Figure 1.

Ii −/− mice on a resistant background control L. major infection. (A) Mice were inoculated in the hind footpads with promastigotes of L. major, and the course of disease followed by measuring the size of the footpads with time. A cohort of BALB/c mice was inoculated concurrently to assess virulence of the inoculum. Designated C57BL/6 Ii −/− mice were treated with neutralizing anti–IFN-γ antibody as noted. Data points are means and standard deviations of groups of animals, and are representative of nine separate experiments involving 30 Ii −/− mice. (B) Ii −/− mice on a resistant background were crossed to βm −/− to create double mutant animals and infected with promastigotes of L. major in the hind footpads. Cohorts of β2m −/− and Ii +/− animals, together with susceptible BALB/c mice, were inoculated at the same time. Data points are means and standard deviations and representative of results obtained with 6 Ii −/− β2m −/− mice.