Induction of CD8+ T cell responses by Yersinia vaccine carrier strains

LcrV Delivered via Type III Secretion System of Live Attenuated Yersinia pseudotuberculosis Enhances Immunogenicity against Pneumonic Plague

“…Cellular immunity plays an important role in protection against pneumonic plague (45,46,(85)(86)(87)(88). To stimulate cellular immunity, heterologous antigens fused with YopE (aa 1 to 138) allow the chimeric protein to be specifically transported via the T3SS of live attenuated Y. pseudotuberculosis strains to become accessible to the major histocompatibility complex (MHC) class I-restricted antigenprocessing pathways and stimulate an antigen-specific cellular immune response (40,41). Thus, we constructed plasmid vectors containing the secretion and translocation signals of the Yersinia T3SS YopE effector protein, which are specified by the first 138 amino acids in the amino-terminal region of YopE (designated YopE Nt138 ).…”

“…Previous studies suggest that Y. pseudotuberculosis is a promising candidate for an oral live carrier vaccine, capable of stimulating antigen specific CD8 ϩ T-cell responses (40,41). Additionally, delivery of heterologous antigens by the type III secretion system (T3SS) in Y. pseudotuberculosis and Salmonella stimulated antigen-specific cytotoxic T-cell responses, antigen-specific CD8 ϩ memory T cells, and protection against challenge with different pathogens (40,42,43).…”

A Protective Epitope in Type III Effector YopE Is a Major CD8 T Cell Antigen during Primary Infection with Yersinia pseudotuberculosis

“…YopP inhibited the CD8 T cell response to YopE-LLO in mice orally infected with Y. enterocolitica, an activity that could be correlated with the killing of APCs by this effector (56). In contrast, YopE was important for a maximal CD8 T cell response to Y. enterocolitica expressing YopE-LLO or YopE-OVA, most likely because this effector was required for bacterial colonization of deep murine lymphatic tissues such as spleen (30,58,61).…”

YopJ-Promoted Cytotoxicity and Systemic Colonization Are Associated with High Levels of Murine Interleukin-18, Gamma Interferon, and Neutrophils in a Live Vaccine Model ofYersinia pseudotuberculosisInfection

“…In addition, the T3SS has been exploited for delivery of heterologous antigens by live attenuated Yersinia carrier vaccines (3,32,55,62,65,67,70). Evidence was obtained that YopP inhibited CD8 T-cell priming to a heterologous antigen in mice infected with a Y. enterocolitica carrier vaccine strain (32,65,67).…”