scholarly journals Kinesin Motor Domain of Leishmania donovani as a Future Vaccine Candidate

2008 ◽  
Vol 15 (5) ◽  
pp. 836-842 ◽  
Author(s):  
Ayan Dey ◽  
Pawan Sharma ◽  
Naresh Singh Redhu ◽  
Sarman Singh
Keyword(s):  
Visceral Leishmaniasis ◽  
Lymphocyte Proliferation ◽  
Leishmania Donovani ◽  
Mononuclear Cells ◽  
Vaccine Candidate ◽  
Ex Vivo ◽  
Interleukin 2 ◽  
Motor Domain ◽  
Enzyme Linked Immunosorbent Assay ◽  
Kinesin Motor

ABSTRACT Visceral leishmaniasis (VL) is one of the important parasitic diseases, with approximately 350 million people at risk. Due to the nonavailability of an ideal drug, development of a safe, effective, and affordable vaccine could be a solution for control and prevention of this disease. The present study was carried out to examine the immunological potential of kinesin protein from the microtubule locus of Leishmania donovani as a suitable vaccine candidate. In silico analysis of this region revealed clusters of major histocompatibility complex class I and II binding epitopes in its motor domain region. A recombinant protein was expressed from this region and named rLvacc. The antigenicity and immunogenicity studies of this protein by Western blot analysis revealed that rLvacc is strongly recognized by sera from acute VL patients. To evaluate its immunogenicity, peripheral blood mononuclear cells from cured VL patients were separated, and a lymphocyte proliferation assay was carried out in the presence of rLvacc. After lymphocyte proliferation, the pooled culture supernatant was assayed for anti-rLvacc antibody titers using an enzyme-linked immunosorbent assay. The results showed that immunoglobulin G2 (IgG2) subtype antibodies were predominant, while IgG1 subtype antibodies were produced in very low titers. On the basis of these ex vivo preliminary findings, its immunogenicity was studied in BALB/c mice. Vaccination with the DNA construct generated a good cellular immune response with significant increases in gamma interferon and interleukin-2 (IL-2) cytokine levels (Th1), but no increase in IL-4 levels (Th2). Taken together, our findings suggest the kinesin motor domain region of L. donovani as a potential vaccine candidate against visceral leishmaniasis.

scholarly journals A T-Cell Epitope-Based Multi-Epitope Vaccine Designed Using Human HLA Specific T Cell Epitopes Induces Sterile Immunity against Experimental Visceral Leishmaniasis in Hamsters

2021 ◽  
Author(s):  
Aryandra Arya ◽  
Sunil K Arora
Keyword(s):  
T Cell ◽  
Visceral Leishmaniasis ◽  
Leishmania Donovani ◽  
Mononuclear Cells ◽  
Ex Vivo ◽  
Human Peripheral Blood ◽  
Cell Epitope ◽  
Effective Vaccine ◽  
Hamster Model ◽  
Vaccine Candidates

Visceral Leishmaniasis is a neglected tropical disease affecting 12 million people annually. Even in the second decade of the 21st century, it has remained without an effective vaccine for human use. In the current study, we have designed three multiepitope vaccine candidates by the selection of multiple IFN-γ inducing MHC-I and MHC-II binder T-cell specific epitopes from 3 previously identified antigen genes of Leishmania donovani from our lab, by immune-informatic approach using IFNepiotpe, NET-MHC-1 and NET MHC-2 webservers. We have tested the protective potential of these three multiepitope proteins as vaccine in a hamster model of visceral leishmaniasis. The immunization data revealed that the vaccine candidates induced a very high level of Th-1 biased protective immune response in-vivo in a hamster model of experimental visceral Leishmaniasis, with one of the candidates inducing a sterile immunity. The vaccinated animals displayed highly activated monocyte macrophages with the capability of clearing intracellular parasites due to increased respiratory burst. Additionally, these proteins induced activation of polyfunctional T cells secreting INF-γ, TNF-α, and IL-2 in ex-vivo stimulation of human peripheral blood mononuclear cells, further supporting the protective nature of designed candidates.

scholarly journals Cytokine production in ex-vivo stimulated fresh and cryopreserved T-cells

2021 ◽  
Vol 67 (2) ◽  
pp. 95-101
Author(s):  
Monica Vuță ◽  
Ionela-Maria Cotoi ◽  
Ion Bogdan Mănescu ◽  
Doina Ramona Manu ◽  
Minodora Dobreanu
Keyword(s):  
T Cells ◽  
Peripheral Blood ◽  
Cd4 T Cells ◽  
Mononuclear Cells ◽  
Cytokine Production ◽  
Ex Vivo ◽  
Gradient Centrifugation ◽  
Intracellular Cytokine Staining ◽  
Interleukin 2 ◽  
Middle Aged

Abstract Objective: In vitro cytokine production by peripheral blood mononuclear cells (PBMCs) is an important and reliable measure of immunocompetence. PBMC can be stimulated directly after isolation or frozen for later use. However, cryopreservation may affect cell recovery, viability and functionality. This study aims to investigate cytokine synthesis in ex-vivo stimulated fresh and cryopreserved CD4+ and CD4- T cells. Methods: PBMCs were obtained by Ficoll gradient centrifugation from heparinized peripheral blood of 6 middle-aged clinically healthy subjects. Half of these cells (labeled “Fresh”) was further processed and the other half (labeled “Cryo”) was cryopreserved at -140°C for up to 3 months. Fresh-PBMCs were activated with Phorbol-Myristate-Acetate/Ionomycin/Monensin for 5 hours immediately after isolation while Cryo-PBMCs were identically activated after thawing and cell resting. Activated cells were fixed, permeabilized and intracellular cytokine staining was performed using Phycoerythrin (PE)-conjugated antibodies for Interleukin-2 (IL-2), Tumor Necrosis Factor-alpha (TNF-a), and Interferon-gamma (IFN-g). All samples were analyzed within 24 hours by flow cytometry. Results: Both Fresh and Cryo CD3+CD4+/CD3+CD4- sub-populations partially produced each of the three cytokines. A higher percentage of CD4+ T cells produced IL-2 and TNF-a and a greater percentage of CD4- T cells were found to produce IFN-g. A significantly higher percentage of Cryo-lymphocytes was shown to produce TNF-a in both CD3+CD4+ (31.4% vs 24.9%, p=0.031) and CD3+CD4- (22.7% vs 17.9%, p=0.031) subpopulations. No notable difference was found for IL-2 and IFN-g production between Fresh and Cryo T cells. Conclusion: Cryopreservation for up to 3 months significantly increases TNF-a production of T-cells in clinically healthy middle-aged subjects.

scholarly journals Immunologic correlates of spontaneous lymphocyte proliferation in human T-lymphotropic virus infection

Blood ◽  
1991 ◽  
Vol 78 (1) ◽  
pp. 169-174 ◽  
Author(s):  
HE Prince ◽  
H Lee ◽  
ER Jensen ◽  
P Swanson ◽  
D Weber ◽  
...  
Keyword(s):  
Lymphocyte Proliferation ◽  
Mononuclear Cells ◽  
Interleukin 2 ◽  
Serum Levels ◽  
Control Group ◽  
Relative Distribution ◽  
T Lymphotropic Virus ◽  
Soluble Cd25 ◽  
Spontaneous Proliferation ◽  
Antibody Levels

Abstract Previously we showed that mononuclear cells from about half of human T- lymphotropic virus (HTLV)-seropositive persons exhibit spontaneous proliferation in vitro. We sought to determine if proliferation was associated with other immunologic changes characteristic of HTLV infection. The parameters assessed were (1) percentages of lymphocytes expressing CD4 and/or CD25 (interleukin-2 receptor), (2) serum levels of soluble CD25, (3) serostatus for other viruses, (4) anti-HTLV antibody levels, and (5) HTLV type determined by polymerase chain reaction or serologic reactivity with type-specific peptides. The proliferation+ HTLV (PROL+) group, proliferation HTLV (PROL-) group, and control group showed similar percentages of CD4+, CD25+, and CD4+CD25+ lymphocytes; serum levels of soluble CD25 were also similar. Antibodies to cytomegalovirus, hepatitis B core, and hepatitis C were present in similar proportions of PROL+ and PROL+ groups. However, a significant association was found between spontaneous proliferation and anti-HTLV antibody levels; sera from 67% of PROL+ persons, but only 18% of PROL- persons, required dilution to yield absorbance values within the linear range of the anti-HTLV antibody assay. In the PROL+ group, persons whose sera required the most dilution had proliferative responses significantly higher than those whose sera required no dilution. The PROL+ and PROL groups were similar with regard to the relative distribution of HTLV-I and HTLV-II infection. These findings indicate that HTLV-related spontaneous lymphocyte proliferation is related to levels of circulating anti-HTLV antibodies, and characterizes both HTLV-I and HTLV-II infection.

scholarly journals Interleukin 2 is an Upstream Regulator of CD4+ T Cells From Visceral Leishmaniasis Patients With Therapeutic Potential

2019 ◽  
Vol 220 (1) ◽  
pp. 163-173 ◽  
Author(s):  
Shashi Bhushan Chauhan ◽  
Rebecca Faleiro ◽  
Rajiv Kumar ◽  
Susanna Ng ◽  
Bhawana Singh ◽  
...  
Keyword(s):  
T Cells ◽  
Visceral Leishmaniasis ◽  
Cd4 T Cells ◽  
Leishmania Donovani ◽  
Therapeutic Potential ◽  
Interleukin 2 ◽  
Interferon Γ ◽  
Immune Functions ◽  
T Regulatory Cell ◽  
Upstream Regulator

Abstract Control of visceral leishmaniasis (VL) caused by Leishmania donovani requires interferon-γ production by CD4+ T cells. In VL patients, antiparasitic CD4+ T-cell responses are ineffective for unknown reasons. In this study, we measured the expression of genes associated with various immune functions in these cells from VL patients and compared them to CD4+ T cells from the same patients after drug treatment and from endemic controls. We found reduced GATA3, RORC, and FOXP3 gene expression in CD4+ T cells of VL patients, associated with reduced Th2, Th17, and FOXP3+CD4+ T regulatory cell frequencies in VL patient blood. Interleukin 2 (IL-2) was an important upstream regulator of CD4+ T cells from VL patients, and functional studies demonstrated the therapeutic potential of IL-2 for improving antiparasitic immunity. Together, these results provide new insights into the characteristics of CD4+ T cells from VL patients that can be used to improve antiparasitic immune responses.

scholarly journals Diagnosis of Visceral Leishmaniasis by Enzyme-Linked Immunosorbent Assay Using Urine Samples

2002 ◽  
Vol 9 (4) ◽  
pp. 789-794 ◽  
Author(s):  
Mohammad Zahidul Islam ◽  
Makoto Itoh ◽  
S. M. Shamsuzzaman ◽  
Rusella Mirza ◽  
Farzana Matin ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Sensitivity And Specificity ◽  
Immunosorbent Assay ◽  
Leishmania Donovani ◽  
Laboratory Diagnosis ◽  
Urine Samples ◽  
Enzyme Linked Immunosorbent Assay ◽  
Healthy Controls ◽  
Serum Samples ◽  
Crude Antigen

ABSTRACT A diagnostic method has been developed to detect anti-Leishmania donovani immunoglobulin G (IgG) in urine by enzyme-linked immunosorbent assay (ELISA). In measuring anti-L. donovani IgG, IgA, and IgM in urine, the method performed best in the detection of IgG. The sensitivity and specificity of the assay were determined with panels of urine samples from 62 visceral leishmaniasis (VL) patients, 59 healthy controls from areas of endemicity, 53 healthy controls from areas of nonendemicity, 59 malaria patients, 13 tuberculosis patients, 23 cutaneous leishmaniasis patients, and 7 patients with other diseases. Using L. donovani promastigote crude antigen, the test had 93.5% sensitivity (58 positives of 62 VL patient samples) and 89.3% specificity (191 negatives of 214 non-VL patient samples). The ELISA with acetone-treated L. donovani promastigote antigen raised the sensitivity and specificity to 95.0 and 95.3%, respectively. Western blot analysis revealed that most of the samples that cross-reacted with crude antigen in ELISA did not recognize any antigenic component of L. donovani crude antigen. We also checked 40 serum samples from the same group of VL patients for anti-L. donovani IgG and got 90.0% sensitivity with both crude and acetone-treated antigens. As collection of urine is much easier than collection of serum, the detection of anti-L. donovani IgG in urine with acetone-treated antigen will be useful in epidemiological studies. It could be an adjunct of laboratory diagnosis.

scholarly journals Antiviral Activity of Shiga Toxin 1: Suppression of Bovine Leukemia Virus-Related Spontaneous Lymphocyte Proliferation

2000 ◽  
Vol 68 (8) ◽  
pp. 4462-4469 ◽  
Author(s):  
Witold A. Ferens ◽  
Carolyn J. Hovde
Keyword(s):  
Antiviral Activity ◽  
Shiga Toxin ◽  
Bovine Leukemia Virus ◽  
Lymphocyte Proliferation ◽  
Mononuclear Cells ◽  
Leukemia Virus ◽  
Interleukin 2 ◽  
Pokeweed Mitogen ◽  
Potent Antiviral Activity ◽  
The Impact

ABSTRACT Human infections with Shiga toxin (Stx)-producing Escherichia coli (STEC) cause hemorrhagic colitis. The Stxs belong to a large family of ribosome-inactivating proteins (RIPs) that are found in a variety of higher plants and some bacteria. Many RIPs have potent antiviral activity for the plants that synthesize them. STEC strains, both virulent and nonvirulent to humans, are frequently isolated from healthy cattle. Interestingly, despite intensive investigations, it is not known why cattle carry STEC. We tested the hypothesis that Stx has antiviral properties for bovine viruses by assessing the impact of Stx type 1 (Stx1) on bovine peripheral blood mononuclear cells (PBMC) from cows infected with bovine leukemia virus (BLV). PBMC from BLV-positive animals invariably displayed spontaneous lymphocyte proliferation (SLP) in vitro. Stx1 or the toxin A subunit (Stx1A) strongly inhibited SLP. Toxin only weakly reduced the pokeweed mitogen- or interleukin-2-induced proliferation of PBMC from normal (BLV-negative) cows and had no effect on concanavalin A-induced proliferation. The toxin activity in PBMC from BLV-positive cattle was selective for viral SLP and did not abrogate cell response to pokeweed mitogen- or interleukin-2-induced proliferation. Antibody to virus or Stx1A was most effective at inhibiting SLP if administered at the start of cell culture, indicating that both reagents likely interfere with BLV-dependent initiation of SLP. Stx1A inhibited expression of BLV p24 protein by PBMC. A well-defined mutant Stx1A (E167D) that has decreased catalytic activity was not effective at inhibiting SLP, suggesting the inhibition of protein synthesis is likely the mechanism of toxin antiviral activity. Our data suggest that Stx has potent antiviral activity and may serve an important role in BLV-infected cattle by inhibiting BLV replication and thus slowing the progression of infection to its malignant end stage.

scholarly journals Use of a Newly Developed β-Mercaptoethanol Enzyme-Linked Immunosorbent Assay To Diagnose Visceral Leishmaniasis in Patients in Eastern Sudan

2007 ◽  
Vol 14 (12) ◽  
pp. 1592-1595 ◽  
Author(s):  
Durria Mansour ◽  
Elfadil M. Abass ◽  
Mohamed el Mutasim ◽  
Abdelhafeiz Mahamoud ◽  
Abdallah el Harith
Keyword(s):  
Visceral Leishmaniasis ◽  
Immunosorbent Assay ◽  
Leishmania Donovani ◽  
Clinical Evidence ◽  
High Reliability ◽  
Agglutination Test ◽  
Enzyme Linked Immunosorbent Assay ◽  
Direct Agglutination Test ◽  
Symptomatic Group ◽  
Eastern Sudan

ABSTRACT Corroboration of serology results is essential for restricting the risk of inappropriate antileishmanial prescription. A direct agglutination test (DAT) and a recently developed β-mercaptoethanol-modified enzyme-linked immunosorbent assay (β-ME ELISA) based on the use of antigen prepared as described for the DAT were applied to 416 sera from two Sudanese populations with and without clinical evidence of visceral leishmaniasis (VL). Of 285 sera with the lowest antileishmanial DAT titers (≤1:100 to 1:1,600), 270 (94.7%) scored comparable minimum β-ME ELISA absorbance values (≤0.1 to 0.26). In 117 sera that demonstrated the highest DAT titers (1:12,800 to ≥1:25,600), 86 (73.5%) scored maximum (0.81 to ≥1.35) and 30 (25.6%) medium (0.27 to 0.80) β-ME ELISA absorbance values. VL diagnosis was established for 142 (44.1%) patients in the VL-symptomatic group (n = 322), based on positive microscopy for Leishmania donovani in lymph node aspirates or positive DAT (titer, ≥1:3,200). Of the 125 sera from the symptomatic patients for whom microscopy was positive for VL, 111 (88.8%) had comparable positive DAT and β-ME ELISA readings. In all 17 sera from the symptomatic DAT-positive patients for whom leishmaniasis was not established by microscopy but who responded favorably to antileishmanial therapy, absorbance values (≥0.27) indicative of VL were obtained by β-ME ELISA. Of 197 symptomatic patients for whom microscopy was negative for VL, 172 (87.3%) tested negative in β-ME ELISA and 180 (91.4%) in DAT. Based on the high reliability demonstrated here for VL detection, β-ME ELISA fulfills the requirement of confirming DAT results in patients manifesting suspected VL.

scholarly journals Tacrolimus Pharmacodynamics and Pharmacogenetics along the Calcineurin Pathway in Human Lymphocytes

2014 ◽  
Vol 60 (10) ◽  
pp. 1336-1345 ◽  
Author(s):  
Ofelia M Noceti ◽  
Jean-Baptiste Woillard ◽  
Ahmed Boumediene ◽  
Patricia Esperón ◽  
Jean-Luc Taupin ◽  
...  
Keyword(s):  
Signal Transduction ◽  
T Cells ◽  
Mononuclear Cells ◽  
Interindividual Variability ◽  
Ex Vivo ◽  
Physiological Activity ◽  
Human Lymphocytes ◽  
Interleukin 2 ◽  
Therapeutic Drug ◽  
Calcineurin Pathway

Abstract BACKGROUND Although therapeutic drug monitoring has improved the clinical use of immunosuppressive drugs, there is still interpatient variability in efficacy and toxicity that pharmacodynamic monitoring may help to reduce. To select the best biomarkers of tacrolimus pharmacodynamics, we explored the strength and variability of signal transduction and the influence of polymorphisms along the calcineurin pathway. METHODS Peripheral blood mononuclear cells from 35 healthy volunteers were incubated with tacrolimus (0.1–50 ng/mL) and stimulated ex vivo. Inhibition of NFAT1 (nuclear factor of activated T cells 1) translocation to the nucleus and intracellular expression of interleukin-2 in CD4+ and CD8+ T cells and the surface activation marker CD25 in CD3+ cells were measured by flow cytometry. We sequenced the promoter regions of immunophilins and calcineurin subunits and characterized selected single nucleotide polymorphisms in the genes of the calcineurin pathway with allelic discrimination assays. RESULTS All responses closely fitted an I/Imax sigmoid model. Large interindividual variability (n = 30) in I0 and IC50 was found for all biomarkers. Moreover, strong and statistically significant associations were found between tacrolimus pharmacodynamic parameters and polymorphisms in the genes coding cyclophilin A, the calcineurin catalytic subunit α isoenzyme, and CD25. CONCLUSIONS This study demonstrates the consistency and large interindividual variability of signal transduction along the calcineurin pathway, as well as the strong influence of pharmacogenetic polymorphisms in the calcineurin cascade on both the physiological activity of this route and tacrolimus pharmacodynamics.

scholarly journals IL-10 and TGF-β Induced Arginase Expression Contributes to Deficient Nitric Oxide Response in Human Visceral Leishmaniasis

2021 ◽  
Vol 10 ◽  
Author(s):  
Manu Kupani ◽  
Smriti Sharma ◽  
Rajeev Kumar Pandey ◽  
Rajiv Kumar ◽  
Shyam Sundar ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Visceral Leishmaniasis ◽  
Leishmania Donovani ◽  
Mononuclear Cells ◽  
Human Peripheral Blood ◽  
No Production ◽  
Peripheral Blood Mononuclear ◽  
Before And After ◽  
Plasma Nitrite

Nitric oxide (NO) is an anti-microbial effector of the innate immune system which plays major role in non-specific killing of various pathogens including protozoan parasites. However, due to subversion of the host’s immune processes by pathogens, suboptimal production of NO is frequently found in many infection models. Previous studies have shown suppressed NO production during Leishmania donovani infection, the causative agent of visceral leishmaniasis (VL). Availability of L-Arginine, a semi-essential amino acid is required for inducible nitric oxide synthase (iNOS) mediated NO production. However, arginase is another enzyme, which if expressed concomitantly, may strongly compete for L-Arginine, and suppress NO production by iNOS. In the present study, plasma nitrite and arginase levels were measured in VL patients before and after successful drug treatment, endemic and non-endemic healthy donors. We observed significantly lower NO levels in the plasma of VL patients as compared to endemic controls, which improved significantly post-treatment. Significantly elevated arginase activity was also observed in the plasma of VL patients, which may be associated with NO deficiency. VL patients also showed significantly higher levels of IL-10 and TGF-β, which are known to regulate expression of arginase in various immune cells. In vitro studies with human peripheral blood mononuclear cells (PBMCs) further corroborated the role of IL-10 and TGF-β in arginase mediated suppression of NO production.

scholarly journals Molecular and serological detection of Leishmania spp. in captive wild animals from Ilha Solteira, SP, Brazil

2011 ◽  
Vol 20 (3) ◽  
pp. 219-222 ◽  
Author(s):  
Márcia Mariza Gomes Jusi ◽  
Wilma Aparecida Starke-Buzetti ◽  
Trícia Maria Ferreira de Sousa Oliveira ◽  
Michely da Silva Tenório ◽  
Lúcio de Oliveira de Sousa ◽  
...  
Keyword(s):  
Visceral Leishmaniasis ◽  
Urban Areas ◽  
Leishmania Donovani ◽  
Complex Analysis ◽  
Fluorescent Antibody ◽  
Mammalian Species ◽  
Health Concern ◽  
Enzyme Linked Immunosorbent Assay ◽  
Wild Animals ◽  
Leishmania Spp

Leishmaniasis is a zoonotic disease that affects 12 million people worldwide. Several mammalian species can serve as a reservoir for this disease. Dogs are the main reservoir for visceral leishmaniasis in urban areas, which has become a serious public health concern in Brazil. The aim of this study was to evaluate the presence of Leishmania spp. in captive wild animals from Ilha Solteira, São Paulo, Brazil. Blood and various tissues samples were collected from animals of five different species: Speothos venaticus, Chrysocyon brachyurus, Cerdocyon thous, Pseudalopex vetulus, and Procyon cancrivorus. Antibodies against Leishmania spp. were detected in three wild canids by indirect fluorescent antibody test (IFAT) and enzyme-linked immunosorbent assay (ELISA). PCR analyses of blood and bone marrow from all animals were negative, but Leishmania DNA was found in the tissues and skin of seropositive animals. Positive PCR samples were also positive for Leishmania donovani complex. Analysis of sequenced PCR products showed similarities with different regions of Leishmania (Leishmania) infantum and Leishmania (Leishmania) chagasi kinetoplastids. Measures to control visceral leishmaniasis in wild animals kept in Brazilian zoos should be established, as no disease control programs are currently available.

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