Interestingly, both the exposure of PBMCs to 500 nm and 3 μm influenza conjugates resulted in a significant increase in the frequency of CD4+ T cells producing IFNγ and TNFα (Figure 6a,b) and in total amounts of these cytokines (Figure 6d,e) compared to exposure of PBMCs to unconjugated particles. Here, TNF is linked to influenza.