RESUMO
Leishmaniasis is a major health problem and it is estimated that 12 million people are currently infected. A vaccine which could cross-protect people against different Leishmania spp. would facilitate control of this disease as more than one species of Leishmania may be present. In this study the ability of a DNA vaccine, using the full gene sequence for L. donovani gamma glutamyl cysteine synthetase (γGCS) incorporated in the pVAX vector (pVAXγGCS), and a protein vaccine, using the corresponding recombinant L. donovani γGCS protein (LdγGCS), to protect against L. major or L. mexicana infection was evaluated. DNA vaccination gave transient protection against L. major and no protection against L. mexicana despite significantly enhancing specific antibody titres in vaccinated infected mice compared to infected controls. Vaccination with the LdγGCS protected against both species but only if the protein was incorporated into non-ionic surfactant vesicles for L. mexicana. The results of this study indicate that a L. donovani γGCS vaccine could be used to vaccinate against more than one Leishmania species but only if the recombinant protein is used.
Assuntos
Antígenos de Protozoários/imunologia , Glutamato-Cisteína Ligase/imunologia , Leishmania donovani/imunologia , Vacinas contra Leishmaniose/imunologia , Leishmaniose Cutânea/prevenção & controle , Leishmaniose Visceral/prevenção & controle , Animais , Anticorpos Antiprotozoários/biossíntese , Anticorpos Antiprotozoários/imunologia , Antígenos de Protozoários/genética , Proteção Cruzada , Epitopos , Glutamato-Cisteína Ligase/genética , Humanos , Leishmania major/imunologia , Leishmania mexicana/imunologia , Vacinas contra Leishmaniose/genética , Leishmaniose Cutânea/imunologia , Leishmaniose Cutânea/parasitologia , Leishmaniose Visceral/imunologia , Leishmaniose Visceral/parasitologia , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Vacinação , Vacinas de DNA , Vacinas de Subunidades AntigênicasRESUMO
Vernonia amygdalina and Annona senegalensis, two plants used by local/smallholder livestock farmers in Nigeria as anthelmintic were screened for in vitro anthelmintic activity using Haemonchus contortus eggs. The extract of V. amygdalina did not show any significant activity at concentrations up to 11.2mg/ml. The extract of A. senegalensis showed significant (P<0.001) reduction in egg hatch at a concentration of 7.1mg/ml. The in vitro fecal culture of eggs with A. senegalensis showed significant (P<0.001) reductions in larval recovery with increasing concentrations from 1 to 10% ((w/w) in fecal culture) when whole ground plant material was used. Although traditional veterinary healers and local livestock farmers claim both plants are effective as anthelmintics, our result indicate that only A. senegalensis showed promising anthelmintic activity especially with use of ground whole plant materials as used by some farmers.