CLASS-I RESTRICTED CTL INDUCTION BY MUCOSAL IMMUNIZATION WITH NAKED DNA ENCODING MEASLES-VIRUS HEMAGGLUTININ

We have investigated the class I-restricted CTL response specific for measles virus haemagglutinin (HA) in the spleens of mice immunized by various mucosal routes with a DNA plasmid carrying the HA gene (pV(1)j -HA). A single immunization with recombinant DNA injected in the bucca l mucosa induced an HA-specific CTL response. Similarly, nasal immuniz ation with the DNA vaccine induced primary CTLs against measles virus HA. Booster immunization did not enhance the CTL activity. Oral or int rajejunal immunization with the plasmid induced a CTL response of lowe r magnitude. However, this could be potentiated by co-administration o f the mucosal adjuvant cholera toxin or cationic lipids (DOTAP). These data show that a CTL response can be generated by mucosal vaccination using DNA vaccines.