Figure 5.

Antigen-specific CD4+ and CD8+ T cells raised by sa-mRNA S and sa-mRNA S-N vaccines or Adj-Pro S vaccines in BALB/c mice

BALB/c female mice (n = 10) were immunized twice, 3 weeks apart, with 1.0 μg or 0.01 μg of sa-mRNA S or sa-mRNA S-N vaccines or with 1.0 μg Adj-Pro S vaccine. Spleens were collected on day 43 and pooled (five spleens/vaccine). Splenocytes were prepared, cultured in the presence or absence of antigen peptide mixtures, and analyzed by flow cytometry. The net (antigen-specific) percentage of cytokine-producing CD4+ and CD8+ T cells induced by each vaccine are shown for S1-specific CD4+ T cells (A), S1-specific CD8+ T cells (B), S2-specific CD4+ T cells (C), S2-specific CD8+ T cells (D), and N-specific CD4+ T cells (E). Contribution of various T helper subsets to the overall CD4 response was determined as follows: Th1, CD4+IFNγ+IL-5negIL-13neg; Th2, CD4+IFNγ−IL-5+/IL-13+; and Th0, CD4+IL-2+/TNFα+.