-
[
Parasitol Res,
2011]
Immune responses to recombinant Brugia malayi pepsin inhibitor homolog (rBm-33) were investigated in patients with human lymphatic filariasis (microfilaremics (MF) and chronic pathology (CP)) along with endemic normals (EN). Flow cytometric analysis (24 h) revealed CD4(+) T cell activation in patients (MF and CP) compared to normals (EN), with increased expression of CD69 and diminished levels of CD62L and CD127. This was associated with an elevated expression of CD154 but not CD28 and CTLA4 in CP patients. However, Bm-33-induced cytokine expression profile (IL-1, IL-12, IL-8, IFN-, IL-10 and TGF-) did not exhibit any significant difference between normals and patients at the same time point. Although CD4(+) T cell activation was observed initially in filarial patients (24 h), lymphoproliferation studies (96 h) suggested diminished proliferation compared to normals, indicating functional inactivation in the former upon prolonged antigen exposure. This indicates that rBm-33 induces an early T cell activation in MF and CP patients followed by a decreased lymphoproliferation that might contribute to immune suppression in these individuals.
-
Alon SA, Ramadhan Lasu AA, Riek LP, Lako R, Levite M, Rivkin M, Benedek G, Miller K, Abed El Latif M, Galun E, Edvardson S
[
PLoS Negl Trop Dis,
2020]
Nodding syndrome (NS) is a devastating and enigmatic childhood epilepsy. NS is accompanied by multiple neurological impairments and neuroinflammation, and associated with the parasite Onchocerca volvulus (Ov) and other environmental factors. Moreover, NS seems to be an 'Autoimmune Epilepsy' since: 1. ~50% of NS patients have neurotoxic cross-reactive Ov/Leimodin-I autoimmune antibodies. 2. Our recently-published findings: Most (~86%) of NS patients have glutamate-receptor AMPA-GluR3B-peptide autoimmune-antibodies that bind, induce Reactive-Oxygen-Species, and kill both neural cells and T cells. Furthermore, NS patient's IgG induce seizures, brain multiple damage alike occurring in brains of NS patients, and elevation of T cells and activated microglia and astrocytes, in brains of normal mice. Human Leukocyte antigen (HLA) class I and II molecules are critical for initiating effective beneficial immunity against foreign microorganisms and contributing to proper brain function, but also predispose to detrimental autoimmunity against self-peptides. We analyzed seven HLA loci, either by next-generation-sequencing or Sequence-Specific-Oligonucleotide-Probe, in 48 NS patients and 51 healthy controls from South Sudan. We discovered that NS associates significantly with both protective HLA haplotype: HLA-B*42:01, C*17:01, DRB1*03:02, DQB1*04:02 and DQA1*04:01, and susceptible motif: Ala24, Glu63 and Phe67, in the HLA-B peptide-binding groove. These amino acids create a hydrophobic and sterically closed peptide-binding HLA pocket, favoring proline residue. Our findings suggest that immunogenetic fingerprints in HLA peptide-binding grooves tentatively associate with protection or susceptibility to NS. Accordingly, different HLA molecules may explain why under similar environmental factors, only some children, within the same families, tribes and districts, develop NS, while others do not.
-
[
Int J Pharm,
2020]
In this work, the increase of the Caenorhabditis elegans (C.elegans) lifespan extension using hyper-branched cyclodextrin-based nanosponges (CD-NS) complexing oxyresveratrol (OXY), and the possible inhibition of C.elegans phosphodiesterase type 4 (PDE4) were evaluated. The titration displacement of fluorescein was used to calculate the apparent complexation constant (K<sub>F</sub>) between CD-NS and OXY. Moreover, PDE4 was expressed in E.coli, purified and refolded in presence of cyclodextrins (CDs) to study its possible inhibition as pharmacological target of OXY. The apparent activity was characterized and the inhibitory effect of OXY on PDE4 displayed a competitive in vitro inhibition corroborated in silico. A maximum increase of the in vivo life expectancy of about 9.6% of using OXY/CD-NS complexes in comparison with the control was obtained, in contrast to the 6.5 % obtained with free OXY. No effect on lifespan or toxicity with CD-NS alone was found. These results as a whole represent new opportunities to use OXY and CD-NS in lifespan products.
-
[
Pan Afr Med J,
2017]
Nodding Syndrome (NS) is a childhood neurological disorder characterized by atonic seizures, cognitive decline, school dropout, muscle weakness, thermal dysfunction, wasting and stunted growth. There are recent published information suggesting associations between Nodding Syndrome (NS) with cerebrospinal fluid (CSF) VGKC antibodies and serum leiomidin-1 antibody cross reacting with Onchocerca Volvulus (OV). These findings suggest a neuro-inflammatory cause of NS and they are important findings in the search for the cause of Nodding Syndrome. These observations perhaps provide further, the unique explanation for the association between Nodding Syndrome and Onchocerca Volvulus. Many clinical and epidemiological studies had shown a significant correlation between NS and infestation with a nematode, Onchocerca volvulus which causes a disease, Onchocerciasis, some of which when left untreated can develop visual defect ("River Blindness"). While these studies conducted in Northern Uganda and Southern Sudan indicate a statistically significant association with (OV infection (using positive skin snips), we observe that (OV is generally endemic in many parts of Sub Saharan Africa and Latin America and that to date, no NS cases have been recorded in those regions. This letter to the Editor is to provide additional information on the current view about the relationship between Nodding Syndrome and Onchocerca Volvulus as seen in Northern Uganda.
-
[
Int J Pharm,
2023]
In this study, the ability of zein nanospheres (NS) and zein nanocapsules containing wheat germ oil (NC) to enhance the bioavailability and efficacy of quercetin was evaluated. Both types of nanocarriers had similar physico-chemical properties, including size (between 230 and 250 nm), spherical shape, negative zeta potential, and surface hydrophobicity. However, NS displayed a higher ability than NC to interact with the intestinal epithelium, as evidenced by an oral biodistribution study in rats. Moreover, both types of nanocarriers offered similar loading efficiencies and release profiles in simulated fluids. In C. elegans, the encapsulation of quercetin in nanospheres (Q-NS) was found to be two twice more effective than the free form of quercetin in reducing lipid accumulation. For nanocapsules, the presence of wheat germ oil significantly increased the storage of lipids in C. elegans; although the incorporation of quercetin (Q-NC) significantly counteracted the presence of the oil. Finally, nanoparticles improved the oral absorption of quercetin in Wistar rats, offering a relative oral bioavailability of 26% and 57% for Q-NS and Q-NC, respectively, compared to a 5% for the control formulation. Overall, the study suggests that zein nanocarriers, particularly nanospheres, could be useful in improving the bioavailability and efficacy of quercetin.
-
[
Protein Expr Purif,
2011]
Bm-33 (pepsin inhibitor homolog) produced by the human filarial parasite Brugia malayi, was expressed in Escherichia coli. Expression of rBm33 in BL21 (DE3), Rosetta-2 gami (DE3) pLysS and GJ1158 bacterial strains, results in the accumulation of a 33 kDa protein in inclusion bodies. Inactive rBm-33 was purified under the denaturing conditions and refolded by step wise dialysis using buffers of pH ranging from 11 to 7. Size exclusion chromatography of rBm-33 (refolded) reveals that nearly 83% of the recombinant protein exhibits pepsin inhibition activity. Circular dichroism studies indicate that the protein is predominantly composed of 85% -helix. rBm-33 (refolded) was assessed for its pepsin inhibition activity using casein agar plate method, UV-spectroscopy and zymogram analysis. These findings suggest that rBm-33 (refolded) has affinity for human pepsin and completely inhibits the proteolytic activity with the gradual increase in rBm-33 (refolded) concentration. Size exclusion chromatography reveals the formation of rBm-33-pepsin complex and was cross checked using immunoblot with glutaraldehyde cross linking. These findings reveal that rBm-33 (refolded) is in native fold to exhibit pepsin inhibition.
-
[
J Enzyme Inhib Med Chem,
2013]
The aspartic protease inhibitory efficiency of rBm-33, an aspin from a filarial parasite Brugia malayi was investigated. rBm-33 was found to be thermostable up to 90C and it forms a stable 'enzyme-product' complex with human pepsin. Aspartic protease inhibitory activity was investigated using UV spectroscopy and isothermal titration calorimetry. Our results suggest that rBm-33 inhibits the activity of important human aspartic proteases that were examined with binding constants (Kb) values between 10.23 x 10(3) and 6.52 x 10(3) M(-1). The binding reactions were enthalpy driven with Hb values between -50.99 and -46.07 kJ mol(-1). From kinetic studies, pepsin inhibition by rBm-33 was found to be linear competitive with an inhibition constant (Ki) of 2.5 (+/-0.8) nM. Because of the inhibitory efficacy of Bm-33 against important human aspartic proteases which play a vital role in immune-regulation along with other functions, Bm-33 can be projected as a drug target for the filariasis.
-
[
Opt Express,
2008]
Nanosecond laser pulses (lambda = 355 nm) were used to cut mechanosensory neurons in Caenorhabditis elegans and motorneurons in Drosophila melanogaster larvae. A pulse energy range of 0.8-1.2 microJ and < 20 pulses in single shot mode were sufficient to generate axonal cuts. Viability post-surgery was >95% for C. elegans and 60% for Drosophila. Cavitation bubble dynamics generated due to laser-induced plasma formation were observed in vivo by time-resolved imaging in both organisms. Bubble oscillations were severely damped in vivo and cavitation dynamics were complete within 100 ns in C. elegans and 800 ns in Drosophila. We report the use of this system to study axonal transport for the first time and discuss advantages of nanosecond lasers compared to femtosecond sources for such procedures.
-
[
Eur J Hum Genet,
2003]
Noonan syndrome (NS, MIM 163950) is an autosomal dominant condition characterised by facial dysmorphy, congenital cardiac defects and short stature. Recently missense mutations in PTPN11, the gene encoding the nonreceptor protein tyrosine phosphatase SHP-2 on 12q24, were identified in 50% of analysed Noonan cases. A large four-generation Belgian family with NS and some features suggestive of cardio-facio-cutaneous syndrome (CFC) was previously used to fine map the Noonan syndrome candidate region to a 5 cM region in 12q24. We now report the identification of a mutation (Gln79Arg) in the PTPN11 gene in this large family. In D. melanogaster and C. elegans the PTPN11 gene has been implicated in oogenesis. In this family two affected females had dizygous twins. This suggests that PTPN11 might also be involved in oogenesis and twinning in humans.European Journal of Human Genetics (2002) 11, 85-88. doi:10.1038/sj.ejhg.5200915
-
[
Infect Immun,
2013]
Acinetobacter baumannii has become a major problem in the clinical setting with the prevalence of infections caused by multidrug-resistant strains on the increase. Nevertheless, only a limited number of molecular mechanisms involved in the success of A. baumannii as a human pathogen have been described. In this study, we examined the virulence features of a hypermotile derivative of A. baumannii strain ATCC 17978, which was found to display enhanced adherence to human pneumocytes and elevated levels of lethality toward Caenorhabditis elegans nematodes. Analysis of cellular lipids revealed modifications to the fatty acid composition, providing a possible explanation for the observed changes in hydrophobicity and subsequent alteration in adherence and motility. Comparison of the genome sequences of the hypermotile variant and parental strain revealed that an insertion sequence had disrupted an hns-like gene in the variant. This gene encodes a homologue of the histone-like nucleoid structuring (H-NS) protein, a known global transcriptional repressor. Transcriptome analysis identified the global effects of this mutation on gene expression, with major changes seen in the autotransporter Ata, a type VI secretion system, and a type I pilus cluster. Interestingly, isolation and analysis of a second independent hypermotile ATCC 17978 variant revealed a mutation to a residue within the DNA binding region of H-NS. Taken together, these mutants indicate that the phenotypic and transcriptomic differences seen are due to loss of regulatory control effected by H-NS.