Person:
Domínguez Bernal, Gustavo Ramón

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First Name
Gustavo Ramón
Last Name
Domínguez Bernal
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Veterinaria
Department
Sanidad Animal
Area
Sanidad Animal
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Now showing 1 - 4 of 4
  • Publication
    A further investigation of the leishmaniosis outbreak in Madrid (Spain): low-infectivity phenotype of the Leishmania infantum BOS1FL1 isolate to establish infection in canine cells
    (Elsevier, 2020-12) Viñals, Luis Miguel; Mas Zubiri, Alicia; Martínez Rodrigo, Abel; Orden Gutiérrez, José Antonio; Domínguez Bernal, Gustavo Ramón; Carrión Herrero, Francisco Javier
    Human leishmaniosis caused by Leishmania infantum is a zoonotic disease, with dogs as the main reservoir in Mediterranean Basin countries. The largest European outbreak of human leishmaniosis declared in the southwestern Madrid region (Spain) is characterized by unusual epidemiological and clinical features, such as the emergence of new wild reservoirs (hares and rabbits), whereas the seroprevalence, infection, and severity of canine leishmaniosis have not substantially changed since the first studies conducted in Madrid before the outbreak. Previous studies reported that L. infantum isolates from the Madrid leishmaniosis focus displayed elevated virulence in in vivo models of infection and increased infectivity in murine target cells. With the aim of studying whether changes in the host-parasite interaction and virulence profile have developed, we first assessed the behaviour of one circulating isolate of the outbreak, IPER/ES/2012/BOS1FL1 (BOS1FL1), compared to that of a well-characterized strain from canine leishmaniosis, MCAN/ES/1996/BCN150 (BCN150), in terms of infection capacity (percentage of infected cells, representing infectivity, and number of amastigotes per infected cell, representing the intensity of infection) in canine monocytes and macrophages. BCN150 displayed significantly higher infectivity (76.82 ±4.40 vs 38.58 ±2.19; P <0.0001) and intensity of infection (3.64 ±0.13 vs 1.83 ±0.12; P <0.0001) than BOS1FL1 when interacting with canine cells. Our ROS induction results did not differ significantly between the two isolates or with the responses previously described for other L. infantum isolates. Paradoxically, increased resilience to hydrogen peroxide exposure was observed for BOS1FL1 (% viability 40.62 ±5.54 vs 26.37 ±2.93; P =0.039). Finally, we demonstrated that a decreased intracellular load of BOS1FL1 was associated with increased IFN-γ (261.21 ±26.29 vs 69.80 ±9.02; P =0.0151) and decreased IL- 10 production (165.06 ±23.87 vs 264.41 ±30.58; P =0.0002). In this study, we provide the first detailed insight into the differences between the isolate BOS1FL1 from the outbreak in Madrid and the well-characterized strain BCN150 MON-1 obtained from a dog in their response to interacting with canine cells. However, further studies are necessary to shed light on the immune mechanisms resulting in BOS1FL1 exhibiting less virulent behaviour in canine cells than in cells derived from other host species.
  • Publication
    Properties of virulence emergence of Leishmania infantum isolates from Phlebotomus perniciosus collected during the human leishmaniosis outbreak in Madrid, Spain. Hepatic histopathology and immunological parameters as virulence markers in the mouse model
    (Wiley, 2020-08) Maribel Jiménez; Mas Zubiri, Alicia; Martínez Rodrigo, Abel; Orden Gutiérrez, José Antonio; Carrión Herrero, Francisco Javier; Domínguez Bernal, Gustavo Ramón; Jiménez Martínez, María De Los Ángeles
    Recent anthropic activity related to the construction of the Bosquesur Green Park in a large urban setting in Madrid (Spain) has resulted in the largest reported community outbreak of human leishmaniosis in Europe. Previous phylogenetic and molecular-typ-ing studies of parasite isolates have implicated the Leishmania infantum ITS-Lombardi genotype in this outbreak. In an unusual scenario, visceral leishmaniosis (VL) is affecting a significant number of individuals, suggesting that an increase in parasite virulence has occurred. In this work, using an in vivo BALB/c model of VL, we aimed to investigate the properties of emergent virulence of the L. infantum POL2FL7 and BOS1FL1 isolates obtained from Phlebotomus perniciosus collected in the outbreak area and compare them with those of the well-characterized strain BCN150 MON-1 isolated from a dog. The P. perniciosus specimens were collected during an entomological survey conducted in the transmission season of 2012. We observed a range of virulence phenotypes from moderately to highly aggressive after 5 weeks of infection. IV challenge of mice with outbreak isolates from sand flies induced higher splenic and liver parasite burdens, higher serological titres of specific anti-Leishmania antibodies and impaired capacities to control infection, as revealed by the arginine metabolism and low ratios of Th1/Th2 cy-tokine profiles analysed, compared with the corresponding measures evaluated in mice infected with the BCN150 strain. The BOS1FL1 isolate showed the highest degree of virulence among the isolates, superior to that of POL2FL7, as evidenced by the analysed biomarkers and the histopathological severity of liver lesions. These results provide in-sight into how L. infantum isolates from sand flies collected in the outbreak area have been able to affect not only immunosuppressed patients but also middle-aged people with normal immunocompetence in the largest human VL outbreak in Europe.
  • Publication
    A Tailored Approach to Leishmaniases Vaccination: Comparative Evaluation of the Efficacy and Cross-Protection Capacity of DNA vs. Peptide-Based Vaccines in a Murine Model
    (MDPI, 2023-08-02) Mas Zubiri, Alicia; Hurtado Morillas, Clara; Martínez Rodrigo, Abel; Orden Gutiérrez, José Antonio; Fuente López, Ricardo De La; Domínguez Bernal, Gustavo Ramón; Carrión Herrero, Francisco Javier
    Zoonotic leishmaniases are a worldwide public health problem for which the development of effective vaccines remains a challenge. A vaccine against leishmaniases must be safe and affordable and should induce cross-protection against the different disease-causing species. In this context, the DNA vaccine pHisAK70 has been demonstrated to induce, in a murine model, a resistant phenotype against L. major, L. infantum, and L. amazonensis. Moreover, a chimeric multiepitope peptide, HisDTC, has been obtained by in silico analysis from the histone proteins encoded in the DNA vaccine and has showed its ability to activate a potent CD4+ and CD8+ T-cell protective immune response in mice against L. infantum infection. In the present study, we evaluated the plasmid DNA vaccine pHisAK70 in comparison with the peptide HisDTC (with and without saponin) against L. major and L. infantum infection. Our preliminary results showed that both formulations were able to induce a potent cellular response leading to a decrease in parasite load against L. infantum. In addition, the DNA candidate was able to induce better lesion control in mice against L. major. These preliminary results indicate that both strategies are potentially effective candidates for leishmaniases control. Furthermore, it is important to carry out such comparative studies to elucidate which vaccine candidates are the most appropriate for further development.
  • Publication
    Mitigating an undesirable immune response of inherent susceptibility to cutaneous leishmaniosis in a mouse model: the role of the pathoantigenic HISA70 DNA vaccine
    (BioMed Central, 2012-08-09) Domínguez Bernal, Gustavo Ramón; Horcajo Iglesias, María Del Pilar; Orden Gutiérrez, José Antonio; Fuente López, Ricardo De La; Herrero Gil, Aldara; Ordóñez Gutiérrez, Lara; Carrión Herrero, Francisco Javier
    Abstract: Leishmania major is the major cause of cutaneous leishmaniosis (CL) outside of the Americas. In the present study we have cloned six Leishmania genes (H2A, H2B, H3, H4, A2 and HSP70) into the eukaryotic expression vector pCMVβ-m2a, resulting in pCMV-HISA70m2A, which encodes all six pathoantigenic proteins as a single polyprotein. This expression plasmid has been evaluated as a novel vaccine candidate in the BALB/c mouse model of CL. The DNA vaccine shifted the immune response normally induced byL. majorinfection away from a Th2-specific pathway to one of basal susceptibility. Immunization with pCMV-HISA70m2A dramatically reduced footpad lesions and lymph node parasite burdens relative to infected control mice. Complete absence of visceral parasite burden was observed in all 12 immunized animals but not in any of the 24 control mice. Moreover, vaccinated mice produced large amounts of IFN-γ, IL-17 and NO at 7 weeks post-infection (pi), and they showed lower arginase activity at the site of infection, lower IL-4 production and a weaker humoral immune response than infected control mice. Taken together, these results demonstrate the ability of the HISA70 vaccine to shift the murine immune response to L. major infection away from an undesirable, Th2-specific pathway to a less susceptible-like pathway involving Th1 and Th17 cytokine profiles.