DNA immunization with fusion genes encoding different regions of hepatitis C virus E2 fused to the gene for hepatitis B surface antigen elicits immune responses to both HCV and HBV

Table 2 Sero-conversion Ratios and Titres of Anti-HCV-E2 in DNA Immunized Mice

Weeks	DNA Immunogen
	pcDNA3S	pcDNA3SE2-A	pcDNA3SE2-B	pcDNA3SE2-C	pcDNA3SE2-D	pcDNA3SE2-E
0a	(0/5)	(0/5)	(0/5)	(0/5)	(0/5)	(0/5)
2	(1/5)	(2/5)	(1/5)	(1/5)	(1/5)	(1/5)
4b	40d (2/5c)	320 (3/5)	160 (1/5)	320 (3/5)	320 (2/5)	320 (1/5)
6	160 (5/5)	640 (5/5)	640 (5/5)	2560 (5/5)	2560 (5/5)	5120 (4/5)
8	880 (5/5)	640 (5/5)	320 (5/5)	5120 (5/5)	5120 (5/5)	5120 (4/5)
10	80 (5/5)	160 (5/5)	320 (5/5)	5120 (5/5)	5120 (5/5)	5120 (4/5)
16	80 (5/5)	80 (5/5)	160 (5/5)	160 (5/5)	320 (5/5)	80 (4/5)
24	40 (5/5)	40 (5/5)	80 (5/5)	80 (5/5)	160 (5/5)	40 (4/5)

Note: Groups of mice (n = 5) were injected i.m. with the respective plasmids, and sero-conversion ratio and anti-HCV E2 antibody titers were measured at different time points by ELISA. With the exception of coating antigen (E2 (385-565)), all experimental procedures were the same as described in Table 1.

^athe first immunization;

^bthe second immunization (boost);

^c(n/n); sero-conversion ratio, numbers of sero-converted mice relative to the total number tested;

^dtiter; reciprocal of the two-fold dilution factor at end point, pools of positive sera from test groups were tested.