a peculiar behavior, bending their abdomens downward and pressing them against the flower. This peculiar behavior, which was observed only in bees parasitized by a female strepsipteran in the larvae-releasing stage, may promote the release of mobile first-instar larvae onto flowers. Our observations suggest that the altered flower-visiting behavior of parasitized bees may benefit the parasite. Moreover, it suggests that strepsipteran parasites may modify their host's behavior only when the larvae reach a certain life stage.


Assuntos
Abelhas/parasitologia , Comportamento Alimentar , Interações Hospedeiro-Parasita , Animais , Artrópodes , Polinização
3.
Nat Commun ; 12(1): 4983, 2021 08 17.
Artigo em Inglês | MEDLINE | ID: mdl-34404783

RESUMO

Parasites of the phylum Apicomplexa cause important diseases including malaria, cryptosporidiosis and toxoplasmosis. These intracellular pathogens inject the contents of an essential organelle, the rhoptry, into host cells to facilitate invasion and infection. However, the structure and mechanism of this eukaryotic secretion system remain elusive. Here, using cryo-electron tomography and subtomogram averaging, we report the conserved architecture of the rhoptry secretion system in the invasive stages of two evolutionarily distant apicomplexans, Cryptosporidium parvum and Toxoplasma gondii. In both species, we identify helical filaments, which appear to shape and compartmentalize the rhoptries, and an apical vesicle (AV), which facilitates docking of the rhoptry tip at the parasite's apical region with the help of an elaborate ultrastructure named the rhoptry secretory apparatus (RSA); the RSA anchors the AV at the parasite plasma membrane. Depletion of T. gondii Nd9, a protein required for rhoptry secretion, disrupts the RSA ultrastructure and AV-anchoring. Moreover, T. gondii contains a line of AV-like vesicles, which interact with a pair of microtubules and accumulate towards the AV, leading to a working model for AV-reloading and discharging of multiple rhoptries. Together, our analyses provide an ultrastructural framework to understand how these important parasites deliver effectors into host cells.


Assuntos
Organelas/metabolismo , Organelas/ultraestrutura , Parasitos/metabolismo , Parasitos/ultraestrutura , Proteínas de Protozoários/química , Animais , Evolução Biológica , Membrana Celular/metabolismo , Microscopia Crioeletrônica , Criptosporidiose , Cryptosporidium , Cryptosporidium parvum/citologia , Cryptosporidium parvum/efeitos dos fármacos , Cryptosporidium parvum/metabolismo , Interações Hospedeiro-Parasita , Microtúbulos/ultraestrutura , Proteínas de Protozoários/metabolismo , Toxoplasma/citologia , Toxoplasma/efeitos dos fármacos , Toxoplasma/metabolismo , Toxoplasmose
4.
BMC Plant Biol ; 21(1): 392, 2021 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-34418971

RESUMO

BACKGROUND: Sorghum yields in sub-Saharan Africa (SSA) are greatly reduced by parasitic plants of the genus Striga (witchweed). Vast global sorghum genetic diversity collections, as well as the availability of modern sequencing technologies, can be potentially harnessed to effectively manage the parasite. RESULTS: We used laboratory assays - rhizotrons to screen a global sorghum diversity panel to identify new sources of resistance to Striga; determine mechanisms of resistance, and elucidate genetic loci underlying the resistance using genome-wide association studies (GWAS). New Striga resistant sorghum determined by the number, size and biomass of parasite attachments were identified. Resistance was by; i) mechanical barriers that blocked parasite entry, ii) elicitation of a hypersensitive reaction that interfered with parasite development, and iii) the inability of the parasite to develop vascular connections with hosts. Resistance genes underpinning the resistance corresponded with the resistance mechanisms and included pleiotropic drug resistance proteins that transport resistance molecules; xylanase inhibitors involved in cell wall fortification and hormonal regulators of resistance response, Ethylene Response Factors. CONCLUSIONS: Our findings are of fundamental importance to developing durable and broad-spectrum resistance against Striga and have far-reaching applications in many SSA countries where Striga threatens the livelihoods of millions of smallholder farmers that rely on sorghum as a food staple.


Assuntos
Geografia , Interações Hospedeiro-Parasita/genética , Doenças das Plantas/parasitologia , Imunidade Vegetal/genética , Sorghum/genética , Sorghum/imunologia , Striga/genética , Striga/parasitologia , África ao Sul do Saara , Grão Comestível/genética , Grão Comestível/imunologia , Variação Genética , Estudo de Associação Genômica Ampla , Genótipo , Interações Hospedeiro-Parasita/fisiologia , Doenças das Plantas/imunologia , Imunidade Vegetal/fisiologia , Raízes de Plantas/genética , Raízes de Plantas/imunologia , Raízes de Plantas/parasitologia
5.
Front Biosci (Landmark Ed) ; 26(8): 379-386, 2021 08 30.
Artigo em Inglês | MEDLINE | ID: mdl-34455767

RESUMO

Background: The world faces the challenge posed by the interaction between hosts and Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) with potential role for arthropod vectors, and the effect of SARS-CoV-2 variants on acquired immunity, vaccine efficacy and coronavirus disease-19 (COVID-19) pandemic control. Proposal: The characterization of the role played by animal hosts and host-virus interactions is essential to address this challenge. Zoonotic (animal-to-human) and reverse zoonotic (human-to-animal) routes may be involved in virus transmission with a possible still unconfirmed role for arthropod vectors. Herein we propose to consider the risks posed by the possible role of arthropod vectors in COVID-19 and that immunity against SARS-CoV-2 may increase the risk for zoonotic virus transmission. These risks should be considered when evaluating vaccine efficacy and monitoring animal SARS-CoV-2 variants. Conclusion: Virus surveillance, epidemiology, sequencing and evaluation of susceptibility to antibodies and other protective immune mechanisms from vaccinated individuals should be improved. A One Health approach such as the one applied by our group SaBio is necessary for a more effective control of COVID-19 and prevention of future pandemics.


Assuntos
Vetores Artrópodes , COVID-19/transmissão , Animais , COVID-19/virologia , Interações Hospedeiro-Parasita , Humanos , SARS-CoV-2/isolamento & purificação , Zoonoses
6.
Front Cell Infect Microbiol ; 11: 702125, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34395313

RESUMO

For the establishment of a successful infection, i.e., long-term parasitism and a complete life cycle, parasites use various diverse mechanisms and factors, which they may be inherently bestowed with, or may acquire from the natural vector biting the host at the infection prelude, or may take over from the infecting host, to outmaneuver, evade, overcome, and/or suppress the host immunity, both innately and adaptively. This narrative review summarizes the up-to-date strategies exploited by a number of representative human parasites (protozoa and helminths) to counteract the target host immune defense. The revisited information should be useful for designing diagnostics and therapeutics as well as vaccines against the respective parasitic infections.


Assuntos
Helmintos , Parasitos , Doenças Parasitárias , Animais , Interações Hospedeiro-Parasita , Humanos , Evasão da Resposta Imune
7.
BMC Plant Biol ; 21(1): 358, 2021 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-34348650

RESUMO

BACKGROUND: The South America pinworm, Tuta absoluta, is a destructive pest of tomato that causes important losses worldwide. Breeding of resistant/tolerant tomato cultivars could be an effective strategy for T. absoluta management but, despite the economic importance of tomato, very limited information is available about its response to this treat. To elucidate the defense mechanisms to herbivore feeding a comparative analysis was performed between a tolerant and susceptible cultivated tomato at both morphological and transcriptome level to highlight constitutive leaf barriers, molecular and biochemical mechanisms to counter the effect of T. absoluta attack. RESULTS: The tolerant genotype showed an enhanced constitutive barrier possibly as result of the higher density of trichomes and increased inducible reactions upon mild infestation thanks to the activation/repression of key transcription factors regulating genes involved in cuticle formation and cell wall strength as well as of antinutritive enzymes, and genes involved in the production of chemical toxins and bioactive secondary metabolites. CONCLUSIONS: Overall, our findings suggest that tomato resilience to the South America pinworm is achieved by a combined strategy between constitutive and induced defense system. A well-orchestrated modulation of plant transcription regulation could ensure a trade-off between defense needs and fitness costs. Our finding can be further exploited for developing T. absoluta tolerant cultivars, acting as important component of integrated pest management strategy for more sustainable production.


Assuntos
Regulação da Expressão Gênica de Plantas , Lycopersicon esculentum/genética , Doenças das Plantas/genética , Folhas de Planta/genética , Transcriptoma , Animais , Perfilação da Expressão Gênica/métodos , Ontologia Genética , Interações Hospedeiro-Parasita , Larva/fisiologia , Lycopersicon esculentum/metabolismo , Lycopersicon esculentum/parasitologia , Mariposas/fisiologia , Doenças das Plantas/parasitologia , Folhas de Planta/metabolismo , Folhas de Planta/parasitologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , RNA-Seq/métodos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Tricomas/genética , Tricomas/metabolismo , Tricomas/parasitologia
8.
Nat Commun ; 12(1): 4806, 2021 08 10.
Artigo em Inglês | MEDLINE | ID: mdl-34376675

RESUMO

The malaria parasite Plasmodium falciparum replicates inside erythrocytes in the blood of infected humans. During each replication cycle, a small proportion of parasites commits to sexual development and differentiates into gametocytes, which are essential for parasite transmission via the mosquito vector. Detailed molecular investigation of gametocyte biology and transmission has been hampered by difficulties in generating large numbers of these highly specialised cells. Here, we engineer P. falciparum NF54 inducible gametocyte producer (iGP) lines for the routine mass production of synchronous gametocytes via conditional overexpression of the sexual commitment factor GDV1. NF54/iGP lines consistently achieve sexual commitment rates of 75% and produce viable gametocytes that are transmissible by mosquitoes. We also demonstrate that further genetic engineering of NF54/iGP parasites is a valuable tool for the targeted exploration of gametocyte biology. In summary, we believe the iGP approach developed here will greatly expedite basic and applied malaria transmission stage research.


Assuntos
Sistemas CRISPR-Cas , Malária Falciparum/sangue , Plasmodium falciparum/genética , Esporos de Protozoários/genética , Animais , Anopheles/parasitologia , Células Cultivadas , Eritrócitos/parasitologia , Hepatócitos/citologia , Hepatócitos/parasitologia , Interações Hospedeiro-Parasita , Humanos , Malária Falciparum/parasitologia , Malária Falciparum/transmissão , Microscopia de Fluorescência , Mosquitos Vetores/parasitologia , Plasmodium falciparum/fisiologia , Esporos de Protozoários/fisiologia , Esporozoítos/genética , Esporozoítos/fisiologia
9.
Nat Commun ; 12(1): 4851, 2021 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-34381047

RESUMO

Pathogens are thought to use host molecular cues to control when to initiate life-cycle transitions, but these signals are mostly unknown, particularly for the parasitic disease malaria caused by Plasmodium falciparum. The chemokine CXCL10 is present at high levels in fatal cases of cerebral malaria patients, but is reduced in patients who survive and do not have complications. Here we show a Pf 'decision-sensing-system' controlled by CXCL10 concentration. High CXCL10 expression prompts P. falciparum to initiate a survival strategy via growth acceleration. Remarkably, P. falciparum inhibits CXCL10 synthesis in monocytes by disrupting the association of host ribosomes with CXCL10 transcripts. The underlying inhibition cascade involves RNA cargo delivery into monocytes that triggers RIG-I, which leads to HUR1 binding to an AU-rich domain of the CXCL10 3'UTR. These data indicate that when the parasite can no longer keep CXCL10 at low levels, it can exploit the chemokine as a cue to shift tactics and escape.


Assuntos
Quimiocina CXCL10/metabolismo , Malária Falciparum/parasitologia , Plasmodium falciparum/fisiologia , Regiões 3' não Traduzidas , Quimiocina CXCL10/genética , Proteína DEAD-box 58/metabolismo , Proteína Semelhante a ELAV 1/metabolismo , Vesículas Extracelulares/metabolismo , Interações Hospedeiro-Parasita , Humanos , Estágios do Ciclo de Vida , Malária Falciparum/imunologia , Monócitos/metabolismo , Plasmodium falciparum/crescimento & desenvolvimento , Plasmodium falciparum/metabolismo , Biossíntese de Proteínas , RNA de Protozoário/metabolismo , Receptores Imunológicos/metabolismo , Ribossomos/metabolismo , Células THP-1
10.
Front Cell Infect Microbiol ; 11: 692134, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34222052

RESUMO

Chagas Disease, caused by the protozoan parasite Trypanosoma cruzi, affects nearly eight million people in the world. T. cruzi is a complex taxon represented by different strains with particular characteristics, and it has the ability to infect and interact with almost any nucleated cell. The T. cruzi-host cell interactions will trigger molecular signaling cascades in the host cell that will depend on the particular cell type and T. cruzi strain, and also on many different experimental variables. In this review we collect data from multiple transcriptomic and functional studies performed in different infection models, in order to highlight key differences between works that in our opinion should be addressed when comparing and discussing results. In particular, we focus on changes in the respiratory chain and oxidative phosphorylation of host cells in response to infection, which depends on the experimental model of T. cruzi infection. Finally, we also discuss host cell responses which reiterate independently of the strain, cell type and experimental conditions.


Assuntos
Doença de Chagas , Trypanosoma cruzi , Comunicação Celular , Interações Hospedeiro-Parasita , Humanos , Transdução de Sinais , Transcriptoma , Trypanosoma cruzi/genética
11.
Int J Mol Sci ; 22(14)2021 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-34299036

RESUMO

Parasitic angiosperms, comprising a diverse group of flowering plants, are partially or fully dependent on their hosts to acquire water, mineral nutrients and organic compounds. Some have detrimental effects on agriculturally important crop plants. They are also intriguing model systems to study adaptive mechanisms required for the transition from an autotrophic to a heterotrophic metabolism. No less than any other plant, parasitic plants are affected by abiotic stress factors such as drought and changes in temperature, saline soils or contamination with metals or herbicides. These effects may be attributed to the direct influence of the stress, but also to diminished host availability and suitability. Although several studies on abiotic stress response of parasitic plants are available, still little is known about how abiotic factors affect host preferences, defense mechanisms of both hosts and parasites and the effects of combinations of abiotic and biotic stress experienced by the host plants. The latter effects are of specific interest as parasitic plants pose additional pressure on contemporary agriculture in times of climate change. This review summarizes the existing literature on abiotic stress response of parasitic plants, highlighting knowledge gaps and discussing perspectives for future research and potential agricultural applications.


Assuntos
Produtos Agrícolas/parasitologia , Interações Hospedeiro-Parasita , Parasitos/fisiologia , Estresse Fisiológico , Animais , Mudança Climática , Produtos Agrícolas/crescimento & desenvolvimento , Secas
12.
Nat Microbiol ; 6(8): 991-999, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34294905

RESUMO

More than one-third of the world's population is exposed to Plasmodium vivax malaria, mainly in Asia1. P. vivax preferentially invades reticulocytes (immature red blood cells)2-4. Previous work has identified 11 parasite proteins involved in reticulocyte invasion, including erythrocyte binding protein 2 (ref. 5) and the reticulocyte-binding proteins (PvRBPs)6-10. PvRBP2b binds to the transferrin receptor CD71 (ref. 11), which is selectively expressed on immature reticulocytes12. Here, we identified CD98 heavy chain (CD98), a heteromeric amino acid transporter from the SLC3 family (also known as SLCA2), as a reticulocyte-specific receptor for the PvRBP2a parasite ligand using mass spectrometry, flow cytometry, biochemical and parasite invasion assays. We characterized the expression level of CD98 at the surface of immature reticulocytes (CD71+) and identified an interaction between CD98 and PvRBP2a expressed at the merozoite surface. Our results identify CD98 as an additional host membrane protein, besides CD71, that is directly associated with P. vivax reticulocyte tropism. These findings highlight the potential of using PvRBP2a as a vaccine target against P. vivax malaria.


Assuntos
Eritrócitos/parasitologia , Cadeia Pesada da Proteína-1 Reguladora de Fusão/metabolismo , Malária Vivax/metabolismo , Plasmodium vivax/metabolismo , Antígenos CD , Antígenos de Protozoários/genética , Antígenos de Protozoários/metabolismo , Eritrócitos/metabolismo , Cadeia Pesada da Proteína-1 Reguladora de Fusão/genética , Interações Hospedeiro-Parasita , Humanos , Malária Vivax/sangue , Malária Vivax/genética , Plasmodium vivax/genética , Ligação Proteica , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Receptores da Transferrina , Reticulócitos/metabolismo , Reticulócitos/parasitologia
13.
Cell Death Dis ; 12(7): 692, 2021 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-34247195

RESUMO

Chagas disease is a life-threatening disorder caused by the protozoan parasite Trypanosoma cruzi. Parasite-specific antibodies, CD8+ T cells, as well as IFN-γ and nitric oxide (NO) are key elements of the adaptive and innate immunity against the extracellular and intracellular forms of the parasite. Bim is a potent pro-apoptotic member of the Bcl-2 family implicated in different aspects of the immune regulation, such as negative selection of self-reactive thymocytes and elimination of antigen-specific T cells at the end of an immune response. Interestingly, the role of Bim during infections remains largely unidentified. To explore the role of Bim in Chagas disease, we infected WT, Bim+/-, Bim-/- mice with trypomastigotes forms of the Y strain of T. cruzi. Strikingly, our data revealed that Bim-/- mice exhibit a delay in the development of parasitemia followed by a deficiency in the control of parasite load in the bloodstream and a decreased survival compared to WT and Bim+/- mice. At the peak of parasitemia, peritoneal macrophages of Bim-/- mice exhibit decreased NO production, which correlated with a decrease in the pro-inflammatory Small Peritoneal Macrophage (SPM) subset. A similar reduction in NO secretion, as well as in the pro-inflammatory cytokines IFN-γ and IL-6, was also observed in Bim-/- splenocytes. Moreover, an impaired anti-T. cruzi CD8+ T-cell response was found in Bim-/- mice at this time point. Taken together, our results suggest that these alterations may contribute to the establishment of a delayed yet enlarged parasitic load observed at day 9 after infection of Bim-/- mice and place Bim as an important protein in the control of T. cruzi infections.


Assuntos
Proteína 11 Semelhante a Bcl-2/deficiência , Doença de Chagas/parasitologia , Trypanosoma cruzi/patogenicidade , Animais , Proteína 11 Semelhante a Bcl-2/genética , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Linfócitos T CD8-Positivos/parasitologia , Células Cultivadas , Doença de Chagas/genética , Doença de Chagas/imunologia , Doença de Chagas/metabolismo , Modelos Animais de Doenças , Feminino , Interações Hospedeiro-Parasita , Interferon gama/metabolismo , Interleucina-6/metabolismo , Macrófagos Peritoneais/imunologia , Macrófagos Peritoneais/metabolismo , Macrófagos Peritoneais/parasitologia , Camundongos Endogâmicos C57BL , Camundongos Knockout , Óxido Nítrico/metabolismo , Carga Parasitária , Baço/imunologia , Baço/metabolismo , Baço/parasitologia , Fatores de Tempo , Trypanosoma cruzi/imunologia
14.
mBio ; 12(4): e0121421, 2021 08 31.
Artigo em Inglês | MEDLINE | ID: mdl-34225494

RESUMO

As access to high-throughput sequencing technology has increased, the bottleneck in biomedical research has shifted from data generation to data analysis. Here, we describe a modular and extensible framework for didactic instruction in bioinformatics using publicly available RNA sequencing data sets from infectious disease studies, with a focus on host-parasite interactions. We highlight lessons learned from adapting this course for virtual learners during the coronavirus disease 2019 (COVID-19) pandemic.


Assuntos
Biologia Computacional/educação , Biologia Computacional/métodos , Interações Hospedeiro-Parasita/fisiologia , Animais , COVID-19/patologia , Análise de Dados , Genômica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/genética , Plasmodium falciparum/fisiologia , Schistosoma mansoni/efeitos dos fármacos , Schistosoma mansoni/genética , Schistosoma mansoni/fisiologia , Toxoplasma/efeitos dos fármacos , Toxoplasma/genética , Toxoplasma/fisiologia
15.
Commun Biol ; 4(1): 847, 2021 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-34234279

RESUMO

The aphid Myzus persicae is a destructive agricultural pest that displays an exceptional ability to develop resistance to both natural and synthetic insecticides. To investigate the evolution of resistance in this species we generated a chromosome-scale genome assembly and living panel of >110 fully sequenced globally sampled clonal lines. Our analyses reveal a remarkable diversity of resistance mutations segregating in global populations of M. persicae. We show that the emergence and spread of these mechanisms is influenced by host-plant associations, uncovering the widespread co-option of a host-plant adaptation that also offers resistance against synthetic insecticides. We identify both the repeated evolution of independent resistance mutations at the same locus, and multiple instances of the evolution of novel resistance mechanisms against key insecticides. Our findings provide fundamental insights into the genomic responses of global insect populations to strong selective forces, and hold practical relevance for the control of pests and parasites.


Assuntos
Afídeos/genética , Evolução Molecular , Variação Genética , Genoma de Inseto/genética , Resistência a Inseticidas/genética , Inseticidas/farmacologia , Animais , Afídeos/classificação , Afídeos/fisiologia , Sequência de Bases , Genômica/métodos , Geografia , Interações Hospedeiro-Parasita/efeitos dos fármacos , Mutação , Filogenia , Plantas/parasitologia , Polimorfismo de Nucleotídeo Único , Homologia de Sequência do Ácido Nucleico
16.
Life Sci ; 282: 119793, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34242658

RESUMO

Visceral leishmaniasis (VL) is a neglected and highly lethal disease. VL is endemic in South American countries, with Brazil being responsible for 96% of the cases. In this continent, VL is caused by the protozoan Leishmania (Leishmania) infantum (L. infantum), transmitted by the bite of infected female phlebotomine sandflies. Immediately after the inoculation of L.infantum promastigotes into the vertebrate host, the complement, as part of the first line of innate response, becomes activated. L. infantum promastigotes glycocalyx is rich in carbohydrates that can activate the lectin pathway of complement system. In this study, we evaluated whether the lectin pathway collectins [manose binding lectin (MBL) and collectin-11 (CL-11)] and ficolins (-1, -2 and -3) interact with L.infantum promastigotes, using confocal microscopy and flow cytometry. The binding of MBL, CL-11 and ficolins -1 and -3, but not ficolin-2, was observed on the surface of live metacyclic promastigotes after incubation with normal human serum (NHS) or recombinant proteins. C3 and C4 deposition as well as complement mediated lyses was also demonstrated after interaction with NHS. These results highlight a role for collectins and ficolins in the initial immune response to L.infantum.


Assuntos
Proteínas do Sistema Complemento/imunologia , Lectinas/imunologia , Leishmania infantum/imunologia , Leishmaniose Visceral/imunologia , Ativação do Complemento , Interações Hospedeiro-Parasita , Humanos , Leishmania infantum/fisiologia
17.
Science ; 373(6554): 535-541, 2021 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-34326235

RESUMO

Interkingdom competition occurs between hymenopteran parasitoids and insect viruses sharing the same insect hosts. It has been assumed that parasitoid larvae die with the death of the infected host or as result of competition for host resources. Here we describe a gene family, parasitoid killing factor (pkf), that encodes proteins toxic to parasitoids of the Microgastrinae group and determines parasitism success. Pkfs are found in several entomopathogenic DNA virus families and in some lepidopteran genomes. We provide evidence of equivalent and specific toxicity against endoparasites for PKFs found in entomopoxvirus, ascovirus, baculovirus, and Lepidoptera through a mechanism that elicits apoptosis in the cells of susceptible parasitoids. This highlights the evolutionary arms race between parasitoids, viruses, and their insect hosts.


Assuntos
Entomopoxvirinae/fisiologia , Proteínas de Insetos/toxicidade , Lepidópteros/parasitologia , Lepidópteros/virologia , Proteínas Virais/toxicidade , Vespas/fisiologia , Animais , Apoptose , Evolução Biológica , Transferência Genética Horizontal , Genoma de Inseto , Interações Hospedeiro-Parasita , Proteínas de Insetos/química , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Vírus de Insetos/fisiologia , Larva/genética , Larva/parasitologia , Larva/virologia , Lepidópteros/genética , Lepidópteros/metabolismo , Nucleopoliedrovírus/fisiologia , Spodoptera/genética , Spodoptera/metabolismo , Spodoptera/parasitologia , Spodoptera/virologia , Proteínas Virais/química , Proteínas Virais/genética , Proteínas Virais/metabolismo , Vespas/crescimento & desenvolvimento
18.
Int J Mol Sci ; 22(13)2021 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-34206906

RESUMO

Leishmania survival inside macrophages depends on factors that lead to the immune response evasion during the infection. In this context, the metabolic scenario of the host cell-parasite relationship can be crucial to understanding how this parasite can survive inside host cells due to the host's metabolic pathways reprogramming. In this work, we aimed to analyze metabolic networks of bone marrow-derived macrophages from C57BL/6 mice infected with Leishmania amazonensis wild type (La-WT) or arginase knocked out (La-arg-), using the untargeted Capillary Electrophoresis-Mass Spectrometry (CE-MS) approach to assess metabolomic profile. Macrophages showed specific changes in metabolite abundance upon Leishmania infection, as well as in the absence of parasite-arginase. The absence of L. amazonensis-arginase promoted the regulation of both host and parasite urea cycle, glycine and serine metabolism, ammonia recycling, metabolism of arginine, proline, aspartate, glutamate, spermidine, spermine, methylhistidine, and glutathione metabolism. The increased L-arginine, L-citrulline, L-glutamine, oxidized glutathione, S-adenosylmethionine, N-acetylspermidine, trypanothione disulfide, and trypanothione levels were observed in La-WT-infected C57BL/6-macrophage compared to uninfected. The absence of parasite arginase increased L-arginine, argininic acid, and citrulline levels and reduced ornithine, putrescine, S-adenosylmethionine, glutamic acid, proline, N-glutamyl-alanine, glutamyl-arginine, trypanothione disulfide, and trypanothione when compared to La-WT infected macrophage. Moreover, the absence of parasite arginase leads to an increase in NO production levels and a higher infectivity rate at 4 h of infection. The data presented here show a host-dependent regulation of metabolomic profiles of C57BL/6 macrophages compared to the previously observed BALB/c macrophages infected with L. amazonensis, an important fact due to the dual and contrasting macrophage phenotypes of those mice. In addition, the Leishmania-arginase showed interference with the urea cycle, glycine, and glutathione metabolism during host-pathogen interactions.


Assuntos
Aminoácidos/metabolismo , Interações Hospedeiro-Parasita , Leishmaniose/metabolismo , Macrófagos/metabolismo , Metaboloma , Poliaminas/metabolismo , Animais , Arginase/metabolismo , Células Cultivadas , Leishmania/enzimologia , Leishmania/patogenicidade , Macrófagos/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Proteínas de Protozoários/metabolismo
19.
Int J Mol Sci ; 22(12)2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34204285

RESUMO

Pathogenic intracellular bacteria, parasites and viruses have evolved sophisticated mechanisms to manipulate mammalian host cells to serve as niches for persistence and proliferation. The intracellular lifestyles of pathogens involve the manipulation of membrane-bound organellar compartments of host cells. In this review, we described how normal structural organization and cellular functions of endosomes, endoplasmic reticulum, Golgi apparatus, mitochondria, or lipid droplets are targeted by microbial virulence mechanisms. We focus on the specific interactions of Salmonella, Legionella pneumophila, Rickettsia rickettsii, Chlamydia spp. and Mycobacterium tuberculosis representing intracellular bacterial pathogens, and of Plasmodium spp. and Toxoplasma gondii representing intracellular parasites. The replication strategies of various viruses, i.e., Influenza A virus, Poliovirus, Brome mosaic virus, Epstein-Barr Virus, Hepatitis C virus, severe acute respiratory syndrome virus (SARS), Dengue virus, Zika virus, and others are presented with focus on the specific manipulation of the organelle compartments. We compare the specific features of intracellular lifestyle and replication cycles, and highlight the communalities in mechanisms of manipulation deployed.


Assuntos
Interações Hospedeiro-Patógeno , Organelas/metabolismo , Animais , Transporte Biológico , Biomarcadores , Metabolismo Energético , Interações Hospedeiro-Parasita , Humanos , Espaço Intracelular/metabolismo , Espaço Intracelular/microbiologia , Espaço Intracelular/parasitologia , Espaço Intracelular/virologia , Organelas/microbiologia , Organelas/parasitologia , Organelas/ultraestrutura , Fagocitose
20.
Int J Mol Sci ; 22(12)2021 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-34208611

RESUMO

Transcription factors are proteins that directly bind to regulatory sequences of genes to modulate and adjust plants' responses to different stimuli including biotic and abiotic stresses. Sedentary plant parasitic nematodes, such as beet cyst nematode, Heterodera schachtii, have developed molecular tools to reprogram plant cell metabolism via the sophisticated manipulation of genes expression, to allow root invasion and the induction of a sequence of structural and physiological changes in plant tissues, leading to the formation of permanent feeding sites composed of modified plant cells (commonly called a syncytium). Here, we report on the AtMYB59 gene encoding putative MYB transcription factor that is downregulated in syncytia, as confirmed by RT-PCR and a promoter pMyb59::GUS activity assays. The constitutive overexpression of AtMYB59 led to the reduction in A. thaliana susceptibility, as indicated by decreased numbers of developed females, and to the disturbed development of nematode-induced syncytia. In contrast, mutant lines with a silenced expression of AtMYB59 were more susceptible to this parasite. The involvement of ABA in the modulation of AtMYB59 gene transcription appears feasible by several ABA-responsive cis regulatory elements, which were identified in silico in the gene promoter sequence, and experimental assays showed the induction of AtMYB59 transcription after ABA treatment. Based on these results, we suggest that AtMYB59 plays an important role in the successful parasitism of H. schachtii on A. thaliana roots.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Arabidopsis/parasitologia , Regulação da Expressão Gênica de Plantas , Doenças das Plantas/genética , Doenças das Plantas/parasitologia , Fatores de Transcrição/genética , Tylenchoidea/fisiologia , Animais , Arabidopsis/ultraestrutura , Resistência à Doença/genética , Interações Hospedeiro-Parasita , Fenótipo , Reguladores de Crescimento de Plantas/metabolismo , Raízes de Plantas/genética , Raízes de Plantas/metabolismo , Raízes de Plantas/parasitologia , Raízes de Plantas/ultraestrutura , Regiões Promotoras Genéticas
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