Ex Vivo Restimulation of Human PBMC Expands a CD3⁺CD4⁻CD8⁻𝛾𝛿⁺ T Cell Population That Can Confound the Evaluation of CD4 and CD8 T Cell Responses to Vaccination

Figure 2

Alternative gating strategy applied to influenza vaccine trial data to eliminate confounding CMI responses from the IFN-𝛾-producing 𝛾𝛿⁺ T cells. PBMCs from an IFN-𝛾-producing CD3⁺CD4⁻CD8⁻𝛾𝛿⁺ T cell-positive subject at day 7 after vaccination were restimulated in (a) the absence of antigen or (b) the presence of exogenous influenza virus antigen (30 HA units per strain/mL), and antigen-specific CD4⁺ and CD8⁺ T-cell responses were assessed. For each of the restimulation conditions, the top panels represent the standard gating strategy, and the bottom panels represent the alternative gating strategy, whereby CD3⁺𝛾𝛿⁺ T cells were selectively excluded during post acquisition analysis to avoid reporting misleading cytokine responses that could confound the antigen-specific CD4⁺ and CD8⁺ T cell responses.

(a)

(b)