VIA breadth scores are correlated with CD8 T cell IFN-γ ELISpot responses
PTE
To understand how the antigenic specificity of CD8+ T cells induced upon vaccination relates to the inhibition of viral replication, CD8+ T cells collected post 3rd vaccination were assessed for IFN-γ ELISpot responses to Gag, Pol, and Env PTE peptide subpools. ELISpot was performed after CD8+ T cell expansion when sufficient cells remained after VIA analysis (CD8 IFN-γ ELISpot magnitudes to Env, Gag, and Pol pools. (Analyzing the number of HIV-1 Env, Gag, or Pol peptide pools targeted in ELISpot for all vaccinees combined (When considering protein-level responses (all peptides for Env, Gag, or Pol), the Ad26/MVA + gp140 group did respond to more HIV-1 proteins (mean 2, median 2.5) compared with those vaccinated with Ad26/Ad26 + gp140 (mean 1.38, median 1.5), but the differences were not significant (Viral inhibition breadth demonstrated positive Pearson correlations with both CD8 ELISpot magnitude (Squared Pearson correlation To contextualize the findings that specific targeting does not appear to be crucial for viral inhibition breadth, we looked into individual patterns of T cell responses. Barouch et al. have previously investigated breadth of T cell responses in participants from the same Ad26/Ad26 + gp140 and Ad26/MVA + gp140 vaccine groups from the APPROACH study post 3rd vaccination by ELISpot subpool stimulations consisting of 10 peptides (