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1.
Nat Commun ; 12(1): 3065, 2021 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-34031406

RESUMO

In living cells, microtubules (MTs) play pleiotropic roles, which require very different mechanical properties. Unlike the dynamic MTs found in the cytoplasm of metazoan cells, the specialized cortical MTs from Toxoplasma gondii, a prevalent human pathogen, are extraordinarily stable and resistant to detergent and cold treatments. Using single-particle cryo-EM, we determine their ex vivo structure and identify three proteins (TrxL1, TrxL2 and SPM1) as bona fide microtubule inner proteins (MIPs). These three MIPs form a mesh on the luminal surface and simultaneously stabilize the tubulin lattice in both longitudinal and lateral directions. Consistent with previous observations, deletion of the identified MIPs compromises MT stability and integrity under challenges by chemical treatments. We also visualize a small molecule like density at the Taxol-binding site of ß-tubulin. Our results provide the structural basis to understand the stability of cortical MTs and suggest an evolutionarily conserved mechanism of MT stabilization from the inside.


Assuntos
Microscopia Crioeletrônica , Interações Hospedeiro-Parasita/fisiologia , Proteínas dos Microtúbulos/ultraestrutura , Microtúbulos/ultraestrutura , Toxoplasma/metabolismo , Sítios de Ligação , Sistemas CRISPR-Cas , Humanos , Proteínas dos Microtúbulos/metabolismo , Proteínas Associadas aos Microtúbulos/química , Proteínas Associadas aos Microtúbulos/metabolismo , Microtúbulos/metabolismo , Paclitaxel/química , Tubulina (Proteína)/química , Tubulina (Proteína)/metabolismo
2.
Int J Mol Sci ; 22(7)2021 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-33808261

RESUMO

In host-parasitoid interactions, antagonistic relationship drives parasitoids to vary in virulence in facing different hosts, which makes these systems excellent models for stress-induced evolutionary studies. Venom compositions varied between two strains of Tetrastichus brontispae, Tb-Bl and Tb-On. Tb-Bl targets Brontispa longissima pupae as hosts, and Tb-On is a sub-population of Tb-Bl, which has been experimentally adapted to a new host, Octodonta nipae. Aiming to examine variation in parasitoid virulence of the two strains toward two hosts, we used reciprocal injection experiments to compare effect of venom/ovarian fluids from the two strains on cytotoxicity, inhibition of immunity and fat body lysis of the two hosts. We found that Tb-Onvenom was more virulent towards plasmatocyte spreading, granulocyte function and phenoloxidase activity than Tb-Blvenom. Tb-Blovary was able to suppress encapsulation and phagocytosis in both hosts; however, Tb-Onovary inhibition targeted only B. longissima. Our data suggest that the venom undergoes rapid evolution when facing different hosts, and that the wasp has good evolutionary plasticity.


Assuntos
Besouros/parasitologia , Especificidade de Hospedeiro/genética , Interações Hospedeiro-Parasita/fisiologia , Animais , Evolução Molecular , Himenópteros/fisiologia , Fagocitose/fisiologia , Pupa/parasitologia , Virulência , Vespas/fisiologia
3.
Nat Commun ; 12(1): 1172, 2021 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-33608523

RESUMO

Mature red blood cells (RBCs) lack internal organelles and canonical defense mechanisms, making them both a fascinating host cell, in general, and an intriguing choice for the deadly malaria parasite Plasmodium falciparum (Pf), in particular. Pf, while growing inside its natural host, the human RBC, secretes multipurpose extracellular vesicles (EVs), yet their influence on this essential host cell remains unknown. Here we demonstrate that Pf parasites, cultured in fresh human donor blood, secrete within such EVs assembled and functional 20S proteasome complexes (EV-20S). The EV-20S proteasomes modulate the mechanical properties of naïve human RBCs by remodeling their cytoskeletal network. Furthermore, we identify four degradation targets of the secreted 20S proteasome, the phosphorylated cytoskeletal proteins ß-adducin, ankyrin-1, dematin and Epb4.1. Overall, our findings reveal a previously unknown 20S proteasome secretion mechanism employed by the human malaria parasite, which primes RBCs for parasite invasion by altering membrane stiffness, to facilitate malaria parasite growth.


Assuntos
Transporte Biológico/fisiologia , Eritrócitos/metabolismo , Interações Hospedeiro-Parasita/fisiologia , Malária Falciparum/metabolismo , Plasmodium falciparum/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Citoesqueleto/metabolismo , Eritrócitos/citologia , Eritrócitos/parasitologia , Humanos , Malária Falciparum/parasitologia , Proteínas de Membrana/metabolismo , Fosforilação , Plasmodium falciparum/crescimento & desenvolvimento , Proteômica
4.
Zool Res ; 42(2): 217-220, 2021 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-33496092

RESUMO

Recent studies have examined the cost of raising parasitic cuckoos and highlighted the importance of "no extra cost" in explaining the low levels of defense in hosts. To clarify the reasons for parasitization in typical hosts, we present a simple model to explore the immediate and future costs of parasitism in shaping the evolution of defense behavior in hosts. Our results suggest that any cost of parasitization is maladaptive to the host and learned egg recognition is always favored to overcome these costs. Furthermore, although facing a potential cost of mis-imprinting, learned nestling recognition may still evolve when there is a non-zero immediate cost from raising a parasitic nestling. Therefore, we contend that "no extra cost" does not provide sufficient evidence to explain the low levels of defense behavior in hosts per se.


Assuntos
Metabolismo Energético/fisiologia , Comportamento de Nidação/fisiologia , Aves Canoras/fisiologia , Aves Canoras/parasitologia , Animais , Evolução Biológica , Feminino , Interações Hospedeiro-Parasita/fisiologia , Comportamento Materno/fisiologia , Oviposição/fisiologia , Especificidade da Espécie
5.
Nat Commun ; 12(1): 129, 2021 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-33420082

RESUMO

The recent Californian hot drought (2012-2016) precipitated unprecedented ponderosa pine (Pinus ponderosa) mortality, largely attributable to the western pine beetle (Dendroctonus brevicomis; WPB). Broad-scale climate conditions can directly shape tree mortality patterns, but mortality rates respond non-linearly to climate when local-scale forest characteristics influence the behavior of tree-killing bark beetles (e.g., WPB). To test for these cross-scale interactions, we conduct aerial drone surveys at 32 sites along a gradient of climatic water deficit (CWD) spanning 350 km of latitude and 1000 m of elevation in WPB-impacted Sierra Nevada forests. We map, measure, and classify over 450,000 trees within 9 km2, validating measurements with coincident field plots. We find greater size, proportion, and density of ponderosa pine (the WPB host) increase host mortality rates, as does greater CWD. Critically, we find a CWD/host size interaction such that larger trees amplify host mortality rates in hot/dry sites. Management strategies for climate change adaptation should consider how bark beetle disturbances can depend on cross-scale interactions, which challenge our ability to predict and understand patterns of tree mortality.


Assuntos
Secas , Pinus ponderosa/parasitologia , Doenças das Plantas/parasitologia , Árvores/parasitologia , Gorgulhos/patogenicidade , Animais , California , Monitorização de Parâmetros Ecológicos/estatística & dados numéricos , Interações Hospedeiro-Parasita/fisiologia , Feromônios/metabolismo , Pinus ponderosa/fisiologia , Casca de Planta/parasitologia , Dispersão Vegetal , Árvores/fisiologia , Água , Gorgulhos/fisiologia
6.
PLoS Biol ; 18(9): e3000828, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32936797

RESUMO

Many herbivorous insects are mono- or oligophagous, having evolved to select a limited range of host plants. They specifically identify host-plant leaves using their keen sense of taste. Plant secondary metabolites and sugars are thought to be key chemical cues that enable insects to identify host plants and evaluate their quality as food. However, the neuronal and behavioral mechanisms of host-plant recognition are poorly understood. Here, we report a two-factor host acceptance system in larvae of the silkworm Bombyx mori, a specialist on several mulberry species. The first step is controlled by a chemosensory organ, the maxillary palp (MP). During palpation at the leaf edge, the MP detects trace amounts of leaf-surface compounds, which enables host-plant recognition without biting. Chemosensory neurons in the MP are tuned with ultrahigh sensitivity (thresholds of attomolar to femtomolar) to chlorogenic acid (CGA), quercetin glycosides, and ß-sitosterol (ßsito). Only if these 3 compounds are detected does the larva make a test bite, which is evaluated in the second step. Low-sensitivity neurons in another chemosensory organ, the maxillary galea (MG), mainly detect sucrose in the leaf sap exuded by test biting, allowing larvae to accept the leaf and proceed to persistent biting (feeding). The two-factor host acceptance system reported here may commonly underlie stereotyped feeding behavior in many phytophagous insects and determine their feeding habits.


Assuntos
Bombyx/fisiologia , Comportamento de Escolha , Dieta , Comportamento Alimentar/fisiologia , Larva/fisiologia , Papilas Gustativas/fisiologia , Fenômenos Fisiológicos da Nutrição Animal , Animais , Comportamento Animal/fisiologia , Bombyx/anatomia & histologia , Bombyx/crescimento & desenvolvimento , Células Quimiorreceptoras/fisiologia , Quimiotaxia/fisiologia , Sinais (Psicologia) , Comportamento Exploratório/fisiologia , Interações Hospedeiro-Parasita/fisiologia , Larva/anatomia & histologia , Larva/citologia , Morus/química , Folhas de Planta/química , Paladar/fisiologia , Papilas Gustativas/anatomia & histologia
7.
PLoS Negl Trop Dis ; 14(9): e0008626, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32898175

RESUMO

Parasite-released extracellular vesicles (EVs) deliver signals to the host immune system that are critical to maintaining the long-term relationship between parasite and host. In the present study, total EVs (FhEVs) released in vitro by adults of the helminth parasite Fasciola hepatica were isolated using a recently described gravity flow method that protects their structural integrity. The FhEVs molecular cargo was defined using proteomic analysis and their surface topology characterised by glycan microarrays. The proteomic analysis identified 618 proteins, 121 of which contained putative N-linked glycosylation sites while 132 proteins contained putative O-linked glycosylation sites. Glycan arrays revealed surface-exposed glycans with a high affinity for mannose-binding lectins indicating the predominance of oligo mannose-rich glycoproteins, as well as other glycans with a high affinity for complex-type N-glycans. When added to bone-marrow derived dendritic cells isolated FhEV induced a novel phenotype that was categorised by the secretion of low levels of TNF, enhanced expression of cell surface markers (CD80, CD86, CD40, OX40L, and SIGNR1) and elevation of intracellular markers (SOCS1 and SOCS3). When FhEV-stimulated BMDCs were introduced into OT-II mice by adoptive transfer, IL-2 secretion from skin draining lymph nodes and spleen cells was inhibited in response to both specific and non-specific antigen stimulation. Immunisation of mice with a suspension of FhEV did not elicit significant immune responses; however, in the presence of alum, FhEVs induced a mixed Th1/Th2 immune response with high antigen specific antibody titres. Thus, we have demonstrated that FhEVs induce a unique phentotype in DC capable of suppressing IL-2 secretion from T-cells. Our studies add to the growing immuno-proteomic database that will be an important source for the discovery of future parasite vaccines and immunotherapeutic biologicals.


Assuntos
Células Dendríticas/metabolismo , Vesículas Extracelulares/metabolismo , Fasciola hepatica/metabolismo , Interações Hospedeiro-Parasita/fisiologia , Fenótipo , Animais , Antígenos de Helmintos/análise , Biomarcadores , Medula Óssea , Citocinas/metabolismo , Modelos Animais de Doenças , Fasciola hepatica/isolamento & purificação , Fasciolíase/imunologia , Fasciolíase/parasitologia , Glicoproteínas , Manose , Lectinas de Ligação a Manose/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Polissacarídeos/metabolismo , Proteômica , Linfócitos T/imunologia
8.
Nat Commun ; 11(1): 4483, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32900993

RESUMO

The Drosophila lymph gland, the larval hematopoietic organ comprised of prohemocytes and mature hemocytes, has been a valuable model for understanding mechanisms underlying hematopoiesis and immunity. Three types of mature hemocytes have been characterized in the lymph gland: plasmatocytes, lamellocytes, and crystal cells, which are analogous to vertebrate myeloid cells, yet molecular underpinnings of the lymph gland hemocytes have been less investigated. Here, we use single-cell RNA sequencing to comprehensively analyze heterogeneity of developing hemocytes in the lymph gland, and discover previously undescribed hemocyte types including adipohemocytes, stem-like prohemocytes, and intermediate prohemocytes. Additionally, we identify the developmental trajectory of hemocytes during normal development as well as the emergence of the lamellocyte lineage following active cellular immunity caused by wasp infestation. Finally, we establish similarities and differences between embryonically derived- and larval lymph gland hemocytes. Altogether, our study provides detailed insights into the hemocyte development and cellular immune responses at single-cell resolution.


Assuntos
Drosophila melanogaster/citologia , Drosophila melanogaster/genética , Hemócitos/citologia , Hemócitos/metabolismo , Transcriptoma , Animais , Animais Geneticamente Modificados , Diferenciação Celular/genética , Linhagem da Célula/genética , Drosophila melanogaster/metabolismo , Ectoparasitoses/genética , Ectoparasitoses/metabolismo , Ectoparasitoses/patologia , Perfilação da Expressão Gênica , Hematopoese/genética , Interações Hospedeiro-Parasita/genética , Interações Hospedeiro-Parasita/fisiologia , Tecido Linfoide/citologia , Tecido Linfoide/metabolismo , Tecido Linfoide/parasitologia , RNA-Seq , Análise de Célula Única , Vespas/patogenicidade
9.
Proc Natl Acad Sci U S A ; 117(37): 23125-23130, 2020 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-32868415

RESUMO

Many plants use environmental cues, including seasonal changes of day length (photoperiod), to control their flowering time. Under inductive conditions, FLOWERING LOCUS T (FT) protein is synthesized in leaves, and FT protein is a mobile signal, which is able to travel to the shoot apex to induce flowering. Dodders (Cuscuta, Convolvulaceae) are root- and leafless plants that parasitize a large number of autotrophic plant species with varying flowering time. Remarkably, some dodder species, e.g., Cuscuta australis, are able to synchronize their flowering with the flowering of their hosts. Detailed sequence inspection and expression analysis indicated that the FT gene in dodder C. australis very likely does not function in activating flowering. Using soybean host plants cultivated under inductive and noninductive photoperiod conditions and soybean and tobacco host plants, in which FT was overexpressed and knocked out, respectively, we show that FT-induced flowering of the host is likely required for both host and parasite flowering. Biochemical analysis revealed that host-synthesized FT signals are able to move into dodder stems, where they physically interact with a dodder FD transcription factor to activate dodder flowering. This study demonstrates that FTs can function as an important interplant flowering signal in host-dodder interactions. The unique means of flowering regulation of dodder illustrates how regressive evolution, commonly found in parasites, may facilitate the physiological synchronization of parasite and host, here allowing the C. australis parasite to time reproduction exactly with that of their hosts, likely optimizing parasite fitness.


Assuntos
Cuscuta/fisiologia , Cuscuta/parasitologia , Flores/fisiologia , Flores/parasitologia , Interações Hospedeiro-Parasita/fisiologia , Parasitos/fisiologia , Animais , Regulação da Expressão Gênica de Plantas/fisiologia , Folhas de Planta/parasitologia , Folhas de Planta/fisiologia , Soja/parasitologia , Soja/fisiologia , Tabaco/parasitologia , Tabaco/fisiologia , Fatores de Transcrição/metabolismo
10.
Nat Commun ; 11(1): 4185, 2020 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-32826898

RESUMO

Adaptive responses to ecological uncertainty may affect the dynamics of interspecific interactions and shape the course of evolution within symbioses. Obligate avian brood parasites provide a particularly tractable system for understanding how uncertainty, driven by environmental variability and symbiont phenology, influences the evolution of species interactions. Here, we use phylogenetically-informed analyses and a comprehensive dataset on the behaviour and geographic distribution of obligate avian brood parasites and their hosts to demonstrate that increasing uncertainty in thermoregulation and parental investment of parasitic young are positively associated with host richness and diversity. Our findings are consistent with the theoretical expectation that ecological risks and environmental unpredictability should favour the evolution of bet-hedging. Additionally, these highly consistent patterns highlight the important role that ecological uncertainty is likely to play in shaping the evolution of specialisation and generalism in complex interspecific relationships.


Assuntos
Aves/fisiologia , Interações Hospedeiro-Parasita/fisiologia , Parasitos/fisiologia , Incerteza , Animais , Biodiversidade , Coevolução Biológica , Aves/classificação , Clima , Comportamento de Nidação , Parasitos/classificação , Filogenia , Fatores de Risco , Especificidade da Espécie
11.
PLoS One ; 15(8): e0229277, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32817698

RESUMO

Human activities are changing landscape structure and function globally, affecting wildlife space use, and ultimately increasing human-wildlife conflicts and zoonotic disease spread. Capybaras (Hydrochoerus hydrochaeris) are linked to conflicts in human-modified landscapes (e.g. crop damage, vehicle collision), as well as the spread and amplification of Brazilian spotted fever (BSF), the most human-lethal tick-borne disease in the world. Even though it is essential to understand the link between capybaras, ticks and BSF, many knowledge gaps still exist regarding the effects of human disturbance in capybara space use. Here, we analyzed diurnal and nocturnal habitat selection strategies of capybaras across natural and human-modified landscapes using resource selection functions (RSF). Selection for forested habitats was higher across human-modified landscapes, mainly during day- periods, when compared to natural landscapes. Across natural landscapes, capybaras avoided forests during both day- and night periods. Water was consistently selected across both landscapes, during day- and nighttime. Distance to water was also the most important variable in predicting capybara habitat selection across natural landscapes. Capybaras showed slightly higher preferences for areas near grasses/shrubs across natural landscapes, and distance to grasses/shrubs was the most important variable in predicting capybara habitat selection across human-modified landscapes. Our results demonstrate human-driven variation in habitat selection strategies by capybaras. This behavioral adjustment across human-modified landscapes may be related to increases in A. sculptum density, ultimately affecting BSF.


Assuntos
Ecossistema , Roedores/psicologia , Animais , Animais Selvagens , Brasil , Meio Ambiente , Pradaria , Interações Hospedeiro-Parasita/fisiologia , Humanos , Febre Maculosa das Montanhas Rochosas/epidemiologia , Carrapatos , Água , Zoonoses
12.
Proc Biol Sci ; 287(1932): 20200347, 2020 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-32781954

RESUMO

Circadian clocks coordinate organisms' activities with daily cycles in their environment. Parasites are subject to daily rhythms in the within-host environment, resulting from clock-control of host activities, including immune responses. Parasites also exhibit rhythms in their activities: the timing of within-host replication by malaria parasites is coordinated to host feeding rhythms. Precisely which host feeding-related rhythm(s) parasites align with and how this is achieved are unknown. Understanding rhythmic replication in malaria parasites matters because it underpins disease symptoms and fuels transmission investment. We test if rhythmicity in parasite replication is coordinated with the host's feeding-related rhythms and/or rhythms driven by the host's canonical circadian clock. We find that parasite rhythms coordinate with the time of day that hosts feed in both wild-type and clock-mutant hosts, whereas parasite rhythms become dampened in clock-mutant hosts that eat continuously. Our results hold whether infections are initiated with synchronous or with desynchronized parasites. We conclude that malaria parasite replication is coordinated to rhythmic host processes that are independent of the core-clock proteins PERIOD 1 and 2; most likely, a periodic nutrient made available when the host digests food. Thus, novel interventions could disrupt parasite rhythms to reduce their fitness, without interference by host clock-controlled homeostasis.


Assuntos
Relógios Circadianos , Interações Hospedeiro-Parasita/fisiologia , Plasmodium chabaudi/fisiologia , Animais , Ritmo Circadiano/fisiologia , Homeostase , Malária , Parasitos , Proteínas Circadianas Period
13.
Nat Commun ; 11(1): 3922, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32764664

RESUMO

The Plasmodium falciparum chloroquine resistance transporter (PfCRT) is a key contributor to multidrug resistance and is also essential for the survival of the malaria parasite, yet its natural function remains unresolved. We identify host-derived peptides of 4-11 residues, varying in both charge and composition, as the substrates of PfCRT in vitro and in situ, and show that PfCRT does not mediate the non-specific transport of other metabolites and/or ions. We find that drug-resistance-conferring mutations reduce both the peptide transport capacity and substrate range of PfCRT, explaining the impaired fitness of drug-resistant parasites. Our results indicate that PfCRT transports peptides from the lumen of the parasite's digestive vacuole to the cytosol, thereby providing a source of amino acids for parasite metabolism and preventing osmotic stress of this organelle. The resolution of PfCRT's native substrates will aid the development of drugs that target PfCRT and/or restore the efficacy of existing antimalarials.


Assuntos
Antimaláricos/farmacologia , Cloroquina/farmacologia , Proteínas de Membrana Transportadoras/metabolismo , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/metabolismo , Proteínas de Protozoários/metabolismo , Animais , Transporte Biológico Ativo , Resistência a Medicamentos/genética , Feminino , Interações Hospedeiro-Parasita/genética , Interações Hospedeiro-Parasita/fisiologia , Humanos , Malária Falciparum/tratamento farmacológico , Malária Falciparum/metabolismo , Malária Falciparum/parasitologia , Proteínas de Membrana Transportadoras/genética , Modelos Biológicos , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Oligopeptídeos/metabolismo , Oócitos/metabolismo , Plasmodium falciparum/genética , Transporte Proteico , Proteínas de Protozoários/genética , Xenopus laevis
14.
Proc Natl Acad Sci U S A ; 117(36): 22580-22589, 2020 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-32848066

RESUMO

The global movement of pathogens is altering populations and communities through a variety of direct and indirect ecological pathways. The direct effect of a pathogen on a host is reduced survival, which can lead to decreased population densities. However, theory also suggests that increased mortality can lead to no change or even increases in the density of the host. This paradoxical result can occur in a regulated population when the pathogen's negative effect on survival is countered by increased reproduction at the lower density. Here, we analyze data from a long-term capture-mark-recapture experiment of Trinidadian guppies (Poecilia reticulata) that were recently infected with a nematode parasite (Camallanus cotti). By comparing the newly infected population with a control population that was not infected, we show that decreases in the density of the infected guppy population were transient. The guppy population compensated for the decreased survival by a density-dependent increase in recruitment of new individuals into the population, without any change in the underlying recruitment function. Increased recruitment was related to an increase in the somatic growth of uninfected fish. Twenty months into the new invasion, the population had fully recovered to preinvasion densities even though the prevalence of infection of fish in the population remained high (72%). These results show that density-mediated indirect effects of novel parasites can be positive, not negative, which makes it difficult to extrapolate to how pathogens will affect species interactions in communities. We discuss possible hypotheses for the rapid recovery.


Assuntos
Interações Hospedeiro-Parasita/fisiologia , Modelos Biológicos , Infecções por Nematoides/epidemiologia , Poecilia/parasitologia , Dinâmica Populacional/estatística & dados numéricos , Animais , Feminino , Masculino
15.
Nat Commun ; 11(1): 2761, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32487994

RESUMO

Plasmodium vivax is the most widely distributed human malaria parasite. Previous studies have shown that circulating microparticles during P. vivax acute attacks are indirectly associated with severity. Extracellular vesicles (EVs) are therefore major components of circulating plasma holding insights into pathological processes. Here, we demonstrate that plasma-derived EVs from Plasmodium vivax patients (PvEVs) are preferentially uptaken by human spleen fibroblasts (hSFs) as compared to the uptake of EVs from healthy individuals. Moreover, this uptake induces specific upregulation of ICAM-1 associated with the translocation of NF-kB to the nucleus. After this uptake, P. vivax-infected reticulocytes obtained from patients show specific adhesion properties to hSFs, reversed by inhibiting NF-kB translocation to the nucleus. Together, these data provide physiological EV-based insights into the mechanisms of human malaria pathology and support the existence of P. vivax-adherent parasite subpopulations in the microvasculature of the human spleen.


Assuntos
Vesículas Extracelulares/metabolismo , Fibroblastos/metabolismo , NF-kappa B/metabolismo , Plasma , Plasmodium vivax/fisiologia , Reticulócitos/metabolismo , Baço/metabolismo , Animais , Adesão Celular , Micropartículas Derivadas de Células , Modelos Animais de Doenças , Vesículas Extracelulares/parasitologia , Fibroblastos/patologia , Interações Hospedeiro-Parasita/fisiologia , Humanos , Molécula 1 de Adesão Intercelular/metabolismo , Malária Vivax/parasitologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microvasos/parasitologia , Proteômica , Reticulócitos/parasitologia , Baço/patologia
16.
Nat Commun ; 11(1): 2763, 2020 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-32488076

RESUMO

Malaria parasites complete their intra-erythrocytic developmental cycle (IDC) in multiples of 24 h suggesting a circadian basis, but the mechanism controlling this periodicity is unknown. Combining in vivo and in vitro approaches utilizing rodent and human malaria parasites, we reveal that: (i) 57% of Plasmodium chabaudi genes exhibit daily rhythms in transcription; (ii) 58% of these genes lose transcriptional rhythmicity when the IDC is out-of-synchrony with host rhythms; (iii) 6% of Plasmodium falciparum genes show 24 h rhythms in expression under free-running conditions; (iv) Serpentine receptor 10 (SR10) has a 24 h transcriptional rhythm and disrupting it in rodent malaria parasites shortens the IDC by 2-3 h; (v) Multiple processes including DNA replication, and the ubiquitin and proteasome pathways, are affected by loss of coordination with host rhythms and by disruption of SR10. Our results reveal malaria parasites are at least partly responsible for scheduling the IDC and coordinating their development with host daily rhythms.


Assuntos
Ritmo Circadiano/fisiologia , Eritropoese/fisiologia , Interações Hospedeiro-Parasita/fisiologia , Malária/metabolismo , Proteínas de Protozoários/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Alcaloides de Triptamina e Secologanina/metabolismo , Animais , Proteínas de Caenorhabditis elegans , Modelos Animais de Doenças , Feminino , Expressão Gênica , Interações Hospedeiro-Parasita/genética , Humanos , Malária/parasitologia , Camundongos , Camundongos Knockout , Plasmodium chabaudi/genética , Plasmodium chabaudi/crescimento & desenvolvimento , Plasmodium falciparum/genética , Plasmodium falciparum/crescimento & desenvolvimento , Proteínas de Protozoários/genética , Receptores Acoplados a Proteínas G/genética , Roedores , Transcriptoma
17.
Trends Parasitol ; 36(8): 668-676, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32540194

RESUMO

Understanding the origin of sex differences in lifespan and aging patterns remains a salient challenge in both biogerontology and evolutionary biology. Different factors have been studied but the potential influence of pathogens has never been investigated. Sex differences, especially in hormones and resource allocation, generate a differential response to pathogens and thereby shape sex differences in lifespan or aging. We provide an integrative framework linking host pathogenic environment with both sex-specific selections on immune performance and mortality trajectories. We propose future directions to fill existing knowledge gaps about mechanisms that link sex differences, not only to exposition and sensitivity to pathogens, but also to mortality patterns, whilst emphasizing the urgent need to consider the role of sex in medicine.


Assuntos
Envelhecimento/fisiologia , Interações Hospedeiro-Parasita/fisiologia , Mamíferos/parasitologia , Doenças Parasitárias/epidemiologia , Envelhecimento/imunologia , Animais , Evolução Biológica , Interações Hospedeiro-Parasita/imunologia , Humanos , Longevidade , Mamíferos/imunologia , Doenças Parasitárias/parasitologia , Fatores Sexuais
18.
PLoS One ; 15(6): e0235000, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32589676

RESUMO

Phoresy is a behavior in which an organism, the phoront, travels from one location to another by 'hitching a ride' on the body of a host as it disperses. Some phoronts are generalists, taking advantage of any available host. Others are specialists and travel only when specific hosts are located using chemical cues to identify and move (chemotax) toward the preferred host. Free-living nematodes, like Caenorhabditis elegans, are often found in natural environments that contain terrestrial isopods and other invertebrates. Additionally, the C. elegans wild strain PB306 was isolated associated with the isopod Porcellio scaber. However, it is currently unclear if C. elegans is a phoront of terrestrial isopods, and if so, whether it is a specialist, generalist, or developmental stage-specific combination of both strategies. Because the relevant chemical stimuli might be secreted compounds or volatile odorants, we used different types of chemotaxis assays across diverse extractions of compounds or odorants to test whether C. elegans is attracted to P. scaber. We show that two different strains-the wild isolate PB306 and the laboratory-adapted strain N2 -are not attracted to P. scaber during either the dauer or adult life stages. Our results indicate that C. elegans was not attracted to chemical compounds or volatile odorants from P. scaber, providing valuable empirical evidence to suggest that any associations between these two species are likely opportunistic rather than specific phoresy.


Assuntos
Caenorhabditis elegans/fisiologia , Interações Hospedeiro-Parasita/fisiologia , Isópodes/parasitologia , Animais , Caenorhabditis elegans/isolamento & purificação , Quimiotaxia/fisiologia , Isópodes/fisiologia , Estágios do Ciclo de Vida , Odorantes
19.
Arch Microbiol ; 202(8): 2245-2253, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32533207

RESUMO

Venturia inaequalis is a notorious fungal pathogen and show classical gene for gene interaction with its apple host. Neutral markers provide clues about history, evolutionary potential, genetic diversity and population structure of V. inaequalis. The genetic diversity and population structure of fungus indicates that the pathogen is highly diverse with the capacity to breach the scab resistance genes. In the present study, we collected 108 V. inaequalis isolates from three apple cultivars differing in Rvi1 resistance gene. Based on the AMOVA, the variation was mostly distributed among the isolates, providing evidence of non-existence of subpopulation in orchards thus founder population is difficult to arise in Kashmir apple orchards. Pair wise genetic differentiation is less due to regular occurrence of gene flow between the populations residing on different orchard as infected material is transported without stringent quarantine measures. Based on principal coordinate analysis and clustering algorithm as implemented in STRUCTURE, we observed admixture between the two subpopulations, which is quite low, suggesting the existence of pre-zygotic and post-zygotic barriers to gene flow and we cannot rule out the existence of other structures shared by accessions belonging to different varieties. Due to the continuous increase in introduction and monoculture of apple varieties, mixed orchard with different host resistance specificities are more suitable for managing the apple scab in Kashmir valley.


Assuntos
Ascomicetos/fisiologia , Especificidade de Hospedeiro , Interações Hospedeiro-Parasita/fisiologia , Malus/microbiologia , Ascomicetos/genética , Evolução Biológica , Análise por Conglomerados , Interações Hospedeiro-Parasita/genética , Índia , Malus/genética , Doenças das Plantas/microbiologia
20.
Science ; 368(6492): 746-753, 2020 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-32409471

RESUMO

Malarial rhythmic fevers are the consequence of the synchronous bursting of red blood cells (RBCs) on completion of the malaria parasite asexual cell cycle. Here, we hypothesized that an intrinsic clock in the parasite Plasmodium chabaudi underlies the 24-hour-based rhythms of RBC bursting in mice. We show that parasite rhythms are flexible and lengthen to match the rhythms of hosts with long circadian periods. We also show that malaria rhythms persist even when host food intake is evenly spread across 24 hours, suggesting that host feeding cues are not required for synchrony. Moreover, we find that the parasite population remains synchronous and rhythmic even in an arrhythmic clock mutant host. Thus, we propose that parasite rhythms are generated by the parasite, possibly to anticipate its circadian environment.


Assuntos
Ritmo Circadiano/fisiologia , Febre/fisiopatologia , Febre/parasitologia , Interações Hospedeiro-Parasita/fisiologia , Malária/fisiopatologia , Malária/parasitologia , Plasmodium chabaudi/fisiologia , Animais , Proteínas CLOCK/genética , Ritmo Circadiano/genética , Sinais (Psicologia) , Escuridão , Ingestão de Alimentos , Eritrócitos/parasitologia , Comportamento Alimentar , Regulação da Expressão Gênica , Interações Hospedeiro-Parasita/genética , Camundongos , Camundongos Mutantes , Plasmodium chabaudi/genética , Transcrição Genética
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