Biostimulated-sesame sprout extracts as potential agents against Leishmania mexicana.

Leishmania mexicana is one of the causal agents of cutaneous leishmaniasis. Current antileishmanial chemotherapeutics have demonstrated adverse side effects; thus, alternative treatments are needed. In this study, we performed in silico and in vitro analyses of the leishmanicidal potential of the most abundant phenolic compounds identified in black sesame sprouts biostimulated with Bacillus clausii. The molecular docking analysis showed strong interactions (binding free energies between -6.5 and -9.5 kcal/mol) of sesaminol 2-O-triglucoside, pinoresinol dihexoside, isoverbascoside, and apigenin with the arginase, leishmanolysin, cysteine peptidase B, and pyruvate kinase leishmanial enzymes. Furthermore, almost all phenolic compounds interacted with the active site residues of L. mexicana enzymes. In vitro, the B. clausii-biostimulated sprout phenolic extracts and apigenin inhibited the growth of promastigotes with IC50 values of 0.08 mg gallic acid equivalent/mL and 6.42 µM (0.0017 mg/mL), respectively. Additionally, in the macrophage infection model, cells treated with B. clausii-biostimulated sprout phenolic extracts and infected with L. mexicana exhibited significantly (P < 0.05) reduced nitric oxide production and decreased parasite burden. Altogether, our study provides important data related to high efficacy and less toxic natural antileishmanial candidates against promastigotes of L. mexicana.

First evidence of systemic infection and specific cytotoxic T lymphocyte immune response evoked by oral infection with recombinant Salmonella enterica serovar Albany-Ovalbumin in C57BL/6 mice.

Our group isolated Salmonella enterica serovar Albany from food and feces of wild captive carnivores in a zoo from northwestern Mexico. This serovar was also associated with the death of an ocelot (Leopardus pardalis) in the same zoo. Another group associated S. Albany with the death of a human patient. It is due to this zoonotic potential that the in vivo study of the host-S. Albany relationship is critical. The recombinant S. Albany-Ovalbumin (rSAO) strain was used to analyze a murine oral infection and its specific cytotoxic T lymphocyte (CTL) response. Our results have shown for the first time that rSAO establishes a systemic infection and evokes epitope-specific lysis with a Th1-like cytokine profile in vivo.

The plasmacytoid dendritic cells evoke Salmonella-specific CTL effector response / Las células dendríticas plasmacitoides evocan la respuesta efectora de los linfocitos T citotóxicos específicos para Salmonella

Introduction: The immunological role of plasmacytoid dendritic cells (pDC) in bacterial infections such as Salmonella has been poorly documented. Therefore, we analyzed the effector function of these cells by presenting cytotoxic T lymphocytes (CTL) with Salmonella Typhimurium antigens. Objective: To analyze the Salmonella-specific CTL response evoked by pDCs. Materials and methods: We used plasmacytoid dendritic cells stained with carboxyfluorescein succinimidyl ester (CFSE) and pulsed with OmpC73, Salmonella Kb restricted epitopes or S. Typhimurium as targets for cytotoxicity assays. Results: Specific lysis was shown to be statistically significant in pDC + OmpC73 for all effector:target ratios (p≤0.05). For pDC + S. Typhimurium, statistical significance was only observed at a 1:100 ratio (p≤0.05) using OmpC73. Conclusion: Plasmacytoid dendritic cells evoke CTL response during S. Typhimurium infection.

Introducción. La función inmunológica de las células dendríticas plasmacitoides durante las infecciones bacterianas, como la de Salmonella spp., es poco conocida. En ese contexto, se analizó su función efectora para presentar antígenos de Salmonella Typhimurium ante linfocitos T citotóxicos. Objetivo. Analizar la respuesta de los linfocitos T citotóxicos específicos para Salmonella evocada por las células dendríticas plasmacitoides. Materiales y métodos. Se usaron células dendríticas plasmacitoides marcadas con éster de succinimidil-carboxifluoresceína, pulsadas con el epítopo de Salmonella OmpC73 Kb restringido o infectadas con S. Typhimurium como blanco en ensayos de citotoxicidad. Resultados. La lisis específica tuvo significación estadística usando células dendríticas plasmacitoides positivas pulsadas con OmpC73 en todas las relaciones de células efectoras y blanco (E:B) (p≤0,05); en cuanto a las células dendríticas plasmacitoides positivas para S. Typhimurium, solo se observó significación estadística en la relación de 1:100 (p≤0,05) usando las células efectoras OmpC73. Conclusión. Las células dendríticas plasmacitoides pueden evocar la respuesta de los linfocitos T citotóxicos durante la infección con S. Typhimurium.

Las células dendríticas plasmacitoides evocan la respuesta efectora de los linfocitos T citotóxicos específicos para Salmonella / The plasmacytoid dendritic cells evoke Salmonella-specific CTL effector response

Resumen Introducción. La función inmunológica de las células dendríticas plasmacitoides durante las infecciones bacterianas, como la de Salmonella spp., es poco conocida. En ese contexto, se analizó su función efectora para presentar antígenos de Salmonella Typhimurium ante linfocitos T citotóxicos. Objetivo. Analizar la respuesta de los linfocitos T citotóxicos específicos para Salmonella evocada por las células dendríticas plasmacitoides. Materiales y métodos. Se usaron células dendríticas plasmacitoides marcadas con éster de succinimidil-carboxifluoresceína, pulsadas con el epítopo de Salmonella OmpC73 Kb- restringido o infectadas con S. Typhimurium como blanco en ensayos de citotoxicidad. Resultados. La lisis específica tuvo significación estadística usando células dendríticas plasmacitoides positivas pulsadas con OmpC73 en todas las relaciones de células efectoras y blanco (E:B) (p≤0,05); en cuanto a las células dendríticas plasmacitoides positivas para S. Typhimurium, solo se observó significación estadística en la relación de 1:100 (p≤0,05) usando las células efectoras OmpC73. Conclusión. Las células dendríticas plasmacitoides pueden evocar la respuesta de los linfocitos T citotóxicos durante la infección con S. Typhimurium.

Abstract Introduction: The immunological role of plasmacytoid dendritic cells (pDC) in bacterial infections such as Salmonella has been poorly documented. Therefore, we analyzed the effector function of these cells by presenting cytotoxic T lymphocytes (CTL) with Salmonella Typhimurium antigens. Objective: To analyze the Salmonella-specific CTL response evoked by pDCs. Materials and methods: We used plasmacytoid dendritic cells stained with carboxyfluorescein succinimidyl ester (CFSE) and pulsed with OmpC73, Salmonella Kb- restricted epitopes or S. Typhimurium as targets for cytotoxicity assays. Results: Specific lysis was shown to be statistically significant in pDC + OmpC73 for all effector:target ratios (p≤0.05). For pDC + S. Typhimurium, statistical significance was only observed at a 1:100 ratio (p≤0.05) using OmpC73. Conclusion: Plasmacytoid dendritic cells evoke CTL response during S. Typhimurium infection.

Cloning and Recombinant Expression of Elongation Factor-1α of Leishmania mexicana.

Leishmania mexicana is an intracellular parasite that causes cutaneous leishmaniasis (CL) in some countries, including Mexico. Recently, we identified the elongation factor-1α (EF-1α) of L. mexicana by immunoproteomic analysis. In Leishmania donovani, this molecule has been reported as a virulence factor involved in downregulation of macrophages by no-canonical function when EF-1α interacts with protein tyrosine phosphatase-1 (SHP-1). However, in L. mexicana the key role of EF-1α in host-parasite relationship has not been elucidated, by this reason we started with cloning and recombinant expression of this antigen. A sequence of 1350 bp corresponding to EF-1α (EF-Lm) full-length gene was amplified from genomic DNA of L. mexicana (GenBank: MG256973); this gene contains only one nucleotide change: C464T, compared with L. mexicana reference sequence (GenBank: FR799570.1). The gene cloned (EF-Lm) codes for a protein of 449 residues. It was expressed in Escherichia coli and purified as 63 kDa sumo-fusion protein, which was recognized in the sera of patients diagnosed with CL. Our results show that EF-Lm is immunogenic during infection, and the rEF-Lm could be used for further analyses in the host-parasite relationship.