Resistance to cutaneous leishmaniasis in genetically susceptible BALB/c mice.

When injected cutaneously with promastigotes of an isolate of Leishmania tropica, BALB/c mice develop progressive cutaneous disease whereas lesions in BALB/c.H-2k mice heal after several weeks. Lesions in BALB/c mice injected into deep subcutaneous tissues with promastigotes are less obvious early but much more prominent later than in mice after strict intradermal injection. BALB/c mice injected with Corynebacterium parvum together with a preparation of frozen and thawed infected macrophages are more resistant to cutaneous disease than mice injected with either adjuvant or crude antigen mixture alone. Results of these experiments, and those on other mouse strains reported previously, will aid in the choice of mouse and injection regime to be used in testing the efficacy of isolated L. tropica antigens as vaccines.