20 research outputs found
A dhfr-ts- Leishmania major Knockout Mutant Cross-protects against Leishmania amazonensis
E10-5A3 is a dhfr-ts- Leishmania major double knockout auxotrophic shown previously to induce substantial protection against virulent L. major infection in both genetically susceptible and resistant mice. We investigated the capacity of dhfr-ts- to protect against heterologous infection by L. amazonensis. The degree of protection was evaluated by immunization of BALB/c or C57BL/6 mice with E10-5A3, followed by L. amazonensis challenge. Whether immunized by subcutaneous (SC) or intravenous (IV) inoculation, susceptible and resistant mice displayed a partial degree of protection against challenge with virulent L. amazonensis. SC-immunized BALB/c mice developed lesions 40 to 65% smaller than non immunized mice, while IV immunization led to protection ranging from 40 to 75% in four out of six experiments compared to non immunized animals. The resistant C57BL/6 mice displayed comparable degrees of protection, 57% by SC and 49% by IV immunization. Results are encouraging as it has been previously difficult to obtain protection by SC vaccination against Leishmania, the preferred route for human immunization
Modulation of Hoogsteen dynamics on DNA recognition
DNA is found in a dynamic equilibrium between standard Watson-Crick (WC) base pairs and non-standard Hoogsteen (HG) base pairs. Here the authors describe the influence of echinomycin and actinomycin D ligands binding on the HG-WC base pair dynamics in DNA