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Liposomes carrying differential charges have been extensively studied for their role in stimulating dendritic cells (DCs), major antigen-presenting cells, known to serve as a pivotal bridge between innate and adaptive immunity. However, the impact of the differentially charged liposomes on activating DCs remains to be understood. In this study, we have investigated the impact of 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC)-based neutral, anionic, and cationic liposomes on the uptake, immunostimulation, and intracellular fate in mouse bone-marrow-derived DCs. We observed that liposomes could induce phenotypic maturation of DCs by inducing the expression of costimulatory molecules (CD40 and CD86) and production of cytokines tumor necrosis factor-α, interleukin-12,and nitric oxide. Interestingly, admixing monophosphoryl lipid A with charged liposomes further enhances the expression of the costimulatory molecules and production of cytokines, with preferential activation by positively charged liposomes. Fluorometric analysis using a pH-sensitive dye and flow-cytometry-based pathway inhibition assays revealed that cationic liposomes were taken up more efficiently by DCs through endocytosis and transported to neutral compartments for further processing, whereas anionic and neutral liposomes were inclined to accumulate in acidic compartments. These findings therefore endorse the use of cationic DSPC liposomes as a preferred option for vaccine delivery vehicles over neutral and negatively charged liposomes, particularly for the preferential activation of DCs.
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Deciphering how hesperadin, a repurposed mammalian aurora kinase B inhibitor, affects the cellular pathways in Leishmania donovani might be beneficial. This investigation sought to assess the physiological effects of hesperadin on promastigotes of L. donovani, by altering the duration of treatment following exposure to hesperadin. Groups pre-treated with inhibitors such as EGTA, NAC, and z-VAD-fmk before hesperadin exposure were also included. Morphological changes by microscopy, ATP and ROS changes by luminometry; DNA degradation using agarose gel electrophoresis and metacaspase levels through RT-PCR were assessed. Flow cytometry was used to study mitochondrial depolarization using JC-1 and MitoTracker Red; mitochondrial-superoxide accumulation using MitoSOX; plasma membrane modifications using Annexin-V and propidium iodide, and lastly, caspase activation using ApoStat. Significant alterations in promastigote morphology were noted. Caspase activity and mitochondrial-superoxide rose early after exposure whereas mitochondrial membrane potential demonstrated uncharacteristic variations, with significant functional disturbances such as leakage of superoxide radicals after prolonged treatments. ATP depletion and ROS accumulation demonstrated inverse patterns, genomic DNA showed fragmentation and plasma membrane showed Annexin-V binding, soon followed by propidium iodide uptake. Multilobed macronuclei and micronuclei accumulated in hesperadin exposed cells before they disintegrated into necrotic debris. The pathologic alterations were unlike the intrinsic or extrinsic pathways of classical apoptosis and suggest a caspase-mediated cell death most akin to mitotic-catastrophe. Most likely, a G2/M transition block caused accumulation of death signals, disorganized spindles and mechanical stresses, causing changes in morphology, organellar functions and ultimately promastigote death. Thus, death was a consequence of mitotic-arrest followed by ablation of kinetoplast functions, often implicated in L. donovani killing.
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Leishmania donovani , Potencial da Membrana Mitocondrial , Leishmania donovani/efeitos dos fármacos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Morte Celular/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Apoptose/efeitos dos fármacos , Trifosfato de Adenosina/metabolismo , Caspases/metabolismo , Fragmentação do DNA/efeitos dos fármacosRESUMO
BACKGROUND: Subclinical pulmonary tuberculosis, which presents without recognisable symptoms, is frequently detected in community screening. However, the disease category is poorly clinically defined. We explored the prevalence of subclinical pulmonary tuberculosis according to different case definitions. METHODS: We did a one-stage individual participant data meta-analysis of nationally representative surveys that were conducted in countries with high incidence of tuberculosis between 2007 and 2020, that reported the prevalence of pulmonary tuberculosis based on chest x-ray and symptom screening in participants aged 15 years and older. Screening and diagnostic criteria were standardised across the surveys, and tuberculosis was defined by positive Mycobacterium tuberculosis sputum culture. We estimated proportions of subclinical tuberculosis for three case definitions: no persistent cough (ie, duration ≥2 weeks), no cough at all, and no symptoms (ie, absence of cough, fever, chest pain, night sweats, and weight loss), both unadjusted and adjusted for false-negative chest x-rays and uninterpretable culture results. FINDINGS: We identified 34 surveys, of which 31 were eligible. Individual participant data were obtained and included for 12 surveys (620 682 participants) across eight countries in Africa and four in Asia. Data on 602 863 participants were analysed, of whom 1944 had tuberculosis. The unadjusted proportion of subclinical tuberculosis was 59·1% (n=1149/1944; 95% CI 55·8-62·3) for no persistent cough and 39·8% (773/1944; 36·6-43·0) for no cough of any duration. The adjusted proportions were 82·8% (95% CI 78·6-86·6) for no persistent cough and 62·5% (56·6-68·7) for no cough at all. In a subset of four surveys, the proportion of participants with tuberculosis but without any symptoms was 20·3% (n=111/547; 95% CI 15·5-25·1) before adjustment and 27·7% (95% CI 21·0-36·4) after adjustment. Tuberculosis without cough, irrespective of its duration, was more frequent among women (no persistent cough: adjusted odds ratio 0·79, 95% CI 0·63-0·97; no cough: adjusted odds ratio 0·76, 95% CI 0·62-0·93). Among participants with tuberculosis, 29·1% (95% CI 25·2-33·3) of those without persistent cough and 23·1% (18·8-27·4) of those without any cough had positive smear examinations. INTERPRETATION: The majority of people in the community who have pulmonary tuberculosis do not report cough, a quarter report no tuberculosis-suggestive symptoms at all, and a quarter of those not reporting any cough have positive sputum smears, suggesting infectiousness. In high-incidence settings, subclinical tuberculosis could contribute considerably to the tuberculosis burden and to Mycobacterium tuberculosis transmission. FUNDING: Mr Willem Bakhuys Roozeboom Foundation.
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Tuberculose Pulmonar , Humanos , Tuberculose Pulmonar/epidemiologia , Tuberculose Pulmonar/diagnóstico , Prevalência , Adulto , Masculino , Feminino , Pessoa de Meia-Idade , Tosse/epidemiologia , Tosse/microbiologia , África/epidemiologia , Ásia/epidemiologia , Mycobacterium tuberculosis/isolamento & purificação , Adulto Jovem , Adolescente , Escarro/microbiologia , Programas de Rastreamento/métodos , IdosoRESUMO
The intracellular protozoan parasite Leishmania donovani causes debilitating human diseases that involve visceral and dermal manifestations. Type 3 interferons (IFNs), also referred to as lambda IFNs (IFNL, IFN-L, or IFN-λ), are known to play protective roles against intracellular pathogens at the epithelial surfaces. Herein, we show that L. donovani induces IFN-λ3 in human as well as mouse cell line-derived macrophages. Interestingly, IFN-λ3 treatment significantly decreased parasite load in infected cells, mainly by increasing reactive oxygen species production. Microscopic examination showed that IFN-λ3 inhibited uptake but not replication, while the phagocytic ability of the cells was not affected. This was confirmed by experiments that showed that IFN-λ3 could decrease parasite load only when added to the medium at earlier time points, either during or soon after parasite uptake, but had no effect on parasite load when added at 24 h post-infection, suggesting that an early event during parasite uptake was targeted. Furthermore, the parasites could overcome the inhibitory effect of IFN-λ3, which was added at earlier time points, within 2-3 days post-infection. BALB/c mice treated with IFN-λ3 before infection led to a significant increase in expression of IL-4 and ARG1 post-infection in the spleen and liver, respectively, and to different pathological changes, especially in the liver, but not to changes in parasite load. Treatment with IFN-λ3 during infection did not decrease the parasite load in the spleen either. However, IFN-λ3 was significantly increased in the sera of visceral leishmaniasis patients, and the IFNL genetic variant rs12979860 was significantly associated with susceptibility to leishmaniasis.
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Leishmania donovani , Leishmaniose Visceral , Parasitos , Animais , Humanos , Camundongos , Linhagem Celular , Leishmaniose Visceral/tratamento farmacológico , Leishmaniose Visceral/parasitologia , Macrófagos/parasitologia , Camundongos Endogâmicos BALB CRESUMO
Introduction Sonography is a non-invasive and painless technique used for assessing pelvic anatomy and disorder in children and adolescents. Ovarian growth patterns during infancy and puberty are not completely understood. No consensus exists about the normal measures and morphologic appearance of the ovaries in the southern region of Saudi Arabia. Therefore, this study determined the pattern of ovarian and uterine sizes among Saudi girls and their correlation with age. Methods This study was conducted in the radiology department at Abha Maternity and Children Hospital among girls between 0-13 years. All the participants underwent transabdominal ultrasound, and we measured ovarian volume, uterine length, and endometrial thickness to correlate with chronologic age using the Chi-squared test. Results A Total of 152 females were included in this study. The median age was 72 months, with a minimum of one month and a maximum of 156 months. The Chi-squared test showed a significant correlation between age and ovarian measurement. Age was positively associated with ovarian volume, uterine length, and endometrial thickness (p<0.001). Conclusion The study concluded that age strongly correlated with the size of the uterus and ovaries, which is crucial in interpreting ultrasound measurements of the pelvic organs correctly.
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Virginal breast hypertrophy, also known as juvenile macromastia or juvenile gigantomastia, is an uncommon condition characterized by the rapid and excessive growth of breasts in prepubertal or peripubertal girls in the absence of any hormonal or physiological causes. While virginal breast hypertrophy is a rare benign disorder that occurs independent of hormonal stimulation, it can cause a diagnostic challenge to physicians and requires a multidisciplinary team to get it right. It also results in detrimental effects, both physical and psychological, for young girls. We present a case of virginal breast hypertrophy in an 11-year-old Saudi girl, which was successfully managed. This report will contribute to knowledge sharing with healthcare professionals in Saudi Arabia about this rare case. It can also pave roads for further research to understand the underlying mechanisms and to standardize treatment modalities.
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The Aja and Salma mountains in the Hail region are home to a variety of indigenous wild plants, some of which are used in Bedouin folk medicine to treat various ailments. The purpose of the current study was to unveil the chemical, antioxidant and antibacterial properties of Fagonia indica (Showeka) grown widely in these mountains, as data on the biological activities of this plant in this remote area are scarce. XRF spectrometry indicated the presence of some essential elements, which were in the order of Ca > S > K > AL > CL > Si > P > Fe > Mg > Na > Ti > Sr > Zn > Mn. Qualitative chemical screening revealed the presence of saponins, terpenes, flavonoids, tannins, phenols and cardiac glycosides in the methanolic extract (80% v/v). GC-MS showed the presence of 2-chloropropanoic acid 18.5%, tetrahydro-2-methylfuran 20.1%, tridecanoic acid 12-methyl-, methyl ester 2.2%, hexadecanoic acid, methyl ester 8.6%, methyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate 13.4%, methyl linoleate 7.0%, petroselinic acid methyl ester 15%, erucylamide 6.7% and diosgenin 8.5%. Total phenols, total tannins, flavonoids, DPPH, reducing power, -carotene and ABTS IC50 (mg/mL) scavenging activity were used to measure the antioxidant capabilities of Fagonia indica, which exhibited prominent antioxidant properties at low concentrations when compared to ascorbic acid, butylate hydroxytoluene and beta-carotene. The antibacterial investigation revealed significant inhibitory effects against Bacillus subtilis MTCC121 and Pseudomona aeruginosa MTCC 741 with inhibition zones of 15.00 ± 1.5 and 12.0 ± 1.0 mm, respectively. The MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) ranged between 125 to 500 µg/mL. The MBC/MIC ratio indicated possible bactericidal efficacy against Bacillus subtilis and bacteriostatic activity against Pseudomona aeruginosa. The study also showed that this plant has anti-biofilm formation activity.
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Leishmania is an intracellular, zoonotic, kinetoplastid eukaryote with more than 1.2 million cases all over the world. The leishmanial chromosomes are divided into polymorphic chromosomal ends, conserved central domains, and antigen-encoding genes found in telomere-proximal regions. The genome flexibility of chromosomal ends of the leishmanial parasite is known to cause drug resistance and intracellular survival through the evasion of host defense mechanisms. Therefore, in this review, we discuss the plasticity of Leishmania genome organization which is the primary cause of drug resistance and parasite survival. Moreover, we have not only elucidated the causes of such genome plasticity which includes aneuploidy, epigenetic factors, copy number variation (CNV), and post-translation modification (PTM) but also highlighted their impact on drug resistance and parasite survival.
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Leishmania donovani , Parasitos , Animais , Leishmania donovani/genética , Variações do Número de Cópias de DNA , Resistência a Medicamentos , PercepçãoRESUMO
Isolation of extraordinarily long-length super-enhancers (SEs) using typical chromatin immune precipitation (ChIP) techniques can lead to DNA breakage due to uncontrolled cross-linking. We present a redefined ChIP technique for SE purification. After controlled paraformaldehyde-based cross-linking, glycine was used to quench the cross-linker followed by mild sonication. The sonication produced ideal fragment length of long-length SE chromatin. Presently, miR146a-5p SE of macrophages was pulled using BRD4 protein. Our protocol can reproducibly simplify the SE element isolation issues, in a quality-controlled manner. For complete details on the use and execution of this protocol, please refer to Das et al. (2021).1.
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Proteínas Nucleares , Fatores de Transcrição , Proteínas Nucleares/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Cromatina/genética , Macrófagos/metabolismo , Elementos Facilitadores Genéticos , ImunoprecipitaçãoRESUMO
An in-house enzyme-linked immunosorbent assay (ELISA) based on crude antigen of Leishmania reported a high sero-prevalence (82.0%) in Leishmania donovani induced cutaneous leishmaniasis (CL) in Sri Lanka. ELISA was further compared with established serological tools to identify a suitable point of care diagnostic tool. Sero-prevalence of 100 CL samples were analyzed using in-house ELISA, Indian dipstick test and rK39 strip test. Results obtained were further compared with direct agglutination test (DAT) for 40 CL. Test performance was evaluated using Kappa index value. Clinico-epidemiological characteristics of patients were analyzed using SPSSv25.0. Cost analysis of tests was carried out. ELISA showed a high sero-positivity of 81.0% (n = 81/100) while DAT (57.5%,n = 23/40), Indian dipstick test (22.0%,n = 22/100) and rK39 test (15.0%,n = 15/100) showed a comparatively less sero-positivity. According to Kappa index values, there were no perfect agreement between tests. Among ELISA positive patients (n = 81/100), DAT, Indian dipstick test and rK39 demonstrated sero-positivity rates of 61.3% (n = 19/31), 25.9% (n = 21/81) and 16.0% (n = 13/81) respectively. Among ELISA negative patients (n = 19/100), three assays demonstrated sero-positivity rates of 44.4% (n = 4/9), 5.3% (n = 1/9) and 10.5% (n = 2/19) respectively. DAT can be used as an alternative test when ELISA is not available or negative. Clinico-epidemiological profiles of patients that showed sero-positivity by each assay were different. Cost per patient was approximately 5.5 USD for DAT and 3.0 USD for each other tests. Established serological tests demonstrated different and relatively lower detection rates. Species, strain and antigen heterogeneity, inconsistency in amount of used antigens, sera, antibody expression patterns and testing methodologies could be responsible. This study highlighted the importance of designing an in-house serological assay based on local parasite.
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Leishmania donovani , Leishmaniose Cutânea , Humanos , Prevalência , Leishmaniose Cutânea/diagnóstico , Leishmaniose Cutânea/epidemiologia , Testes Hematológicos , Testes de AglutinaçãoRESUMO
Kala-azar/Visceral Leishmaniasis (VL) caused by Leishmania donovani (LD) is often associated with Leptomonas seymouri (LS) co-infection in India. Leptomonas seymouri narna-like virus 1 (Lepsey NLV1) has been reported in multi-passaged laboratory isolates of VL samples which showed LD-LS co-infection. A pertinent question was whether this virus of LS is detectable in direct clinical samples. DNA from the serum of twenty-eight LD diagnosed patients was subjected to LD-specific and LS-specific PCR to reconfirm the presence of LD parasites and to detect LD-LS co-infections. RNA extracted from same samples was subjected to RT-PCR, qRT-PCR and sequencing using virus-specific primers to detect/identify and quantify the virus. The presence of the virus was confirmed in thirteen of eighteen (72%) recently collected VL and PKDL samples. Cytokine profiling showed significantly elevated IL-18 in only LD infected patients compared to the virus-positive LD and control samples. IL-18 is crucial for Th1 and macrophage activation which eventually clears the parasite. The Lepsey NLV1 interaction with the immune system results in reduced IL-18 which favors LD survival and increased parasitic burden. The study emphasizes the need to revisit LD pathogenesis in the light of the association and persistence of a protozoan virus in kala-azar and PKDL patients.
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Coinfecção , Leishmania donovani , Leishmaniose Cutânea , Leishmaniose Visceral , Trypanosomatina , Coinfecção/diagnóstico , Humanos , Índia , Interleucina-18 , Leishmania donovani/genética , Leishmaniose Visceral/parasitologia , Trypanosomatina/genéticaRESUMO
Canine visceral leishmaniasis (CVL) due to Leishmania infantum infection is a zoonotic disease prevalent in the areas of South America and the Mediterranean. Infected dogs as reservoirs can contribute to disease transmission and can be a scourge to public health. Therefore, early diagnosis of infected dogs may play a pivotal role in circumscribing disease progression. Invasive tissue aspiration and insufficient serological methods impair a single assay for prompt CVL diagnosis. In the present study, we aimed to evaluate the potential of Leishmania donovani isolated membrane protein, LAg, for the diagnosis of CVL through immunological assays. Initially, enzyme-linked immunosorbent assay was done with Brazilian dog sera to evaluate the performance of LAg in diagnosing CVL and found sensitivity and specificity of 92.50% and 95%, respectively. The study further confirmed the diagnostic efficacy of LAg in a dipstick format. The dipstick test of canine sera from three centers in Brazil and one center in Italy collectively showed sensitivity values in the range of 53.33% to 100% in recognizing symptomatic dogs and specificity values between 75% and 100% to rule out healthy dogs. Moreover, a rapid immunochromatographic test was developed and optimized using LAg. This test was able to identify 94.73% of CVL of Brazilian origin with specificity of 97.29%. The current results highlight the reactive potential of the L. donovani antigen, LAg, for L. infantum CVL diagnosis and support our previous findings, which suggest the utility of LAg for the diagnosis of both L. donovani and L. infantum human VL in a variety of endemic regions. LAg as a diagnostic candidate may be employed to identify comprehensive CVL cases in epidemiological areas.
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Doenças do Cão , Leishmania donovani , Leishmania infantum , Leishmaniose Visceral , Animais , Anticorpos Antiprotozoários , Antígenos de Protozoários , Brasil/epidemiologia , Doenças do Cão/diagnóstico , Doenças do Cão/epidemiologia , Cães , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/veterinária , Humanos , Leishmaniose Visceral/diagnóstico , Leishmaniose Visceral/veterinária , Sensibilidade e EspecificidadeRESUMO
INTRODUCTION: Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has emerged as one of the biggest global health issues. Spike protein (S) and nucleoprotein (N), the major immunogenic components of SARS-CoV-2, have been shown to be involved in the attachment and replication of the virus inside the host cell. AREAS COVERED: Several investigations have shown that the SARS-CoV-2 nucleoprotein can elicit a cell-mediated immune response capable of regulating viral replication and lowering viral burden. However, the development of an effective vaccine that can stop the transmission of SARS-CoV-2 remains a matter of concern. Literature was retrieved using the keywords COVID-19 vaccine, role of nucleoprotein as vaccine candidate, spike protein, nucleoprotein immune responses against SARS-CoV-2, and chimera vaccine in PubMed, Google Scholar, and Google. EXPERT OPINION: We have focussed on the use of chimera protein, consisting of N and S-1 protein components of SARS-CoV-2, as a potential vaccine candidate. This may act as a polyvalent mixed recombinant protein vaccine to elicit a strong T and B cell immune response, which will be capable of neutralizing the wild and mutated variants of SARS-CoV-2, and also restricting its attachment, replication, and budding in the host cell.
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COVID-19 , Proteínas Virais de Fusão , Vacinas Virais , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Humanos , Nucleoproteínas , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/genéticaRESUMO
Leishmaniasis is a group of disease caused by the intracellular protozoan parasite of the genus Leishmania. Infection by different species of Leishmania results in various host immune responses, which usually lead to parasite clearance and may also contribute to pathogenesis and, hence, increasing the complexity of the disease. Interestingly, the parasite tends to reside within the unfriendly environment of the macrophages and has evolved various survival strategies to evade or modulate host immune defense. This can be attributed to the array of virulence factors of the vicious parasite, which target important host functioning and machineries. This review encompasses a holistic overview of leishmanial virulence factors, their role in assisting parasite-mediated evasion of host defense weaponries, and modulating epigenetic landscapes of host immune regulatory genes. Furthermore, the review also discusses the diagnostic potential of various leishmanial virulence factors and the advent of immunomodulators as futuristic antileishmanial drug therapy.
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Leishmania , Leishmaniose , Interações Hospedeiro-Parasita , Humanos , Leishmania/genética , Leishmaniose/tratamento farmacológico , Leishmaniose/parasitologia , Virulência , Fatores de Virulência/genéticaRESUMO
Visceral leishmaniasis (VL) is one of the major global health concerns due to its association with morbidity and mortality. All available diagnostic tools have been, until now, unable to provide a very specific and cost-effective mode of detection for VL globally. Therefore, the design of robust, specific, and commercially translatable diagnostic tests is urgently required. Currently, we are attempting to identify and explore the diagnostic potential of a novel parasite antigen. Repressor of differentiation kinase 2 (RDK2), a serine/threonine kinase, has a versatile role in parasite life cycle progression. However, its role as a diagnostic candidate for VL has not been investigated. Herein, we cloned and over-expressed LdRDK2 and studied the recombinant RDK2 for the diagnosis of human VL using serum and urine samples. In silico analysis predicted that RDK2 is conserved among Leishmania species with the least conservation in humans. RDK2 developed immune-reactive bands with antibodies present in VL patients' sera, and it demonstrated no cross-reactivity with sera from healthy controls and other diseases. Additionally, RDK2 antigen demonstrated a significant reactivity with IgG antibodies of VL patients' sera, with 78% sensitivity and 86.67% specificity as compared to healthy controls and other diseases. Furthermore, we evaluated its utility for non-invasive diagnosis of VL using patients' urine samples and found 93.8% sensitivity and 85.7% specificity. RDK2 was found to have better sensitivity and treatment response in patients' urine compared to serum samples, indicating its role as a promising point of care (POC) antigen. In a nutshell, we explored the role of RDK2 as a potential diagnostic marker for VL in both invasive and non-invasive modes as well as its utility as a promising POC antigen for treatment response cases.
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Lack of vaccine and increasing chemotherapeutic toxicities currently necessitate the development of effective and safe drugs against various forms of leishmaniases. We characterized the cellular stress induced by a novel curcumin analogue, HO-3867, encapsulated within the phosphatidylcholine-stearylamine (PC-SA) liposome for the first time against Leishmania. The liposomal formulation of HO-3867 (i.e., PC-SA/HO-3867) initiated oxidative stress-induced apoptosis in L. donovani, revealed by altered cell morphology, phosphatidylserine externalization, mitochondrial depolarization, intracellular lipid accumulation, and cell cycle arrest in promastigotes. Liposomal HO-3867 was observed to be a strong apoptosis inducer in L. donovani and L. major in a dose-dependent manner, yet completely safe for normal murine macrophages. Moreover, PC-SA/HO-3867 treatment induced L. donovani metacaspase and PARP1 activation along with downregulation of the Sir2 gene. PC-SA/HO-3867 arrested intracellular L. donovani amastigote burden in vitro, with reactive oxygen species (ROS) and nitric oxide (NO)-mediated parasite killing. These data suggest that liposomal HO-3867 represents a highly promising and non-toxic nanoparticle-based therapeutic platform against leishmaniasis inspiring further preclinical developments.
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Antiprotozoários , Leishmania donovani , Animais , Antiprotozoários/farmacologia , Antiprotozoários/uso terapêutico , Apoptose , Camundongos , Camundongos Endogâmicos BALB C , Piperidonas , Espécies Reativas de OxigênioRESUMO
Aging weakens and deregulates the immune system and plays an impact on the central nervous system (CNS). A crosstalk in between the CNS-mediated immune system and the body's overall innate immunity is often found to increase and subsequently accelerate neurodegeneration and behavioural impairment during aging. Dietary calorie restriction (CR) is found to be a beneficial non-invasive anti-aging therapy as it shows rejuvenation of stress response, brain functions and behaviour during aging. The present investigation deals with the consequence of CR diet supplementation for two different duration (one and two consecutive months) on aging-related alteration of the immune response in male albino Wistar rats at the level of (a) lymphocyte viability, proliferation, cytotoxicity, and DNA fragmentation in blood, spleen, and thymus and (b) cytokines (IL-6, IL-10, and TNF-α) in blood, spleen, thymus and different brain-regions to understand the effect of CR diet on neuroimmune system. The results depict that CR diet consumption for consecutive one and two months by the aged (18 and 24 months) rats significantly attenuated the aging-related (a) decrease of blood, splenic and thymic lymphocyte viability, proliferative activity, cytotoxicity, and IL-10 level and (b) increase of (i) blood, splenic and thymic DNA fragmentation and (ii) IL-6 and TNF-α level in those tissues and also in different brain regions. Unlike older rats, in young (4 months) rats, the consumption of CR diet under similar conditions affected those above-mentioned immune parameters reversibly and adversely. This study concludes that (a) aging significantly (p < 0.01) deregulates the above-mentioned immune parameters, (b) consecutive consumption of CR diet for one and two months is (i) beneficial (p < 0.05) to the aging-related immune system [lymphocyte viability, lymphocyte proliferation, cytotoxicity, pro (IL-6 and TNF-α)- and anti (IL-10)-inflammatory cytokines], but (ii) adverse (p < 0.05) to the immune parameters of the young rats, and (c) consumption of CR diet for consecutive two months is more potent (p < 0.05) than that due to one month.
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Envelhecimento/imunologia , Encéfalo/imunologia , Restrição Calórica , Neuroimunomodulação , Baço/imunologia , Linfócitos T/imunologia , Timo/imunologia , Fatores Etários , Envelhecimento/metabolismo , Animais , Encéfalo/metabolismo , Proliferação de Células , Células Cultivadas , Citocinas/metabolismo , Citotoxicidade Imunológica , Ativação Linfocitária , Masculino , Ratos Wistar , Baço/metabolismo , Linfócitos T/metabolismo , Timo/metabolismo , Fatores de TempoRESUMO
INTRODUCTION: Vaccination is so far the most effective way of eradicating infections. Rapidly emerging drug resistance against infectious diseases and chemotherapy-related toxicities in cancer warrant immediate vaccine development to save mankind. Subunit vaccines alone, however, fail to elicit sufficiently strong and long-lasting protective immunity against deadly pathogens. Nanoparticle (NP)-based delivery vehicles like microemulsions, liposomes, virosomes, nanogels, micelles and dendrimers offer promising strategies to overcome limitations of traditional vaccine adjuvants. Nanovaccines can improve targeted delivery, antigen presentation, stimulation of body's innate immunity, strong T cell response combined with safety to combat infectious diseases and cancers. Further, nanovaccines can be highly beneficial to generate effective immutherapeutic formulations against cancer. AREAS COVERED: This review summarizes the emerging nanoparticle strategies highlighting their success and challenges in preclinical and clinical trials in infectious diseases and cancer. It provides a concise overview of current nanoparticle-based vaccines, their adjuvant potential and their cellular delivery mechanisms. EXPERT OPINION: The nanovaccines (50-250 nm in size) are most efficient in terms of tissue targeting, prolonged circulation and preferential uptake by the professional APCs chiefly due to their small size. More rational designing, improved antigen loading, extensive functionalization and targeted delivery are some of the future goals of ideal nanovaccines.
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Nanopartículas , Vacinação/métodos , Vacinas/administração & dosagem , Adjuvantes Imunológicos/administração & dosagem , Animais , Antígenos/imunologia , Vacinas contra COVID-19/administração & dosagem , Vacinas Anticâncer/administração & dosagem , Vacinas Anticâncer/imunologia , Humanos , Tamanho da Partícula , Vacinas/imunologiaRESUMO
Visceral leishmaniasis (VL) is a debilitating human pathogenesis in which the body's immune functions are severely compromised. Various subsets of T cells, including Th17 cells are important regulators of immune responses observed in various pathologies. The role of Th17 cells and its correlation with immuno-regulatory cytokines are however not well understood in human VL. Herein we studied how IL-17 is associated with the progression of Leishmania donovani infection using murine model of VL. We found induction of a strong IL-17 response at the early phase of infection which progressively reduced to basal level during chronic VL. The mechanistic study of this behavior was found to be linked with the role of regulatory T cells (CD4+ CD25+ T cells) that suppresses the proliferation of the Th17 cell population. Moreover, TGF-ß and IL-35 derived from CD4+ CD25+ T cells are the key mediators for the downregulation of IL-17 during chronic VL. Thus, this study points to an antagonistic effect of Tregs and Th17 cells that can be used for designing better therapeutic and preventive strategies against leishmaniasis.
Assuntos
Interleucinas/imunologia , Leishmaniose Visceral/imunologia , Células Th17/imunologia , Fator de Crescimento Transformador beta/imunologia , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/parasitologia , Células Cultivadas , Subunidade alfa de Receptor de Interleucina-2/imunologia , Leishmania donovani/parasitologia , Leishmaniose Visceral/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Células Th17/parasitologiaRESUMO
Visceral leishmaniasis (VL), a fatal parasitic infection, is categorized as being neglected among tropical diseases. The use of conventional tissue aspiration for diagnosis is not possible in every setting. The immunochromatography-based lateral flow assay (LFA) has attracted attention for a long time due to its ability to give results within a few minutes, mainly in resource-poor settings. In the present study, we optimized and developed the LFA to detect anti-Leishmania antibodies for VL diagnosis. The performance of the developed test was evaluated with serum and urine samples of Indian VL patients and Brazilian sera. The new test exploits well-studied and highly-sensitive purified antigens, LAg isolated from Leishmania donovani promastigotes and protein G conjugated colloidal-gold as a signal reporter. The intensity of the bands depicting the antigen-antibody complex was optimized under different experimental conditions and quantitatively analyzed by the ImageJ software. For the diagnosis of human VL in India, LFA was found to be 96.49% sensitive and 95% specific with serum, and 95.12% sensitive and 96.36% specific with urine samples, respectively. The sensitivity and specificity of LFA were 88.57% and 94.73%, respectively, for the diagnosis of Brazilian VL using patients' sera infected with Leishmania infantum. LFA is rapid and simple to apply, suitable for field usage where results can be interpreted visually and particularly sensitive and specific in the diagnosis of human VL. Serum and urine LFA may improve diagnostic outcomes and could be an alternative for VL diagnosis in settings where tissue aspiration is difficult to perform.