Both CD4⁺ and CD8⁺ Lymphocytes Participate in the IFN-γ Response to Filamentous Hemagglutinin from Bordetella pertussis in Infants, Children, and Adults

Figure 2

Percentages and absolute numbers of FHA-induced IFN-γ producing CD4⁺ and CD8⁺ T cells in B. pertussis-infected (𝑛=6) or vaccinated children (𝑛=4). Isolated PBMC were stimulated in vitro for 24 h with 5 μg/mL FHA, and IFN-γ-containing CD4⁺ (left columns) and CD8⁺ (right columns) T lymphocytes were detected by flow cytometry. (a) represents the percentages of positive cells and the absolute numbers of IFN-γ-producing cells expressed for 10⁶ CD3⁺ T lymphocytes are shown on (b). The lines join the results obtained for the same children. Percentages obtained for unstimulated cells were subtracted from those obtained for stimulated cells. *𝑃<0.05, **𝑃<0.001.

(a)

(b)