FIGURE 5.

L. major infected DM^−/− DC present newer epitopes not displayed by infected wild-type DC. A, Sixteen L. major-specific hybridomas derived from infected DM^−/− mice were examined for activation using L. major-infected or uninfected wild-type or DM^−/− BMDC (10⁴ DC per well) as described in Fig. 4. The data show that while 15 of the 16 DM^−/−-derived hybridomas responded to infected DM^−/− APC, only 7 of 16 recognized infected wild-type APC, thus indicating that L. major-infected wild-type DC failed to express epitopes recognized by 8 DM^−/− T cell hybridoms. The horizontal dotted line represents the cutoff point for the T hybridomas not recognizing L. major infected APC (with an exception of 1C3, which shows a minor response to wild-type-infected APC). Symbols are: wild-type uninfected (○), infected (●); BALB/c DM^−/− uninfected (□), infected (■). B, Three DM^−/−-derived T hybridomas were examined for stimulation with varying doses of uninfected or infected BMDC as described in A. The data show that 2E5 and 1F7 hybridomas (representing the eight T cell hybridomas that fail to be stimulated by infected wild-type APC) are not stimulated despite the presence of 192,000 infected wild-type DC per well. The hybridoma 2D8 (representing seven T hybridomas that are stimulated by both the infected wild-type and DM^−/− DC) shows an enhanced response to wild-type DC as compared with infected DM^−/− DC. Symbols used are as in A.