Effect of Antigen, Type I IFN and STING Signaling on CD8 T Cell Immunity With Adenoviral Vaccines. Mus musculus

Recombinant adenoviral vectors (rAds), derived from distinct species with different serotypes, are lead vaccine candidates against Ebola, HIV, Tuberculosis and Malaria based on their potent induction of T cell immunity in humans. Importantly, rAds vary in their ability to induce protective cellular immunity. Here, the in vivo mechanisms controlling potency of CD8 T cell responses were assessed after vaccination with human-, chimpanzee- and simian-derived rAds encoding SIV-Gag. After rAd vaccination, we quantified antigen (Ag) expression and performed expression profiling of innate immune response genes in the draining lymph node. The most potent rAds (human-derived rAd5 and chimpanzee-derived chAd3) induced high and persistent Ag expression with low innate gene activation, while the less potent rAds exhibited reduced Ag expression with robust innate gene activation associated primarily with interferon (IFN) signaling. Abrogation of type I IFN or stimulator of IFN genes (STING) signaling increased Ag expression and accelerated CD8 T cell response kinetics, but did not alter memory responses or protection. Thus, the magnitude of memory CD8 T cell immune responses induced by rAds correlates with Ag expression but is independent of IFN and STING. These findings provide criteria for optimal induction of protective CD8 T cell immunity with rAd vaccines. Overall design: Each microarray comes from an RNA sample obtained from a unique mouse. There were no repeated RNA samples obtained from any mouse. 207 arrays were run overall, 189 from dLN and 18 from PBMCs obtained from mice vaccinated with different rAd vectors. The dLN arrays were run in three batches, denoted A-C, and the PBMCs were run in Batch D. Batch A (108 arrays)consisted of six biological replicates at each of three time points (8, 24 and 72 hours) post-vaccination with PBS, rAd5 (1 x 10^8 PU), rAd28 (1 x 10^8 PU), rAd35 (1 x 10^9 PU), sAd11 (1 x 10^8 PU) and sAd16 (1 x 10^8 PU). Batch B (46 arrays) consisted of four biological replicates at each of three time points (8, 24 and 72 hours) post-vaccination with chAd3 (1 x 10^8 PU), chAd63 (1 x 10^8 PU) and Poly I:C. Batch B also consisted of two biological replicates at each of three time points (8, 24 and 72 hours) post-vaccination with rAd5 (1 x 10^8 PU) and four biological replicates at each 8 hour time point post-vaccination with PBS (control). Batch C (35 arrays) consisted of five biological replicates at each 8 hour time point post-vaccination of WT, IFNabR-/- and STING gt/gt mice with PBS and chAd63 (3 x 10^7 PU). Batch C also consisted of five biological replicates at each 8 hour time point post-vaccination with rAd5 (3 x 10^7 PU). Batch D (18 arrays) consisted of the PBMC microarray set, which included six biological replicates at each 24 hour time point post-vaccination with PBS, rAd5 and rAd28.