The naturally occurring metalArsenic (AS) poses a hazard to human health as itcan generate oxygen free radicals and oxidative stress.The build-up of free radicals may cause chronic renalinsufficiency and abrupt renal failure.The significant lignan in flaxseed, secoisolariciresinol diglucoside (SDG), provides various health benefits.The current research investigates the preventive benefits of SDG against Arsenic trioxide (As 2 O 3 )-induced kidney damage.Four groups of healthy Wistar rats were equally distributed and received daily injections for 5 days as follows: Group1 got injections (IP) of saline as a control; Group2 got subcutaneous (SC) injections of SDG at 10mg/kg/day; Group-3 got intraperitoneal (IP) injections of Arsenic trioxide (As 2 O 3 ) at 20 mg/kg/day, and Group-4 got 20 mg/kg/day As 2 O 3 IP followed by 10 mg/kg/day SDG subcutaneously one hour later.The impact of As 2 O 3 on the kidney was measured using a variety of indicators including the Greatest Distributable, ROS levels in renal tissues, and malondialdehyde (MDA), as well as two renal function markers the blood urea nitrogen (BUN) and serum creatinine (CREA).Besides the histological examinations, the antioxidant molecule glutathione was evaluated, and so were the functions of superoxide dismutase (SOD), catalase, and glutathione peroxidase (GSH-Px).Arsenic trioxide (As 2 O 3 ) enhanced MDA generation, oxygen free radicals, and As 2 O 3 levels in kidney tissue while decreasing SODand GSH-Px activity, and the ratio of reduced glutathione to oxidized glutathione.Moreover, serum As 2 O 3 elevated BUN and serum CREA activity.As 2 O 3 induced kidney damage, according to histopathological alterations.Interestingly, SDG treatment reduced ROS generation in serum and kidney and restored antioxidant enzyme levels.In addition, the SDG-treated rats showed significant improvement in all nephrotoxic features.According to the results of this investigation, SDG exhibited an exceptional restorative impact on Arsenic trioxide-mediated kidney cytotoxicity.
Background To date, no universally effective and safe vaccine has been developed for general human use. Leishmania donovani Peroxidoxin-1 (LdPxn-1) is a member of the antioxidant family of proteins and is predominantly expressed in the amastigote stage of the parasite. The aim of this study was to evaluate the immunogenicity and protective efficacy of LdPxn-1 in BALB/c mice in heterologous DNA-Protein immunization regimen in the presence of fusion murine granulocyte-macrophage colony-stimulating factor (mGMCSF) DNA adjuvant. Methodology and Principal Findings A fusion DNA of LdPxn1 and mGMCSF was cloned into a modified pcDNA vector. To confirm the expression in mammalian system, Chinese hamster ovary cells were transfected with the plasmid vector containing LdPxn1 gene. BALB/c mice were immunized twice with pcDNA-mGMCSF-LdPxn-1 or pcDNA-LdPxn1 DNA and boosted once with recombinant LdPxn-1 protein. Three weeks after the last immunization, mice were infected with Leishmania major promastigotes. The result showed that immunization with pcDNA-mGMCSF-LdPxn1 elicited a mixed Th-1/Th-2 immune response with significantly higher production of IFN-γ than controls. Intracellular cytokine staining of antigen-stimulated spleen cells showed that immunization with this antigen elicited significantly higher proportion of CD4+ T cells that express IFN-γ, TNF-α, or IL-2. The antigen also induced significantly higher proportion of multipotent CD4+ cells that simultaneously express the three Th-1 cytokines. Moreover, a significant reduction in the footpad swelling was seen in mice immunized with pcDNA-mGMCSF-LdPxn1 antigen. Expression study in CHO cells demonstrated that pcDNA-mGMCSF-LdPxn-1 was expressed in mammalian system. Conclusion The result demonstrates that immunization of BALB/c mice with a plasmid expressing LdPxn1 in the presence of mGMCSF adjuvant elicits a strong specific immune response with high level induction of multipotent CD4+ cells that mediate protection of the mice from Leishmania major infection. To our knowledge, this is the first study showing the vaccine potential of Leishmania peroxidoxin -1.
Abstract The existence of therapeutic agents and the bacille Calmette-Guérin (BCG) vaccine have not significantly affected the current tuberculosis pandemic. BCG vaccine protects against serious pediatric forms of tuberculosis but not against adult pulmonary tuberculosis, the most common and contagious form of the disease. Several vaccine candidates, including Mycobacterium tuberculosis recombinant proteins formulated in newer adjuvants or delivered in bacterial plasmid DNA have recently been described. An attractive source of vaccine candidates has been M. tuberculosis Ags present in culture supernatants of the initial phases of the bacterial growth in vitro. In this study we describe an Ag discovery approach to select for such Ags produced in vivo during the initial phases of the infection. We combined RP-HPLC and mass spectrometry to identify secreted or shed M. tuberculosis proteins eliminated in animal urine within 14 days after the infection. A peptide containing sequence homology with a hypothetical M. tuberculosis protein was identified and the recombinant protein produced in Escherichia coli. The protein was recognized by Ab (IgG2a and IgG1) and T cells (Th1) of mice infected with M. tuberculosis and by lymphoid cells from healthy donors who had a positive purified protein derivative skin test but not from tuberculosis patients. Moreover, this Ag induced protection in mice against M. tuberculosis at levels comparable to protection induced by BCG vaccine. These results validate the Ag discovery approach of M. tuberculosis proteins secreted or shed in vivo during the early phases of the infection and open new possibilities for the development of potential vaccine candidates or of markers of active mycobacterial multiplication and therefore active disease.
In areas were human visceral leishmaniasis (VL) is endemic, the domestic dog is the main parasite reservoir in the infectious cycle of Leishmania infantum. Development of prophylactic strategies to lower the parasite burden in dogs would reduce sand fly transmission thus lowering the incidence of zoonotic VL. Here we demonstrate that vaccination of dogs with a recombinant 14kDa polypeptide of L. infantum nuclear transport factor 2 (Li-ntf2) mixed with adjuvant BpMPLA-SE resulted in the production of specific anti-Li-ntf2 IgG antibodies as well as IFN-γ release by the animals' peripheral blood mononuclear cells stimulated with the antigen. In addition, immunization with this single and small 14kDa poplypeptide resulted in protracted progression of the infection of the animals after challenging with a high dose of virulent L. infantum. Five months after challenge the parasite load was lower in the bone marrow of immunized dogs compared to non-immunized animals. The antibody response to K39, a marker of active VL, at ten months after challenge was strong and significantly higher in the control dogs than in vaccinated animals. At the study termination vaccinated animals showed significantly more liver granulomas and lymphoid hyperplasia than non-vaccinated animals, which are both histological markers of resistance to infection. Together, these results indicate that the 14kDa polypeptide is an attractive protective molecule that can be easily incorporated in a leishmanial polyprotein vaccine candidate to augment/complement the overall protective efficacy of the final product.
ABSTRACT The rK39 enzyme-linked immunosorbent assay (ELISA) was compared with the direct agglutination test (DAT) for Leishmania donovani infection in the Sudan. rK39 ELISA proved more sensitive than DAT in diagnosis of kala-azar (93 and 80%, respectively); both tests may remain positive up to 24 months after treatment. For patients with post-kala-azar dermal leishmaniasis and individuals with subclinical infection, rK39 ELISA performed as well as DAT but could detect infection 6 months earlier in ∼40% of patients. Conversion in DAT and rK39 ELISA also occurred in leishmanin skin test (LST)-positive individuals, suggesting active parasite replication (rK39 is an amastigote antigen) in these presumably immune individuals. In contrast to DAT, rK39 ELISA also detected infection in randomly selected LST-positive individuals (in four of six) and endemicity (LST-negative) controls (in one of five). rK39 ELISA appears more sensitive than DAT and may prove an important tool in epidemiological studies.
Identification of pathogen-specific biomarkers present in patients' serum or urine samples can be a useful diagnostic approach. In efforts to discover Mycobacterium tuberculosis (Mtb) biomarkers we identified by mass spectroscopy a unique 21-mer Mtb peptide sequence (VVLGLTVPGGVELLPGVALPR) present in the urines of TB patients from Zimbabwe. This peptide has 100% sequence homology with the protein TBCG_03312 from the C strain of Mtb (a clinical isolate identified in New York, NY, USA) and 95% sequence homology with Mtb oxidoreductase (MRGA423_21210) from the clinical isolate MTB423 (identified in Kerala, India). Alignment of the genes coding for these proteins show an insertion point mutation relative to Rv3368c of the reference H37Rv strain, which generated a unique C-terminus with no sequence homology with any other described protein. Phylogenetic analysis utilizing public sequence data shows that the insertion mutation is apparently a rare event. However, sera from TB patients from distinct geographical areas of the world (Peru, Vietnam, and South Africa) contain antibodies that recognize a purified recombinant C-terminus of the protein, thus suggesting a wider distribution of isolates that produce this protein.
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