• Liposome-encapsulated antigens induce a protective CTL response against Listeria monocytogenes independent of CD4+ T cell help.

      Grenningloh, R; Darj, A; Bauer, H; zur Lage, S; Chakraborty, T; Jacobs, T; Weiss, S; Molecular Immunology, Helmholtz Centre for Infection Research, Braunschweig, Germany. (2008-06)
      Protection against intracellular pathogens is usually mediated by cytotoxic T lymphocytes (CTL). Induction of a protective CTL response for vaccination purposes has proven difficult because of the limited access of protein antigens or attenuated pathogens to the MHC class I presentation pathway. We show here that pH-sensitive PE/CHEMS liposomes can be used as a vehicle to efficiently deliver intact proteins for presentation by MHC class I. Mice immunized with listerial proteins encapsulated in such liposomes launched a strong CTL response and were protected against a subsequent challenge with L. monocytogenes. Remarkably, the CTL response was induced independently of detectable CD4(+) T cell help.