Efeito do exossomas de Trypanosoma brucei na imunoactivação de Macrófagos Murinos

A tripanossomose africana é uma doença parasitária negligenciada de grande importância para a saúde pública e constitui um grave problema para a agricultura nas áreas endémicas. Esta doença parasitária afeta por ano cerca de 5000 humanos e milhões de animais na África subsaariana. Os tratamentos atuais são limitados, difíceis de administrar e muitas vezes tóxicos, causando lesões ou morte em muitos doentes. A transmissão do parasita aos hospedeiros mamíferos é efetuada através da picada da mosca Tsé-tsé. Após a picada, o parasita é introduzido no hospedeiro mamífero e gera uma série acontecimentos que conduzem à intervenção do sistema imunitário do hospedeiro. Os macrófagos desempenham um papel fundamental na defesa inata contra o tripanossoma. No entanto, este mecanismo de defesa, bem como as estratégias que o parasita usa para escapar ao sistema imunitário do hospedeiro, estão longe de ser totalmente compreendidas. As formas sanguíneas (BSFs) de T. brucei têm a capacidade de produzir nanotubos na membrana flagelar que se dissociam para formar nanovesículas extracelulares, os exossomas. Os exossomas contém várias proteínas flagelares que funcionam como fatores de virulência, bem como, um tipo de proteína associada à resistência ao soro (SRA) que protege o parasita dos efeitos nocivos da resposta imunitária do hospedeiro. O presente estudo tem como objetivo a análise do efeito dos exossomas de Trypanosoma brucei brucei na atividade dos macrófagos, avaliando os níveis de ureia e óxido nítrico e a expressão de moléculas de classe I (MCHI) e classe II (MHCII) do complexo maior de histocompatibilidade na superfície membranar dos macrófagos. A caracterização da ativação macrofágica através dos ensaios colorimétricos demonstrou que ambos os fenótipos M1 e M2 foram expressos e que os exossomas de T. b. brucei desempenham um papel na indução desses dois tipos de macrófagos. Os resultados da citometria de fluxo indicaram que o parasita inibe a diferenciação das subpopulações de macrófagos MHCI+ e macrófagos MHCII+, mas os exossomas promovem a expansão dessas subpopulações Contudo, apenas os exossomas iniciais (48h) promoveram a expansão de macrófagos MHCII+ e induziram o aumento das moléculas de superfície MHCII, possibilitando a apresentação antigénica aos linfócitos Th e induzindo a imunidade adaptativa. Este estudo analisou pela primeira vez o efeito dos exossomas de T. b. brucei na atividade macrofágica. Os exossomas podem comportar-se de modo semelhante ao parasita, amplificando a modulação do sistema imunitário do hospedeiro ou podem comportar-se de modo oposto ao do parasita, favorecendo a progressão da infeção, mas também interferindo na regulação da resposta adaptativa do hospedeiro. Esses resultados possibilitaram esclarecer alguns dos aspetos da resposta imunitária inata e da indução da resposta adaptativa na fase inicial da infeção por T. b. brucei. Compreender esses mecanismos pode contribuir para o desenvolvimento de novas estratégias de controlo que conduzam à eliminação da tripanossomose africana.African trypanosomiasis is a neglected parasitic disease that still is of great public health relevance and a severe impediment to successful agriculture activities in endemic areas. This parasitic disease affects 5000 humans and millions of livestock in sub-Saharan Africa every year. Current treatments are limited, difficult to administer and often toxic, causing long-term injury or death in many patients. The parasite is transmitted to mammalian hosts by the bite of tse-tse fly. After the bite, the parasite will generate a series of events, leading to the intervention of the host immune system Macrophages are known to play a key role in the innate defense against trypanosomiasis. However, this defense mechanism and the parasite strategies to escape the host immune response are far from being fully understood. Trypanosoma brucei bloodstream forms (BSFs) have the ability to produce nanotubes from the flagellar membrane. These nanotubes dissociate to form extracellular nanovesicles, the exosomes. Exosomes incorporate flagellar proteins that are identified as virulent factors and a type of serum resistant associated protein (SRA) that protects the parasite from the harmful effects of host immune response. Thus, the present study aims to analyze the effect of T. brucei brucei exosomes on macrophage activity, evaluating the levels of urea and nitric oxide and assessing the membrane expression of class I (MHCI) and class II (MHCII) molecules of major histocompatibility complex. Characterization of macrophage activation through colorimetric assays demonstrated that both M1 and M2 phenotypes were expressed and that T. b. brucei exosomes had a role in inducing both macrophage types. In addition, flow cytometry results indicated that the parasite inhibits the differentiation MHCI+ and MHCII+ macrophages. Exosomes induce the expansion of both these subpopulations. Only the initial (48h) exosomes promoted the expansion of MHCII+ macrophages and increase the density of MHCII surface molecules, enabling antigen presentation to Th lymphocytes and inducing adaptive immunity. To the best of our knowledge, this study evaluates for the first time first the effect of T. b. brucei exosomes in macrophage activity. Parasite and exosomes may have similar effects on macrophages, amplifying the modulation of the host's immune system or may have opposite effects, favoring infection outcome, but also regulating host adaptive immune response. These results made it possible to clarify some aspects of the innate immune response and the induction of the adaptive response in the initial phase of T. b. brucei. Understanding these mechanisms can contribute to the development of new control strategies leading to the elimination of African trypanosomiasis. These results have made possible to clarify some aspects of innate immune response in the initial phase of infection and investigate the induction of adaptive immune response. Understanding these mechanisms may contribute to the development of new strategies for control and elimination of African Trypanosomiasis

the complexity of host's effective immune response against a polymorphic parasitic disease

This review is aimed at providing a comprehensive outline of the immune response displayed against cutaneous leishmaniasis (CL), the more common zoonotic infection caused by protozoan parasites of the genus Leishmania. Although of polymorphic clinical presentation, classically CL is characterized by leishmaniotic lesions on the face and extremities of the patients, which can be ulcerative, and even after healing can lead to permanent injuries and disfigurement, affecting significantly their psychological, social, and economic well-being. According a report released by the World Health Organization, the disability-adjusted life years (DALYs) lost due to leishmaniasis are close to 2.4 million, annually there are 1.0-1.5 million new cases of CL, and a numerous population is at risk in the endemic areas. Despite its increasing worldwide incidence, it is one of the so-called neglected tropical diseases. Furthermore, this review provides an overview of the existing knowledge of the host innate and acquired immune response to cutaneous species of Leishmania. The use of animal models and of in vitro studies has improved the understanding of parasite-host interplay and the complexity of immune mechanisms involved. The importance of diagnosis accuracy associated with effective patient management in CL reduction is highlighted. However, the multiple factors involved in CL epizoology associated with the unavailability of vaccines or drugs to prevent infection make difficult to formulate an effective strategy for CL control.publishersversionpublishe

Extracellular vesicles shed by trypanosoma brucei brucei manipulate host mononuclear cells

Funding Information: Funding: This study was supported by FCT—Foundation for Science and Technology, I.P., through research grant PTDC/CVT-CVT/28908/2017 and by national funds within the scope of Centro de Investigação Interdisciplinar em Sanidade Animal (CIISA, UIDB/00276/2020) and Global Health and Tropical Medicine (GHTM, UID/04413/2020). Funding Information: This study was supported by FCT?Foundation for Science and Technology, I.P., through research grant PTDC/CVT-CVT/28908/2017 and by national funds within the scope of Centro de Investiga??o Interdisciplinar em Sanidade Animal (CIISA, UIDB/00276/2020) and Global Health and Tropical Medicine (GHTM, UID/04413/2020). Publisher Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland.African trypanosomiasis or sleeping sickness is a zoonotic disease caused by Trypanosoma brucei, a protozoan parasite transmitted by Glossina spp. (tsetse fly). Parasite introduction into mammal hosts triggers a succession of events, involving both innate and adaptive immunity. Macrophages (MΦ) have a key role in innate defence since they are antigen-presenting cells and have a micro-bicidal function essential for trypanosome clearance. Adaptive immune defence is carried out by lymphocytes, especially by T cells that promote an integrated immune response. Like mammal cells, T. b. brucei parasites release extracellular vesicles (TbEVs), which carry macromolecules that can be transferred to host cells, transmitting biological information able to manipulate cell immune response. However, the exact role of TbEVs in host immune response remains poorly understood. Thus, the current study examined the effect elicited by TbEVs on MΦ and T lymphocytes. A combined approach of microscopy, nanoparticle tracking analysis, multiparametric flow cytometry, colourimetric assays and detailed statistical analyses were used to evaluate the influence of TbEVs in mouse mononuclear cells. It was shown that TbEVs can establish direct communication with cells of innate and adaptative immunity. TbEVs induce the differentiation of both M1-and M2-MΦ and elicit the expansion of MHCI+, MHCII+ and MHCI+ MHCII+ MΦ subpopulations. In T lymphocytes, TbEVs drive the overexpression of cell-surface CD3 and the nuclear factor FoxP3, which lead to the differentiation of regulatory CD4+ and CD8+ T cells. Moreover, this study indicates that T. b. brucei and TbEVs seem to display opposite but complementary effects in the host, establishing a balance between parasite growth and controlled immune response, at least during the early phase of infection.publishersversionpublishe

Exploiting Leishmania—Primed Dendritic Cells as Potential Immunomodulators of Canine Immune Response

Funding Information: This research was funded by the FCT-Foundation for Science and Technology, I.P., through research grants PTDC/CVT-CVT/28908/2017 (http://doi.org/10.54499/PTDC/CVT-CVT/28908/2017) and PTDC/CVT-CVT/0228/2020 (http://doi.org/10.54499/PTDC/CVT-CVT/0228/2020) and by national funds within the scope of Centro de Investigação Interdisciplinar em Sanidade Animal (CIISA, UIDB/00276/2020), AL4AnimalS—LA/P/0059/2020, Global Health and Tropical Medicine (GHTM, UID/04413/2020), and LA-REAL—LA/P/0117/2020. Publisher Copyright: © 2024 by the authors.Dendritic cells (DCs) capture pathogens and process antigens, playing a crucial role in activating naïve T cells, bridging the gap between innate and acquired immunity. However, little is known about DC activation when facing Leishmania parasites. Thus, this study investigates in vitro activity of canine peripheral blood-derived DCs (moDCs) exposed to L. infantum and L. amazonensis parasites and their extracellular vesicles (EVs). L. infantum increased toll-like receptor 4 gene expression in synergy with nuclear factor κB activation and the generation of pro-inflammatory cytokines. This parasite also induced the expression of class II molecules of major histocompatibility complex (MHC) and upregulated co-stimulatory molecule CD86, which, together with the release of chemokine CXCL16, can attract and help in T lymphocyte activation. In contrast, L. amazonensis induced moDCs to generate a mix of pro- and anti-inflammatory cytokines, indicating that this parasite can establish a different immune relationship with DCs. EVs promoted moDCs to express class I MHC associated with the upregulation of co-stimulatory molecules and the release of CXCL16, suggesting that EVs can modulate moDCs to attract cytotoxic CD8+ T cells. Thus, these parasites and their EVs can shape DC activation. A detailed understanding of DC activation may open new avenues for the development of advanced leishmaniasis control strategies.publishersversionpublishe

A Silent Threat for Dogs and Humans

Funding Information: This study was supported by FCT\u2014Foundation for Science and Technology, I.P., through research grants EXPL/CVT-CVT/0175/2021 (DOI 10.54499/EXPL/CVT-CVT/0175/2021) and PTDC/CVT-CVT/0228/2020 (DOI 10.54499/PTDC/CVT-CVT/0228/2020) and by national funds within the scope of Centro de Investiga\u00E7\u00E3o Interdisciplinar em Sanidade Animal (CIISA, UIDB/00276/2020), Al4AnimalS (LA/P/0059/2020), Global Health and Tropical Medicine (GHTM, UID/04413/2020) and LA-REAL (LA/P/0117/2020). Joana Palma Marques and Marta Monteiro have Ph.D. scholarship references 2021.05579BD and UI/BD/152819/2022, respectively. A. Rodrigues awards a CEECIND/CP1725/CT0023 (10.54499/2022.00499.CEECIND/CP1725/CT0023). Publisher Copyright: © 2024 by the authors.Chagas disease (CD) is a vector-borne Neglected Zoonotic Disease (NZD) caused by a flagellate protozoan, Trypanosoma cruzi, that affects various mammalian species across America, including humans and domestic animals. However, due to an increase in population movements and new routes of transmission, T. cruzi infection is presently considered a worldwide health concern, no longer restricted to endemic countries. Dogs play a major role in the domestic cycle by acting very efficiently as reservoirs and allowing the perpetuation of parasite transmission in endemic areas. Despite the significant progress made in recent years, still there is no vaccine against human and animal disease, there are few drugs available for the treatment of human CD, and there is no standard protocol for the treatment of canine CD. In this review, we highlight human and canine Chagas Disease in its different dimensions and interconnections. Dogs, which are considered to be the most important peridomestic reservoir and sentinel for the transmission of T. cruzi infection in a community, develop CD that is clinically similar to human CD. Therefore, an integrative approach, based on the One Health concept, bringing together the advances in genomics, immunology, and epidemiology can lead to the effective development of vaccines, new treatments, and innovative control strategies to tackle CD.publishersversionpublishe

Taste compounds and consumer acceptance of chicken soups as affected by cooking conditions

Este estudio aborda los acontecimientos que tienen lugar durante la cocción de sopas de pollo en diferentes condiciones, así como sus implicaciones en la calidad sensorial. Para eso, se investigó el efecto de la temperatura (103 ° C y 85 ° C) y el tiempo (3, 4 y 5 h) de la cocción en compuestos de sabor y atributos sensoriales de las sopas de pollo. Los aminoácidos, nucleótidos y umami equivalentes mostraron los valores más altos a 103 ° C y 5 h de sopas y los más bajos a 85 ° C y 3 h. Los compuestos del gusto aumentan con la temperatura y el tiempo de cocción. Los atributos sensoriales obtuvieron puntuaciones más altas a 103 ° C que a 85 ° C. Inosina-5'-monofosfato y guanosina-5'-monofosfato y aminoácidos menores (ácido α-aminoadípico, ornitina, triptófano, cistina y metionina) influyeron notablemente en los compuestos del sabor. Además, este estudio utiliza primero un método fácil y rápido para el análisis de aminoácidos, con sarcosina, ácido α-aminobutírico, ácido β-aminoisobutírico, alo-isoleucina y ácido α-aminoadípico que se detectan por primera vez en sopas.This study deals with the occurrences that take place during the cooking of chicken soups under different conditions as well as their implications on the sensory quality. For that, the effect of temperature (103°C and 85°C) and time (3, 4, and 5 h) of cooking on taste compounds and sensory attributes of chicken soups was investigated. Amino acids, nucleotides, and equivalent umami showed the highest values at 103°C and 5 h soups and the lowest at 85°C and 3 h. Taste compounds increased with temperature and cooking time. Sensory attributes obtained higher scores at 103°C than at 85°C. Inosine-5’-monophosphate and guanosine-5’-monophosphate and minor amino acids (α-aminoadipic acid, ornithine, tryptophan, cystine, and methionine) influenced taste compounds notably. In addition, this study firstly uses an easy and rapid method for amino acid analysis, with sarcosine, α-aminobutiric acid, ß-aminoisobutiric acid, allo-isoleucine, and α-aminoadipic acid being detected for the first time in soups.peerReviewe

Measurement of the differential cross-section of B+B^{+} meson production in pp collisions at s\sqrt{s} = 7 TeV at ATLAS

The production cross-section of B+ mesons is measured as a function of transverse momentum pT and rapidity y in proton--proton collisions at center-of-mass energy sqrt(s) = 7 TeV, using 2.4 fb-1 of data recorded with the ATLAS detector at the Large Hadron Collider. The differential production cross-sections, determined in the range 9<pT<120 GeV and y<2.25, are compared to next-to-leading-order theoretical predictions.Peer Reviewe

Dynamics of isolated-photon plus jet production in pp collisions at (s)=7\sqrt(s)=7 TeV with the ATLAS detector

The dynamics of isolated-photon plus jet production in pp collisions at a centre-of-mass energy of 7 TeV has been studied with the ATLAS detector at the LHC using an integrated luminosity of 37 pb^-^1. Measurements of isolated-photon plus jet bin-averaged cross sections are presented as functions of photon transverse energy, jet transverse momentum and jet rapidity. In addition, the bin-averaged cross sections as functions of the difference between the azimuthal angles of the photon and the jet, the photon-jet invariant mass and the scattering angle in the photon-jet centre-of-mass frame have been measured. Next-to-leading-order QCD calculations are compared to the measurements and provide a good description of the data, except for the case of the azimuthal opening angle.Peer Reviewe

Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, $H\rightarrow\gamma\gamma$, $H\rightarrow ZZ^{*}\rightarrow 4 \ell$ and $H\rightarrow W W \rightarrow \ell\nu\ell\nu$. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of 7 TeV and 8 TeV, corresponding to an integrated luminosity of about 25 fb$^{-1}$. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson.Peer Reviewe

Observation of an Excited Bc±B_c^\pm Meson State with the ATLAS Detector

A search for excited states of the Bc± meson is performed using 4.9  fb-1 of 7 TeV and 19.2  fb-1 of 8 TeV pp collision data collected by the ATLAS experiment at the LHC. A new state is observed through its hadronic transition to the ground state, with the latter detected in the decay Bc±→J/ψπ±. The state appears in the m(Bc±π+π-)-m(Bc±)-2m(π±) mass difference distribution with a significance of 5.2 standard deviations. The mass of the observed state is 6842±4±5  MeV, where the first error is statistical and the second is systematic. The mass and decay of this state are consistent with expectations for the second S-wave state of the Bc± meson, Bc±(2S).Peer Reviewe