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Rostami MN, Khamesipour A. Potential biomarkers of immune protection in human leishmaniasis. Med Microbiol Immunol 2021; 210:81-100. [PMID: 33934238 PMCID: PMC8088758 DOI: 10.1007/s00430-021-00703-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2020] [Accepted: 03/22/2021] [Indexed: 12/30/2022]
Abstract
Leishmaniasis is a vector-borne neglected tropical disease endemic in over 100 countries around the world. Available control measures are not always successful, therapeutic options are limited, and there is no vaccine available against human leishmaniasis, although several candidate antigens have been evaluated over the last decades. Plenty of studies have aimed to evaluate the immune response development and a diverse range of host immune factors have been described to be associated with protection or disease progression in leishmaniasis; however, to date, no comprehensive biomarker(s) have been identified as surrogate marker of protection or exacerbation, and lack of enough information remains a barrier for vaccine development. Most of the current understanding of the role of different markers of immune response in leishmaniasis has been collected from experimental animal models. Although the data generated from the animal models are crucial, it might not always be extrapolated to humans. Here, we briefly review the events during Leishmania invasion of host cells and the immune responses induced against Leishmania in animal models and humans and their potential role as a biomarker of protection against human leishmaniasis.
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Affiliation(s)
| | - Ali Khamesipour
- Center for Research and Training in Skin Diseases and Leprosy, Tehran University of Medical Sciences, 14155-6383, Tehran, Iran.
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2
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A biomarker for tegumentary and visceral leishmaniasis based on a recombinant Leishmania hypothetical protein. Immunobiology 2019; 224:477-484. [DOI: 10.1016/j.imbio.2019.05.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Revised: 05/08/2019] [Accepted: 05/28/2019] [Indexed: 12/11/2022]
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3
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Immuno-informatics based approaches to identify CD8+ T cell epitopes within the Leishmania donovani 3-ectonucleotidase in cured visceral leishmaniasis subjects. Microbes Infect 2017; 19:358-369. [DOI: 10.1016/j.micinf.2017.03.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Revised: 03/10/2017] [Accepted: 03/24/2017] [Indexed: 01/22/2023]
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4
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Gene deleted live attenuated Leishmania vaccine candidates against visceral leishmaniasis elicit pro-inflammatory cytokines response in human PBMCs. Sci Rep 2016; 6:33059. [PMID: 27624408 PMCID: PMC5021981 DOI: 10.1038/srep33059] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2016] [Accepted: 08/08/2016] [Indexed: 02/03/2023] Open
Abstract
Currently no effective vaccine is available for human visceral leishmaniasis(VL) caused by Leishmania donovani. Previously, we showed that centrin1 and p27gene deleted live attenuated Leishmania parasites (LdCen1(-/-) and Ldp27(-/-)) are safe, immunogenic and protective in animal models. Here, to assess the correlates of protection, we evaluated immune responses induced by LdCen1(-/-) and Ldp27(-/-) in human blood samples obtained from healthy, healed VL (HVL), post kala-azar dermal leishmaniasis(PKDL) and VL subjects. Both parasites infected human macrophages, as effectively as the wild type parasites. Further, LdCen1(-/-) and Ldp27(-/-) strongly stimulated production of pro-inflammatory cytokines including, IL-12, IFN-γ, TNF-α, IL-2, IL-6 and IL-17 in the PBMCs obtained from individuals with a prior exposure to Leishmania (HVL and PKDL). There was no significant stimulation of anti-inflammatory cytokines (IL-4 and IL-10). Induction of Th1 biased immune responses was supported by a remarkable increase in IFN-γ secreting CD4(+) and CD8(+) T cells and IL-17 secreting CD4(+) cells in PBMCs from HVL cases with no increase in IL-10 secreting T cells. Hence, LdCen1(-/-) and Ldp27(-/-) are promising as live vaccine candidates against VL since they elicit strong protective immune response in human PBMCs from HVL, similar to the wild type parasite infection, mimicking a naturally acquired protection following cure.
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5
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Khare P, Jaiswal AK, Tripathi CDP, Sundar S, Dube A. Immunoprotective responses of T helper type 1 stimulatory protein-S-adenosyl-L-homocysteine hydrolase against experimental visceral leishmaniasis. Clin Exp Immunol 2016; 185:165-79. [PMID: 26898994 DOI: 10.1111/cei.12780] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 02/15/2016] [Accepted: 02/16/2016] [Indexed: 11/29/2022] Open
Abstract
It is well known that a patient in clinical remission of visceral leishmaniasis (VL) remains immune to reinfection, which provides a rationale for the feasibility of a vaccine against this deadly disease. In earlier studies, observation of significant cellular responses in treated Leishmania patients as well as in hamsters against leishmanial antigens from different fractions led to its further proteomic characterization, wherein S-adenosyl-L-homocysteine hydrolase (AdoHcy) was identified as a helper type 1 (Th1) stimulatory protein. The present study includes immunological characterization of this protein, its cellular responses [lymphoproliferation, nitric oxide (NO) production and cytokine responses] in treated Leishmania-infected hamsters and patients as well as prophylactic efficacy against Leishmania challenge in hamsters and the immune responses generated thereof. Significantly higher cellular responses were noticed against recombinant L. donovani S-adenosyl-L-homocysteine hydrolase (rLdAdoHcy) compared to soluble L. donovani antigen in treated samples. Moreover, stimulation of peripheral blood mononuclear cells with rLdAdoHcy up-regulated the levels of interferon (IFN)-γ, interleukin (IL)-12 and down-regulated IL-10. Furthermore, vaccination with rLdAdoHcy generated perceptible delayed-type hypersensitivity response and exerted considerably good prophylactic efficacy (∼70% inhibition) against L. donovani challenge. The efficacy was confirmed by the increased expression levels of inducible NO synthase and Th1-type cytokines, IFN-γ and IL-12 and down-regulation of IL-4, IL-10 and transforming growth factor (TGF)-β. The results indicate the potentiality of rLdAdoHcy protein as a suitable vaccine candidate against VL.
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Affiliation(s)
- P Khare
- Division of Parasitology, CSIR - Central Drug Research Institute, Lucknow
| | - A K Jaiswal
- Division of Parasitology, CSIR - Central Drug Research Institute, Lucknow
| | - C D P Tripathi
- Division of Parasitology, CSIR - Central Drug Research Institute, Lucknow
| | - S Sundar
- Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - A Dube
- Division of Parasitology, CSIR - Central Drug Research Institute, Lucknow
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Joshi S, Yadav NK, Rawat K, Tripathi CDP, Jaiswal AK, Khare P, Tandon R, Baharia RK, Das S, Gupta R, Kushawaha PK, Sundar S, Sahasrabuddhe AA, Dube A. Comparative Analysis of Cellular Immune Responses in Treated Leishmania Patients and Hamsters against Recombinant Th1 Stimulatory Proteins of Leishmania donovani. Front Microbiol 2016; 7:312. [PMID: 27047452 PMCID: PMC4801884 DOI: 10.3389/fmicb.2016.00312] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2016] [Accepted: 02/26/2016] [Indexed: 12/17/2022] Open
Abstract
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.
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Affiliation(s)
- Sumit Joshi
- Parasitology Division, Council of Scientific and Industrial Research-Central Drug Research Institute Lucknow, India
| | - Narendra K Yadav
- Parasitology Division, Council of Scientific and Industrial Research-Central Drug Research Institute Lucknow, India
| | - Keerti Rawat
- Parasitology Division, Council of Scientific and Industrial Research-Central Drug Research Institute Lucknow, India
| | - Chandra Dev P Tripathi
- Parasitology Division, Council of Scientific and Industrial Research-Central Drug Research Institute Lucknow, India
| | - Anil K Jaiswal
- Parasitology Division, Council of Scientific and Industrial Research-Central Drug Research Institute Lucknow, India
| | - Prashant Khare
- Parasitology Division, Council of Scientific and Industrial Research-Central Drug Research Institute Lucknow, India
| | - Rati Tandon
- Parasitology Division, Council of Scientific and Industrial Research-Central Drug Research Institute Lucknow, India
| | - Rajendra K Baharia
- Parasitology Division, Council of Scientific and Industrial Research-Central Drug Research Institute Lucknow, India
| | - Sanchita Das
- Parasitology Division, Council of Scientific and Industrial Research-Central Drug Research Institute Lucknow, India
| | - Reema Gupta
- Parasitology Division, Council of Scientific and Industrial Research-Central Drug Research Institute Lucknow, India
| | - Pramod K Kushawaha
- Parasitology Division, Council of Scientific and Industrial Research-Central Drug Research Institute Lucknow, India
| | - Shyam Sundar
- Department of Medicine, Institute of Medical Sciences, Banaras Hindu University Varanasi, India
| | - Amogh A Sahasrabuddhe
- Molecular and Structural Biology Division, Council of Scientific and Industrial Research-Central Drug Research Institute Lucknow, India
| | - Anuradha Dube
- Parasitology Division, Council of Scientific and Industrial Research-Central Drug Research Institute Lucknow, India
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Gupta R, Kumar V, Kushawaha PK, Tripathi CP, Joshi S, Sahasrabuddhe AA, Mitra K, Sundar S, Siddiqi MI, Dube A. Characterization of glycolytic enzymes--rAldolase and rEnolase of Leishmania donovani, identified as Th1 stimulatory proteins, for their immunogenicity and immunoprophylactic efficacies against experimental visceral leishmaniasis. PLoS One 2014; 9:e86073. [PMID: 24475071 PMCID: PMC3901665 DOI: 10.1371/journal.pone.0086073] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2013] [Accepted: 12/04/2013] [Indexed: 11/18/2022] Open
Abstract
Th1 immune responses play an important role in controlling Visceral Leishmaniasis (VL) hence, Leishmania proteins stimulating T-cell responses in host, are thought to be good vaccine targets. Search of such antigens eliciting cellular responses in Peripheral blood mononuclear cells (PBMCs) from cured/exposed/Leishmania patients and hamsters led to the identification of two enzymes of glycolytic pathway in the soluble lysate of a clinical isolate of Leishmania donovani--Enolase (LdEno) and aldolase (LdAld) as potential Th1 stimulatory proteins. The present study deals with the molecular and immunological characterizations of LdEno and LdAld. The successfully cloned and purified recombinant proteins displayed strong ability to proliferate lymphocytes of cured hamsters' along with significant nitric-oxide production and generation of Th1-type cytokines (IFN-γ and IL-12) from stimulated PBMCs of cured/endemic VL patients. Assessment of their prophylactic potentials revealed ∼ 90% decrease in parasitic burden in rLdEno vaccinated hamsters against Leishmania challenge, strongly supported by an increase in mRNA expression levels of iNOS, IFN-γ, TNF-α and IL-12 transcripts along with extreme down-regulation of TGF-β, IL-4 and IL-10. However, animals vaccinated with rLdAld showed comparatively lesser prophylactic efficacy (∼ 65%) with inferior immunological response. Further, with a possible implication in vaccine design against VL, identification of potential T-cell epitopes of both the proteins was done using computational approach. Additionally, in-silico 3-D modelling of the proteins was done in order to explore the possibility of exploiting them as potential drug targets. The comparative molecular and immunological characterizations strongly suggest rLdEno as potential vaccine candidate against VL and supports the notion of its being effective T-cell stimulatory protein.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antigens, Protozoan/immunology
- Cricetinae
- Cytokines/biosynthesis
- Disease Models, Animal
- Epitopes, T-Lymphocyte/chemistry
- Epitopes, T-Lymphocyte/immunology
- Fructose-Bisphosphate Aldolase/chemistry
- Fructose-Bisphosphate Aldolase/genetics
- Fructose-Bisphosphate Aldolase/metabolism
- Glycolysis
- Hypersensitivity, Delayed/immunology
- Immunoglobulin G/immunology
- Leishmania donovani/enzymology
- Leishmania donovani/genetics
- Leishmania donovani/immunology
- Leishmaniasis Vaccines/immunology
- Leishmaniasis, Visceral/immunology
- Leishmaniasis, Visceral/prevention & control
- Leukocytes, Mononuclear/immunology
- Leukocytes, Mononuclear/metabolism
- Lymphocyte Activation/immunology
- Male
- Models, Molecular
- Mycobacterium bovis/immunology
- Nitric Oxide/metabolism
- Phosphopyruvate Hydratase/chemistry
- Phosphopyruvate Hydratase/genetics
- Phosphopyruvate Hydratase/metabolism
- Protein Conformation
- Th1 Cells/immunology
- Th1 Cells/metabolism
- Vaccination
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Affiliation(s)
- Reema Gupta
- Divisions of Parasitology, CSIR-Central Drug Research Institute, Lucknow, India
| | - Vikash Kumar
- Molecular and Structural Biology, CSIR-Central Drug Research Institute, Lucknow, India
| | | | | | - Sumit Joshi
- Divisions of Parasitology, CSIR-Central Drug Research Institute, Lucknow, India
| | | | - Kalyan Mitra
- Electron Microscopy, CSIR-Central Drug Research Institute, Lucknow, India
| | - Shyam Sundar
- Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, India
| | | | - Anuradha Dube
- Divisions of Parasitology, CSIR-Central Drug Research Institute, Lucknow, India
- * E-mail:
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Erratum. Clin Exp Immunol 2013. [DOI: 10.1111/cei.12222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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9
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Kheiri Manjili H, Jafari H, Ramazani A, Davoudi N. Anti-leishmanial and toxicity activities of some selected Iranian medicinal plants. Parasitol Res 2012; 111:2115-21. [PMID: 22875395 DOI: 10.1007/s00436-012-3059-7] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Accepted: 07/17/2012] [Indexed: 11/28/2022]
Abstract
Leishmaniasis is caused by protozoan parasites belonging to the genus Leishmania. Cutaneous leishmaniasis is the most common form of leishmaniasis in Iran. As there is not any vaccine for leishmaniasis, treatment is important to prevent the spreading of parasites. There is, therefore, a need to develop newer drugs from different sources. The aim of this study was to assess anti-leishmanial activity of the ethanolic extracts of 17 different medicinal plants against Leishmania major promastigotes and macrophage cell line J774. The selection of the hereby studied 17 plants was based on the existing information on their local ethnobotanic history. Plants were dried, powdered, and macerated in a hydroalcoholic solution. Resulting extracts have been assessed for in vitro anti-leishmanial and brine shrimp toxicity activities. Four plants, Caesalpinia gilliesii, Satureia hortensis, Carum copticum heirm, and Thymus migricus, displayed high anti-leishmanial activity (IC50, 9.76 ± 1.27, 15.625 ± 3.76, 15.625 ± 5.46, and 31.25 ± 15.44 μM, respectively) and were toxic against the J774 macrophage cell line at higher concentrations than those needed to inhibit the parasite cell growth (IC50, 45.13 ± 3.17, 100.44 ± 17.48, 43.76 ± 0.78, and 39.67 ± 3.29 μM, respectively). Glucantime as positive control inhibited the growth of L. major promastigotes with IC50 = 254 μg/ml on promastigotes (1 × 10(6)/100 μ/well) of a log phase culture, without affecting the growth of J774 macrophages. These data revealed that C. gilliesii, S. hortensis, C. copticum heirm, and T. migricus extracts contain active compounds, which could serve as alternative agents in the control of cutaneous leishmaniasis. The activity of these herbs against L. major promastigotes and macrophage cell line J774 was reported for the first time in our study.
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Gupta R, Kushawaha PK, Tripathi CDP, Sundar S, Dube A. A novel recombinant Leishmania donovani p45, a partial coding region of methionine aminopeptidase, generates protective immunity by inducing a Th1 stimulatory response against experimental visceral leishmaniasis. Int J Parasitol 2012; 42:429-35. [DOI: 10.1016/j.ijpara.2012.02.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 02/08/2012] [Accepted: 02/09/2012] [Indexed: 10/28/2022]
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Kumari S, Misra P, Tandon R, Samant M, Sundar S, Dube A. Leishmania donovani: immunostimulatory cellular responses of membrane and soluble protein fractions of splenic amastigotes in cured patient and hamsters. PLoS One 2012; 7:e30746. [PMID: 22292030 PMCID: PMC3266919 DOI: 10.1371/journal.pone.0030746] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Accepted: 12/28/2011] [Indexed: 11/19/2022] Open
Abstract
Visceral leishmaniasis (VL), caused by the intracellular parasite Leishmania donovani, L. chagasi and L. infantum is characterized by defective cell-mediated immunity (CMI) and is usually fatal if not treated properly. An estimated 350 million people worldwide are at risk of acquiring infection with Leishmania parasites with approximately 500,000 cases of VL being reported each year. In the absence of an efficient and cost-effective antileishmanial drug, development of an appropriate long-lasting vaccine against VL is the need of the day. In VL, the development of a CMI, capable of mounting Th1-type of immune responses, play an important role as it correlate with recovery from and resistance to disease. Resolution of infection results in lifelong immunity against the disease which indicates towards the feasibility of a vaccine against the disease. Most of the vaccination studies in Leishmaniasis have been focused on promastigote- an infective stage of parasite with less exploration of pathogenic amastigote form, due to the cumbersome process of its purified isolation. In the present study, we have isolated and purified splenic amastigotes of L. donovani, following the traditional protocol with slight modification. These were fractionated into five membranous and soluble subfractions each i.e MAF1-5 and SAF1-5 and were subjected for evaluation of their ability to induce cellular responses. Out of five sub-fractions from each of membrane and soluble, only four viz. MAF2, MAF3, SAF2 and SAF3 were observed to stimulate remarkable lymphoproliferative, IFN-γ, IL-12 responses and Nitric Oxide production, in Leishmania-infected cured/exposed patients and hamsters. Results suggest the presence of Th-1 type immunostimulatory molecules in these sub-fractions which may further be exploited for developing a successful subunit vaccine from the less explored pathogenic stage against VL.
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Affiliation(s)
- Shraddha Kumari
- Parasitology Division, Central Drug Research Institute, CSIR, Lucknow, Uttar Pradesh, India
- Department of Immunology, Rikshospitalet-Radiumhospitalet Medical Centre, Institute for Cancer Research, Montebello, Oslo, Norway
| | - Pragya Misra
- Parasitology Division, Central Drug Research Institute, CSIR, Lucknow, Uttar Pradesh, India
| | - Rati Tandon
- Parasitology Division, Central Drug Research Institute, CSIR, Lucknow, Uttar Pradesh, India
| | - Mukesh Samant
- Parasitology Division, Central Drug Research Institute, CSIR, Lucknow, Uttar Pradesh, India
- Department of Medical Biology, Research Center in Infectious Diseases, CHUL Research Center, Laval University, Quebec, Canada
| | - Shyam Sundar
- Department of Medicine, Institute of Medical Sciences, Banaras Hindu University, Varanasi, Uttar Pradesh, India
| | - Anuradha Dube
- Parasitology Division, Central Drug Research Institute, CSIR, Lucknow, Uttar Pradesh, India
- * E-mail:
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Immunity to visceral leishmaniasis using genetically defined live-attenuated parasites. J Trop Med 2011; 2012:631460. [PMID: 21912560 PMCID: PMC3168768 DOI: 10.1155/2012/631460] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Accepted: 07/01/2011] [Indexed: 11/18/2022] Open
Abstract
Leishmaniasis is a protozoan parasitic disease endemic to the tropical and subtropical regions of the world, with three major clinical forms, self-healing cutaneous leishmaniasis (CL), mucocutaneous leishmaniasis (MCL), and visceral leishmaniasis (VL). Drug treatments are expensive and often result in the development of drug resistance. No vaccine is available against leishmaniasis. Subunit Leishmania vaccine immunization in animal models has shown some efficacy but little or none in humans. However, individuals who recover from natural infection are protected from reinfection and develop life-long protection, suggesting that infection may be a prerequisite for immunological memory. Thus, genetically altered live-attenuated parasites with controlled infectivity could achieve such memory. In this paper, we discuss development and characteristics of genetically altered, live-attenuated Leishmania donovani parasites and their possible use as vaccine candidates against VL. In addition, we discuss the challenges and other considerations in the use of live-attenuated parasites.
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Tripathi P, Gupta SK, Sinha S, Sundar S, Dube A, Naik S. Prophylactic efficacy of high-molecular-weight antigenic fractions of a recent clinical isolate of Leishmania donovani against visceral leishmaniasis. Scand J Immunol 2008; 68:492-501. [PMID: 18803606 DOI: 10.1111/j.1365-3083.2008.02171.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
T-cell mediated immune responses are key determinants to the natural course of infection caused by intracellular parasites such as Leishmania. Thus, T-cell activating proteins of these microbes continue to generate active interest particularly in view of their possible role in the design and development of newer and more effective vaccines. We have recently reported the presence of T-cell immunostimulatory antigens with the high-molecular-weight (MW) fractions (134-64.2 kDa) of whole Leishmania donovani antigen (strain 2001), which stimulated variable amounts of IFN-gamma, IL-12 and IL-10 in exposed immune individuals. The present study was undertaken to further evaluate these high-MW antigenic fractions (MW range >100-60 kDa) for potential protective efficacy. The high-MW region of the parasite was resolved into five antigenic fractions (Prep A-E) using continuous elution gel electrophoresis. Prior to in vivo protection studies in hamsters, these fractions were used to evaluate in vitro cellular responses in eight Leishmania-exposed individuals and treated cured hamsters. The protective efficacy of prep (A + B), C, D and E in combination with BCG was evaluated in inbred hamsters using standard immunization protocol. Proliferative responses were seen in all eight of eight exposed individuals to prep D [median stimulation index (SI): 5.2 (range 3.9-7.1)] and E [median SI: 5.6 (range 4.4-8.2)], five of eight individuals to prep B and prep C and three of eight to prep A [median SI: 0.2 (range 0.1-7.2)]. The median proliferative responses to prep D and prep E were significantly higher than to fraction prep A; (P < 0.05) but not to prep B and prep C. However, prep A-E induced equivalent levels of IFN-gamma, IL-10 and IL-12 cytokines. Fractions D and E also exhibited marked parasite inhibition in spleen (52.5% and 73.7%) and liver (65% and 80.2%) as compared with prep (A + B) (23% in spleen and 24% in liver) and prep C (38% in spleen and 24% in liver). Prep D and prep E vaccinated animals showed higher in vitro stimulatory responses (mean SI: 6.6 and 8.8) and nitric oxide (NO) induction (mean NO levels: 6.4 and 10.7 mug/ml) against whole cell extract as compared with other groups. The protection also correlated with presence of suppressed Leishmania-specific IgG levels in prep D and prep E immunized hamsters. These studies indicate the presence of immunostimulatory and protective molecules in 60-80 kDa region of L. donovani, which may be further exploited for developing a subunit vaccine.
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Affiliation(s)
- P Tripathi
- Department of Immunology, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
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Induction of Th1-type cellular responses in cured/exposed Leishmania-infected patients and hamsters against polyproteins of soluble Leishmania donovani promastigotes ranging from 89.9 to 97.1kDa. Vaccine 2008; 26:4813-8. [DOI: 10.1016/j.vaccine.2008.06.102] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Revised: 06/24/2008] [Accepted: 06/30/2008] [Indexed: 11/21/2022]
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