Immunization of susceptible BALB/c mice against Leishmania braziliensis,: II. Use of temperature-sensitive avirulent clones of parasite for vaccination purposes

Abstract Avirulent clones of Leishmania braziliensis were produced by treatment of parental parasite stock with the mutagen N -methyl- N′ -methyl- N′ -nitro- N -nitrosoguanidine and selection for growth at 19 °C. These clones have a clear preference for infection and growth in vitro at 19 °C rather than the normal 28 °C. In addition, they can be used to vaccinate naive mice successfully against growth of the parental parasite clones. Immunity can be adoptively transferred from vaccinated mice by Lyt-1 + cells from immunized animals.