Project Title: Strategies to enhance the immunogenicity of vectored vaccines

ESR7: to construct p/DNA vaccines expressing C. trachomatis antigens; ii) to standardise protocols for testing of vaccine-induced humoral and T-cell responses, with ESR 9 and ESR 10 and to determine C. trachomatis CD4⁺ T cell epitopes;  iii) to determine the phenotype of C. trachomatis -specific T cell responses elicited by single prime and prime boost tattoo-immunisation with the p/DNA vaccines; iv) to test whether fusion of p/DNA vector-encoded antigens to TTFC or Ub enhances vaccine efficacy, with ESR 8; v) to perform a detailed ex vivo analysis of induced immune responses at transcriptomics level ; vi) based on obtained results, to optimise vectored vaccines, together with relevant VacPath partners; vi) if applicable, to test vaccine efficacy.

ESR8: to construct and test immunogenicity (with ESR 7) of p/DNA vaccines expressing C. trachomatis MOMP, fused to Ub or TTFC and  to identify linear C. trachomatis CD8⁺ T cell epitopes; ii); to perform cellular and biochemical assays and transcriptomics analyses on (cross) presenting DC, with ESR 1, 3 and 9, to unravel the mechanism by which (stable) antigen fusion to a single Ub moiety enhances immunogenicity; iv) to identify C. trachomatis-encoded non-contiguous (spliced) CD8⁺ T cell epitopes, targeted by C. trachomatis vaccine- and by C. trachomatis infection-primed CD8 T cells.

Project Title: Approaches to optimise MVA-based vaccines and to enhance MVA-mediated T cell response

ESR3: to construct, produce and validate recombinant MVA expressing variants of the C. trachomatis antigen MOMP for usage in comparative in vivo immunisation studies; ii) to elucidate the relevant processing- / presentation routes for MOMP antigen variants in vitro in T cell activation assays and on transcriptional level (transcriptomics); iii) to perform detailed phenotypical and functional ex vivo CD4⁺ and CD8⁺ T cell analyses and analysis of humoral responses following different vaccination regimens (ICS, multimer, ELISA) iv) optimise vector-induced immune responses by integrating immunomodulators into the vaccine vectors; and v) if applicable:  to evaluate the vaccine efficacy in a murine C. trachomatis challenge model.

ESR4: to construct, produce and validate recombinant MVA encoding C. trachomatis antigens such as  MOMP in comparative homologous prime/boost in vivo immunisation studies; ii) to perform a detailed T cell analysis following DNA/MVA prime/boost at cellular (ICS, multimer) and transcriptomics level; iii) test prime/boost combinations with other MOMP expressing vectors available in the network, such as rec-S. typhimurium (AB) or rLCMV (UNIBAS); iv) optional: optimise vector-induced immune responses based on results obtained from network strategies using antigen modifications or immune modulators; and v) evaluation of  efficacy in a murine challenge model.

Project Title: Arenavirus-based vaccine vectors to enhance T cell and antibody responses in homologous and heterologous prime – boost vaccination

ESR1: to construct and characterise rLCMV, expressing the C. trachomatis antigen MOMP as well as MOMP variants fused to immune stimulatory sequences; ii) to elucidate the relevant processing- / presentation routes for MOMP antigen variants in vitro in T cell activation assays and at transcriptional level (transcriptomics); iii) to analyse MOMP-specific CD4⁺ and CD8⁺ T cell responses following different prime and homologous prime-boost vaccination regimens (ICS, multimer); iv) if applicable, to test vaccine efficacy in a C. trachomatis challenge model.

ESR2: to set up a system to generate replication-deficient vaccine vectors based on  arenaviruses  (such as Cand#1), and to express C. trachomatis MOMP in the generated vector; ii) to analyse MOMP-specific CD4⁺ and CD8⁺ T cell responses following different vaccination regimens , including heterologous prime-boost combinations (ICS, multimer); iii) to analyse the molecular signatures of prime- vs prime-boost vaccination-induced MOMP-specific CD8⁺ T cells; iv) if time allows, to elucidate the relevant processing- / presentation routes for MOMP antigen variants in vitro in T cell activation assays and at transcriptional level (transcriptomics); iv) if applicable, to test vaccine efficacy in a C. trachomatis challenge model.

Project Title: Novel vaccine technologies to protect against genital C. trachomatis infections

ESR10: to develop SOPs for ex vivo testing of vaccine-induced humoral and T cell-mediated responses, with ESR 7 and 9; ii) together with ESR 5, to express Chlamydia antigens in the S. typhimurium-based vaccine platforms of AB; iii) to establish murine Chlamydia challenge models and read out at SSI;  iv) to evaluate immunogenicity of S. typhimurium-based vaccines; v) to test the efficacy of (combinations) of the most promising vaccine candidates, selected at UU based on immunogenicity profile, in prime ( / boost) vaccination, together with relevant ESR.

Project Title: Recombinant S. gordonii to modulate host immune responses

ESR6: to construct and characterise rec-S. gordonii expressing the C. trachomatis MOMP antigen; ii) to analyse MOMP-specific immune responses in mice immunised with heterologous prime-boost schemes with recombinant strains of S. gordonii and purified recombinant MOMP protein, ex vivo; iii) to perform a detailed analysis of induced immune responses at transcriptomics level; iv) to further tailor rec-S. gordonii vectors based on results, also of UU, UDUS, UNIBAS, or AB; v) to test the efficacy of  resulting prime-boost immunisation regimen in the murine C. trachomatis challenge model.

Project Title: Transcriptome analysis to profile vaccine-induced immune responses

ESR9: to receive appropriate vocational training on RNA-Seq data as well as statistical and computational methods used for data analysis; ii) to apply these methods for ex vivo transcriptomics analyses to profile the molecular pathways activated in (cross) presenting DC or mice vaccinated with rec-S. gordonii in collaboration with ESR 1-4, and 6-8; iii) to participate in SOP development for ex vivo analysis of cellular and humoral responses

Project Title: Production of S. typhimurium-based vaccine vectors for mucosal immunisation 

ESR5: to design and construct new S. typhimurium-based vaccine candidates, expressing Chlamydia antigens, with ESR 10 (P. 4); ii) to test the immunogenicity of constructed vaccines in comparative, in vivo mucosal immunisation studies; iii) to test for possible adjuvant effects, for example of OMV; and iv) to evaluate vaccine efficacy in a murine C. trachomatis challenge model.