Inmunización con una vacuna heteróloga, ADN/proteína recombinante (tcvac2), como alternativa en la profilaxis de la enfermedad de Chagas en un modelo canino

La Tripanosomiasis americana también conocida como enfermedad de Chagas es producida por el parásito Trypanosoma cruzi el cual puede ingresar al organismo por diversas vías (vectorial y no vectoriales) produciendo en el organismo del hospedero vertebrado una serie de reacciones que van desde los síntomas que produce un resfriado común hasta una enfermedad debilitante que conlleva el riesgo de muerte súbita (Carrada-Bravo 2004a;de Jogna Prat 1997;Diario Oficial de la Federación 2001). Algunos de los inconvenientes más graves de este padecimiento es que en la actualidad se carece de un tratamiento que sea efectivo e inocuo (Urbina 2010), por otro lado, si bien se ha trabajado en la búsqueda de una vacuna que prevenga los daños ocasionados por T. cruzi con resultados esperanzadores, todavía no existe una vacuna capaz de detener la infección (Aparicio-Burgos et al. 2011;Cazorla et al. 2009;Garg and Bhatia 2005;Gupta and Garg 2010). A lo largo de los últimos años se han estudiado diferentes antígenos del Trypanosoma cruzi tanto en su estadio extracelular como en su estadio intracelular, además de metodologías de inmunización que exhiben un buen potencial como vacunas, esto se ha hecho de forma experimental in vivo, in vitro e in silico (Bhatia et al. 2004). En este último caso, Bhatia y colaboradores analizaron la base de datos de la secuencia de T. cruzi e identificaron 71 candidatos únicos para T. cruzi, entre los cuales, ocho eran filogenéticamente conservados en las cepas de T. cruzi de importancia clínica. Entre estos últimos, tres (TcG1, TcG2 y TcG4) son expresados en las fases presentes en el hospedero mamífero (Tripomastigote y amastigote) y provocan niveles significativos de anticuerpos líticos en ratón (Bhatia and Garg 2008) por lo que sugieren ser una alternativa importante para su estudio en otras especies, tal es el caso del perro. Los trabajos realizados en el estudio de los antígenos antes mencionados incluyen desde las vacunas tradicionales con cepas atenuadas del parásito, utilización de otros parásitos emparentados que comparten epítopes antigénicos (T. rangeli), hasta las nuevas generaciones de vacunas en las que se encuentran las vacunas génicas y las de proteínas recombinantes (Garg & Bhatia 2005). Paralelamente se ha trabajado en la selección de adyuvantes para mejorar la respuesta inmune protectora, en estos podemos encontrar proteínas de bacterias como Mycoplasma, aluminio, saponina, interleucinas, entre muchos otros (Cazorla, Frank, & Malchiodi 2009). En lo referente a las vacunas de nueva generación se ha demostrado que las compuestas de ADN son capaces de ofrecer protección ante un desafío con cepas patógenas de T. cruzi, además, se ha demostrado que cuando se inmuniza con ADN utilizando un antígeno específico, y se administra posteriormente un refuerzo con el mismo antígeno pero como proteína recombinante, se estimula la respuesta inmunitaria humoral y celular de mejor forma, en comparación con el uso solo de ADN (Mota-Sánchez 2009)

Cardiopatía Chagásica en Perros: reporte de caso clínico

Articulo derivado de Tesis de Cuauhtémoc Gutiérrez EspinosaEl objetivo de este artículo es dar a conocer los avances en el diagnóstico y evaluación de la cardiomiopatía dilatada secundaria a enfermedad de Chagas en perros, a través de una experiencia clínica. Se presentó un perro macho de 1 año de edad, entero, de raza mestizo, que fue referido para la evaluación cardiológica por sospecha de enfermedad cardíaca congénita, con pronóstico desfavorable. La ecocardiografía confirmó cardiomiopatía dilatada y presencia de efusión abdominal, pero se descartó displasia de la válvula tricúspide y por lo tanto el diagnóstico presuntivo inicial. La anamnesis nos permitió sospechar de infección por Trypanosoma cruzi, por lo que se utilizaron métodos diagnósticos dirigidos a la confirmación de esa afección, que incluyeron; ensayo inmunoenzimático (ELISA) en busca de anticuerpos anti-T. cruzi en suero, PCR punto final y PCR anidado a partir de muestra sanguínea y de la efusión abdominal en busca de parásitos, biometría hemática, química sanguínea, troponina I y NTpro-BNP, que pudieran dar pistas diagnósticas complementarias para realizar un pronóstico más confiable. Se confirmó la infección por T. cruzi y se procedió a dar tratamiento antiparasitario y de soporte cardiovascular. Después de una recuperación inicial de ganancia de peso y estado de animo significativas, el animal murió súbitamente después de un episodio de estrés; condición frecuentemente observada en perros infectados por T. cruzi.UAEMEX 4518/2018/CI Correlacion de las consentraciones séricas de troponina I con los cambios clínicos cardivasculares en perros infectados con Trypanosoma cruzi en fase crónic

Effects of astaxanthin in mice acutely infected with Trypanosoma cruzi

During Trypanosoma cruzi infection, oxidative stress is considered a contributing factor for dilated cardiomyopathy development. In this study, the effects of astaxanthin (ASTX) were evaluated as an alternative drug treatment for Chagas disease in a mouse model during the acute infection phase, given its anti-inflammatory, immunomodulating, and anti-oxidative properties. ASTX was tested in vitro in parasites grown axenically and in co-culture with Vero cells. In vivo tests were performed in BALB/c mice (4–6 weeks old) infected with Trypanosoma cruzi and supplemented with ASTX (10 mg/kg/day) and/or nifurtimox (NFMX; 100 mg/kg/day). Results show that ASTX has some detrimental effects on axenically cultured parasites, but not when cultured with mammalian cell monolayers. In vivo, ASTX did not have any therapeutic value against acute Trypanosoma cruzi infection, used either alone or in combination with NFMX. Infected animals treated with NFMX or ASTX/NFMX survived the experimental period (60 days), while infected animals treated only with ASTX died before day 30 post-infection. ASTX did not show any effect on the control of parasitemia; however, it was associated with an increment in focal heart lymphoplasmacytic infiltration, a reduced number of amastigote nests in cardiac tissue, and less hyperplasic spleen follicles when compared to control groups. Unexpectedly, ASTX showed a negative effect in infected animals co-treated with NFMX. An increment in parasitemia duration was observed, possibly due to ASTX blocking of free radicals, an antiparasitic mechanism of NFMX. In conclusion, astaxanthin is not recommended during the acute phase of Chagas disease, either alone or in combination with nifurtimox.CONACYT PROY NO. 000000000156701. (REGISTRO INTERNO UAEM 3326

TcVac1 vaccine delivery by intradermal electroporation enhances vaccine induced immune protection against Trypanosoma cruzi infection in mice

Trabajo de investigación doctoral de Wael Hegazy Hassan Moustafa bajo la dirección de Juan Carlos Vázquez ChagoyánThe efforts for the development and testing of vaccines against Trypanosoma cruzi infection have increased during the past years. We have designed a TcVac series of vaccines composed of T. cruzi derived, GPI-anchored membrane antigens. The TcVac vaccines have been shown to elicit humoral and cellular mediated immune responses and provide significant (but not complete) control of experimental infection in mice and dogs. Herein, we aimed to test two immunization protocols for the delivery of DNA-prime/ DNA-boost vaccine (TcVac1) composed of TcG2 and TcG4 antigens in a BALB/c mouse model. Mice were immunized with TcVac1 through intradermal/electroporation (IDE) or intramuscular (IM) routes, challenged with T. cruzi, and evaluated during acute phase of infection. The humoral immune response was evaluated through the assessment of anti-TcG2 and anti-TcG4 IgG subtypes by using an ELISA. Cellular immune response was assessed through a lymphocyte proliferation assay. Finally, clinical and morphopathological aspects were evaluated for all experimental animals. Our results demonstrated that when comparing TcVac1 IDE delivery vs IM delivery, the former induced significantly higher level of antigen-specific antibody response (IgG2a + IgG2b > IgG1) and lymphocyte proliferation, which expanded in response to challenge infection. Histological evaluation after challenge infection showed infiltration of inflammatory cells (macrophages and lymphocytes) in the heart and skeletal tissue of all infected mice. However, the largest increase in inflammatory infiltrate was observed in TcVac1_IDE/Tc mice when compared with TcVac1_IM/Tc or non-vaccinated/infected mice. The extent of tissue inflammatory infiltrate was directly associated with the control of tissue amastigote nests in vaccinated/ infected (vs. non-vaccinated/infected) mice. Our results suggest that IDE delivery improves the protective efficacy of TcVac1 vaccine against T. cruzi infection in mice when compared with IM delivery of the vaccine.Universidad Autónoma de Estado de México (proyecto No. 3326/2012C), Consejo Nacional de Ciencia y Tecnología (Proyecto No. 156701) . Beca CONACyT a M.Sc. Wael Hegazy Hassan Moustafa (Beca numero No. 518232/291117)

Immune protection against Trypanosoma cruzi induced by TcVac4 in a canine model

Chagas disease, caused by Trypanosoma cruzi, is endemic in southern parts of the American continent. Herein, we have tested the protective efficacy of a DNA-prime/T. rangeli-boost (TcVac4) vaccine in a dog (Canis familiaris) model. Dogs were immunized with two-doses of DNA vaccine (pcDNA3.1 encoding TcG1, TcG2, and TcG4 antigens plus IL-12- and GMCSF- encoding plasmids) followed by two doses of glutaraldehyde-inactivated T. rangeli epimastigotes (TrIE); and challenged with highly pathogenic T. cruzi (SylvioX10/4) isolate. Dogs given TrIE or empty pcDNA3.1 were used as controls. We monitored post-vaccination and post-challenge infection antibody response by an ELISA, parasitemia by blood analysis and xenodiagnosis, and heart function by electrocardiography. Post-mortem anatomic and pathologic evaluation of the heart was conducted. TcVac4 induced a strong IgG response (IgG2>IgG1) that was significantly expanded post-infection, and moved to a nearly balanced IgG2/IgG1 response in chronic phase. In comparison, dogs given TrIE or empty plasmid DNA only developed high IgG titers with IgG2 predominance in response to T. cruzi infection. Blood parasitemia, tissue parasite foci, parasite transmission to triatomines, electrocardiographic abnormalities were significantly lower in TcVac4-vaccinated dogs than was observed in dogs given TrIE or empty plasmid DNA only. Macroscopic and microscopic alterations, the hallmarks of chronic Chagas disease, were significantly decreased in the myocardium of TcVac4-vaccinated dogs.We conclude that TcVac4 induced immunity was beneficial in providing resistance to T. cruzi infection, evidenced by control of chronic pathology of the heart and preservation of cardiac function in dogs. Additionally, TcVac4 vaccination decreased the transmission of parasites from vaccinated/infected animals to triatomines.CONACYT PROY No. 156701 UAEM PROY No. 2381/2006U National Institutes of Health/National Institute of Allergy and Infectious Diseases http://www.niaid.nih.gov/Pages/ default.aspx GRANT NUMBER (AI072538) NJG; American Heart Association http://www.heart.org/ HEARTORG/ GRANT NUMBER (0855059F) to NJG

una mirada desde las Ciencias de la Conducta

Este libro es el resultado de los trabajos presentados en el 1er Congreso Internacional "Convivencia y bienestar con sentido humanista para una cultura de paz"

Testing the Efficacy of a Multi-Component DNA-Prime/DNA-Boost Vaccine against Trypanosoma cruzi Infection in Dogs

Immunization of dogs with DNA-prime/DNA-boost vaccine (TcVac1) enhanced the Trypanosoma cruzi-specific type 1 antibody and CD8+ T cell responses that resulted in an early control of acute parasitemia and a moderate decline in pathological symptoms during chronic phase. Further improvement of vaccine-induced immunity would be required to achieve clinical and epidemiological benefits and prevent transmission of parasites from vaccinated/infected dogs to triatomines

Effects of astaxanthin in mice acutely infected with

During Trypanosoma cruzi infection, oxidative stress is considered a contributing factor for dilated cardiomyopathy development. In this study, the effects of astaxanthin (ASTX) were evaluated as an alternative drug treatment for Chagas disease in a mouse model during the acute infection phase, given its anti-inflammatory, immunomodulating, and anti-oxidative properties. ASTX was tested in vitro in parasites grown axenically and in co-culture with Vero cells. In vivo tests were performed in BALB/c mice (4–6 weeks old) infected with Trypanosoma cruzi and supplemented with ASTX (10 mg/kg/day) and/or nifurtimox (NFMX; 100 mg/kg/day). Results show that ASTX has some detrimental effects on axenically cultured parasites, but not when cultured with mammalian cell monolayers. In vivo, ASTX did not have any therapeutic value against acute Trypanosoma cruzi infection, used either alone or in combination with NFMX. Infected animals treated with NFMX or ASTX/NFMX survived the experimental period (60 days), while infected animals treated only with ASTX died before day 30 post-infection. ASTX did not show any effect on the control of parasitemia; however, it was associated with an increment in focal heart lymphoplasmacytic infiltration, a reduced number of amastigote nests in cardiac tissue, and less hyperplasic spleen follicles when compared to control groups. Unexpectedly, ASTX showed a negative effect in infected animals co-treated with NFMX. An increment in parasitemia duration was observed, possibly due to ASTX blocking of free radicals, an anti-parasitic mechanism of NFMX. In conclusion, astaxanthin is not recommended during the acute phase of Chagas disease, either alone or in combination with nifurtimox

Effects of astaxanthin in mice acutely infected with Trypanosoma cruzi

During Trypanosoma cruzi infection, oxidative stress is considered a contributing factor for dilated cardiomyopathy development. In this study, the effects of astaxanthin (ASTX) were evaluated as an alternative drug treatment for Chagas disease in a mouse model during the acute infection phase, given its anti-inflammatory, immunomodulating, and anti-oxidative properties. ASTX was tested in vitro in parasites grown axenically and in co-culture with Vero cells. In vivo tests were performed in BALB/c mice (4–6 weeks old) infected with Trypanosoma cruzi and supplemented with ASTX (10 mg/kg/day) and/or nifurtimox (NFMX; 100 mg/kg/day). Results show that ASTX has some detrimental effects on axenically cultured parasites, but not when cultured with mammalian cell monolayers. In vivo, ASTX did not have any therapeutic value against acute Trypanosoma cruzi infection, used either alone or in combination with NFMX. Infected animals treated with NFMX or ASTX/NFMX survived the experimental period (60 days), while infected animals treated only with ASTX died before day 30 post-infection. ASTX did not show any effect on the control of parasitemia; however, it was associated with an increment in focal heart lymphoplasmacytic infiltration, a reduced number of amastigote nests in cardiac tissue, and less hyperplasic spleen follicles when compared to control groups. Unexpectedly, ASTX showed a negative effect in infected animals co-treated with NFMX. An increment in parasitemia duration was observed, possibly due to ASTX blocking of free radicals, an anti-parasitic mechanism of NFMX. In conclusion, astaxanthin is not recommended during the acute phase of Chagas disease, either alone or in combination with nifurtimox

TcVac1 vaccine delivery by intradermal electroporation enhances vaccine induced immune protection against Trypanosoma cruzi infection in mice

Trabajo de investigación doctoral de Wael Hegazy Hassan Moustafa bajo la dirección de Juan Carlos Vázquez ChagoyánThe efforts for the development and testing of vaccines against Trypanosoma cruzi infection have increased during the past years. We have designed a TcVac series of vaccines composed of T. cruzi derived, GPI-anchored membrane antigens. The TcVac vaccines have been shown to elicit humoral and cellular mediated immune responses and provide significant (but not complete) control of experimental infection in mice and dogs. Herein, we aimed to test two immunization protocols for the delivery of DNA-prime/ DNA-boost vaccine (TcVac1) composed of TcG2 and TcG4 antigens in a BALB/c mouse model. Mice were immunized with TcVac1 through intradermal/electroporation (IDE) or intramuscular (IM) routes, challenged with T. cruzi, and evaluated during acute phase of infection. The humoral immune response was evaluated through the assessment of anti-TcG2 and anti-TcG4 IgG subtypes by using an ELISA. Cellular immune response was assessed through a lymphocyte proliferation assay. Finally, clinical and morphopathological aspects were evaluated for all experimental animals. Our results demonstrated that when comparing TcVac1 IDE delivery vs IM delivery, the former induced significantly higher level of antigen-specific antibody response (IgG2a + IgG2b > IgG1) and lymphocyte proliferation, which expanded in response to challenge infection. Histological evaluation after challenge infection showed infiltration of inflammatory cells (macrophages and lymphocytes) in the heart and skeletal tissue of all infected mice. However, the largest increase in inflammatory infiltrate was observed in TcVac1_IDE/Tc mice when compared with TcVac1_IM/Tc or non-vaccinated/infected mice. The extent of tissue inflammatory infiltrate was directly associated with the control of tissue amastigote nests in vaccinated/ infected (vs. non-vaccinated/infected) mice. Our results suggest that IDE delivery improves the protective efficacy of TcVac1 vaccine against T. cruzi infection in mice when compared with IM delivery of the vaccine.Universidad Autónoma de Estado de México (proyecto No. 3326/2012C), Consejo Nacional de Ciencia y Tecnología (Proyecto No. 156701) . Beca CONACyT a M.Sc. Wael Hegazy Hassan Moustafa (Beca numero No. 518232/291117)