Fig. 4 | npj Vaccines

Fig. 4

From: Neutrophil swarming and extracellular trap formation play a significant role in Alum adjuvant activity

Fig. 4

Alum induces cell death and the release of NETs at the site of immunisation. Cell nuclei became accessible to the cell-impermeant DNA dye, Sytox orange following a Alum/OVA or b OVA injection of LysM-eGFP mice. a Neutrophil (GFP+) nuclei only became Sytox orange-positive following Alum/OVA injection, and this was accompanied by the appearance of long strands of stained DNA (arrowheads). c High-resolution-rendered images using cell-permeant Hoechst 33342 nuclear dye at the injection site confirmed that these structures resembled NETs. d DNAse treatment at the site of alum immunisation degraded the extracellular DNA structures released from neutrophils, visualised with Hoechst 33342. Images in a, b are representative of n = 3, c, d of n = 5. (e) OVA/Alum does not induce the release of extracellular traps at the site immunisation in PAD4KO mice compared with f control littermates. NETs were visualised using Hoechst 33342 as above, and data shown are representative of five mice. g Histone H3 and DNA (Sytox Orange) co-localise within NETs, with a local release of myeloperoxidase evident at the injection site

Back to article page