The CD4 T cell response to NC infection.

<p>(A–D) Cytokine production by peptide-specific CD4 T cells. DR1 (A and B) and B10 (C and D) mice were infected intranasally with 40,000 EID₅₀ NC. Enriched CD4 T cells from the MedLN and spleen were analyzed on day 10 after infection. Frequencies of CD4 T cells secreting IL-2, IFN-γ, or IL-4 were determined by ELISpot assay after in vitro stimulation with antigen-presenting cells and individual 17-mer peptides. Peptide designations (x-axis) include the viral proteins of origin (HA, NA, NP, M1, and NS1). <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0034377#s3" target="_blank">Results</a> are normalized to spot counts per 10⁶ CD4 T cells and are shown as the mean+SEM for 2–6 independent experiments for each peptide. Cells from at least three mice were pooled for each experiment. (E, F) Proportions of peptide-specific CD4 T cells secreting IL-2, IFN-γ, or IL-4. <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0034377#s3" target="_blank">Results</a> are compiled from the data shown in A–D and represent 4 (MedLN) or 6 (spleen) independent experiments evaluating 3–12 (MedLN) or 12–20 (spleen) individual peptides. The mean+SEM is shown.