MUCOSAL IMMUNIZATION WITH A MEASLES-VIRUS CTL EPITOPE ENCAPSULATED INBIODEGRADABLE PLG MICROPARTICLES

The immunogenicity of a cytotoxic T cell epitope (CTL) representing re sidues 52-60 from measles virus (MV) nucleoprotein, encapsulated in po ly(lactide-co-glycolide) (PLG) microparticles was evaluated after muco sal immunization. After intranasal administration of the encapsulated CTL epitope linked at the carboxyl terminus of two copies of a T-helpe r epitope (TT-NP6), peptide-specific and MV-specific CTL responses wer e detected in splenocytes. However, these responses were lower than th e responses observed when the TT-NP6 peptide was administered intranas ally in saline or using CTB as an adjuvant. Intranasal coadministratio n of the encapsulated TT-NP6 peptide with CTB did not result in any si gnificant potentiation of the CTL responses, The effectiveness of biod egradable PLG microparticles for mucosal delivery of CTL epitopes, com bined with their excellent tissue compatibility and biodegradability s uggests that they represent a valuable delivery system for synthetic i mmunogens. However, further work is needed to define the requirements for effective absorption by the nasal epithelium.