Fig. 3

CD4⁺ T cell proliferation in lung draining lymph nodes was measured after intra nasal instillation of positively charged (Au⁺; NH2) and negatively charged (Au⁻; COOH) gold NPs or polymer shells alone followed by ovalbumin in a mouse model of ovalbumin induced experimental allergic airways disease. Positively charged gold NPs induced enhanced ovalbumin specific T cell proliferation compared to controls (non-exposed), negatively charged gold NPs or positively charged polymer alone. These findings highlight the importance of surface charge of a biomedical NP in modulating a specific adaptive immune response. Adapted from [11]