LmjF.22.0810 from Leishmania major Modulates the Th2-Type Immune Response and Is Involved in Leishmaniasis Outcome

A novel serine/threonine protein kinase, LmjF.22.0810, was recently described in Leishmania major. After generating an L. major cell line overexpressing LmjF.22.0810 (named LmJ3OE), the ability of this novel protein to modulate the Th2-type immune response was analyzed. Our results suggest that the protein kinase LmjF.22.0810 might be involved in leishmaniasis outcomes. Indeed, our study outlined the LmJ3OE parasites infectivity in vitro and in vivo. Transgenic parasites displayed lower phagocytosis rates in vitro, and their promastigote forms exhibited lower expression levels of virulence factors compared to their counterparts in control parasites. In addition, LmJ3OE parasites developed significantly smaller footpad swelling in susceptible BALB/c mice. Hematoxylin–eosin staining allowed the observation of a lower inflammatory infiltrate in the footpad from LmJ3OE-infected mice compared to animals inoculated with control parasites. Gene expression of Th2-associated cytokines and effectors revealed a dramatically lower induction in interleukin (IL)-4, IL-10, and arginase 1 (ARG1) mRNA levels at the beginning of the swelling; no expression change was found in Th1-associated cytokines except forIL-12. Accordingly, such results were validated by immunohistochemistry studies, illustrating a weaker expression of ARG1 and a similar induction for inducible NO synthase (iNOS) in footpads from LmJ3OE-infected mice compared to control L. major infected animals. Furthermore, the parasite burden was lower in footpads from LmJ3OE-infected mice. Our analysis indicated that such significant smaller footpad swellings might be due to an impairment of the Th2 immune response that subsequently benefits Th1 prevalence. Altogether, these studies depict LmjF.22.0810 as a potential modulator of host immune responses to Leishmania. Finally, this promising target might be involved in the modulation of infection outcome

Schistosoma haematobium and Plasmodium falciparum co-infection in Nigeria 2001–2018: A systematic review and meta-analysis

Malaria and schistosomiasis continue to contribute a big burden to infectious disease prevalence in the tropical areas, mainly in sub Saharan African countries. We previously reported high levels of schistosome specific antibody IgG3 in children coinfected with malaria and schistosomiasis. The aim of the current study was to examine the current co-infection rates of these diseases in Nigeria. Published and unpublished studies on coinfection of human urogenital schistosomiasis and malaria carried out in Nigeria between 2001 and August 2018 were retrieved through literature searches in PubMed, Google Scholar, AJOL, and university theses repositories. The filtered and relevant articles were reviewed and combined in a meta-analysis. Studies involving children reported higher rates of coinfection. The fourteen research articles involving 6,559 individuals were combined in a meta-analysis. Our analyses revealed an estimated 15% co-infection for the country, though with wide variability depending on location. In addition, there are few and welldesigned research publications in Nigeria on prevalence and mechanism of malaria and schistosomiasis coinfection

Structural characterization by scattering and spectroscopic methods and biological evaluation of polymeric micelles of poloxamines and TPGS as nanocarriers for miltefosine delivery

Miltefosine (MF), an alkylphospholipid originally developed for breast cancer treatment, is a highly active drug for the treatment against leishmaniasis, a neglected tropical disease considered the world’s second leading cause of death by a parasitic agent after malaria. MF exhibits dose-limiting gastrointestinal side effects in patients and its penetration through lipophilic barriers is reduced. In this work we propose a reformulation of MF by incorporating the drug to poly(ethylene)oxide (PEO)-based polymeric micelles, specifically, D-α-tocopheryl polyethylene glycol succinate (TPGS) and Tetronic block copolymers (T904 and T1107). A full structural characterization of the aggregates has been carried out by SANS (small-angle neutron scattering) and dynamic light scattering (DLS), in combination with proton 1D and 2D nuclear magnetic resonance (NMR) spectroscopy, to determine the precise location of the drug. The structure of MF micelles has been characterized as a function of the temperature and concentration. In the presence of the block-copolymers, MF forms mixed micelles in a wide range of temperatures, TPGS being the co-surfactant that incorporates more MF unimers. The hydrophobic tail of MF and those of the block copolymers are in close contact within the micelles, which present a core-shell structure with a hydrophilic corona formed by the PEG blocks of the TPGS and the zwitterion head group of the MF. In order to identify the best carrier, the antileishmanicidal activity of MF in the different formulations has been tested on macrophages, promastigotes and intracellular amastigotes. The combination of the three vehicles with MF makes the formulated drug more active than MF alone against L. major promastigotes, however, only the combination with T904 increases the MF activity against intracellular amastigotes. With the aim of exploring gel-based formulations of the drug, the combination of MF and T1107 under gelation conditions has also been investigated.The authors gratefully acknowledge the financial support provided by MINECO (Project MAT2014-59116-C2), Obra Social La Caixa (LCF/PR/PR13/11080005), University Carlos III Strategic Action in Composites materials and interphases 2011/00287/002, Fundación Caja Navarra, Gobierno de Navarra-Salud (12/2017), Fundación Roviralta, Ubesol, Government of Navarre, Laser Ebro, Inversiones Garcilaso de la Vega and COST actions CA18217 and CA18218. JCNS is acknowledged for the access to the KWS-2 diffractometer at the Heinz Maier-Leibnitz Zentrum (MLZ), Garching, Germany. J.P-R. also acknowledges the Asociación de Amigos de la Universidad de Navarra for his doctoral grant. This work benefited from the use of the SasView application, originally developed under NSF award DMR-0520547. Sasview contains code developed with funding from the European Union's Horizon 2020 research and innovation program under the SINE2020 project, grant agreement No 654000

Leishmaniasis in Navarra, Spain (1976-2018): an update

La leishmaniasis es endémica en países de la cuenca mediterránea. En el presente estudio se revisa la información disponible sobre la leishmaniasis en Navarra y en regiones limítrofes en el periodo 1976-2018, y se aporta una visión general de la situación de esta enfermedad a nivel nacional, desde el vector hasta el hombre. La tasa de incidencia de leishmaniasis disminuyó en Aragón entre 2008 y 2018 respecto a la década anterior, mientras que en Navarra y La Rioja casi se duplicaron los casos por 100.000 habitantes; el País Vasco también presentó un aumento en la incidencia. El incremento de casos a nivel nacional ha sido significativo desde 2015, en parte debido a la inclusión de la leishmaniasis como enfermedad de declaración obligatoria. Si bien su incidencia en humanos no parece preocupante, la leishmaniasis es hoy una realidad en España, por lo que es necesario vigilar globalmente su evolución.Leishmaniasis is endemic in countries of the Mediterranean area. In this study, the information available on leishmaniasis in Navarra in the period 1976-2018 and in the bordering regions was collected, along with an overview of the situation of this disease at the national level, from the vector to humans. Aragón exhibited a lower incidence rate in the last ten years (2008-2018) compared to the previous decade, while Navarra and La Rioja have almost doubled the number of cases per 100,000 inhabitants and, likewise, incidence in the Basque Country has also increased. At the national level, since 2015, such an increase has become significant due to the inclusion of human leishmaniasis as a mandatory notifiable disease. Currently in Spain, although the incidence of human leishmaniasis is not a situation of high concern, it is however a reality. Therefore, it is necessary to monitor its evolution

Mixed micelles and gels of a hydrophilic poloxamine (Tetronic 1307) and miltefosine: Structural characterization by small-angle neutron scattering and in vitro evaluation for the treatment of leishmaniasis

Hypothesis/background: Tetronic is a family of four-armed amphiphilic block copolymers of polyethylene oxide (PEO) and polypropylene oxide (PPO) that self-aggregate to form micelles and hydrogels. Due to their temperature and pH-responsiveness, they are emerging as smart nanomaterials in the area of drug delivery. Here we propose the use of Tetronic 1307 (T1307) as a nanocarrier of miltefosine (MF), a zwitterionic alkylphospholipid highly active against leishmaniasis, one of the most threating neglected tropical diseases. Given the amphiphilic nature of the drug, both surfactants can combine to form mixed micelles, reducing the cytotoxicity of MF by lowering its dose and improving its internalization, hence its antileishmanial effect. Experiments: The structure of the T1307 micelles, MF micelles, mixed micelles and hydrogels, formed in buffered solution (pH = 7.4) at different concentrations has been investigated in-depth by a combination of small-angle neutron scattering (SANS), dynamic light scattering (DLS), fluorescence spectroscopy and nuclear magnetic resonance methods (1D, 2D NOESY, and diffusion NMR). The cytotoxicity of the aggregates in macrophages has been assessed, as well as the antileishmanial activity in both Leishmania major promastigotes and amastigotes. Findings: T1307 and MF combine into mixed aggregates over a wide range of temperatures and compositions, forming ellipsoidal core–shell mixed micelles. The shell is highly hydrated and comprises most of the PEO blocks, while the hydrophobic core contains the PO blocks and the MF along with a fraction of EO and water molecules, depending on the molar ratio in the mixture. The combination with T1307 amplified the leishmanicidal activity of the drug against both forms of the parasite and dramatically reduced drug cytotoxicity. T1307 micelles also showed a considerable leishmanicidal activity without exhibiting macrophage toxicity. These results support the use of T1307 as a MF carrier for the treatment of human and animal leishmaniasis, in its different clinical forms

Seasonality in diabetes in Yaounde, Cameroon: a relation with precipitation and temperature

Abstract Background Diabetes is a growing health concern in developing countries, with Cameroon population having an estimated 6% affected. Of note, hospital attendees appear to be increasing all over the country, with fluctuating numbers throughout the annual calendar. The aim of the study was to investigate the relationship between diabete hospitalization admission rates and climate variations in Yaounde. Methods A retrospectively designed study was conducted in four health facilities of Yaounde (Central Hospital, University teaching hospital, Biyem-Assi and Djoungolo District Hospitals), using medical records from 2000 to 2008. A relationship between diabetes (newly diagnosed diabetes patients or decompensated diabetics) hospitalization admissions and climate variations was determined using the “2000–2008” national meteorological database (precipitation and temperature). Results The monthly medians of precipitation and temperature were 154mm and 25 °C, respectively. The month of October received 239mm of precipitation. The monthly medians of diabetic admissions rates (newly diagnosed or decompensated diabetes patients) were 262 and 72 respectively. October received 366 newly diagnosed diabetics and 99 decompensated diabetics. Interestingly, diabetic hospitalization admissions rates were higher during the rainy (51 %, 1633/3232) than the dry season, though the difference was non-significant. The wettest month (October) reported the highest cases (10 %, 336/3232) corresponding to the month with the highest precipitation level (239mm). Diabetes hospitalization admissions rates varied across health facilities [from 6 % (189/3232) in 2000 to 15 % (474/3232) in 2008]. Conclusion Diabetes is an important epidemiological disease in the city of Yaounde. The variation in the prevalence of diabetes is almost superimposed to that of precipitation; and the prevalence seems increasing during raining seasons in Yaoundé

Identification of Importin 8 (IPO8) as the most accurate reference gene for the clinicopathological analysis of lung specimens

<p>Abstract</p> <p>Background</p> <p>The accurate normalization of differentially expressed genes in lung cancer is essential for the identification of novel therapeutic targets and biomarkers by real time RT-PCR and microarrays. Although classical "housekeeping" genes, such as GAPDH, HPRT1, and beta-actin have been widely used in the past, their accuracy as reference genes for lung tissues has not been proven.</p> <p>Results</p> <p>We have conducted a thorough analysis of a panel of 16 candidate reference genes for lung specimens and lung cell lines. Gene expression was measured by quantitative real time RT-PCR and expression stability was analyzed with the softwares <it>GeNorm </it>and <it>NormFinder</it>, mean of |ΔCt| (= |Ct Normal-Ct tumor|) ± SEM, and correlation coefficients among genes. Systematic comparison between candidates led us to the identification of a subset of suitable reference genes for clinical samples: IPO8, ACTB, POLR2A, 18S, and PPIA. Further analysis showed that IPO8 had a very low mean of |ΔCt| (0.70 ± 0.09), with no statistically significant differences between normal and malignant samples and with excellent expression stability.</p> <p>Conclusion</p> <p>Our data show that IPO8 is the most accurate reference gene for clinical lung specimens. In addition, we demonstrate that the commonly used genes GAPDH and HPRT1 are inappropriate to normalize data derived from lung biopsies, although they are suitable as reference genes for lung cell lines. We thus propose IPO8 as a novel reference gene for lung cancer samples.</p

Identification of importin (IPO-8) as the most accurate reference gene for the clinicopathological analysis of lung specimens

Abstract Background: The accurate normalization of differentially expressed genes in lung cancer is essential for the identification of novel therapeutic targets and biomarkers by real time RT-PCR and microarrays. Although classical "housekeeping" genes, such as GAPDH, HPRT1, and beta-actin have been widely used in the past, their accuracy as reference genes for lung tissues has not been proven. Results: We have conducted a thorough analysis of a panel of 16 candidate reference genes for lung specimens and lung cell lines. Gene expression was measured by quantitative real time RTPCR and expression stability was analyzed with the softwares GeNorm and NormFinder, mean of |ΔCt| (= |Ct Normal-Ct tumor|) ± SEM, and correlation coefficients among genes. Systematic comparison between candidates led us to the identification of a subset of suitable reference genes for clinical samples: IPO8, ACTB, POLR2A, 18S, and PPIA. Further analysis showed that IPO8 had a very low mean of |ΔCt| (0.70 ± 0.09), with no statistically significant differences between normal and malignant samples and with excellent expression stability. Conclusion: Our data show that IPO8 is the most accurate reference gene for clinical lung specimens. In addition, we demonstrate that the commonly used genes GAPDH and HPRT1 are inappropriate to normalize data derived from lung biopsies, although they are suitable as reference genes for lung cell lines. We thus propose IPO8 as a novel reference gene for lung cancer samples

Processing of metacaspase into a cytoplasmic catalytic domain mediating cell death in Leishmania major

Metacaspases are cysteine peptidases that could play a role similar to caspases in the cell death programme of plants, fungi and protozoa. The human protozoan parasite Leishmania major expresses a single metacaspase (LmjMCA) harbouring a central domain with the catalytic dyad histidine and cysteine as found in caspases. In this study, we investigated the processing sites important for the maturation of LmjMCA catalytic domain, the cellular localization of LmjMCA polypeptides, and the functional role of the catalytic domain in the cell death pathway of Leishmania parasites. Although LmjMCA polypeptide precursor form harbours a functional mitochondrial localization signal (MLS), we determined that LmjMCA polypeptides are mainly localized in the cytoplasm. In stress conditions, LmjMCA precursor forms were extensively processed into soluble forms containing the catalytic domain. This domain was sufficient to enhance sensitivity of parasites to hydrogen peroxide by impairing the mitochondrion. These data provide experimental evidences of the importance of LmjMCA processing into an active catalytic domain and of its role in disrupting mitochondria, which could be relevant in the design of new drugs to fight leishmaniasis and likely other protozoan parasitic diseases