FIG. 7.

Protection by T-cell clones. Four strongly growing hsp65-responsive clones of CD4⁺/CD44^lo and four of CD4⁺/CD44^hi, four of CD8⁺/CD44^lo, and four of CD8⁺/CD44^hi phenotypes were selected from spleens of M. tuberculosis-infected and from hsp65 DNA-immunized mice. After characterization for hsp65 antigen-dependent cytotoxicity and IL-4 and IFN-γ production, they were tested for the ability to protect naive mice from challenge with M. tuberculosis as described in the legend to Fig. 5. The numbers of live bacteria in spleens 4 weeks after challenge are shown as mean log₁₀ ± SD for groups of five animals. Dark-shaded and unshaded bars represent data from clones that produced IL-4 and IFN-γ, respectively. Controls were as follows: 1, untreated; 2 and 3, reconstituted, respectively, with CD4⁺/CD8⁻ and CD8⁺/CD4⁻ clones having irrelevant antigenic specificity.