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Enzyme
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Target Concepts:
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Query: EC:3.6.4.4 (
kinesin
)
5,033
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
rK39 is a recombinant product of the 39 amino acid repeats found in a
kinesin
-like gene of visceral Leishmania spp. This and other antigens were compared for immunodiagnostic potential by enzyme-linked immunosorbent assay with sera from confirmed cases of Asian cutaneous and visceral
leishmaniasis
. In preliminary trials, rK39 proved superior to 2 purified Leishmania antigens, a cytosolic protein (p36) and a membrane protein (gp63), for immunodiagnosis of visceral
leishmaniasis
. Of the 53 visceral cases from China and Pakistan assayed, 52 were seropositive (98%) at a 10(-1) dilution with 36 ng of rK39. End point titrations of 27 highly positive samples yielded anti-rK39 antibody titres ranging from c. 10(-3) to beyond 10(-4). Antigen titrations with one positive serum further revealed that rK39 was 25-fold more sensitive than Leishmania whole cell soluble lysates. 31 cutaneous
leishmaniasis
cases from Turkey assayed for anti-rK39 antibody gave reactions ranging from negative or marginally positive to positive. In Brazil, all cutaneous and mucocutaneous
leishmaniasis
cases gave negative results in this assay.
...
PMID:Serodiagnosis of Asian leishmaniasis with a recombinant antigen from the repetitive domain of a Leishmania kinesin. 799 33
We report the cloning of a Leishmania chagasi antigen gene and an evaluation of
leishmaniasis
patient antibody responses to the recombinant protein, rK39. rK39 contains a 39-amino acid repeat that is part of a 230-kDa protein predominant in L. chagasi tissue amastigotes. Sequence analyses showed this protein, LcKin, to be related to the
kinesin
superfamily of motor proteins. Southern blot analyses demonstrated LcKin-related sequences in seven species of Leishmania, with conservation of the repeat between L. chagasi and Leishmania donovani. Serological evaluation revealed that 98% (56 of 57) of Brazilian and 100% (52 of 52) of Sudanese visceral
leishmaniasis
patients have high antibody levels to the rK39 repeat. Detectable anti-K39 antibody was virtually absent in cutaneous and mucosal
leishmaniasis
patients and in individuals infected with Trypanosoma cruzi. The data show that rK39 may replace crude parasite antigens as a basis for serological diagnosis of visceral
leishmaniasis
.
...
PMID:Molecular characterization of a kinesin-related antigen of Leishmania chagasi that detects specific antibody in African and American visceral leishmaniasis. 842 15
The recombinant product (rK39) of the 39 amino acid repeats encoded by a
kinesin
-like gene of visceral Leishmania spp. was further evaluated by enzyme-linked immunosorbent assay (ELISA) for its diagnostic potential in Indian kala-azar (VL) and post kala-azar dermal
leishmaniasis
(PKDL). Anti-rK39 antibodies were highly positive in 20 symptomatic cases, including 6 resistant to single or double chemotherapy, but became negligible or absent in 9 recently cured patients. Endpoint titration of samples from the 20 active cases showed that the anti-rK39 IgG titers fell within a wide range of 10(-2) to > 10(-6), and that their mean was > 1 order of magnitude higher than in VL reported previously. The anti-rK39 IgG titers were correlated with parasite burden found in the patients and remained undiminished in those refractory to chemotherapy. These results indicate that: (1) the K39 epitope is conserved in Indian strains of Leishmania donovani, (2) the extremely high levels of K39 antibodies in both VL and PKDL suggest the application of rK39 for sensitive and specific serodiagnosis, and (3) rK39 ELISA is also valuable for prognostic evaluation of both diseases.
...
PMID:Diagnostic and prognostic value of K39 recombinant antigen in Indian leishmaniasis. 854 37
This article reviews the recent advances made in the field of human
leishmaniasis
. Special emphasis is placed upon the application of various molecular tools for accurate and rapid diagnosis, understanding the mechanisms of drug resistance and identification of vaccine candidates. The focus will be on the major role played by recombinant antigens in the immunoserodiagnosis and progress of the Leishmania genome project, which has enabled researchers to design better PCR primers and molecular probes for microarrays. A special interest is placed on the recombinant antigen (rK39) cloned from the Leishmania chagasi
kinesin
gene and a very recently cloned recombinant antigen (KE16) from the Old World Leishmania donovani species with high sensitivity and specificity. Advances made in the specific PCR primer designed to diagnose and differentiate various species and strains of Leishmania causing visceral and post-kala-azar-dermal
leishmaniasis
have been covered. Molecular methods (e.g., DNA and protein microarrays) applied to understanding the pathobiology of the parasite, mechanism of host invasion, drug interaction and drug resistance to develop effective therapeutic molecules, gene expression profiling studies that have opened doors to understand many host-parasite relations, effective therapy and vaccine candidates are extensively covered in this review.
...
PMID:Applications of molecular methods for Leishmania control. 1583 54
Visceral leishmaniasis (VL) is a major health problem in the tropical and subtropical regions of the world. The conventional methods for diagnosis of Old World Visceral leishmaniasis are difficult, insensitive, and hazardous. There is no recombinant antigen from old world Leishmania species which can be commercially used for rapid diagnosis. There is an urgent need for a less invasive and accurate method. Here, we report a recombinant antigen from Indian Leishmania donovani for its diagnosis. The
kinesin
gene of a L. donovani clinical isolate (KE16) from India was PCR amplified for cloning and the immunodominant domain was expressed in Escherichia coli. This recombinant protein or Ld-rKE16 was evaluated for serodiagnosis of Indian kala-azar by ELISA. The recombinant antigen was found to be 100% sensitive and specific for Old World VL cases from India, Pakistan, China, and Turkey. The antigen showed no cross-reactivity with sera from other endemic diseases or healthy controls. The expressed Ld-rKE16 antigen is highly specific and sensitive for diagnosing visceral and post-kala-azar dermal
leishmaniasis
and is ready for commercialization.
...
PMID:Cloning, expression, and purification of a novel recombinant antigen from Leishmania donovani. 1617 2
Control of human visceral
leishmaniasis
in regions where it is endemic is hampered in part by limited accessibility to medical care and emerging drug resistance. There is no available protective vaccine. Leishmania spp. protozoa express multiple antigens recognized by the vertebrate immune system. Since there is not one immunodominant epitope recognized by most hosts, strategies must be developed to optimize selection of antigens for prevention and immunodiagnosis. For this reason, we generated a cDNA library from the intracellular amastigote form of Leishmania chagasi, the cause of South American visceral
leishmaniasis
. We employed a two-step expression screen of the library to systematically identify T-cell antigens and T-dependent B-cell antigens. The first step was aimed at identifying the largest possible number of clones producing an epitope-containing polypeptide by screening with a pool of sera from Brazilians with documented visceral
leishmaniasis
. After removal of clones encoding heat shock proteins, positive clones underwent a second-step screen for their ability to cause proliferation and gamma interferon responses in T cells from immune mice. Six unique clones were selected from the second screen for further analysis. The corresponding antigens were derived from glutamine synthetase, a transitional endoplasmic reticulum ATPase, elongation factor 1gamma,
kinesin
K39, repetitive protein A2, and a hypothetical conserved protein. Humans naturally infected with L. chagasi mounted both cellular and antibody responses to these proteins. Preparations containing multiple antigens may be optimal for immunodiagnosis and protective vaccines.
...
PMID:Leishmania chagasi T-cell antigens identified through a double library screen. 1700 Jul 24
Visceral leishmaniasis is endemic in the eastern states of India, but central India remains free of leishmaniais. This report describes the first indigenous case of visceral
leishmaniasis
in a seven-year-old girl from central India. The child presented with fever for 10 days and was diagnosed by bone marrow examination, serology using rKE16 and rK39 antigens, and a polymerase chain reaction specific for the
kinesin
gene. Sequencing of the immunodominant region of the
kinesin
gene of the parasite showed four tandem repeats, each 117 basepairs. The first tandem repeat of this strain had 97% homology with the corresponding first tandem repeat of the Leishmania donovani KE16 strain and 92% homology with the L. chagasi BA-2 strain. The second, third, and fourth tandem repeats had 97%, 98%, and 99% homology, respectively, with the L. donovani KE16 strain, and 89%, 96%, and 92% homology, respectively, with the L. chagasi BA-2 strain. This case shows that more than one genetic variant of L. donovani is circulating in various parts of India.
...
PMID:First case of indigenous visceral leishmaniasis from central India. 1762 Jun 36
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
.
...
PMID:Kinesin motor domain of Leishmania donovani as a future vaccine candidate. 1835 21
Recently we had prepared a recombinant antigen (Ld-rKE16) from a newly isolated Indian strain of Leishmania donovani (MHOM/IN/KE16/1998) with high sensitivity and specificity and the same has been commercialized. While comparing the sequence data of
kinesin
gene of this (KE16) strain and its expressed protein with another commercially available recombinant antigen (Lc-rK39) from
kinesin
gene of L. chagasi we found significant genetic and amino acid variations. This prompted us to undertake the present study to unravel whether the
kinesin
gene and its expressed protein from another old but Indian isolate of L. donovani (MHOM/IN/DD8/1968) had any genetic and amino acid heterogeneity. Sequencing of the
kinesin
gene revealed that the
kinesin
gene of DD8 strain is 3016bp long and has immunodominant region consisting of 4.8 tandem repeats, 117 base pairs each. Further blast analysis of the immunodominant regions of 5 strains of L. donovani revealed that it has only 79% homology with L. chagasi, and 80% homology with L. infantum; while it had 82% homology with Sudan strain of L. donovani, 82% with another (Morena) strain of Indian L. donovani but highest homology of 83% with L. donovani KE16 strain of India. We also evaluated the diagnostic potential of the recombinant DD8 antigen (Ld-rDD8) and compared the results with that of Ld-rKE16. The study revealed that Ld-rKDD8 antigen was less sensitive and specific as compared to rKE16 antigen for the diagnosis of visceral and post-kala-azar dermal
leishmaniasis
. This was probably due to prolong in vitro culture maintenance of the DD8 strain.
...
PMID:Expression and characterization of a recombinant kinesin antigen from an old Indian strain (DD8) of Leishmania donovani and comparing it with a commercially available antigen from a newly isolated (KE16) strain of L. donovani. 1837 35
Mycobacterium tuberculosis and Leishmania donovani are important intracellular pathogens, especially in Indian context. In India and other South East Asian countries, both these infections are highly endemic and in about 20% cases co-infection of these pathogens is reported. For both these pathogens cell mediated immunity plays most important role. The available treatment of these infections is either prolonged or cumbersome or it is ineffective in controlling the outbreaks and spread. Therefore, potentiation of a common host defense mechanism can be used to prevent both the infections simultaneously. In this study we have developed a novel chimeric DNA vaccine candidate comprising the esat-6 gene of M. tuberculosis and
kinesin
motor domain gene of L. donovani. After developing this novel chimera, its immunogenicity was studied in mouse model. The immune response was compared with individual constructs of esat-6 and
kinesin
motor domain. The results showed that immunization with chimeric DNA vaccine construct resulted in stronger IFN-gamma and IL-2 response against
kinesin
(3012+/-102 and 367.5+/-8.92pg/ml) and ESAT-6 (1334+/-46.5 and 245.1+/-7.72pg/ml) in comparison to the individual vaccine constructs. The reciprocal immune response (IFN-gamma and IL-2) against individual construct was lower (
kinesin
motor domain: 1788+/-36.48 and 341.8+/-9.801pg/ml and ESAT-6: 867.0+/-47.23 and 170.8+/-4.578pg/ml, respectively). The results also suggest that using the chimeric construct both proteins yielded a reciprocal adjuvant affect over each other as the IFN-gamma production against chimera vaccination is statistically significant (p<0.0001) than individual construct vaccination. From this pilot study we could envisage that the chimeric DNA vaccine construct may offer an attractive strategy in controlling co-infection of
leishmaniasis
and tuberculosis and have important implication in future vaccine design.
...
PMID:Immunogenicity of candidate chimeric DNA vaccine against tuberculosis and leishmaniasis. 1955 11
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