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1.
J Viral Hepat ; 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38727597

RESUMO

Hepatitis E virus (HEV) is a foodborne virus transmitted through the faecal-oral route that causes viral hepatitis in humans worldwide. Ever since its discovery as a zoonotic agent, HEV was isolated from several species with an expanding range of hosts. HEV possesses several features of other RNA viruses but also has certain HEV-specific traits that make its viral-host interactions inimitable. HEV leads to severe morbidity and mortality in immunocompromised people and pregnant women across the world. The situation in underdeveloped countries is even more alarming. Even after creating a menace across the world, we still lack an effective vaccine against HEV. Till date, there is only one licensed vaccine for HEV available only in China. The development of an anti-HEV vaccine that can reduce HEV-induced morbidity and mortality is required. Live attenuated and killed vaccines against HEV are not accessible due to the lack of a tolerant cell culture system, slow viral replication kinetics and varying growth conditions. Thus, the main focus for anti-HEV vaccine development is now on the molecular approaches. In the current study, we have designed a multi-epitope vaccine against HEV through a reverse vaccinology approach. For the first time, we have used viral ORF3, capsid protein and polyprotein altogether for epitope prediction. These are crucial for viral replication and persistence and are major vaccine targets against HEV. The proposed in silico vaccine construct comprises of highly immunogenic and antigenic T-cell and B-cell epitopes of HEV proteins. The construct is capable of inducing an effective and long-lasting host immune response as evident from the simulation results. In addition, the construct is stable, non-allergic and antigenic for the host. Altogether, our findings suggest that the in silico vaccine construct may be useful as a vaccine candidate for preventing HEV infections.

2.
Diagnostics (Basel) ; 13(3)2023 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-36766473

RESUMO

It is estimated that approximately 260 million people worldwide are infected with the hepatitis B virus (HBV), which is one of the leading causes of liver disease and liver cancer throughout the world. Compared with developed countries, low-income and middle-income countries have limited access to resources and advanced technologies that require highly specialized staff for HBV diagnosis. In spite of the heavy burden caused by hepatitis B virus, 90% of people are still undiagnosed. The World Health Organization (WHO) goal of eliminating hepatitis B by 2030 seems very difficult to achieve due to the existing diagnostic infrastructure in low-resource regions. The majority of diagnostic laboratories still use hepatitis B surface antigen (HBsAg)-based tests. WHO's elimination plan is at risk of derailment due to phases like the window period, immune control, and occult HBV infection (OBI) not being detected by standard tests. Here, in this article, we are focusing on various diagnostic platforms for the better diagnosis of HBV. The aim of the elimination of HBV can only be achieved by detecting all phases of HBV infection, which can be executed by a combined approach of using new marker assays along with advanced pretesting and testing methods.

3.
Front Psychol ; 14: 1266425, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38463643

RESUMO

Organizational responsibilities can give people power but also expose them to scrutiny. This tension leads to divergent predictions about the use of potentially sensitive language: power might license it, while exposure might inhibit it. Analysis of peoples' language use in a large corpus of organizational emails using standardized Linguistic Inquiry and Word Count (LIWC) measures shows a systematic difference in the use of words with potentially sensitive (ethnic, religious, or political) connotations. People in positions of relative power are ~3 times less likely to use sensitive words than people more junior to them. The tendency to avoid potentially sensitive language appears to be independent of whether other people are using sensitive language in the same email exchanges, and also independent of whether these words are used in a sensitive context. These results challenge a stereotype about language use and the exercise of power. They suggest that, in at least some circumstances, the exposure and accountability associated with organizational responsibilities are a more significant influence on how people communicate than social power.

4.
Pharmaceutics ; 14(8)2022 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-36015216

RESUMO

Leishmaniasis is a tropical disease caused by a protozoan parasite Leishmania that is transmitted via infected female sandflies. At present, leishmaniasis treatment mainly counts on chemotherapy. The currently available drugs against leishmaniasis are costly, toxic, with multiple side effects, and limitations in the administration route. The rapid emergence of drug resistance has severely reduced the potency of anti-leishmanial drugs. As a result, there is a pressing need for the development of novel anti-leishmanial drugs with high potency, low cost, acceptable toxicity, and good pharmacokinetics features. Due to the availability of preclinical data, drug repurposing is a valuable approach for speeding up the development of effective anti-leishmanial through pointing to new drug targets in less time, having low costs and risk. Metabolic pathways of this parasite play a crucial role in the growth and proliferation of Leishmania species during the various stages of their life cycle. Based on available genomics/proteomics information, known pathways-based (sterol biosynthetic pathway, purine salvage pathway, glycolysis, GPI biosynthesis, hypusine, polyamine biosynthesis) Leishmania-specific proteins could be targeted with known drugs that were used in other diseases, resulting in finding new promising anti-leishmanial therapeutics. The present review discusses various metabolic pathways of the Leishmania parasite and some drug candidates targeting these pathways effectively that could be potent drugs against leishmaniasis in the future.

5.
Sci Rep ; 12(1): 9521, 2022 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-35681036

RESUMO

Cervical cancer is the most common gynaecological cancer and reaches an alarming stage. HPVs are considered the main causative agents for cervical cancer and other sexually transmitted infections across the globe. Currently, three prophylactic vaccines are available against HPV infections with no therapeutic values. Due to a lack of effective therapeutic and prophylactic measures, the HPV infection is spreading in an uncontrolled manner. Next-generation of vaccine is needed to have both prophylactic and therapeutic values against HPV. Here first time we have designed a multi-epitope chimeric vaccine using the most oncogenic strain HPV 16 and HPV 18 through an immunoinformatic approach. In this study, we have used the L1, E5, E6 and E7 oncoproteins from both HPV 16 and HPV 18 strains for epitope prediction. Our recombinant chimeric vaccine construct consists, selected helper and cytotoxic T cell epitopes. Our computational analysis suggests that this chimeric construct is highly stable, non-toxic and also capable of inducing both cell-mediated and humoral immune responses. Furthermore, in silico cloning of the multi-epitope chimeric vaccine construct was done and the stabilization of the vaccine construct is validated with molecular dynamics simulation studies. Finally, our results indicated that our construct could be used for an effective prophylactic and therapeutic vaccine against HPV.


Assuntos
Proteínas Oncogênicas Virais , Infecções por Papillomavirus , Vacinas contra Papillomavirus , Neoplasias do Colo do Útero , Epitopos de Linfócito T/genética , Feminino , Papillomavirus Humano 16/genética , Papillomavirus Humano 18 , Humanos , Papillomaviridae , Vacinas contra Papillomavirus/genética , Vacinas Sintéticas
6.
Microb Pathog ; 161(Pt B): 105294, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34798279

RESUMO

Human papillomavirus infection is among the leading viral infections in the world, causing severe mortality and morbidity. The virus mainly targets the female genital tract-cervix, vulva, anus but it is also reported to infect the lungs and oropharyngeal region of the body. The host immune response plays a vital role in the persistence of viral infection. Interleukin 17 (IL-17) is mainly secreted by Th17 cells and mediates the immune response that enhances the disease severity in HPV infection. IL-17 is reported to promote lesions and tumour progression by creating a hyperinflammatory condition leading to cancer. The current minireview summarizes the pathogenic role of IL-17 in HPV infection and HPV-induced malignancies. Further study on IL-17 associated pathology of HPV infection would be useful in developing therapeutic measures.


Assuntos
Interleucina-17/imunologia , Neoplasias , Infecções por Papillomavirus , Colo do Útero , Feminino , Humanos , Neoplasias/imunologia , Neoplasias/virologia , Papillomaviridae , Infecções por Papillomavirus/complicações , Infecções por Papillomavirus/imunologia
7.
J Cell Physiol ; 236(12): 8000-8019, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34133758

RESUMO

Viral infections are a major threat to the human population due to the lack of selective therapeutic measures. The morbidity and mortality reported worldwide are very alarming against viral pathogens. The proinflammatory environment is required for viral inhibition by initiating the host immune response. The host immune response fights these pathogens by secreting different cytokines. Interleukin-17 (IL-17) a proinflammatory cytokine mainly produced by T helper type 17 cells, plays a vital role in the regulation of host immune response against various pathogens, including viruses. However, dysregulated production of IL-17 induces chronic inflammation, autoimmune disorders, and may lead to cancer. Recent studies suggest that IL-17 is not only involved in the antiviral immune response but also promotes virus-mediated illnesses. In this review, we discuss the protective and pathogenic role of IL-17 against various viral infections. A detailed understanding of IL-17 during viral infections could contribute to improve therapeutic measures and enable the development of an efficient and safe IL-17 based immunotherapy.


Assuntos
Citocinas/metabolismo , Inflamação/metabolismo , Interleucina-17/metabolismo , Viroses/imunologia , Animais , Doença Crônica , Citocinas/imunologia , Humanos , Interleucina-17/imunologia
8.
Virusdisease ; 32(2): 211-219, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33969150

RESUMO

SARS CoV-2, a causative agent of human respiratory tract infection, was first identified in late 2019. It is a newly emerging viral disease with unsatisfactory treatments. The virus is highly contagious and has caused pandemic globally. The number of deaths is increasing exponentially, which is an alarming situation for mankind. The detailed mechanism of the pathogenesis and host immune responses to this virus are not fully known. Here we discuss an overview of SARS CoV-2 pathogenicity, its entry and replication mechanism, and host immune response against this deadly pathogen. Understanding these processes will help to lead the development and identification of drug targets and effective therapies.

9.
Iran J Microbiol ; 13(1): 1-7, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33889356

RESUMO

The magnitude and pace of global affliction caused by Coronavirus Disease-19 (COVID-19) is unprecedented in the recent past. From starting in a busy seafood market in the Chinese city of Wuhan, the virus has spread across the globe in less than a year, infecting over 76 million people and causing death of close to 1.7 million individuals worldwide. As no specific antiviral treatment is currently available, the major strategy in containing the pandemic is focused on early diagnosis and prompt isolation of the infected individuals. Several diagnostic modalities have emerged within a relatively short period, which can be broadly classified into molecular and immunological assays. While the former category is centered around real-time PCR, which is currently considered the gold standard of diagnosis, the latter aims to detect viral antigens or antibodies specific to the viral antigens and is yet to be recommended as a stand-alone diagnostic tool. This review aims to provide an update on the different diagnostic modalities that are currently being used in diagnostic laboratories across the world as well as the upcoming methods and challenges associated with each of them. In a rapidly evolving diagnostic landscape with several testing platforms going through various phases of development and/or regulatory clearance, it is prudent that the clinical community familiarizes itself with the nuances of different testing modalities currently being employed for this condition.

10.
Front Cell Infect Microbiol ; 11: 624009, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33680991

RESUMO

Visceral Leishmaniasis (VL) is the most fatal form of disease leishmaniasis. To date, there are no effective prophylactic measures and therapeutics available against VL. Recently, new immunotherapy-based approaches have been established for the management of VL. Cytokines, which are predominantly produced by helper T cells (Th) and macrophages, have received great attention that could be an effective immunotherapeutic approach for the treatment of human VL. Cytokines play a key role in forming the host immune response and in managing the formation of protective and non-protective immunities during infection. Furthermore, immune response mediated through different cytokines varies from different host or animal models. Various cytokines viz. IFN-γ, IL-2, IL-12, and TNF-α play an important role during protection, while some other cytokines viz. IL-10, IL-6, IL-17, TGF-ß, and others are associated with disease progression. Therefore, comprehensive knowledge of cytokine response and their interaction with various immune cells is very crucial to determine appropriate immunotherapies for VL. Here, we have discussed the role of cytokines involved in VL disease progression or host protection in different animal models and humans that will determine the clinical outcome of VL and open the path for the development of rapid and accurate diagnostic tools as well as therapeutic interventions against VL.


Assuntos
Leishmania donovani , Leishmaniose Visceral , Animais , Citocinas , Humanos , Interleucina-12 , Leishmaniose Visceral/terapia , Macrófagos
11.
Virus Res ; 290: 198169, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32979476

RESUMO

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) recently caused a pandemic outbreak called coronavirus disease 2019 (COVID-19). This disease has initially been reported in China and also now it is expeditiously spreading around the globe directly among individuals through coughing and sneezing. Since it is a newly emerging viral disease and obviously there is a lack of anti-SARS-CoV-2 therapeutic agents, it is urgently required to develop an effective anti-SARS-CoV-2-agent.Through recent advancements in computational biology and biological assays, several natural compounds and their derivatives have been reported to confirm their target specific antiviral potential against Middle East respiratory syndrome coronavirus (MERS-CoV) or Severe Acute Respiratory Syndrome(SARS-CoV).These targets including an important host cell receptor, i.e., angiotensin-converting enzyme ACE2 and several viral proteins e.g. spike glycoprotein (S) containing S1 and S2 domains, SARS CoV Chymotrypsin-like cysteine protease (3CLpro), papain-like cysteine protease (PLpro), helicases and RNA-dependent RNA polymerase (RdRp). Due to physical, chemical, and some genetic similarities of SARS CoV-2 with SARS-COV and MERS-COV, repurposing various anti-SARS-COV or anti-MERS-COV natural therapeutic agents could be helpful for the development of anti-COVID-19 herbal medicine. Here we have summarized various drug targets in SARS-COV and MERS-COV using several natural products and their derivatives, which could guide researchers to design and develop a safe and cost-effective anti-SARS-COV-2 drugs.


Assuntos
Antivirais/farmacologia , Tratamento Farmacológico da COVID-19 , Plantas Medicinais/química , SARS-CoV-2/efeitos dos fármacos , Enzima de Conversão de Angiotensina 2/antagonistas & inibidores , Antivirais/química , Antivirais/uso terapêutico , COVID-19/virologia , Humanos , Coronavírus da Síndrome Respiratória do Oriente Médio/efeitos dos fármacos , Inibidores de Proteases/farmacologia , Inibidores de Proteases/uso terapêutico , Coronavírus Relacionado à Síndrome Respiratória Aguda Grave/efeitos dos fármacos , Proteínas Virais/antagonistas & inibidores
12.
Nat Commun ; 9(1): 4515, 2018 10 30.
Artigo em Inglês | MEDLINE | ID: mdl-30375383

RESUMO

Dysregulated ROR-γt-mediated IL-17 transcription is central to the pathogenesis of several inflammatory disorders, yet the molecular mechanisms that govern the transcription factor activity of ROR-γt in the regulation of IL-17 are not fully defined. Here we show that SUMO-conjugating enzyme Ubc9 interacts with a conserved GKAE motif in ROR-γt to induce SUMOylation of ROR-γt and suppress IL-17 expression. Th17 cells expressing SUMOylation-defective ROR-γt are highly colitogenic upon transfer to Rag1-/- mice. Mechanistically, SUMOylation of ROR-γt facilitates the binding of HDAC2 to the IL-17 promoter and represses IL-17 transcription. Mice with conditional deletion of HDAC2 in CD4+ T cells have elevated IL-17 expression and severe colitis. The identification of the Ubc9/ROR-γt/HDAC2 axis that governs IL-17 expression may open new venues for the development of therapeutic measures for inflammatory disorders.


Assuntos
Histona Desacetilase 2/metabolismo , Interleucina-17/metabolismo , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Sumoilação/imunologia , Células Th17/imunologia , Enzimas de Conjugação de Ubiquitina/metabolismo , Animais , Colite/genética , Colite/imunologia , Colite/metabolismo , Histona Desacetilase 2/imunologia , Proteínas de Homeodomínio/genética , Inflamação , Interleucina-17/imunologia , Camundongos , Camundongos Knockout , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/imunologia
13.
Int J Antimicrob Agents ; 48(6): 695-702, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27876275

RESUMO

Green fluorescent protein produces significant fluorescence and is extremely stable, however its excitation maximum is close to the ultraviolet range and thus can damage living cells. Hence, Leishmania donovani stably expressing DsRed were developed and their suitability for flow cytometry-based antileishmanial screening was assessed by evaluating the efficacies of standard drugs as well as newly synthesised chalcone thiazolyl-hydrazone compounds. The DsRed gene was successfully integrated at the 18S rRNA locus of L. donovani and transfectants (LdDsRed) were selected using hygromycin B. Enhanced expression of DsRed and a high level of infectivity to J774A.1 macrophages were achieved, which was confirmed by fluorescence microscopy and flow cytometry. Furthermore, these LdDsRed transfectants were utilised for development of an in vitro screening assay using the standard antileishmanial drugs miltefosine, amphotericin B, pentamidine and paromomycin. The response of transfectants to standard drugs correlated well with previous reports. Subsequently, the suitability of this system was further assessed by screening a series of 18 newly synthesised chalcone thiazolyl-hydrazone compounds in vitro for their antileishmanial activity, wherein 8 compounds showed moderate antileishmanial activity. The most active compound 5g, with ca. 73% splenic parasite reduction, exerted its activity via generating nitric oxide and reactive oxygen species and inducing apoptosis in LdDsRed-infected macrophages. Thus, these observations established the applicability of LdDsRed transfectants for flow cytometry-based antileishmanial screening. Further efforts aimed at establishing a high-throughput screening assay and determining the in vivo screening of potential antileishmanial leads are required.


Assuntos
Antiprotozoários/farmacologia , Chalcona/farmacologia , Avaliação Pré-Clínica de Medicamentos/métodos , Citometria de Fluxo/métodos , Leishmania donovani/efeitos dos fármacos , Proteínas Luminescentes/análise , Coloração e Rotulagem/métodos , Animais , Antiprotozoários/administração & dosagem , Antiprotozoários/isolamento & purificação , Linhagem Celular , Chalcona/administração & dosagem , Cricetinae , DNA de Protozoário/genética , DNA Ribossômico/genética , Modelos Animais de Doenças , Feminino , Genes Reporter , Hidrazonas/administração & dosagem , Hidrazonas/farmacologia , Leishmania donovani/genética , Leishmaniose Visceral/tratamento farmacológico , Leishmaniose Visceral/parasitologia , Proteínas Luminescentes/genética , Macrófagos/parasitologia , Masculino , Camundongos , RNA Ribossômico 18S/genética , Recombinação Genética , Resultado do Tratamento
14.
Nat Immunol ; 17(8): 997-1004, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27322655

RESUMO

Dysregulated expression of interleukin 17 (IL-17) in the colonic mucosa is associated with colonic inflammation and cancer. However, the cell-intrinsic molecular mechanisms by which IL-17 expression is regulated remain unclear. We found that deficiency in the ubiquitin ligase Itch led to spontaneous colitis and increased susceptibility to colon cancer. Itch deficiency in the TH17 subset of helper T cells, innate lymphoid cells and γδ T cells resulted in the production of elevated amounts of IL-17 in the colonic mucosa. Mechanistically, Itch bound to the transcription factor ROR-γt and targeted ROR-γt for ubiquitination. Inhibition or genetic inactivation of ROR-γt attenuated IL-17 expression and reduced spontaneous colonic inflammation in Itch(-/-) mice. Thus, we have identified a previously unknown role for Itch in regulating IL-17-mediated colonic inflammation and carcinogenesis.


Assuntos
Colite/imunologia , Colo/patologia , Neoplasias Colorretais/imunologia , Mucosa Intestinal/imunologia , Linfócitos/imunologia , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/metabolismo , Células Th17/fisiologia , Ubiquitina-Proteína Ligases/metabolismo , Animais , Células Cultivadas , Sulfato de Dextrana , Humanos , Interleucina-17/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Membro 3 do Grupo F da Subfamília 1 de Receptores Nucleares/genética , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Ubiquitina-Proteína Ligases/genética , Ubiquitinação
15.
Int J Parasitol Drugs Drug Resist ; 6(2): 125-32, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27183429

RESUMO

We investigated efficacy of nitric oxide (NO) against Leishmania donovani. NO is a mediator of host response to infection, with direct parasiticidal activity in addition to its role in signalling to evoke innate macrophage responses. However, it is short-lived and volatile, and is therefore difficult to introduce into infected cells and maintain inracellular concentrations for meaningful periods of time. We incorporated diethylenetriamine NO adduct (DETA/NO), a prodrug, into poly(lactide-co-glycolide) particles of ∼200 nm, with or without amphotericin B (AMB). These particles sustained NO levels in mouse macrophage culture supernatants, generating an area under curve (AUC0.08-24h) of 591.2 ± 95.1 mM × h. Free DETA/NO resulted in NO peaking at 3 h and declining rapidly to yield an AUC of 462.5 ± 193.4. Particles containing AMB and DETA/NO were able to kill ∼98% of promastigotes and ∼76% of amastigotes in 12 h when tested in vitro. Promastigotes and amastigotes were killed less efficiently by particles containing a single drug- either DETA/NO (∼42%, 35%) or AMB (∼90%, 50%) alone, or by equivalent concentrations of drugs in solution. In a pre-clinical efficacy study of power >0.95 in the hamster model, DETA/NO particles were non-inferior to Fungizone® but not Ambisome®, resulting in significant (∼73%) reduction in spleen parasites in 7 days. Particles containing both DETA/NO and AMB were superior (∼93% reduction) to Ambisome®. We conclude that NO delivered to the cytosol of macrophages infected with Leishmania possesses intrinsic activity and adds significantly to the efficacy of AMB.


Assuntos
Anfotericina B/administração & dosagem , Antiprotozoários/administração & dosagem , Leishmania donovani/efeitos dos fármacos , Leishmaniose Visceral/tratamento farmacológico , Macrófagos/imunologia , Macrófagos/metabolismo , Compostos Nitrosos/administração & dosagem , Animais , Sobrevivência Celular/efeitos dos fármacos , Cricetinae , Modelos Animais de Doenças , Quimioterapia Combinada , Leishmania donovani/fisiologia , Camundongos , Nanopartículas/administração & dosagem , Resultado do Tratamento
16.
Front Microbiol ; 7: 312, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27047452

RESUMO

Our prior studies demonstrated that cellular response of T helper 1 (Th1) type was generated by a soluble antigenic fraction (ranging from 89.9 to 97.1 kDa) of Leishmania donovani promastigote, in treated Leishmania patients as well as hamsters and showed significant prophylactic potential against experimental visceral leishmaniasis (VL). Eighteen Th1 stimulatory proteins were identified through proteomic analysis of this subfraction, out of which 15 were developed as recombinant proteins. In the present work, we have evaluated these 15 recombinant proteins simultaneously for their comparative cellular responses in treated Leishmania patients and hamsters. Six proteins viz. elongation factor-2, enolase, aldolase, triose phosphate isomerase, protein disulfide isomerase, and p45 emerged as most immunogenic as they produced a significant lymphoproliferative response, nitric oxide generation and Th1 cytokine response in PBMCs and lymphocytes of treated Leishmania patients and hamsters respectively. The results suggested that these proteins may be exploited for developing a successful poly-protein and/or poly-epitope vaccine against VL.

17.
Parasitol Int ; 64(4): 1-5, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25582929

RESUMO

Leishmania and Leptomonas are protozoan parasites of the family Trypanosomatidae. Leishmania donovani causes the fatal visceral leishmaniasis (VL; kala-azar) in mammals and is transmitted by sand fly vector. Certain VL-cured human populations in India and Sudan develop post kala-azar dermal leishmaniasis (PKDL) due to the same parasite. Although Leptomonas is parasitic mainly in insects, several recent reports on the clinical isolates of L. donovani from VL and PKDL patients in India confirm co-infection of Leptomonas seymouri, probably due to immune suppression in those individuals. Detection of L. seymouri in the in vitro cultures of L. donovani from clinical origin is difficult due to many similarities between L. seymouri and L. donovani. We describe here ways to detect L. seymouri and L. donovani in co-culture. In addition, based on our observation regarding the growth of L. seymouri in different culture conditions, we report here a novel procedure, which can selectively eliminate L. seymouri from the in vitro co-culture with L. donovani. This would be beneficial to researchers who prefer to deal with pure populations of Leishmania parasites for various downstream immunological and genetic studies.


Assuntos
Leishmania donovani/crescimento & desenvolvimento , Leishmania donovani/isolamento & purificação , Parasitologia/métodos , Trypanosomatina/crescimento & desenvolvimento , Trypanosomatina/isolamento & purificação , Técnicas de Cocultura , Meios de Cultura , Humanos , Leishmania donovani/genética , Reação em Cadeia da Polimerase , Polimorfismo de Fragmento de Restrição , Temperatura , Trypanosomatina/genética
18.
Parasitology ; 142(5): 728-44, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25498563

RESUMO

In earlier studies, proteomic characterization of splenic amastigote fractions from clinical isolates of Leishmania donovani, exhibiting significant cellular responses in cured Leishmania subjects, led to the identification of cytosolic tryparedoxin peroxidase (LdcTryP) and chaperonin-TCP20 (LdTCP20) as Th1-stimulatory proteins. Both the proteins, particularly LdTCP20 for the first time, were successfully cloned, overexpressed, purified and were found to be localized in the cytosol of purified splenic amastigotes. When evaluated against lymphocytes of cured Leishmania-infected hamsters, the purified recombinant proteins (rLdcTryP and rLdTCP20) induced their proliferations as well as nitric oxide production. Similarly, these proteins also generated Th1-type cytokines (IFN-γ/IL-12) from stimulated PBMCs of cured/endemic Leishmania patients. Further, vaccination with rLdcTryP elicited noticeable delayed-type hypersensitivity response and offered considerably good prophylactic efficacy (~78% inhibition) against L. donovani challenge in hamsters, which was well supported by the increased mRNA expression of Th1 and Th2 cytokines. However, animals vaccinated with rLdTCP20 exhibited comparatively lesser prophylactic efficacy (~55%) with inferior immunological response. The results indicate the potentiality of rLdcTryP protein, between the two, as a suitable anti-leishmanial vaccine. Since, rLdTCP20 is also an important target, for optimization, further attempts towards determination of immunodominant regions for designing fusion peptides may be taken up.


Assuntos
Proteínas de Choque Térmico/imunologia , Leishmania donovani/imunologia , Leishmaniose Visceral/imunologia , Peroxidases/imunologia , Proteínas de Protozoários/imunologia , Animais , Chaperoninas/imunologia , Cricetinae , Feminino , Humanos , Immunoblotting , Leishmania donovani/enzimologia , Leishmaniose Visceral/parasitologia , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/imunologia , Linfonodos/citologia , Masculino , Mesocricetus , Óxido Nítrico/metabolismo , Proteínas Recombinantes/imunologia , Baço/parasitologia
19.
PLoS One ; 9(9): e108556, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25268700

RESUMO

In visceral leishmaniasis, the recovery from the disease is always associated with the generation of Th1-type of cellular responses. Based on this, we have previously identified several Th1-stimulatory proteins of Leishmania donovani -triose phosphate isomerase (TPI), protein disulfide isomerase (PDI) and elongation factor-2 (EL-2) etc. including heat shock protein 70 (HSP70) which induced Th1-type of cellular responses in both cured Leishmania patients/hamsters. Since, HSPs, being the logical targets for vaccines aimed at augmenting cellular immunity and can be early targets in the immune response against intracellular pathogens; they could be exploited as vaccine/adjuvant to induce long-term immunity more effectively. Therefore, in this study, we checked whether HSP70 can further enhance the immunogenicity and protective responses of the above said Th1-stimulatory proteins. Since, in most of the studies, immunogenicity of HSP70 of L. donovani was assessed in native condition, herein we generated recombinant HSP70 and tested its potential to stimulate immune responses in lymphocytes of cured Leishmania infected hamsters as well as in the peripheral blood mononuclear cells (PBMCs) of cured patients of VL either individually or in combination with above mentioned recombinant proteins. rLdHSP70 alone elicited strong cellular responses along with remarkable up-regulation of IFN-γ and IL-12 cytokines and extremely lower level of IL-4 and IL-10. Among the various combinations, rLdHSP70 + rLdPDI emerged as superior one augmenting improved cellular responses followed by rLdHSP70 + rLdEL-2. These combinations were further evaluated for its protective potential wherein rLdHSP70 + rLdPDI again conferred utmost protection (∼80%) followed by rLdHSP70 + rLdEL-2 (∼75%) and generated a strong cellular immune response with significant increase in the levels of iNOS transcript as well as IFN-γ and IL-12 cytokines which was further supported by the high level of IgG2 antibody in vaccinated animals. These observations indicated that vaccine(s) based on combination of HSP70 with Th1-stimulatory protein(s) may be a viable proposition against intracellular pathogens.


Assuntos
Proteínas de Choque Térmico HSP70/imunologia , Vacinas contra Leishmaniose/imunologia , Leishmaniose Visceral/prevenção & controle , Fator 2 de Elongação de Peptídeos/imunologia , Isomerases de Dissulfetos de Proteínas/imunologia , Proteínas de Protozoários/imunologia , Triose-Fosfato Isomerase/imunologia , Animais , Anticorpos Antiprotozoários/biossíntese , Antígenos de Protozoários/química , Antígenos de Protozoários/genética , Antígenos de Protozoários/imunologia , Cricetinae , Feminino , Expressão Gênica , Proteínas de Choque Térmico HSP70/administração & dosagem , Proteínas de Choque Térmico HSP70/genética , Imunidade Celular/efeitos dos fármacos , Imunização , Leishmania donovani/imunologia , Vacinas contra Leishmaniose/administração & dosagem , Vacinas contra Leishmaniose/genética , Leishmaniose Visceral/imunologia , Leishmaniose Visceral/mortalidade , Leishmaniose Visceral/parasitologia , Masculino , Fator 2 de Elongação de Peptídeos/administração & dosagem , Fator 2 de Elongação de Peptídeos/genética , Isomerases de Dissulfetos de Proteínas/administração & dosagem , Isomerases de Dissulfetos de Proteínas/genética , Proteínas de Protozoários/administração & dosagem , Proteínas de Protozoários/genética , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Análise de Sobrevida , Células Th1/efeitos dos fármacos , Células Th1/imunologia , Células Th1/parasitologia , Triose-Fosfato Isomerase/administração & dosagem , Triose-Fosfato Isomerase/genética
20.
Expert Opin Drug Deliv ; 11(5): 633-46, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24606222

RESUMO

OBJECTIVE: The principle objective of this study was to develop 1,2-diacyl-sn-glycero-3-phospho-l-serine (PS)-coated gelatin nanoparticles (GNPs) bearing amphotericin B (AmB) for specific targeting to the macrophages involved in visceral leishmaniasis (VL). METHOD: The two-step desolvation method has been used for the preparation of GNPs with AmB, which was further coated with PS (PS-AmB-GNPs). The targeting potential of it was compared with uncoated AmB-loaded GNPs (AmB-GNPs) for in vitro and in vivo macrophage uptake. RESULTS: The results of flow cytometric data revealed enhanced uptake of PS-AmB-GNPs in J774A.1 macrophage cell lines compared with AmB-GNPs. In vivo organ distribution studies in Wistar rats demonstrated a significantly higher extent of accumulation of PS-AmB-GNPs compared with AmB-GNPs in macrophage-rich organs, particularly in liver and spleen. The in vivo anti-leishmanial activity of plain AmB, AmB-GNPs and PS-AmB-GNPs was tested against VL in Leishmania donovani-infected hamsters. Highly significant anti-leishmanial activity (p < 0.05 compared with AmB-GNPs) was observed with PS-AmB-GNPs, causing 85.3 ± 7.89% inhibition of splenic parasitic burden. AmB-GNPs and plain AmB caused only 71.0 ± 3.87 and 50.5 ± 5.12% parasite inhibitions, respectively, in Leishmania-infected hamsters (p < 0.05 for PS-AmB-GNPs versus plain AmB and AmB-GNPs versus plain AmB). CONCLUSION: The objective of the preparation was achieved and high accumulation of AmB in liver and spleen has been found, which resulted in enhanced anti-leishmanial activity.


Assuntos
Anfotericina B/administração & dosagem , Antiprotozoários/administração & dosagem , Materiais Revestidos Biocompatíveis , Portadores de Fármacos , Gelatina/química , Leishmaniose Visceral/tratamento farmacológico , Fosfatidilserinas/química , Anfotericina B/química , Anfotericina B/farmacocinética , Animais , Antiprotozoários/química , Antiprotozoários/farmacocinética , Linhagem Celular , Química Farmacêutica , Cricetinae , Citometria de Fluxo , Leishmania donovani/efeitos dos fármacos , Fígado/metabolismo , Macrófagos/metabolismo , Macrófagos/parasitologia , Masculino , Mesocricetus , Microscopia Confocal , Nanopartículas/química , Óxido Nítrico/metabolismo , Tamanho da Partícula , Ratos , Ratos Wistar , Baço/metabolismo
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