TABLE 3.

MHC-I up-regulation and CTL in vivo responses

Lipo- peptidea	Class I H-2Db up-regulation (mean fluorescence ± SD at 100 μM lipopeptide)b	CTL response (mean % cytotoxicity ± SD at T/E ratio of 1:80)c
LP3	100 ± 6	32 ± 13
LP4	70 ± 1	29 ± 11
LP1	61 ± 8	8 ± 11
None	54 ± 3

^aImmunization with lipopeptide-IFA. 

^bMHC-I up-regulation was measured as described in the legend to Fig. 1, and CTL induction was measured as described in Table 2. The estimated minimal concentrations of lipopeptide required for stabilization were 10 μM for LP3, >50 μM for LP4, and none for LP1. The results of class I H-2D^b up-regulation are from one of two representative experiments. Statistical differences were found between lipopeptides LP3 and LP4 (P < 0.01), LP3 and LP1 (P < 0.025), LP3 and none (P < 0.005), and LP4 and none (P < 0.005). 

^cResults from CTL responses are means of four or five experiments. Statistical differences were found between LP3 and LP1 (P < 0.05) and LP4 and LP1 (P < 0.05).